newline battles continue

vendor/github.com/minio/minio-go/pkg/credentials/chain.go

@@ -0,0 +1,89 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+// A Chain will search for a provider which returns credentials
+// and cache that provider until Retrieve is called again.
+//
+// The Chain provides a way of chaining multiple providers together
+// which will pick the first available using priority order of the
+// Providers in the list.
+//
+// If none of the Providers retrieve valid credentials Value, ChainProvider's
+// Retrieve() will return the no credentials value.
+//
+// If a Provider is found which returns valid credentials Value ChainProvider
+// will cache that Provider for all calls to IsExpired(), until Retrieve is
+// called again after IsExpired() is true.
+//
+//     creds := credentials.NewChainCredentials(
+//         []credentials.Provider{
+//             &credentials.EnvAWSS3{},
+//             &credentials.EnvMinio{},
+//         })
+//
+//     // Usage of ChainCredentials.
+//     mc, err := minio.NewWithCredentials(endpoint, creds, secure, "us-east-1")
+//     if err != nil {
+//          log.Fatalln(err)
+//     }
+//
+type Chain struct {
+	Providers []Provider
+	curr      Provider
+}
+
+// NewChainCredentials returns a pointer to a new Credentials object
+// wrapping a chain of providers.
+func NewChainCredentials(providers []Provider) *Credentials {
+	return New(&Chain{
+		Providers: append([]Provider{}, providers...),
+	})
+}
+
+// Retrieve returns the credentials value, returns no credentials(anonymous)
+// if no credentials provider returned any value.
+//
+// If a provider is found with credentials, it will be cached and any calls
+// to IsExpired() will return the expired state of the cached provider.
+func (c *Chain) Retrieve() (Value, error) {
+	for _, p := range c.Providers {
+		creds, _ := p.Retrieve()
+		// Always prioritize non-anonymous providers, if any.
+		if creds.AccessKeyID == "" && creds.SecretAccessKey == "" {
+			continue
+		}
+		c.curr = p
+		return creds, nil
+	}
+	// At this point we have exhausted all the providers and
+	// are left without any credentials return anonymous.
+	return Value{
+		SignerType: SignatureAnonymous,
+	}, nil
+}
+
+// IsExpired will returned the expired state of the currently cached provider
+// if there is one. If there is no current provider, true will be returned.
+func (c *Chain) IsExpired() bool {
+	if c.curr != nil {
+		return c.curr.IsExpired()
+	}
+
+	return true
+}

vendor/github.com/minio/minio-go/pkg/credentials/config.json.sample

@@ -0,0 +1,17 @@
+{
+	"version": "8",
+	"hosts": {
+		"play": {
+			"url": "https://play.minio.io:9000",
+			"accessKey": "Q3AM3UQ867SPQQA43P2F",
+			"secretKey": "zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG",
+			"api": "S3v2"
+		},
+		"s3": {
+			"url": "https://s3.amazonaws.com",
+			"accessKey": "accessKey",
+			"secretKey": "secret",
+			"api": "S3v4"
+		}
+	}
+}

vendor/github.com/minio/minio-go/pkg/credentials/credentials.go

@@ -0,0 +1,175 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"sync"
+	"time"
+)
+
+// A Value is the AWS credentials value for individual credential fields.
+type Value struct {
+	// AWS Access key ID
+	AccessKeyID string
+
+	// AWS Secret Access Key
+	SecretAccessKey string
+
+	// AWS Session Token
+	SessionToken string
+
+	// Signature Type.
+	SignerType SignatureType
+}
+
+// A Provider is the interface for any component which will provide credentials
+// Value. A provider is required to manage its own Expired state, and what to
+// be expired means.
+type Provider interface {
+	// Retrieve returns nil if it successfully retrieved the value.
+	// Error is returned if the value were not obtainable, or empty.
+	Retrieve() (Value, error)
+
+	// IsExpired returns if the credentials are no longer valid, and need
+	// to be retrieved.
+	IsExpired() bool
+}
+
+// A Expiry provides shared expiration logic to be used by credentials
+// providers to implement expiry functionality.
+//
+// The best method to use this struct is as an anonymous field within the
+// provider's struct.
+//
+// Example:
+//     type IAMCredentialProvider struct {
+//         Expiry
+//         ...
+//     }
+type Expiry struct {
+	// The date/time when to expire on
+	expiration time.Time
+
+	// If set will be used by IsExpired to determine the current time.
+	// Defaults to time.Now if CurrentTime is not set.
+	CurrentTime func() time.Time
+}
+
+// SetExpiration sets the expiration IsExpired will check when called.
+//
+// If window is greater than 0 the expiration time will be reduced by the
+// window value.
+//
+// Using a window is helpful to trigger credentials to expire sooner than
+// the expiration time given to ensure no requests are made with expired
+// tokens.
+func (e *Expiry) SetExpiration(expiration time.Time, window time.Duration) {
+	e.expiration = expiration
+	if window > 0 {
+		e.expiration = e.expiration.Add(-window)
+	}
+}
+
+// IsExpired returns if the credentials are expired.
+func (e *Expiry) IsExpired() bool {
+	if e.CurrentTime == nil {
+		e.CurrentTime = time.Now
+	}
+	return e.expiration.Before(e.CurrentTime())
+}
+
+// Credentials - A container for synchronous safe retrieval of credentials Value.
+// Credentials will cache the credentials value until they expire. Once the value
+// expires the next Get will attempt to retrieve valid credentials.
+//
+// Credentials is safe to use across multiple goroutines and will manage the
+// synchronous state so the Providers do not need to implement their own
+// synchronization.
+//
+// The first Credentials.Get() will always call Provider.Retrieve() to get the
+// first instance of the credentials Value. All calls to Get() after that
+// will return the cached credentials Value until IsExpired() returns true.
+type Credentials struct {
+	sync.Mutex
+
+	creds        Value
+	forceRefresh bool
+	provider     Provider
+}
+
+// New returns a pointer to a new Credentials with the provider set.
+func New(provider Provider) *Credentials {
+	return &Credentials{
+		provider:     provider,
+		forceRefresh: true,
+	}
+}
+
+// Get returns the credentials value, or error if the credentials Value failed
+// to be retrieved.
+//
+// Will return the cached credentials Value if it has not expired. If the
+// credentials Value has expired the Provider's Retrieve() will be called
+// to refresh the credentials.
+//
+// If Credentials.Expire() was called the credentials Value will be force
+// expired, and the next call to Get() will cause them to be refreshed.
+func (c *Credentials) Get() (Value, error) {
+	c.Lock()
+	defer c.Unlock()
+
+	if c.isExpired() {
+		creds, err := c.provider.Retrieve()
+		if err != nil {
+			return Value{}, err
+		}
+		c.creds = creds
+		c.forceRefresh = false
+	}
+
+	return c.creds, nil
+}
+
+// Expire expires the credentials and forces them to be retrieved on the
+// next call to Get().
+//
+// This will override the Provider's expired state, and force Credentials
+// to call the Provider's Retrieve().
+func (c *Credentials) Expire() {
+	c.Lock()
+	defer c.Unlock()
+
+	c.forceRefresh = true
+}
+
+// IsExpired returns if the credentials are no longer valid, and need
+// to be refreshed.
+//
+// If the Credentials were forced to be expired with Expire() this will
+// reflect that override.
+func (c *Credentials) IsExpired() bool {
+	c.Lock()
+	defer c.Unlock()
+
+	return c.isExpired()
+}
+
+// isExpired helper method wrapping the definition of expired credentials.
+func (c *Credentials) isExpired() bool {
+	return c.forceRefresh || c.provider.IsExpired()
+}

vendor/github.com/minio/minio-go/pkg/credentials/credentials.sample

@@ -0,0 +1,12 @@
+[default]
+aws_access_key_id = accessKey
+aws_secret_access_key = secret
+aws_session_token = token
+
+[no_token]
+aws_access_key_id = accessKey
+aws_secret_access_key = secret
+
+[with_colon]
+aws_access_key_id: accessKey
+aws_secret_access_key: secret

vendor/github.com/minio/minio-go/pkg/credentials/doc.go

@@ -0,0 +1,62 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Package credentials provides credential retrieval and management
+// for S3 compatible object storage.
+//
+// By default the Credentials.Get() will cache the successful result of a
+// Provider's Retrieve() until Provider.IsExpired() returns true. At which
+// point Credentials will call Provider's Retrieve() to get new credential Value.
+//
+// The Provider is responsible for determining when credentials have expired.
+// It is also important to note that Credentials will always call Retrieve the
+// first time Credentials.Get() is called.
+//
+// Example of using the environment variable credentials.
+//
+//     creds := NewFromEnv()
+//     // Retrieve the credentials value
+//     credValue, err := creds.Get()
+//     if err != nil {
+//         // handle error
+//     }
+//
+// Example of forcing credentials to expire and be refreshed on the next Get().
+// This may be helpful to proactively expire credentials and refresh them sooner
+// than they would naturally expire on their own.
+//
+//     creds := NewFromIAM("")
+//     creds.Expire()
+//     credsValue, err := creds.Get()
+//     // New credentials will be retrieved instead of from cache.
+//
+//
+// Custom Provider
+//
+// Each Provider built into this package also provides a helper method to generate
+// a Credentials pointer setup with the provider. To use a custom Provider just
+// create a type which satisfies the Provider interface and pass it to the
+// NewCredentials method.
+//
+//     type MyProvider struct{}
+//     func (m *MyProvider) Retrieve() (Value, error) {...}
+//     func (m *MyProvider) IsExpired() bool {...}
+//
+//     creds := NewCredentials(&MyProvider{})
+//     credValue, err := creds.Get()
+//
+package credentials

vendor/github.com/minio/minio-go/pkg/credentials/env_aws.go

@@ -0,0 +1,71 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import "os"
+
+// A EnvAWS retrieves credentials from the environment variables of the
+// running process. EnvAWSironment credentials never expire.
+//
+// EnvAWSironment variables used:
+//
+// * Access Key ID:     AWS_ACCESS_KEY_ID or AWS_ACCESS_KEY.
+// * Secret Access Key: AWS_SECRET_ACCESS_KEY or AWS_SECRET_KEY.
+// * Secret Token:      AWS_SESSION_TOKEN.
+type EnvAWS struct {
+	retrieved bool
+}
+
+// NewEnvAWS returns a pointer to a new Credentials object
+// wrapping the environment variable provider.
+func NewEnvAWS() *Credentials {
+	return New(&EnvAWS{})
+}
+
+// Retrieve retrieves the keys from the environment.
+func (e *EnvAWS) Retrieve() (Value, error) {
+	e.retrieved = false
+
+	id := os.Getenv("AWS_ACCESS_KEY_ID")
+	if id == "" {
+		id = os.Getenv("AWS_ACCESS_KEY")
+	}
+
+	secret := os.Getenv("AWS_SECRET_ACCESS_KEY")
+	if secret == "" {
+		secret = os.Getenv("AWS_SECRET_KEY")
+	}
+
+	signerType := SignatureV4
+	if id == "" || secret == "" {
+		signerType = SignatureAnonymous
+	}
+
+	e.retrieved = true
+	return Value{
+		AccessKeyID:     id,
+		SecretAccessKey: secret,
+		SessionToken:    os.Getenv("AWS_SESSION_TOKEN"),
+		SignerType:      signerType,
+	}, nil
+}
+
+// IsExpired returns if the credentials have been retrieved.
+func (e *EnvAWS) IsExpired() bool {
+	return !e.retrieved
+}

vendor/github.com/minio/minio-go/pkg/credentials/env_minio.go

@@ -0,0 +1,62 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import "os"
+
+// A EnvMinio retrieves credentials from the environment variables of the
+// running process. EnvMinioironment credentials never expire.
+//
+// EnvMinioironment variables used:
+//
+// * Access Key ID:     MINIO_ACCESS_KEY.
+// * Secret Access Key: MINIO_SECRET_KEY.
+type EnvMinio struct {
+	retrieved bool
+}
+
+// NewEnvMinio returns a pointer to a new Credentials object
+// wrapping the environment variable provider.
+func NewEnvMinio() *Credentials {
+	return New(&EnvMinio{})
+}
+
+// Retrieve retrieves the keys from the environment.
+func (e *EnvMinio) Retrieve() (Value, error) {
+	e.retrieved = false
+
+	id := os.Getenv("MINIO_ACCESS_KEY")
+	secret := os.Getenv("MINIO_SECRET_KEY")
+
+	signerType := SignatureV4
+	if id == "" || secret == "" {
+		signerType = SignatureAnonymous
+	}
+
+	e.retrieved = true
+	return Value{
+		AccessKeyID:     id,
+		SecretAccessKey: secret,
+		SignerType:      signerType,
+	}, nil
+}
+
+// IsExpired returns if the credentials have been retrieved.
+func (e *EnvMinio) IsExpired() bool {
+	return !e.retrieved
+}

vendor/github.com/minio/minio-go/pkg/credentials/file_aws_credentials.go

@@ -0,0 +1,120 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-ini/ini"
+	homedir "github.com/mitchellh/go-homedir"
+)
+
+// A FileAWSCredentials retrieves credentials from the current user's home
+// directory, and keeps track if those credentials are expired.
+//
+// Profile ini file example: $HOME/.aws/credentials
+type FileAWSCredentials struct {
+	// Path to the shared credentials file.
+	//
+	// If empty will look for "AWS_SHARED_CREDENTIALS_FILE" env variable. If the
+	// env value is empty will default to current user's home directory.
+	// Linux/OSX: "$HOME/.aws/credentials"
+	// Windows:   "%USERPROFILE%\.aws\credentials"
+	filename string
+
+	// AWS Profile to extract credentials from the shared credentials file. If empty
+	// will default to environment variable "AWS_PROFILE" or "default" if
+	// environment variable is also not set.
+	profile string
+
+	// retrieved states if the credentials have been successfully retrieved.
+	retrieved bool
+}
+
+// NewFileAWSCredentials returns a pointer to a new Credentials object
+// wrapping the Profile file provider.
+func NewFileAWSCredentials(filename string, profile string) *Credentials {
+	return New(&FileAWSCredentials{
+		filename: filename,
+		profile:  profile,
+	})
+}
+
+// Retrieve reads and extracts the shared credentials from the current
+// users home directory.
+func (p *FileAWSCredentials) Retrieve() (Value, error) {
+	if p.filename == "" {
+		p.filename = os.Getenv("AWS_SHARED_CREDENTIALS_FILE")
+		if p.filename == "" {
+			homeDir, err := homedir.Dir()
+			if err != nil {
+				return Value{}, err
+			}
+			p.filename = filepath.Join(homeDir, ".aws", "credentials")
+		}
+	}
+	if p.profile == "" {
+		p.profile = os.Getenv("AWS_PROFILE")
+		if p.profile == "" {
+			p.profile = "default"
+		}
+	}
+
+	p.retrieved = false
+
+	iniProfile, err := loadProfile(p.filename, p.profile)
+	if err != nil {
+		return Value{}, err
+	}
+
+	// Default to empty string if not found.
+	id := iniProfile.Key("aws_access_key_id")
+	// Default to empty string if not found.
+	secret := iniProfile.Key("aws_secret_access_key")
+	// Default to empty string if not found.
+	token := iniProfile.Key("aws_session_token")
+
+	p.retrieved = true
+	return Value{
+		AccessKeyID:     id.String(),
+		SecretAccessKey: secret.String(),
+		SessionToken:    token.String(),
+		SignerType:      SignatureV4,
+	}, nil
+}
+
+// IsExpired returns if the shared credentials have expired.
+func (p *FileAWSCredentials) IsExpired() bool {
+	return !p.retrieved
+}
+
+// loadProfiles loads from the file pointed to by shared credentials filename for profile.
+// The credentials retrieved from the profile will be returned or error. Error will be
+// returned if it fails to read from the file, or the data is invalid.
+func loadProfile(filename, profile string) (*ini.Section, error) {
+	config, err := ini.Load(filename)
+	if err != nil {
+		return nil, err
+	}
+	iniProfile, err := config.GetSection(profile)
+	if err != nil {
+		return nil, err
+	}
+	return iniProfile, nil
+}

vendor/github.com/minio/minio-go/pkg/credentials/file_minio_client.go

@@ -0,0 +1,133 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	homedir "github.com/mitchellh/go-homedir"
+)
+
+// A FileMinioClient retrieves credentials from the current user's home
+// directory, and keeps track if those credentials are expired.
+//
+// Configuration file example: $HOME/.mc/config.json
+type FileMinioClient struct {
+	// Path to the shared credentials file.
+	//
+	// If empty will look for "MINIO_SHARED_CREDENTIALS_FILE" env variable. If the
+	// env value is empty will default to current user's home directory.
+	// Linux/OSX: "$HOME/.mc/config.json"
+	// Windows:   "%USERALIAS%\mc\config.json"
+	filename string
+
+	// Minio Alias to extract credentials from the shared credentials file. If empty
+	// will default to environment variable "MINIO_ALIAS" or "default" if
+	// environment variable is also not set.
+	alias string
+
+	// retrieved states if the credentials have been successfully retrieved.
+	retrieved bool
+}
+
+// NewFileMinioClient returns a pointer to a new Credentials object
+// wrapping the Alias file provider.
+func NewFileMinioClient(filename string, alias string) *Credentials {
+	return New(&FileMinioClient{
+		filename: filename,
+		alias:    alias,
+	})
+}
+
+// Retrieve reads and extracts the shared credentials from the current
+// users home directory.
+func (p *FileMinioClient) Retrieve() (Value, error) {
+	if p.filename == "" {
+		if value, ok := os.LookupEnv("MINIO_SHARED_CREDENTIALS_FILE"); ok {
+			p.filename = value
+		} else {
+			homeDir, err := homedir.Dir()
+			if err != nil {
+				return Value{}, err
+			}
+			p.filename = filepath.Join(homeDir, ".mc", "config.json")
+			if runtime.GOOS == "windows" {
+				p.filename = filepath.Join(homeDir, "mc", "config.json")
+			}
+		}
+	}
+
+	if p.alias == "" {
+		p.alias = os.Getenv("MINIO_ALIAS")
+		if p.alias == "" {
+			p.alias = "s3"
+		}
+	}
+
+	p.retrieved = false
+
+	hostCfg, err := loadAlias(p.filename, p.alias)
+	if err != nil {
+		return Value{}, err
+	}
+
+	p.retrieved = true
+	return Value{
+		AccessKeyID:     hostCfg.AccessKey,
+		SecretAccessKey: hostCfg.SecretKey,
+		SignerType:      parseSignatureType(hostCfg.API),
+	}, nil
+}
+
+// IsExpired returns if the shared credentials have expired.
+func (p *FileMinioClient) IsExpired() bool {
+	return !p.retrieved
+}
+
+// hostConfig configuration of a host.
+type hostConfig struct {
+	URL       string `json:"url"`
+	AccessKey string `json:"accessKey"`
+	SecretKey string `json:"secretKey"`
+	API       string `json:"api"`
+}
+
+// config config version.
+type config struct {
+	Version string                `json:"version"`
+	Hosts   map[string]hostConfig `json:"hosts"`
+}
+
+// loadAliass loads from the file pointed to by shared credentials filename for alias.
+// The credentials retrieved from the alias will be returned or error. Error will be
+// returned if it fails to read from the file.
+func loadAlias(filename, alias string) (hostConfig, error) {
+	cfg := &config{}
+	configBytes, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return hostConfig{}, err
+	}
+	if err = json.Unmarshal(configBytes, cfg); err != nil {
+		return hostConfig{}, err
+	}
+	return cfg.Hosts[alias], nil
+}

vendor/github.com/minio/minio-go/pkg/credentials/iam_aws.go

@@ -0,0 +1,214 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"bufio"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/url"
+	"path"
+	"time"
+)
+
+// DefaultExpiryWindow - Default expiry window.
+// ExpiryWindow will allow the credentials to trigger refreshing
+// prior to the credentials actually expiring. This is beneficial
+// so race conditions with expiring credentials do not cause
+// request to fail unexpectedly due to ExpiredTokenException exceptions.
+const DefaultExpiryWindow = time.Second * 10 // 10 secs
+
+// A IAM retrieves credentials from the EC2 service, and keeps track if
+// those credentials are expired.
+type IAM struct {
+	Expiry
+
+	// Required http Client to use when connecting to IAM metadata service.
+	Client *http.Client
+
+	// Custom endpoint to fetch IAM role credentials.
+	endpoint string
+}
+
+// IAM Roles for Amazon EC2
+// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+const (
+	defaultIAMRoleEndpoint      = "http://169.254.169.254"
+	defaultIAMSecurityCredsPath = "/latest/meta-data/iam/security-credentials"
+)
+
+// NewIAM returns a pointer to a new Credentials object wrapping
+// the IAM. Takes a ConfigProvider to create a EC2Metadata client.
+// The ConfigProvider is satisfied by the session.Session type.
+func NewIAM(endpoint string) *Credentials {
+	if endpoint == "" {
+		endpoint = defaultIAMRoleEndpoint
+	}
+	p := &IAM{
+		Client: &http.Client{
+			Transport: http.DefaultTransport,
+		},
+		endpoint: endpoint,
+	}
+	return New(p)
+}
+
+// Retrieve retrieves credentials from the EC2 service.
+// Error will be returned if the request fails, or unable to extract
+// the desired
+func (m *IAM) Retrieve() (Value, error) {
+	roleCreds, err := getCredentials(m.Client, m.endpoint)
+	if err != nil {
+		return Value{}, err
+	}
+
+	// Expiry window is set to 10secs.
+	m.SetExpiration(roleCreds.Expiration, DefaultExpiryWindow)
+
+	return Value{
+		AccessKeyID:     roleCreds.AccessKeyID,
+		SecretAccessKey: roleCreds.SecretAccessKey,
+		SessionToken:    roleCreds.Token,
+		SignerType:      SignatureV4,
+	}, nil
+}
+
+// A ec2RoleCredRespBody provides the shape for unmarshaling credential
+// request responses.
+type ec2RoleCredRespBody struct {
+	// Success State
+	Expiration      time.Time
+	AccessKeyID     string
+	SecretAccessKey string
+	Token           string
+
+	// Error state
+	Code    string
+	Message string
+
+	// Unused params.
+	LastUpdated time.Time
+	Type        string
+}
+
+// Get the final IAM role URL where the request will
+// be sent to fetch the rolling access credentials.
+// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+func getIAMRoleURL(endpoint string) (*url.URL, error) {
+	if endpoint == "" {
+		endpoint = defaultIAMRoleEndpoint
+	}
+	u, err := url.Parse(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = defaultIAMSecurityCredsPath
+	return u, nil
+}
+
+// listRoleNames lists of credential role names associated
+// with the current EC2 service. If there are no credentials,
+// or there is an error making or receiving the request.
+// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+func listRoleNames(client *http.Client, u *url.URL) ([]string, error) {
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, errors.New(resp.Status)
+	}
+
+	credsList := []string{}
+	s := bufio.NewScanner(resp.Body)
+	for s.Scan() {
+		credsList = append(credsList, s.Text())
+	}
+
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return credsList, nil
+}
+
+// getCredentials - obtains the credentials from the IAM role name associated with
+// the current EC2 service.
+//
+// If the credentials cannot be found, or there is an error
+// reading the response an error will be returned.
+func getCredentials(client *http.Client, endpoint string) (ec2RoleCredRespBody, error) {
+	// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+	u, err := getIAMRoleURL(endpoint)
+	if err != nil {
+		return ec2RoleCredRespBody{}, err
+	}
+
+	// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+	roleNames, err := listRoleNames(client, u)
+	if err != nil {
+		return ec2RoleCredRespBody{}, err
+	}
+
+	if len(roleNames) == 0 {
+		return ec2RoleCredRespBody{}, errors.New("No IAM roles attached to this EC2 service")
+	}
+
+	// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+	// - An instance profile can contain only one IAM role. This limit cannot be increased.
+	roleName := roleNames[0]
+
+	// http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html
+	// The following command retrieves the security credentials for an
+	// IAM role named `s3access`.
+	//
+	//    $ curl http://169.254.169.254/latest/meta-data/iam/security-credentials/s3access
+	//
+	u.Path = path.Join(u.Path, roleName)
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return ec2RoleCredRespBody{}, err
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return ec2RoleCredRespBody{}, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return ec2RoleCredRespBody{}, errors.New(resp.Status)
+	}
+
+	respCreds := ec2RoleCredRespBody{}
+	if err := json.NewDecoder(resp.Body).Decode(&respCreds); err != nil {
+		return ec2RoleCredRespBody{}, err
+	}
+
+	if respCreds.Code != "Success" {
+		// If an error code was returned something failed requesting the role.
+		return ec2RoleCredRespBody{}, errors.New(respCreds.Message)
+	}
+
+	return respCreds, nil
+}

vendor/github.com/minio/minio-go/pkg/credentials/signature-type.go

@@ -0,0 +1,77 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import "strings"
+
+// SignatureType is type of Authorization requested for a given HTTP request.
+type SignatureType int
+
+// Different types of supported signatures - default is SignatureV4 or SignatureDefault.
+const (
+	// SignatureDefault is always set to v4.
+	SignatureDefault SignatureType = iota
+	SignatureV4
+	SignatureV2
+	SignatureV4Streaming
+	SignatureAnonymous // Anonymous signature signifies, no signature.
+)
+
+// IsV2 - is signature SignatureV2?
+func (s SignatureType) IsV2() bool {
+	return s == SignatureV2
+}
+
+// IsV4 - is signature SignatureV4?
+func (s SignatureType) IsV4() bool {
+	return s == SignatureV4 || s == SignatureDefault
+}
+
+// IsStreamingV4 - is signature SignatureV4Streaming?
+func (s SignatureType) IsStreamingV4() bool {
+	return s == SignatureV4Streaming
+}
+
+// IsAnonymous - is signature empty?
+func (s SignatureType) IsAnonymous() bool {
+	return s == SignatureAnonymous
+}
+
+// Stringer humanized version of signature type,
+// strings returned here are case insensitive.
+func (s SignatureType) String() string {
+	if s.IsV2() {
+		return "S3v2"
+	} else if s.IsV4() {
+		return "S3v4"
+	} else if s.IsStreamingV4() {
+		return "S3v4Streaming"
+	}
+	return "Anonymous"
+}
+
+func parseSignatureType(str string) SignatureType {
+	if strings.EqualFold(str, "S3v4") {
+		return SignatureV4
+	} else if strings.EqualFold(str, "S3v2") {
+		return SignatureV2
+	} else if strings.EqualFold(str, "S3v4Streaming") {
+		return SignatureV4Streaming
+	}
+	return SignatureAnonymous
+}

vendor/github.com/minio/minio-go/pkg/credentials/static.go

@@ -0,0 +1,67 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+// A Static is a set of credentials which are set programmatically,
+// and will never expire.
+type Static struct {
+	Value
+}
+
+// NewStaticV2 returns a pointer to a new Credentials object
+// wrapping a static credentials value provider, signature is
+// set to v2. If access and secret are not specified then
+// regardless of signature type set it Value will return
+// as anonymous.
+func NewStaticV2(id, secret, token string) *Credentials {
+	return NewStatic(id, secret, token, SignatureV2)
+}
+
+// NewStaticV4 is similar to NewStaticV2 with similar considerations.
+func NewStaticV4(id, secret, token string) *Credentials {
+	return NewStatic(id, secret, token, SignatureV4)
+}
+
+// NewStatic returns a pointer to a new Credentials object
+// wrapping a static credentials value provider.
+func NewStatic(id, secret, token string, signerType SignatureType) *Credentials {
+	return New(&Static{
+		Value: Value{
+			AccessKeyID:     id,
+			SecretAccessKey: secret,
+			SessionToken:    token,
+			SignerType:      signerType,
+		},
+	})
+}
+
+// Retrieve returns the static credentials.
+func (s *Static) Retrieve() (Value, error) {
+	if s.AccessKeyID == "" || s.SecretAccessKey == "" {
+		// Anonymous is not an error
+		return Value{SignerType: SignatureAnonymous}, nil
+	}
+	return s.Value, nil
+}
+
+// IsExpired returns if the credentials are expired.
+//
+// For Static, the credentials never expired.
+func (s *Static) IsExpired() bool {
+	return false
+}

vendor/github.com/minio/minio-go/pkg/encrypt/server-side.go

@@ -0,0 +1,195 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package encrypt
+
+import (
+	"crypto/md5"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"golang.org/x/crypto/argon2"
+)
+
+const (
+	// sseGenericHeader is the AWS SSE header used for SSE-S3 and SSE-KMS.
+	sseGenericHeader = "X-Amz-Server-Side-Encryption"
+
+	// sseKmsKeyID is the AWS SSE-KMS key id.
+	sseKmsKeyID = sseGenericHeader + "-Aws-Kms-Key-Id"
+	// sseEncryptionContext is the AWS SSE-KMS Encryption Context data.
+	sseEncryptionContext = sseGenericHeader + "-Encryption-Context"
+
+	// sseCustomerAlgorithm is the AWS SSE-C algorithm HTTP header key.
+	sseCustomerAlgorithm = sseGenericHeader + "-Customer-Algorithm"
+	// sseCustomerKey is the AWS SSE-C encryption key HTTP header key.
+	sseCustomerKey = sseGenericHeader + "-Customer-Key"
+	// sseCustomerKeyMD5 is the AWS SSE-C encryption key MD5 HTTP header key.
+	sseCustomerKeyMD5 = sseGenericHeader + "-Customer-Key-MD5"
+
+	// sseCopyCustomerAlgorithm is the AWS SSE-C algorithm HTTP header key for CopyObject API.
+	sseCopyCustomerAlgorithm = "X-Amz-Copy-Source-Server-Side-Encryption-Customer-Algorithm"
+	// sseCopyCustomerKey is the AWS SSE-C encryption key HTTP header key for CopyObject API.
+	sseCopyCustomerKey = "X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key"
+	// sseCopyCustomerKeyMD5 is the AWS SSE-C encryption key MD5 HTTP header key for CopyObject API.
+	sseCopyCustomerKeyMD5 = "X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key-MD5"
+)
+
+// PBKDF creates a SSE-C key from the provided password and salt.
+// PBKDF is a password-based key derivation function
+// which can be used to derive a high-entropy cryptographic
+// key from a low-entropy password and a salt.
+type PBKDF func(password, salt []byte) ServerSide
+
+// DefaultPBKDF is the default PBKDF. It uses Argon2id with the
+// recommended parameters from the RFC draft (1 pass, 64 MB memory, 4 threads).
+var DefaultPBKDF PBKDF = func(password, salt []byte) ServerSide {
+	sse := ssec{}
+	copy(sse[:], argon2.IDKey(password, salt, 1, 64*1024, 4, 32))
+	return sse
+}
+
+// Type is the server-side-encryption method. It represents one of
+// the following encryption methods:
+//  - SSE-C: server-side-encryption with customer provided keys
+//  - KMS:   server-side-encryption with managed keys
+//  - S3:    server-side-encryption using S3 storage encryption
+type Type string
+
+const (
+	// SSEC represents server-side-encryption with customer provided keys
+	SSEC Type = "SSE-C"
+	// KMS represents server-side-encryption with managed keys
+	KMS Type = "KMS"
+	// S3 represents server-side-encryption using S3 storage encryption
+	S3 Type = "S3"
+)
+
+// ServerSide is a form of S3 server-side-encryption.
+type ServerSide interface {
+	// Type returns the server-side-encryption method.
+	Type() Type
+
+	// Marshal adds encryption headers to the provided HTTP headers.
+	// It marks an HTTP request as server-side-encryption request
+	// and inserts the required data into the headers.
+	Marshal(h http.Header)
+}
+
+// NewSSE returns a server-side-encryption using S3 storage encryption.
+// Using SSE-S3 the server will encrypt the object with server-managed keys.
+func NewSSE() ServerSide { return s3{} }
+
+// NewSSEKMS returns a new server-side-encryption using SSE-KMS and the provided Key Id and context.
+func NewSSEKMS(keyID string, context interface{}) (ServerSide, error) {
+	if context == nil {
+		return kms{key: keyID, hasContext: false}, nil
+	}
+	serializedContext, err := json.Marshal(context)
+	if err != nil {
+		return nil, err
+	}
+	return kms{key: keyID, context: serializedContext, hasContext: true}, nil
+}
+
+// NewSSEC returns a new server-side-encryption using SSE-C and the provided key.
+// The key must be 32 bytes long.
+func NewSSEC(key []byte) (ServerSide, error) {
+	if len(key) != 32 {
+		return nil, errors.New("encrypt: SSE-C key must be 256 bit long")
+	}
+	sse := ssec{}
+	copy(sse[:], key)
+	return sse, nil
+}
+
+// SSE transforms a SSE-C copy encryption into a SSE-C encryption.
+// It is the inverse of SSECopy(...).
+//
+// If the provided sse is no SSE-C copy encryption SSE returns
+// sse unmodified.
+func SSE(sse ServerSide) ServerSide {
+	if sse == nil || sse.Type() != SSEC {
+		return sse
+	}
+	if sse, ok := sse.(ssecCopy); ok {
+		return ssec(sse)
+	}
+	return sse
+}
+
+// SSECopy transforms a SSE-C encryption into a SSE-C copy
+// encryption. This is required for SSE-C key rotation or a SSE-C
+// copy where the source and the destination should be encrypted.
+//
+// If the provided sse is no SSE-C encryption SSECopy returns
+// sse unmodified.
+func SSECopy(sse ServerSide) ServerSide {
+	if sse == nil || sse.Type() != SSEC {
+		return sse
+	}
+	if sse, ok := sse.(ssec); ok {
+		return ssecCopy(sse)
+	}
+	return sse
+}
+
+type ssec [32]byte
+
+func (s ssec) Type() Type { return SSEC }
+
+func (s ssec) Marshal(h http.Header) {
+	keyMD5 := md5.Sum(s[:])
+	h.Set(sseCustomerAlgorithm, "AES256")
+	h.Set(sseCustomerKey, base64.StdEncoding.EncodeToString(s[:]))
+	h.Set(sseCustomerKeyMD5, base64.StdEncoding.EncodeToString(keyMD5[:]))
+}
+
+type ssecCopy [32]byte
+
+func (s ssecCopy) Type() Type { return SSEC }
+
+func (s ssecCopy) Marshal(h http.Header) {
+	keyMD5 := md5.Sum(s[:])
+	h.Set(sseCopyCustomerAlgorithm, "AES256")
+	h.Set(sseCopyCustomerKey, base64.StdEncoding.EncodeToString(s[:]))
+	h.Set(sseCopyCustomerKeyMD5, base64.StdEncoding.EncodeToString(keyMD5[:]))
+}
+
+type s3 struct{}
+
+func (s s3) Type() Type { return S3 }
+
+func (s s3) Marshal(h http.Header) { h.Set(sseGenericHeader, "AES256") }
+
+type kms struct {
+	key        string
+	context    []byte
+	hasContext bool
+}
+
+func (s kms) Type() Type { return KMS }
+
+func (s kms) Marshal(h http.Header) {
+	h.Set(sseGenericHeader, "aws:kms")
+	h.Set(sseKmsKeyID, s.key)
+	if s.hasContext {
+		h.Set(sseEncryptionContext, base64.StdEncoding.EncodeToString(s.context))
+	}
+}

vendor/github.com/minio/minio-go/pkg/s3signer/request-signature-streaming.go

@@ -0,0 +1,306 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3signer
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Reference for constants used below -
+// http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html#example-signature-calculations-streaming
+const (
+	streamingSignAlgorithm = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD"
+	streamingPayloadHdr    = "AWS4-HMAC-SHA256-PAYLOAD"
+	emptySHA256            = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+	payloadChunkSize       = 64 * 1024
+	chunkSigConstLen       = 17 // ";chunk-signature="
+	signatureStrLen        = 64 // e.g. "f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2"
+	crlfLen                = 2  // CRLF
+)
+
+// Request headers to be ignored while calculating seed signature for
+// a request.
+var ignoredStreamingHeaders = map[string]bool{
+	"Authorization": true,
+	"User-Agent":    true,
+	"Content-Type":  true,
+}
+
+// getSignedChunkLength - calculates the length of chunk metadata
+func getSignedChunkLength(chunkDataSize int64) int64 {
+	return int64(len(fmt.Sprintf("%x", chunkDataSize))) +
+		chunkSigConstLen +
+		signatureStrLen +
+		crlfLen +
+		chunkDataSize +
+		crlfLen
+}
+
+// getStreamLength - calculates the length of the overall stream (data + metadata)
+func getStreamLength(dataLen, chunkSize int64) int64 {
+	if dataLen <= 0 {
+		return 0
+	}
+
+	chunksCount := int64(dataLen / chunkSize)
+	remainingBytes := int64(dataLen % chunkSize)
+	streamLen := int64(0)
+	streamLen += chunksCount * getSignedChunkLength(chunkSize)
+	if remainingBytes > 0 {
+		streamLen += getSignedChunkLength(remainingBytes)
+	}
+	streamLen += getSignedChunkLength(0)
+	return streamLen
+}
+
+// buildChunkStringToSign - returns the string to sign given chunk data
+// and previous signature.
+func buildChunkStringToSign(t time.Time, region, previousSig string, chunkData []byte) string {
+	stringToSignParts := []string{
+		streamingPayloadHdr,
+		t.Format(iso8601DateFormat),
+		getScope(region, t),
+		previousSig,
+		emptySHA256,
+		hex.EncodeToString(sum256(chunkData)),
+	}
+
+	return strings.Join(stringToSignParts, "\n")
+}
+
+// prepareStreamingRequest - prepares a request with appropriate
+// headers before computing the seed signature.
+func prepareStreamingRequest(req *http.Request, sessionToken string, dataLen int64, timestamp time.Time) {
+	// Set x-amz-content-sha256 header.
+	req.Header.Set("X-Amz-Content-Sha256", streamingSignAlgorithm)
+	if sessionToken != "" {
+		req.Header.Set("X-Amz-Security-Token", sessionToken)
+	}
+
+	req.Header.Set("X-Amz-Date", timestamp.Format(iso8601DateFormat))
+	// Set content length with streaming signature for each chunk included.
+	req.ContentLength = getStreamLength(dataLen, int64(payloadChunkSize))
+	req.Header.Set("x-amz-decoded-content-length", strconv.FormatInt(dataLen, 10))
+}
+
+// buildChunkHeader - returns the chunk header.
+// e.g string(IntHexBase(chunk-size)) + ";chunk-signature=" + signature + \r\n + chunk-data + \r\n
+func buildChunkHeader(chunkLen int64, signature string) []byte {
+	return []byte(strconv.FormatInt(chunkLen, 16) + ";chunk-signature=" + signature + "\r\n")
+}
+
+// buildChunkSignature - returns chunk signature for a given chunk and previous signature.
+func buildChunkSignature(chunkData []byte, reqTime time.Time, region,
+	previousSignature, secretAccessKey string) string {
+
+	chunkStringToSign := buildChunkStringToSign(reqTime, region,
+		previousSignature, chunkData)
+	signingKey := getSigningKey(secretAccessKey, region, reqTime)
+	return getSignature(signingKey, chunkStringToSign)
+}
+
+// getSeedSignature - returns the seed signature for a given request.
+func (s *StreamingReader) setSeedSignature(req *http.Request) {
+	// Get canonical request
+	canonicalRequest := getCanonicalRequest(*req, ignoredStreamingHeaders)
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(s.reqTime, s.region, canonicalRequest)
+
+	signingKey := getSigningKey(s.secretAccessKey, s.region, s.reqTime)
+
+	// Calculate signature.
+	s.seedSignature = getSignature(signingKey, stringToSign)
+}
+
+// StreamingReader implements chunked upload signature as a reader on
+// top of req.Body's ReaderCloser chunk header;data;... repeat
+type StreamingReader struct {
+	accessKeyID     string
+	secretAccessKey string
+	sessionToken    string
+	region          string
+	prevSignature   string
+	seedSignature   string
+	contentLen      int64         // Content-Length from req header
+	baseReadCloser  io.ReadCloser // underlying io.Reader
+	bytesRead       int64         // bytes read from underlying io.Reader
+	buf             bytes.Buffer  // holds signed chunk
+	chunkBuf        []byte        // holds raw data read from req Body
+	chunkBufLen     int           // no. of bytes read so far into chunkBuf
+	done            bool          // done reading the underlying reader to EOF
+	reqTime         time.Time
+	chunkNum        int
+	totalChunks     int
+	lastChunkSize   int
+}
+
+// signChunk - signs a chunk read from s.baseReader of chunkLen size.
+func (s *StreamingReader) signChunk(chunkLen int) {
+	// Compute chunk signature for next header
+	signature := buildChunkSignature(s.chunkBuf[:chunkLen], s.reqTime,
+		s.region, s.prevSignature, s.secretAccessKey)
+
+	// For next chunk signature computation
+	s.prevSignature = signature
+
+	// Write chunk header into streaming buffer
+	chunkHdr := buildChunkHeader(int64(chunkLen), signature)
+	s.buf.Write(chunkHdr)
+
+	// Write chunk data into streaming buffer
+	s.buf.Write(s.chunkBuf[:chunkLen])
+
+	// Write the chunk trailer.
+	s.buf.Write([]byte("\r\n"))
+
+	// Reset chunkBufLen for next chunk read.
+	s.chunkBufLen = 0
+	s.chunkNum++
+}
+
+// setStreamingAuthHeader - builds and sets authorization header value
+// for streaming signature.
+func (s *StreamingReader) setStreamingAuthHeader(req *http.Request) {
+	credential := GetCredential(s.accessKeyID, s.region, s.reqTime)
+	authParts := []string{
+		signV4Algorithm + " Credential=" + credential,
+		"SignedHeaders=" + getSignedHeaders(*req, ignoredStreamingHeaders),
+		"Signature=" + s.seedSignature,
+	}
+
+	// Set authorization header.
+	auth := strings.Join(authParts, ",")
+	req.Header.Set("Authorization", auth)
+}
+
+// StreamingSignV4 - provides chunked upload signatureV4 support by
+// implementing io.Reader.
+func StreamingSignV4(req *http.Request, accessKeyID, secretAccessKey, sessionToken,
+	region string, dataLen int64, reqTime time.Time) *http.Request {
+
+	// Set headers needed for streaming signature.
+	prepareStreamingRequest(req, sessionToken, dataLen, reqTime)
+
+	if req.Body == nil {
+		req.Body = ioutil.NopCloser(bytes.NewReader([]byte("")))
+	}
+
+	stReader := &StreamingReader{
+		baseReadCloser:  req.Body,
+		accessKeyID:     accessKeyID,
+		secretAccessKey: secretAccessKey,
+		sessionToken:    sessionToken,
+		region:          region,
+		reqTime:         reqTime,
+		chunkBuf:        make([]byte, payloadChunkSize),
+		contentLen:      dataLen,
+		chunkNum:        1,
+		totalChunks:     int((dataLen+payloadChunkSize-1)/payloadChunkSize) + 1,
+		lastChunkSize:   int(dataLen % payloadChunkSize),
+	}
+
+	// Add the request headers required for chunk upload signing.
+
+	// Compute the seed signature.
+	stReader.setSeedSignature(req)
+
+	// Set the authorization header with the seed signature.
+	stReader.setStreamingAuthHeader(req)
+
+	// Set seed signature as prevSignature for subsequent
+	// streaming signing process.
+	stReader.prevSignature = stReader.seedSignature
+	req.Body = stReader
+
+	return req
+}
+
+// Read - this method performs chunk upload signature providing a
+// io.Reader interface.
+func (s *StreamingReader) Read(buf []byte) (int, error) {
+	switch {
+	// After the last chunk is read from underlying reader, we
+	// never re-fill s.buf.
+	case s.done:
+
+	// s.buf will be (re-)filled with next chunk when has lesser
+	// bytes than asked for.
+	case s.buf.Len() < len(buf):
+		s.chunkBufLen = 0
+		for {
+			n1, err := s.baseReadCloser.Read(s.chunkBuf[s.chunkBufLen:])
+			// Usually we validate `err` first, but in this case
+			// we are validating n > 0 for the following reasons.
+			//
+			// 1. n > 0, err is one of io.EOF, nil (near end of stream)
+			// A Reader returning a non-zero number of bytes at the end
+			// of the input stream may return either err == EOF or err == nil
+			//
+			// 2. n == 0, err is io.EOF (actual end of stream)
+			//
+			// Callers should always process the n > 0 bytes returned
+			// before considering the error err.
+			if n1 > 0 {
+				s.chunkBufLen += n1
+				s.bytesRead += int64(n1)
+
+				if s.chunkBufLen == payloadChunkSize ||
+					(s.chunkNum == s.totalChunks-1 &&
+						s.chunkBufLen == s.lastChunkSize) {
+					// Sign the chunk and write it to s.buf.
+					s.signChunk(s.chunkBufLen)
+					break
+				}
+			}
+			if err != nil {
+				if err == io.EOF {
+					// No more data left in baseReader - last chunk.
+					// Done reading the last chunk from baseReader.
+					s.done = true
+
+					// bytes read from baseReader different than
+					// content length provided.
+					if s.bytesRead != s.contentLen {
+						return 0, io.ErrUnexpectedEOF
+					}
+
+					// Sign the chunk and write it to s.buf.
+					s.signChunk(0)
+					break
+				}
+				return 0, err
+			}
+
+		}
+	}
+	return s.buf.Read(buf)
+}
+
+// Close - this method makes underlying io.ReadCloser's Close method available.
+func (s *StreamingReader) Close() error {
+	return s.baseReadCloser.Close()
+}

vendor/github.com/minio/minio-go/pkg/s3signer/request-signature-v2.go

@@ -0,0 +1,316 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2015-2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3signer
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+	"fmt"
+	"net/http"
+	"net/url"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/pkg/s3utils"
+)
+
+// Signature and API related constants.
+const (
+	signV2Algorithm = "AWS"
+)
+
+// Encode input URL path to URL encoded path.
+func encodeURL2Path(req *http.Request, virtualHost bool) (path string) {
+	if virtualHost {
+		reqHost := getHostAddr(req)
+		dotPos := strings.Index(reqHost, ".")
+		if dotPos > -1 {
+			bucketName := reqHost[:dotPos]
+			path = "/" + bucketName
+			path += req.URL.Path
+			path = s3utils.EncodePath(path)
+			return
+		}
+	}
+	path = s3utils.EncodePath(req.URL.Path)
+	return
+}
+
+// PreSignV2 - presign the request in following style.
+// https://${S3_BUCKET}.s3.amazonaws.com/${S3_OBJECT}?AWSAccessKeyId=${S3_ACCESS_KEY}&Expires=${TIMESTAMP}&Signature=${SIGNATURE}.
+func PreSignV2(req http.Request, accessKeyID, secretAccessKey string, expires int64, virtualHost bool) *http.Request {
+	// Presign is not needed for anonymous credentials.
+	if accessKeyID == "" || secretAccessKey == "" {
+		return &req
+	}
+
+	d := time.Now().UTC()
+	// Find epoch expires when the request will expire.
+	epochExpires := d.Unix() + expires
+
+	// Add expires header if not present.
+	if expiresStr := req.Header.Get("Expires"); expiresStr == "" {
+		req.Header.Set("Expires", strconv.FormatInt(epochExpires, 10))
+	}
+
+	// Get presigned string to sign.
+	stringToSign := preStringToSignV2(req, virtualHost)
+	hm := hmac.New(sha1.New, []byte(secretAccessKey))
+	hm.Write([]byte(stringToSign))
+
+	// Calculate signature.
+	signature := base64.StdEncoding.EncodeToString(hm.Sum(nil))
+
+	query := req.URL.Query()
+	// Handle specially for Google Cloud Storage.
+	if strings.Contains(getHostAddr(&req), ".storage.googleapis.com") {
+		query.Set("GoogleAccessId", accessKeyID)
+	} else {
+		query.Set("AWSAccessKeyId", accessKeyID)
+	}
+
+	// Fill in Expires for presigned query.
+	query.Set("Expires", strconv.FormatInt(epochExpires, 10))
+
+	// Encode query and save.
+	req.URL.RawQuery = s3utils.QueryEncode(query)
+
+	// Save signature finally.
+	req.URL.RawQuery += "&Signature=" + s3utils.EncodePath(signature)
+
+	// Return.
+	return &req
+}
+
+// PostPresignSignatureV2 - presigned signature for PostPolicy
+// request.
+func PostPresignSignatureV2(policyBase64, secretAccessKey string) string {
+	hm := hmac.New(sha1.New, []byte(secretAccessKey))
+	hm.Write([]byte(policyBase64))
+	signature := base64.StdEncoding.EncodeToString(hm.Sum(nil))
+	return signature
+}
+
+// Authorization = "AWS" + " " + AWSAccessKeyId + ":" + Signature;
+// Signature = Base64( HMAC-SHA1( YourSecretAccessKeyID, UTF-8-Encoding-Of( StringToSign ) ) );
+//
+// StringToSign = HTTP-Verb + "\n" +
+//  	Content-Md5 + "\n" +
+//  	Content-Type + "\n" +
+//  	Date + "\n" +
+//  	CanonicalizedProtocolHeaders +
+//  	CanonicalizedResource;
+//
+// CanonicalizedResource = [ "/" + Bucket ] +
+//  	<HTTP-Request-URI, from the protocol name up to the query string> +
+//  	[ subresource, if present. For example "?acl", "?location", "?logging", or "?torrent"];
+//
+// CanonicalizedProtocolHeaders = <described below>
+
+// SignV2 sign the request before Do() (AWS Signature Version 2).
+func SignV2(req http.Request, accessKeyID, secretAccessKey string, virtualHost bool) *http.Request {
+	// Signature calculation is not needed for anonymous credentials.
+	if accessKeyID == "" || secretAccessKey == "" {
+		return &req
+	}
+
+	// Initial time.
+	d := time.Now().UTC()
+
+	// Add date if not present.
+	if date := req.Header.Get("Date"); date == "" {
+		req.Header.Set("Date", d.Format(http.TimeFormat))
+	}
+
+	// Calculate HMAC for secretAccessKey.
+	stringToSign := stringToSignV2(req, virtualHost)
+	hm := hmac.New(sha1.New, []byte(secretAccessKey))
+	hm.Write([]byte(stringToSign))
+
+	// Prepare auth header.
+	authHeader := new(bytes.Buffer)
+	authHeader.WriteString(fmt.Sprintf("%s %s:", signV2Algorithm, accessKeyID))
+	encoder := base64.NewEncoder(base64.StdEncoding, authHeader)
+	encoder.Write(hm.Sum(nil))
+	encoder.Close()
+
+	// Set Authorization header.
+	req.Header.Set("Authorization", authHeader.String())
+
+	return &req
+}
+
+// From the Amazon docs:
+//
+// StringToSign = HTTP-Verb + "\n" +
+// 	 Content-Md5 + "\n" +
+//	 Content-Type + "\n" +
+//	 Expires + "\n" +
+//	 CanonicalizedProtocolHeaders +
+//	 CanonicalizedResource;
+func preStringToSignV2(req http.Request, virtualHost bool) string {
+	buf := new(bytes.Buffer)
+	// Write standard headers.
+	writePreSignV2Headers(buf, req)
+	// Write canonicalized protocol headers if any.
+	writeCanonicalizedHeaders(buf, req)
+	// Write canonicalized Query resources if any.
+	writeCanonicalizedResource(buf, req, virtualHost)
+	return buf.String()
+}
+
+// writePreSignV2Headers - write preSign v2 required headers.
+func writePreSignV2Headers(buf *bytes.Buffer, req http.Request) {
+	buf.WriteString(req.Method + "\n")
+	buf.WriteString(req.Header.Get("Content-Md5") + "\n")
+	buf.WriteString(req.Header.Get("Content-Type") + "\n")
+	buf.WriteString(req.Header.Get("Expires") + "\n")
+}
+
+// From the Amazon docs:
+//
+// StringToSign = HTTP-Verb + "\n" +
+// 	 Content-Md5 + "\n" +
+//	 Content-Type + "\n" +
+//	 Date + "\n" +
+//	 CanonicalizedProtocolHeaders +
+//	 CanonicalizedResource;
+func stringToSignV2(req http.Request, virtualHost bool) string {
+	buf := new(bytes.Buffer)
+	// Write standard headers.
+	writeSignV2Headers(buf, req)
+	// Write canonicalized protocol headers if any.
+	writeCanonicalizedHeaders(buf, req)
+	// Write canonicalized Query resources if any.
+	writeCanonicalizedResource(buf, req, virtualHost)
+	return buf.String()
+}
+
+// writeSignV2Headers - write signV2 required headers.
+func writeSignV2Headers(buf *bytes.Buffer, req http.Request) {
+	buf.WriteString(req.Method + "\n")
+	buf.WriteString(req.Header.Get("Content-Md5") + "\n")
+	buf.WriteString(req.Header.Get("Content-Type") + "\n")
+	buf.WriteString(req.Header.Get("Date") + "\n")
+}
+
+// writeCanonicalizedHeaders - write canonicalized headers.
+func writeCanonicalizedHeaders(buf *bytes.Buffer, req http.Request) {
+	var protoHeaders []string
+	vals := make(map[string][]string)
+	for k, vv := range req.Header {
+		// All the AMZ headers should be lowercase
+		lk := strings.ToLower(k)
+		if strings.HasPrefix(lk, "x-amz") {
+			protoHeaders = append(protoHeaders, lk)
+			vals[lk] = vv
+		}
+	}
+	sort.Strings(protoHeaders)
+	for _, k := range protoHeaders {
+		buf.WriteString(k)
+		buf.WriteByte(':')
+		for idx, v := range vals[k] {
+			if idx > 0 {
+				buf.WriteByte(',')
+			}
+			if strings.Contains(v, "\n") {
+				// TODO: "Unfold" long headers that
+				// span multiple lines (as allowed by
+				// RFC 2616, section 4.2) by replacing
+				// the folding white-space (including
+				// new-line) by a single space.
+				buf.WriteString(v)
+			} else {
+				buf.WriteString(v)
+			}
+		}
+		buf.WriteByte('\n')
+	}
+}
+
+// AWS S3 Signature V2 calculation rule is give here:
+// http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#RESTAuthenticationStringToSign
+
+// Whitelist resource list that will be used in query string for signature-V2 calculation.
+// The list should be alphabetically sorted
+var resourceList = []string{
+	"acl",
+	"delete",
+	"lifecycle",
+	"location",
+	"logging",
+	"notification",
+	"partNumber",
+	"policy",
+	"requestPayment",
+	"response-cache-control",
+	"response-content-disposition",
+	"response-content-encoding",
+	"response-content-language",
+	"response-content-type",
+	"response-expires",
+	"torrent",
+	"uploadId",
+	"uploads",
+	"versionId",
+	"versioning",
+	"versions",
+	"website",
+}
+
+// From the Amazon docs:
+//
+// CanonicalizedResource = [ "/" + Bucket ] +
+// 	  <HTTP-Request-URI, from the protocol name up to the query string> +
+// 	  [ sub-resource, if present. For example "?acl", "?location", "?logging", or "?torrent"];
+func writeCanonicalizedResource(buf *bytes.Buffer, req http.Request, virtualHost bool) {
+	// Save request URL.
+	requestURL := req.URL
+	// Get encoded URL path.
+	buf.WriteString(encodeURL2Path(&req, virtualHost))
+	if requestURL.RawQuery != "" {
+		var n int
+		vals, _ := url.ParseQuery(requestURL.RawQuery)
+		// Verify if any sub resource queries are present, if yes
+		// canonicallize them.
+		for _, resource := range resourceList {
+			if vv, ok := vals[resource]; ok && len(vv) > 0 {
+				n++
+				// First element
+				switch n {
+				case 1:
+					buf.WriteByte('?')
+				// The rest
+				default:
+					buf.WriteByte('&')
+				}
+				buf.WriteString(resource)
+				// Request parameters
+				if len(vv[0]) > 0 {
+					buf.WriteByte('=')
+					buf.WriteString(vv[0])
+				}
+			}
+		}
+	}
+}

vendor/github.com/minio/minio-go/pkg/s3signer/request-signature-v4.go

@@ -0,0 +1,315 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2015-2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3signer
+
+import (
+	"bytes"
+	"encoding/hex"
+	"net/http"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/pkg/s3utils"
+)
+
+// Signature and API related constants.
+const (
+	signV4Algorithm   = "AWS4-HMAC-SHA256"
+	iso8601DateFormat = "20060102T150405Z"
+	yyyymmdd          = "20060102"
+)
+
+///
+/// Excerpts from @lsegal -
+/// https://github.com/aws/aws-sdk-js/issues/659#issuecomment-120477258.
+///
+///  User-Agent:
+///
+///      This is ignored from signing because signing this causes
+///      problems with generating pre-signed URLs (that are executed
+///      by other agents) or when customers pass requests through
+///      proxies, which may modify the user-agent.
+///
+///  Content-Length:
+///
+///      This is ignored from signing because generating a pre-signed
+///      URL should not provide a content-length constraint,
+///      specifically when vending a S3 pre-signed PUT URL. The
+///      corollary to this is that when sending regular requests
+///      (non-pre-signed), the signature contains a checksum of the
+///      body, which implicitly validates the payload length (since
+///      changing the number of bytes would change the checksum)
+///      and therefore this header is not valuable in the signature.
+///
+///  Content-Type:
+///
+///      Signing this header causes quite a number of problems in
+///      browser environments, where browsers like to modify and
+///      normalize the content-type header in different ways. There is
+///      more information on this in https://goo.gl/2E9gyy. Avoiding
+///      this field simplifies logic and reduces the possibility of
+///      future bugs.
+///
+///  Authorization:
+///
+///      Is skipped for obvious reasons
+///
+var v4IgnoredHeaders = map[string]bool{
+	"Authorization":  true,
+	"Content-Type":   true,
+	"Content-Length": true,
+	"User-Agent":     true,
+}
+
+// getSigningKey hmac seed to calculate final signature.
+func getSigningKey(secret, loc string, t time.Time) []byte {
+	date := sumHMAC([]byte("AWS4"+secret), []byte(t.Format(yyyymmdd)))
+	location := sumHMAC(date, []byte(loc))
+	service := sumHMAC(location, []byte("s3"))
+	signingKey := sumHMAC(service, []byte("aws4_request"))
+	return signingKey
+}
+
+// getSignature final signature in hexadecimal form.
+func getSignature(signingKey []byte, stringToSign string) string {
+	return hex.EncodeToString(sumHMAC(signingKey, []byte(stringToSign)))
+}
+
+// getScope generate a string of a specific date, an AWS region, and a
+// service.
+func getScope(location string, t time.Time) string {
+	scope := strings.Join([]string{
+		t.Format(yyyymmdd),
+		location,
+		"s3",
+		"aws4_request",
+	}, "/")
+	return scope
+}
+
+// GetCredential generate a credential string.
+func GetCredential(accessKeyID, location string, t time.Time) string {
+	scope := getScope(location, t)
+	return accessKeyID + "/" + scope
+}
+
+// getHashedPayload get the hexadecimal value of the SHA256 hash of
+// the request payload.
+func getHashedPayload(req http.Request) string {
+	hashedPayload := req.Header.Get("X-Amz-Content-Sha256")
+	if hashedPayload == "" {
+		// Presign does not have a payload, use S3 recommended value.
+		hashedPayload = unsignedPayload
+	}
+	return hashedPayload
+}
+
+// getCanonicalHeaders generate a list of request headers for
+// signature.
+func getCanonicalHeaders(req http.Request, ignoredHeaders map[string]bool) string {
+	var headers []string
+	vals := make(map[string][]string)
+	for k, vv := range req.Header {
+		if _, ok := ignoredHeaders[http.CanonicalHeaderKey(k)]; ok {
+			continue // ignored header
+		}
+		headers = append(headers, strings.ToLower(k))
+		vals[strings.ToLower(k)] = vv
+	}
+	headers = append(headers, "host")
+	sort.Strings(headers)
+
+	var buf bytes.Buffer
+	// Save all the headers in canonical form <header>:<value> newline
+	// separated for each header.
+	for _, k := range headers {
+		buf.WriteString(k)
+		buf.WriteByte(':')
+		switch {
+		case k == "host":
+			buf.WriteString(getHostAddr(&req))
+			fallthrough
+		default:
+			for idx, v := range vals[k] {
+				if idx > 0 {
+					buf.WriteByte(',')
+				}
+				buf.WriteString(v)
+			}
+			buf.WriteByte('\n')
+		}
+	}
+	return buf.String()
+}
+
+// getSignedHeaders generate all signed request headers.
+// i.e lexically sorted, semicolon-separated list of lowercase
+// request header names.
+func getSignedHeaders(req http.Request, ignoredHeaders map[string]bool) string {
+	var headers []string
+	for k := range req.Header {
+		if _, ok := ignoredHeaders[http.CanonicalHeaderKey(k)]; ok {
+			continue // Ignored header found continue.
+		}
+		headers = append(headers, strings.ToLower(k))
+	}
+	headers = append(headers, "host")
+	sort.Strings(headers)
+	return strings.Join(headers, ";")
+}
+
+// getCanonicalRequest generate a canonical request of style.
+//
+// canonicalRequest =
+//  <HTTPMethod>\n
+//  <CanonicalURI>\n
+//  <CanonicalQueryString>\n
+//  <CanonicalHeaders>\n
+//  <SignedHeaders>\n
+//  <HashedPayload>
+func getCanonicalRequest(req http.Request, ignoredHeaders map[string]bool) string {
+	req.URL.RawQuery = strings.Replace(req.URL.Query().Encode(), "+", "%20", -1)
+	canonicalRequest := strings.Join([]string{
+		req.Method,
+		s3utils.EncodePath(req.URL.Path),
+		req.URL.RawQuery,
+		getCanonicalHeaders(req, ignoredHeaders),
+		getSignedHeaders(req, ignoredHeaders),
+		getHashedPayload(req),
+	}, "\n")
+	return canonicalRequest
+}
+
+// getStringToSign a string based on selected query values.
+func getStringToSignV4(t time.Time, location, canonicalRequest string) string {
+	stringToSign := signV4Algorithm + "\n" + t.Format(iso8601DateFormat) + "\n"
+	stringToSign = stringToSign + getScope(location, t) + "\n"
+	stringToSign = stringToSign + hex.EncodeToString(sum256([]byte(canonicalRequest)))
+	return stringToSign
+}
+
+// PreSignV4 presign the request, in accordance with
+// http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html.
+func PreSignV4(req http.Request, accessKeyID, secretAccessKey, sessionToken, location string, expires int64) *http.Request {
+	// Presign is not needed for anonymous credentials.
+	if accessKeyID == "" || secretAccessKey == "" {
+		return &req
+	}
+
+	// Initial time.
+	t := time.Now().UTC()
+
+	// Get credential string.
+	credential := GetCredential(accessKeyID, location, t)
+
+	// Get all signed headers.
+	signedHeaders := getSignedHeaders(req, v4IgnoredHeaders)
+
+	// Set URL query.
+	query := req.URL.Query()
+	query.Set("X-Amz-Algorithm", signV4Algorithm)
+	query.Set("X-Amz-Date", t.Format(iso8601DateFormat))
+	query.Set("X-Amz-Expires", strconv.FormatInt(expires, 10))
+	query.Set("X-Amz-SignedHeaders", signedHeaders)
+	query.Set("X-Amz-Credential", credential)
+	// Set session token if available.
+	if sessionToken != "" {
+		query.Set("X-Amz-Security-Token", sessionToken)
+	}
+	req.URL.RawQuery = query.Encode()
+
+	// Get canonical request.
+	canonicalRequest := getCanonicalRequest(req, v4IgnoredHeaders)
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(t, location, canonicalRequest)
+
+	// Gext hmac signing key.
+	signingKey := getSigningKey(secretAccessKey, location, t)
+
+	// Calculate signature.
+	signature := getSignature(signingKey, stringToSign)
+
+	// Add signature header to RawQuery.
+	req.URL.RawQuery += "&X-Amz-Signature=" + signature
+
+	return &req
+}
+
+// PostPresignSignatureV4 - presigned signature for PostPolicy
+// requests.
+func PostPresignSignatureV4(policyBase64 string, t time.Time, secretAccessKey, location string) string {
+	// Get signining key.
+	signingkey := getSigningKey(secretAccessKey, location, t)
+	// Calculate signature.
+	signature := getSignature(signingkey, policyBase64)
+	return signature
+}
+
+// SignV4 sign the request before Do(), in accordance with
+// http://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html.
+func SignV4(req http.Request, accessKeyID, secretAccessKey, sessionToken, location string) *http.Request {
+	// Signature calculation is not needed for anonymous credentials.
+	if accessKeyID == "" || secretAccessKey == "" {
+		return &req
+	}
+
+	// Initial time.
+	t := time.Now().UTC()
+
+	// Set x-amz-date.
+	req.Header.Set("X-Amz-Date", t.Format(iso8601DateFormat))
+
+	// Set session token if available.
+	if sessionToken != "" {
+		req.Header.Set("X-Amz-Security-Token", sessionToken)
+	}
+
+	// Get canonical request.
+	canonicalRequest := getCanonicalRequest(req, v4IgnoredHeaders)
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(t, location, canonicalRequest)
+
+	// Get hmac signing key.
+	signingKey := getSigningKey(secretAccessKey, location, t)
+
+	// Get credential string.
+	credential := GetCredential(accessKeyID, location, t)
+
+	// Get all signed headers.
+	signedHeaders := getSignedHeaders(req, v4IgnoredHeaders)
+
+	// Calculate signature.
+	signature := getSignature(signingKey, stringToSign)
+
+	// If regular request, construct the final authorization header.
+	parts := []string{
+		signV4Algorithm + " Credential=" + credential,
+		"SignedHeaders=" + signedHeaders,
+		"Signature=" + signature,
+	}
+
+	// Set authorization header.
+	auth := strings.Join(parts, ", ")
+	req.Header.Set("Authorization", auth)
+
+	return &req
+}

vendor/github.com/minio/minio-go/pkg/s3signer/utils.go

@@ -0,0 +1,49 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2015-2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3signer
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"net/http"
+)
+
+// unsignedPayload - value to be set to X-Amz-Content-Sha256 header when
+const unsignedPayload = "UNSIGNED-PAYLOAD"
+
+// sum256 calculate sha256 sum for an input byte array.
+func sum256(data []byte) []byte {
+	hash := sha256.New()
+	hash.Write(data)
+	return hash.Sum(nil)
+}
+
+// sumHMAC calculate hmac between two input byte array.
+func sumHMAC(key []byte, data []byte) []byte {
+	hash := hmac.New(sha256.New, key)
+	hash.Write(data)
+	return hash.Sum(nil)
+}
+
+// getHostAddr returns host header if available, otherwise returns host from URL
+func getHostAddr(req *http.Request) string {
+	if req.Host != "" {
+		return req.Host
+	}
+	return req.URL.Host
+}

vendor/github.com/minio/minio-go/pkg/s3utils/utils.go

@@ -0,0 +1,302 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2015-2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3utils
+
+import (
+	"bytes"
+	"encoding/hex"
+	"errors"
+	"net"
+	"net/url"
+	"regexp"
+	"sort"
+	"strings"
+	"unicode/utf8"
+)
+
+// Sentinel URL is the default url value which is invalid.
+var sentinelURL = url.URL{}
+
+// IsValidDomain validates if input string is a valid domain name.
+func IsValidDomain(host string) bool {
+	// See RFC 1035, RFC 3696.
+	host = strings.TrimSpace(host)
+	if len(host) == 0 || len(host) > 255 {
+		return false
+	}
+	// host cannot start or end with "-"
+	if host[len(host)-1:] == "-" || host[:1] == "-" {
+		return false
+	}
+	// host cannot start or end with "_"
+	if host[len(host)-1:] == "_" || host[:1] == "_" {
+		return false
+	}
+	// host cannot start or end with a "."
+	if host[len(host)-1:] == "." || host[:1] == "." {
+		return false
+	}
+	// All non alphanumeric characters are invalid.
+	if strings.ContainsAny(host, "`~!@#$%^&*()+={}[]|\\\"';:><?/") {
+		return false
+	}
+	// No need to regexp match, since the list is non-exhaustive.
+	// We let it valid and fail later.
+	return true
+}
+
+// IsValidIP parses input string for ip address validity.
+func IsValidIP(ip string) bool {
+	return net.ParseIP(ip) != nil
+}
+
+// IsVirtualHostSupported - verifies if bucketName can be part of
+// virtual host. Currently only Amazon S3 and Google Cloud Storage
+// would support this.
+func IsVirtualHostSupported(endpointURL url.URL, bucketName string) bool {
+	if endpointURL == sentinelURL {
+		return false
+	}
+	// bucketName can be valid but '.' in the hostname will fail SSL
+	// certificate validation. So do not use host-style for such buckets.
+	if endpointURL.Scheme == "https" && strings.Contains(bucketName, ".") {
+		return false
+	}
+	// Return true for all other cases
+	return IsAmazonEndpoint(endpointURL) || IsGoogleEndpoint(endpointURL)
+}
+
+// Refer for region styles - https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region
+
+// amazonS3HostHyphen - regular expression used to determine if an arg is s3 host in hyphenated style.
+var amazonS3HostHyphen = regexp.MustCompile(`^s3-(.*?)\.amazonaws\.com$`)
+
+// amazonS3HostDualStack - regular expression used to determine if an arg is s3 host dualstack.
+var amazonS3HostDualStack = regexp.MustCompile(`^s3\.dualstack\.(.*?)\.amazonaws\.com$`)
+
+// amazonS3HostDot - regular expression used to determine if an arg is s3 host in . style.
+var amazonS3HostDot = regexp.MustCompile(`^s3\.(.*?)\.amazonaws\.com$`)
+
+// amazonS3ChinaHost - regular expression used to determine if the arg is s3 china host.
+var amazonS3ChinaHost = regexp.MustCompile(`^s3\.(cn.*?)\.amazonaws\.com\.cn$`)
+
+// GetRegionFromURL - returns a region from url host.
+func GetRegionFromURL(endpointURL url.URL) string {
+	if endpointURL == sentinelURL {
+		return ""
+	}
+	if endpointURL.Host == "s3-external-1.amazonaws.com" {
+		return ""
+	}
+	if IsAmazonGovCloudEndpoint(endpointURL) {
+		return "us-gov-west-1"
+	}
+	parts := amazonS3HostDualStack.FindStringSubmatch(endpointURL.Host)
+	if len(parts) > 1 {
+		return parts[1]
+	}
+	parts = amazonS3HostHyphen.FindStringSubmatch(endpointURL.Host)
+	if len(parts) > 1 {
+		return parts[1]
+	}
+	parts = amazonS3ChinaHost.FindStringSubmatch(endpointURL.Host)
+	if len(parts) > 1 {
+		return parts[1]
+	}
+	parts = amazonS3HostDot.FindStringSubmatch(endpointURL.Host)
+	if len(parts) > 1 {
+		return parts[1]
+	}
+	return ""
+}
+
+// IsAmazonEndpoint - Match if it is exactly Amazon S3 endpoint.
+func IsAmazonEndpoint(endpointURL url.URL) bool {
+	if endpointURL.Host == "s3-external-1.amazonaws.com" || endpointURL.Host == "s3.amazonaws.com" {
+		return true
+	}
+	return GetRegionFromURL(endpointURL) != ""
+}
+
+// IsAmazonGovCloudEndpoint - Match if it is exactly Amazon S3 GovCloud endpoint.
+func IsAmazonGovCloudEndpoint(endpointURL url.URL) bool {
+	if endpointURL == sentinelURL {
+		return false
+	}
+	return (endpointURL.Host == "s3-us-gov-west-1.amazonaws.com" ||
+		IsAmazonFIPSGovCloudEndpoint(endpointURL))
+}
+
+// IsAmazonFIPSGovCloudEndpoint - Match if it is exactly Amazon S3 FIPS GovCloud endpoint.
+func IsAmazonFIPSGovCloudEndpoint(endpointURL url.URL) bool {
+	if endpointURL == sentinelURL {
+		return false
+	}
+	return endpointURL.Host == "s3-fips-us-gov-west-1.amazonaws.com"
+}
+
+// IsGoogleEndpoint - Match if it is exactly Google cloud storage endpoint.
+func IsGoogleEndpoint(endpointURL url.URL) bool {
+	if endpointURL == sentinelURL {
+		return false
+	}
+	return endpointURL.Host == "storage.googleapis.com"
+}
+
+// Expects ascii encoded strings - from output of urlEncodePath
+func percentEncodeSlash(s string) string {
+	return strings.Replace(s, "/", "%2F", -1)
+}
+
+// QueryEncode - encodes query values in their URL encoded form. In
+// addition to the percent encoding performed by urlEncodePath() used
+// here, it also percent encodes '/' (forward slash)
+func QueryEncode(v url.Values) string {
+	if v == nil {
+		return ""
+	}
+	var buf bytes.Buffer
+	keys := make([]string, 0, len(v))
+	for k := range v {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	for _, k := range keys {
+		vs := v[k]
+		prefix := percentEncodeSlash(EncodePath(k)) + "="
+		for _, v := range vs {
+			if buf.Len() > 0 {
+				buf.WriteByte('&')
+			}
+			buf.WriteString(prefix)
+			buf.WriteString(percentEncodeSlash(EncodePath(v)))
+		}
+	}
+	return buf.String()
+}
+
+// if object matches reserved string, no need to encode them
+var reservedObjectNames = regexp.MustCompile("^[a-zA-Z0-9-_.~/]+$")
+
+// EncodePath encode the strings from UTF-8 byte representations to HTML hex escape sequences
+//
+// This is necessary since regular url.Parse() and url.Encode() functions do not support UTF-8
+// non english characters cannot be parsed due to the nature in which url.Encode() is written
+//
+// This function on the other hand is a direct replacement for url.Encode() technique to support
+// pretty much every UTF-8 character.
+func EncodePath(pathName string) string {
+	if reservedObjectNames.MatchString(pathName) {
+		return pathName
+	}
+	var encodedPathname string
+	for _, s := range pathName {
+		if 'A' <= s && s <= 'Z' || 'a' <= s && s <= 'z' || '0' <= s && s <= '9' { // §2.3 Unreserved characters (mark)
+			encodedPathname = encodedPathname + string(s)
+			continue
+		}
+		switch s {
+		case '-', '_', '.', '~', '/': // §2.3 Unreserved characters (mark)
+			encodedPathname = encodedPathname + string(s)
+			continue
+		default:
+			len := utf8.RuneLen(s)
+			if len < 0 {
+				// if utf8 cannot convert return the same string as is
+				return pathName
+			}
+			u := make([]byte, len)
+			utf8.EncodeRune(u, s)
+			for _, r := range u {
+				hex := hex.EncodeToString([]byte{r})
+				encodedPathname = encodedPathname + "%" + strings.ToUpper(hex)
+			}
+		}
+	}
+	return encodedPathname
+}
+
+// We support '.' with bucket names but we fallback to using path
+// style requests instead for such buckets.
+var (
+	validBucketName       = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9\.\-\_\:]{1,61}[A-Za-z0-9]$`)
+	validBucketNameStrict = regexp.MustCompile(`^[a-z0-9][a-z0-9\.\-]{1,61}[a-z0-9]$`)
+	ipAddress             = regexp.MustCompile(`^(\d+\.){3}\d+$`)
+)
+
+// Common checker for both stricter and basic validation.
+func checkBucketNameCommon(bucketName string, strict bool) (err error) {
+	if strings.TrimSpace(bucketName) == "" {
+		return errors.New("Bucket name cannot be empty")
+	}
+	if len(bucketName) < 3 {
+		return errors.New("Bucket name cannot be smaller than 3 characters")
+	}
+	if len(bucketName) > 63 {
+		return errors.New("Bucket name cannot be greater than 63 characters")
+	}
+	if ipAddress.MatchString(bucketName) {
+		return errors.New("Bucket name cannot be an ip address")
+	}
+	if strings.Contains(bucketName, "..") {
+		return errors.New("Bucket name contains invalid characters")
+	}
+	if strict {
+		if !validBucketNameStrict.MatchString(bucketName) {
+			err = errors.New("Bucket name contains invalid characters")
+		}
+		return err
+	}
+	if !validBucketName.MatchString(bucketName) {
+		err = errors.New("Bucket name contains invalid characters")
+	}
+	return err
+}
+
+// CheckValidBucketName - checks if we have a valid input bucket name.
+func CheckValidBucketName(bucketName string) (err error) {
+	return checkBucketNameCommon(bucketName, false)
+}
+
+// CheckValidBucketNameStrict - checks if we have a valid input bucket name.
+// This is a stricter version.
+// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingBucket.html
+func CheckValidBucketNameStrict(bucketName string) (err error) {
+	return checkBucketNameCommon(bucketName, true)
+}
+
+// CheckValidObjectNamePrefix - checks if we have a valid input object name prefix.
+//   - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
+func CheckValidObjectNamePrefix(objectName string) error {
+	if len(objectName) > 1024 {
+		return errors.New("Object name cannot be greater than 1024 characters")
+	}
+	if !utf8.ValidString(objectName) {
+		return errors.New("Object name with non UTF-8 strings are not supported")
+	}
+	return nil
+}
+
+// CheckValidObjectName - checks if we have a valid input object name.
+//   - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
+func CheckValidObjectName(objectName string) error {
+	if strings.TrimSpace(objectName) == "" {
+		return errors.New("Object name cannot be empty")
+	}
+	return CheckValidObjectNamePrefix(objectName)
+}

vendor/github.com/minio/minio-go/pkg/set/stringset.go

@@ -0,0 +1,197 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2015-2017 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package set
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+)
+
+// StringSet - uses map as set of strings.
+type StringSet map[string]struct{}
+
+// ToSlice - returns StringSet as string slice.
+func (set StringSet) ToSlice() []string {
+	keys := make([]string, 0, len(set))
+	for k := range set {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// IsEmpty - returns whether the set is empty or not.
+func (set StringSet) IsEmpty() bool {
+	return len(set) == 0
+}
+
+// Add - adds string to the set.
+func (set StringSet) Add(s string) {
+	set[s] = struct{}{}
+}
+
+// Remove - removes string in the set.  It does nothing if string does not exist in the set.
+func (set StringSet) Remove(s string) {
+	delete(set, s)
+}
+
+// Contains - checks if string is in the set.
+func (set StringSet) Contains(s string) bool {
+	_, ok := set[s]
+	return ok
+}
+
+// FuncMatch - returns new set containing each value who passes match function.
+// A 'matchFn' should accept element in a set as first argument and
+// 'matchString' as second argument.  The function can do any logic to
+// compare both the arguments and should return true to accept element in
+// a set to include in output set else the element is ignored.
+func (set StringSet) FuncMatch(matchFn func(string, string) bool, matchString string) StringSet {
+	nset := NewStringSet()
+	for k := range set {
+		if matchFn(k, matchString) {
+			nset.Add(k)
+		}
+	}
+	return nset
+}
+
+// ApplyFunc - returns new set containing each value processed by 'applyFn'.
+// A 'applyFn' should accept element in a set as a argument and return
+// a processed string.  The function can do any logic to return a processed
+// string.
+func (set StringSet) ApplyFunc(applyFn func(string) string) StringSet {
+	nset := NewStringSet()
+	for k := range set {
+		nset.Add(applyFn(k))
+	}
+	return nset
+}
+
+// Equals - checks whether given set is equal to current set or not.
+func (set StringSet) Equals(sset StringSet) bool {
+	// If length of set is not equal to length of given set, the
+	// set is not equal to given set.
+	if len(set) != len(sset) {
+		return false
+	}
+
+	// As both sets are equal in length, check each elements are equal.
+	for k := range set {
+		if _, ok := sset[k]; !ok {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Intersection - returns the intersection with given set as new set.
+func (set StringSet) Intersection(sset StringSet) StringSet {
+	nset := NewStringSet()
+	for k := range set {
+		if _, ok := sset[k]; ok {
+			nset.Add(k)
+		}
+	}
+
+	return nset
+}
+
+// Difference - returns the difference with given set as new set.
+func (set StringSet) Difference(sset StringSet) StringSet {
+	nset := NewStringSet()
+	for k := range set {
+		if _, ok := sset[k]; !ok {
+			nset.Add(k)
+		}
+	}
+
+	return nset
+}
+
+// Union - returns the union with given set as new set.
+func (set StringSet) Union(sset StringSet) StringSet {
+	nset := NewStringSet()
+	for k := range set {
+		nset.Add(k)
+	}
+
+	for k := range sset {
+		nset.Add(k)
+	}
+
+	return nset
+}
+
+// MarshalJSON - converts to JSON data.
+func (set StringSet) MarshalJSON() ([]byte, error) {
+	return json.Marshal(set.ToSlice())
+}
+
+// UnmarshalJSON - parses JSON data and creates new set with it.
+// If 'data' contains JSON string array, the set contains each string.
+// If 'data' contains JSON string, the set contains the string as one element.
+// If 'data' contains Other JSON types, JSON parse error is returned.
+func (set *StringSet) UnmarshalJSON(data []byte) error {
+	sl := []string{}
+	var err error
+	if err = json.Unmarshal(data, &sl); err == nil {
+		*set = make(StringSet)
+		for _, s := range sl {
+			set.Add(s)
+		}
+	} else {
+		var s string
+		if err = json.Unmarshal(data, &s); err == nil {
+			*set = make(StringSet)
+			set.Add(s)
+		}
+	}
+
+	return err
+}
+
+// String - returns printable string of the set.
+func (set StringSet) String() string {
+	return fmt.Sprintf("%s", set.ToSlice())
+}
+
+// NewStringSet - creates new string set.
+func NewStringSet() StringSet {
+	return make(StringSet)
+}
+
+// CreateStringSet - creates new string set with given string values.
+func CreateStringSet(sl ...string) StringSet {
+	set := make(StringSet)
+	for _, k := range sl {
+		set.Add(k)
+	}
+	return set
+}
+
+// CopyStringSet - returns copy of given set.
+func CopyStringSet(set StringSet) StringSet {
+	nset := NewStringSet()
+	for k, v := range set {
+		nset[k] = v
+	}
+	return nset
+}