Update vendor

4 files changed, 1000 insertions, 0 deletions

diff --git a/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-streaming.go b/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-streaming.go
new file mode 100644
index 00000000..7b2ca91d
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/v7/pkg/signer/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 signer
+
+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, ServiceTypeS3),
+		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, ServiceTypeS3)
+	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, getHashedPayload(*req))
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(s.reqTime, s.region, canonicalRequest, ServiceTypeS3)
+
+	signingKey := getSigningKey(s.secretAccessKey, s.region, s.reqTime, ServiceTypeS3)
+
+	// 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, ServiceTypeS3)
+	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, fmt.Errorf("http: ContentLength=%d with Body length %d", s.contentLen, s.bytesRead)
+					}
+
+					// 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()
+}
diff --git a/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v2.go b/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v2.go
new file mode 100644
index 00000000..71821a26
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v2.go
@@ -0,0 +1,317 @@
+/*
+ * 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 signer
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+	"fmt"
+	"net/http"
+	"net/url"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/v7/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",
+	"replication",
+	"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])
+				}
+			}
+		}
+	}
+}
diff --git a/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v4.go b/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v4.go
new file mode 100644
index 00000000..67572b20
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/v7/pkg/signer/request-signature-v4.go
@@ -0,0 +1,318 @@
+/*
+ * 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 signer
+
+import (
+	"bytes"
+	"encoding/hex"
+	"net/http"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/v7/pkg/s3utils"
+)
+
+// Signature and API related constants.
+const (
+	signV4Algorithm   = "AWS4-HMAC-SHA256"
+	iso8601DateFormat = "20060102T150405Z"
+	yyyymmdd          = "20060102"
+)
+
+// Different service types
+const (
+	ServiceTypeS3  = "s3"
+	ServiceTypeSTS = "sts"
+)
+
+///
+/// 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.
+///
+///
+///  Authorization:
+///
+///      Is skipped for obvious reasons
+///
+var v4IgnoredHeaders = map[string]bool{
+	"Authorization": true,
+	"User-Agent":    true,
+}
+
+// getSigningKey hmac seed to calculate final signature.
+func getSigningKey(secret, loc string, t time.Time, serviceType string) []byte {
+	date := sumHMAC([]byte("AWS4"+secret), []byte(t.Format(yyyymmdd)))
+	location := sumHMAC(date, []byte(loc))
+	service := sumHMAC(location, []byte(serviceType))
+	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, serviceType string) string {
+	scope := strings.Join([]string{
+		t.Format(yyyymmdd),
+		location,
+		serviceType,
+		"aws4_request",
+	}, "/")
+	return scope
+}
+
+// GetCredential generate a credential string.
+func GetCredential(accessKeyID, location string, t time.Time, serviceType string) string {
+	scope := getScope(location, t, serviceType)
+	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(signV4TrimAll(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, hashedPayload string) 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),
+		hashedPayload,
+	}, "\n")
+	return canonicalRequest
+}
+
+// getStringToSign a string based on selected query values.
+func getStringToSignV4(t time.Time, location, canonicalRequest, serviceType string) string {
+	stringToSign := signV4Algorithm + "\n" + t.Format(iso8601DateFormat) + "\n"
+	stringToSign = stringToSign + getScope(location, t, serviceType) + "\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, ServiceTypeS3)
+
+	// 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, getHashedPayload(req))
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(t, location, canonicalRequest, ServiceTypeS3)
+
+	// Gext hmac signing key.
+	signingKey := getSigningKey(secretAccessKey, location, t, ServiceTypeS3)
+
+	// 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, ServiceTypeS3)
+	// Calculate signature.
+	signature := getSignature(signingkey, policyBase64)
+	return signature
+}
+
+// SignV4STS - signature v4 for STS request.
+func SignV4STS(req http.Request, accessKeyID, secretAccessKey, location string) *http.Request {
+	return signV4(req, accessKeyID, secretAccessKey, "", location, ServiceTypeSTS)
+}
+
+// Internal function called for different service types.
+func signV4(req http.Request, accessKeyID, secretAccessKey, sessionToken, location, serviceType 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)
+	}
+
+	hashedPayload := getHashedPayload(req)
+	if serviceType == ServiceTypeSTS {
+		// Content sha256 header is not sent with the request
+		// but it is expected to have sha256 of payload for signature
+		// in STS service type request.
+		req.Header.Del("X-Amz-Content-Sha256")
+	}
+
+	// Get canonical request.
+	canonicalRequest := getCanonicalRequest(req, v4IgnoredHeaders, hashedPayload)
+
+	// Get string to sign from canonical request.
+	stringToSign := getStringToSignV4(t, location, canonicalRequest, serviceType)
+
+	// Get hmac signing key.
+	signingKey := getSigningKey(secretAccessKey, location, t, serviceType)
+
+	// Get credential string.
+	credential := GetCredential(accessKeyID, location, t, serviceType)
+
+	// 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
+}
+
+// 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 {
+	return signV4(req, accessKeyID, secretAccessKey, sessionToken, location, ServiceTypeS3)
+}
diff --git a/vendor/github.com/minio/minio-go/v7/pkg/signer/utils.go b/vendor/github.com/minio/minio-go/v7/pkg/signer/utils.go
new file mode 100644
index 00000000..2192a369
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/v7/pkg/signer/utils.go
@@ -0,0 +1,59 @@
+/*
+ * 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 signer
+
+import (
+	"crypto/hmac"
+	"net/http"
+	"strings"
+
+	"github.com/minio/sha256-simd"
+)
+
+// 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
+}
+
+// Trim leading and trailing spaces and replace sequential spaces with one space, following Trimall()
+// in http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
+func signV4TrimAll(input string) string {
+	// Compress adjacent spaces (a space is determined by
+	// unicode.IsSpace() internally here) to one space and return
+	return strings.Join(strings.Fields(input), " ")
+}