1 files changed, 249 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/service/s3/body_hash.go b/vendor/github.com/aws/aws-sdk-go/service/s3/body_hash.go
new file mode 100644
index 0000000..5c8ce5c
--- /dev/null
+++ b/vendor/github.com/aws/aws-sdk-go/service/s3/body_hash.go
@@ -0,0 +1,249 @@
+package s3
+
+import (
+	"bytes"
+	"crypto/md5"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+	"hash"
+	"io"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/aws/request"
+	"github.com/aws/aws-sdk-go/internal/sdkio"
+)
+
+const (
+	contentMD5Header    = "Content-Md5"
+	contentSha256Header = "X-Amz-Content-Sha256"
+	amzTeHeader         = "X-Amz-Te"
+	amzTxEncodingHeader = "X-Amz-Transfer-Encoding"
+
+	appendMD5TxEncoding = "append-md5"
+)
+
+// contentMD5 computes and sets the HTTP Content-MD5 header for requests that
+// require it.
+func contentMD5(r *request.Request) {
+	h := md5.New()
+
+	if !aws.IsReaderSeekable(r.Body) {
+		if r.Config.Logger != nil {
+			r.Config.Logger.Log(fmt.Sprintf(
+				"Unable to compute Content-MD5 for unseekable body, S3.%s",
+				r.Operation.Name))
+		}
+		return
+	}
+
+	if _, err := copySeekableBody(h, r.Body); err != nil {
+		r.Error = awserr.New("ContentMD5", "failed to compute body MD5", err)
+		return
+	}
+
+	// encode the md5 checksum in base64 and set the request header.
+	v := base64.StdEncoding.EncodeToString(h.Sum(nil))
+	r.HTTPRequest.Header.Set(contentMD5Header, v)
+}
+
+// computeBodyHashes will add Content MD5 and Content Sha256 hashes to the
+// request. If the body is not seekable or S3DisableContentMD5Validation set
+// this handler will be ignored.
+func computeBodyHashes(r *request.Request) {
+	if aws.BoolValue(r.Config.S3DisableContentMD5Validation) {
+		return
+	}
+	if r.IsPresigned() {
+		return
+	}
+	if r.Error != nil || !aws.IsReaderSeekable(r.Body) {
+		return
+	}
+
+	var md5Hash, sha256Hash hash.Hash
+	hashers := make([]io.Writer, 0, 2)
+
+	// Determine upfront which hashes can be set without overriding user
+	// provide header data.
+	if v := r.HTTPRequest.Header.Get(contentMD5Header); len(v) == 0 {
+		md5Hash = md5.New()
+		hashers = append(hashers, md5Hash)
+	}
+
+	if v := r.HTTPRequest.Header.Get(contentSha256Header); len(v) == 0 {
+		sha256Hash = sha256.New()
+		hashers = append(hashers, sha256Hash)
+	}
+
+	// Create the destination writer based on the hashes that are not already
+	// provided by the user.
+	var dst io.Writer
+	switch len(hashers) {
+	case 0:
+		return
+	case 1:
+		dst = hashers[0]
+	default:
+		dst = io.MultiWriter(hashers...)
+	}
+
+	if _, err := copySeekableBody(dst, r.Body); err != nil {
+		r.Error = awserr.New("BodyHashError", "failed to compute body hashes", err)
+		return
+	}
+
+	// For the hashes created, set the associated headers that the user did not
+	// already provide.
+	if md5Hash != nil {
+		sum := make([]byte, md5.Size)
+		encoded := make([]byte, md5Base64EncLen)
+
+		base64.StdEncoding.Encode(encoded, md5Hash.Sum(sum[0:0]))
+		r.HTTPRequest.Header[contentMD5Header] = []string{string(encoded)}
+	}
+
+	if sha256Hash != nil {
+		encoded := make([]byte, sha256HexEncLen)
+		sum := make([]byte, sha256.Size)
+
+		hex.Encode(encoded, sha256Hash.Sum(sum[0:0]))
+		r.HTTPRequest.Header[contentSha256Header] = []string{string(encoded)}
+	}
+}
+
+const (
+	md5Base64EncLen = (md5.Size + 2) / 3 * 4 // base64.StdEncoding.EncodedLen
+	sha256HexEncLen = sha256.Size * 2        // hex.EncodedLen
+)
+
+func copySeekableBody(dst io.Writer, src io.ReadSeeker) (int64, error) {
+	curPos, err := src.Seek(0, sdkio.SeekCurrent)
+	if err != nil {
+		return 0, err
+	}
+
+	// hash the body.  seek back to the first position after reading to reset
+	// the body for transmission.  copy errors may be assumed to be from the
+	// body.
+	n, err := io.Copy(dst, src)
+	if err != nil {
+		return n, err
+	}
+
+	_, err = src.Seek(curPos, sdkio.SeekStart)
+	if err != nil {
+		return n, err
+	}
+
+	return n, nil
+}
+
+// Adds the x-amz-te: append_md5 header to the request. This requests the service
+// responds with a trailing MD5 checksum.
+//
+// Will not ask for append MD5 if disabled, the request is presigned or,
+// or the API operation does not support content MD5 validation.
+func askForTxEncodingAppendMD5(r *request.Request) {
+	if aws.BoolValue(r.Config.S3DisableContentMD5Validation) {
+		return
+	}
+	if r.IsPresigned() {
+		return
+	}
+	r.HTTPRequest.Header.Set(amzTeHeader, appendMD5TxEncoding)
+}
+
+func useMD5ValidationReader(r *request.Request) {
+	if r.Error != nil {
+		return
+	}
+
+	if v := r.HTTPResponse.Header.Get(amzTxEncodingHeader); v != appendMD5TxEncoding {
+		return
+	}
+
+	var bodyReader *io.ReadCloser
+	var contentLen int64
+	switch tv := r.Data.(type) {
+	case *GetObjectOutput:
+		bodyReader = &tv.Body
+		contentLen = aws.Int64Value(tv.ContentLength)
+		// Update ContentLength hiden the trailing MD5 checksum.
+		tv.ContentLength = aws.Int64(contentLen - md5.Size)
+		tv.ContentRange = aws.String(r.HTTPResponse.Header.Get("X-Amz-Content-Range"))
+	default:
+		r.Error = awserr.New("ChecksumValidationError",
+			fmt.Sprintf("%s: %s header received on unsupported API, %s",
+				amzTxEncodingHeader, appendMD5TxEncoding, r.Operation.Name,
+			), nil)
+		return
+	}
+
+	if contentLen < md5.Size {
+		r.Error = awserr.New("ChecksumValidationError",
+			fmt.Sprintf("invalid Content-Length %d for %s %s",
+				contentLen, appendMD5TxEncoding, amzTxEncodingHeader,
+			), nil)
+		return
+	}
+
+	// Wrap and swap the response body reader with the validation reader.
+	*bodyReader = newMD5ValidationReader(*bodyReader, contentLen-md5.Size)
+}
+
+type md5ValidationReader struct {
+	rawReader io.ReadCloser
+	payload   io.Reader
+	hash      hash.Hash
+
+	payloadLen int64
+	read       int64
+}
+
+func newMD5ValidationReader(reader io.ReadCloser, payloadLen int64) *md5ValidationReader {
+	h := md5.New()
+	return &md5ValidationReader{
+		rawReader:  reader,
+		payload:    io.TeeReader(&io.LimitedReader{R: reader, N: payloadLen}, h),
+		hash:       h,
+		payloadLen: payloadLen,
+	}
+}
+
+func (v *md5ValidationReader) Read(p []byte) (n int, err error) {
+	n, err = v.payload.Read(p)
+	if err != nil && err != io.EOF {
+		return n, err
+	}
+
+	v.read += int64(n)
+
+	if err == io.EOF {
+		if v.read != v.payloadLen {
+			return n, io.ErrUnexpectedEOF
+		}
+		expectSum := make([]byte, md5.Size)
+		actualSum := make([]byte, md5.Size)
+		if _, sumReadErr := io.ReadFull(v.rawReader, expectSum); sumReadErr != nil {
+			return n, sumReadErr
+		}
+		actualSum = v.hash.Sum(actualSum[0:0])
+		if !bytes.Equal(expectSum, actualSum) {
+			return n, awserr.New("InvalidChecksum",
+				fmt.Sprintf("expected MD5 checksum %s, got %s",
+					hex.EncodeToString(expectSum),
+					hex.EncodeToString(actualSum),
+				),
+				nil)
+		}
+	}
+
+	return n, err
+}
+
+func (v *md5ValidationReader) Close() error {
+	return v.rawReader.Close()
+}