1 files changed, 63 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/aws/signer/v4/stream.go b/vendor/github.com/aws/aws-sdk-go/aws/signer/v4/stream.go
new file mode 100644
index 0000000000..02cbd97e23
--- /dev/null
+++ b/vendor/github.com/aws/aws-sdk-go/aws/signer/v4/stream.go
@@ -0,0 +1,63 @@
+package v4
+
+import (
+	"encoding/hex"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws/credentials"
+)
+
+type credentialValueProvider interface {
+	Get() (credentials.Value, error)
+}
+
+// StreamSigner implements signing of event stream encoded payloads
+type StreamSigner struct {
+	region  string
+	service string
+
+	credentials credentialValueProvider
+
+	prevSig []byte
+}
+
+// NewStreamSigner creates a SigV4 signer used to sign Event Stream encoded messages
+func NewStreamSigner(region, service string, seedSignature []byte, credentials *credentials.Credentials) *StreamSigner {
+	return &StreamSigner{
+		region:      region,
+		service:     service,
+		credentials: credentials,
+		prevSig:     seedSignature,
+	}
+}
+
+// GetSignature takes an event stream encoded headers and payload and returns a signature
+func (s *StreamSigner) GetSignature(headers, payload []byte, date time.Time) ([]byte, error) {
+	credValue, err := s.credentials.Get()
+	if err != nil {
+		return nil, err
+	}
+
+	sigKey := deriveSigningKey(s.region, s.service, credValue.SecretAccessKey, date)
+
+	keyPath := buildSigningScope(s.region, s.service, date)
+
+	stringToSign := buildEventStreamStringToSign(headers, payload, s.prevSig, keyPath, date)
+
+	signature := hmacSHA256(sigKey, []byte(stringToSign))
+	s.prevSig = signature
+
+	return signature, nil
+}
+
+func buildEventStreamStringToSign(headers, payload, prevSig []byte, scope string, date time.Time) string {
+	return strings.Join([]string{
+		"AWS4-HMAC-SHA256-PAYLOAD",
+		formatTime(date),
+		scope,
+		hex.EncodeToString(prevSig),
+		hex.EncodeToString(hashSHA256(headers)),
+		hex.EncodeToString(hashSHA256(payload)),
+	}, "\n")
+}