added signed tree head and get-sth code path

1 files changed, 16 insertions, 1 deletions

diff --git a/reqres.go b/reqres.go
index fe79d51..e223fd9 100644
--- a/reqres.go
+++ b/reqres.go
@@ -55,11 +55,16 @@ type GetProofByHashResponse struct {
 	InclusionProof string `json:"inclusion_proof"` // base64-encoded StItem
 }
 
-// GetAnchorsResponse
+// GetAnchorsResponse is an assembled get-anchor response
 type GetAnchorsResponse struct {
 	Certificates []string `json:"certificates"`
 }
 
+// GetSthResponse is an assembled get-sth response
+type GetSthResponse struct {
+	SignedTreeHead string `json:"sth"` // base64-encoded StItem
+}
+
 // NewAddEntryRequest parses and sanitizes the JSON-encoded add-entry
 // parameters from an incoming HTTP post.  The resulting AddEntryRequest is
 // well-formed, but not necessarily trusted (further sanitization is needed).
@@ -189,6 +194,16 @@ func NewGetAnchorsResponse(anchors []*x509.Certificate) GetAnchorsResponse {
 	return GetAnchorsResponse{Certificates: certificates}
 }
 
+func NewGetSthResponse(sth StItem) (GetSthResponse, error) {
+	b, err := tls.Marshal(sth)
+	if err != nil {
+		return GetSthResponse{}, fmt.Errorf("tls marshal failed: %v", err)
+	}
+	return GetSthResponse{
+		SignedTreeHead: base64.StdEncoding.EncodeToString(b),
+	}, nil
+}
+
 // VerifyAddEntryRequest determines whether a well-formed AddEntryRequest should
 // be inserted into the log.  The corresponding leaf and appendix is returned.
 func VerifyAddEntryRequest(ld *LogParameters, r AddEntryRequest) ([]byte, []byte, error) {