code review 3989052: crypto/openpgp: add package.

src/pkg/crypto/openpgp/write.go

 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package openpgp
 
 import (
         "crypto"
         "crypto/openpgp/armor"
         "crypto/openpgp/error"
         "crypto/openpgp/packet"
-        "crypto/rand"
         "crypto/rsa"
         _ "crypto/sha256"
         "io"
         "os"
         "strconv"
         "time"
 )
 
 // DetachSign signs message with the private key from signer (which must
 // already have been decrypted) and writes the signature to w.
@@ skipping 41 matching lines @@
                 return error.InvalidArgumentError("signing key is encrypted")
         }
 
         sig := new(packet.Signature)
         sig.SigType = sigType
         sig.PubKeyAlgo = signer.PrivateKey.PubKeyAlgo
         sig.Hash = crypto.SHA256
         sig.CreationTime = uint32(time.Seconds())
         sig.IssuerKeyId = &signer.PrivateKey.KeyId
 
-        err = sig.BuildHashSuffix()
-        if err != nil {
-                return
-        }
-
-        h, wrappedHash, err := getHashForSignature(sig.Hash, sig.SigType)
+        h, wrappedHash, err := hashForSignature(sig.Hash, sig.SigType)
         if err != nil {
                 return
         }
         io.Copy(wrappedHash, message)
-        h.Write(sig.HashSuffix)
-        digest := h.Sum()
-        copy(sig.HashTag[:], digest)
 
         switch signer.PrivateKey.PubKeyAlgo {
         case packet.PubKeyAlgoRSA, packet.PubKeyAlgoRSASignOnly:
                 priv := signer.PrivateKey.PrivateKey.(*rsa.PrivateKey)
-                sig.Signature, err = rsa.SignPKCS1v15(rand.Reader, priv, sig.Hash, digest)
+                err = sig.SignRSA(h, priv)
         default:
                 err = error.UnsupportedError("public key algorithm: " + strconv.Itoa(int(sig.PubKeyAlgo)))
         }
 
         if err != nil {
                 return
         }
 
-        return sig.Serialise(w)
+        return sig.Serialize(w)
 }