Introduce RSAPrivateKey::SignDigest

crypto/signature_creator.h

Index: crypto/signature_creator.h
diff --git a/crypto/signature_creator.h b/crypto/signature_creator.h
index 1a1d6e5ce7f6331b1bfd7fde48909a3bd011fd98..6074bcbe9cb4d8d21f2cb503424bf74e84aae318 100644
--- a/crypto/signature_creator.h
+++ b/crypto/signature_creator.h
@@ -34,6 +34,13 @@ class CRYPTO_EXPORT SignatureCreator {
   // instance outlives the created SignatureCreator.
   static SignatureCreator* Create(RSAPrivateKey* key);
 
+  // Signs the precomputed SHA-1 digest |data| using private |key| as
+  // specified in PKCS #1 v1.5.
+  static bool Sign(RSAPrivateKey* key,
+                   const uint8* data,
+                   int data_len,
+                   std::vector<uint8>* signature);
+
   // Update the signature with more data.
   bool Update(const uint8* data_part, int data_part_len);