Add ed25519 SignStream and VerifyStream functions (GH #796, PR #797)

1 files changed, 21 insertions, 0 deletions

diff --git a/xed25519.h b/xed25519.h
index 363d7d7c..f581a586 100644
--- a/xed25519.h
+++ b/xed25519.h
@@ -574,6 +574,18 @@ struct ed25519Signer : public PK_Signer
 

     size_t SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart) const;

 

+    /// \brief Sign a stream

+    /// \param rng a RandomNumberGenerator derived class

+    /// \param stream an std::istream derived class

+    /// \param signature a block of bytes for the signature

+    /// \return actual signature length

+    /// \details SignStream() handles large streams. It was added for signing and verifying

+    ///  files that are too large for a memory allocation.

+    /// \details ed25519 is a determinsitic signature scheme. <tt>IsProbabilistic()</tt>

+    ///  returns false and the random number generator can be <tt>NullRNG()</tt>.

+    /// \pre <tt>COUNTOF(signature) == MaxSignatureLength()</tt>

+    size_t SignStream (RandomNumberGenerator &rng, std::istream& stream, byte *signature) const;

+

 protected:

     ed25519PrivateKey m_key;

 };

@@ -742,6 +754,15 @@ struct ed25519Verifier : public PK_Verifier
 

     bool VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const;

 

+    /// \brief Check whether input signature is a valid signature for input message

+    /// \param stream an std::istream derived class

+    /// \param signature a pointer to the signature over the message

+    /// \param signatureLen the size of the signature

+    /// \return true if the signature is valid, false otherwise

+    /// \details VerifyStream() handles large streams. It was added for signing and verifying

+    ///  files that are too large for a memory allocation.

+    bool VerifyStream(std::istream& stream, const byte *signature, size_t signatureLen) const;

+

     DecodingResult RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const {

         CRYPTOPP_UNUSED(recoveredMessage); CRYPTOPP_UNUSED(messageAccumulator);

         throw NotImplemented("ed25519Verifier: this object does not support recoverable messages");