i2pd/libi2pd/Signature.cpp
2023-12-30 15:55:53 -05:00

154 lines
4.4 KiB
C++

/*
* Copyright (c) 2013-2023, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/
#include <memory>
#include "Log.h"
#include "Signature.h"
namespace i2p
{
namespace crypto
{
#if OPENSSL_EDDSA
EDDSA25519Verifier::EDDSA25519Verifier ():
m_Pkey (nullptr)
{
}
EDDSA25519Verifier::~EDDSA25519Verifier ()
{
EVP_PKEY_free (m_Pkey);
}
void EDDSA25519Verifier::SetPublicKey (const uint8_t * signingKey)
{
if (m_Pkey) EVP_PKEY_free (m_Pkey);
m_Pkey = EVP_PKEY_new_raw_public_key (EVP_PKEY_ED25519, NULL, signingKey, 32);
}
bool EDDSA25519Verifier::Verify (const uint8_t * buf, size_t len, const uint8_t * signature) const
{
if (m_Pkey)
{
EVP_MD_CTX * ctx = EVP_MD_CTX_create ();
EVP_DigestVerifyInit (ctx, NULL, NULL, NULL, m_Pkey);
auto ret = EVP_DigestVerify (ctx, signature, 64, buf, len);
EVP_MD_CTX_destroy (ctx);
return ret;
}
else
LogPrint (eLogError, "EdDSA verification key is not set");
return false;
}
#else
EDDSA25519Verifier::EDDSA25519Verifier ()
{
}
EDDSA25519Verifier::~EDDSA25519Verifier ()
{
}
void EDDSA25519Verifier::SetPublicKey (const uint8_t * signingKey)
{
memcpy (m_PublicKeyEncoded, signingKey, EDDSA25519_PUBLIC_KEY_LENGTH);
BN_CTX * ctx = BN_CTX_new ();
m_PublicKey = GetEd25519 ()->DecodePublicKey (m_PublicKeyEncoded, ctx);
BN_CTX_free (ctx);
}
bool EDDSA25519Verifier::Verify (const uint8_t * buf, size_t len, const uint8_t * signature) const
{
uint8_t digest[64];
SHA512_CTX ctx;
SHA512_Init (&ctx);
SHA512_Update (&ctx, signature, EDDSA25519_SIGNATURE_LENGTH/2); // R
SHA512_Update (&ctx, m_PublicKeyEncoded, EDDSA25519_PUBLIC_KEY_LENGTH); // public key
SHA512_Update (&ctx, buf, len); // data
SHA512_Final (digest, &ctx);
return GetEd25519 ()->Verify (m_PublicKey, digest, signature);
}
#endif
EDDSA25519SignerCompat::EDDSA25519SignerCompat (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey)
{
// expand key
Ed25519::ExpandPrivateKey (signingPrivateKey, m_ExpandedPrivateKey);
// generate and encode public key
BN_CTX * ctx = BN_CTX_new ();
auto publicKey = GetEd25519 ()->GeneratePublicKey (m_ExpandedPrivateKey, ctx);
GetEd25519 ()->EncodePublicKey (publicKey, m_PublicKeyEncoded, ctx);
if (signingPublicKey && memcmp (m_PublicKeyEncoded, signingPublicKey, EDDSA25519_PUBLIC_KEY_LENGTH))
{
// keys don't match, it means older key with 0x1F
LogPrint (eLogWarning, "Older EdDSA key detected");
m_ExpandedPrivateKey[EDDSA25519_PRIVATE_KEY_LENGTH - 1] &= 0xDF; // drop third bit
publicKey = GetEd25519 ()->GeneratePublicKey (m_ExpandedPrivateKey, ctx);
GetEd25519 ()->EncodePublicKey (publicKey, m_PublicKeyEncoded, ctx);
}
BN_CTX_free (ctx);
}
EDDSA25519SignerCompat::~EDDSA25519SignerCompat ()
{
}
void EDDSA25519SignerCompat::Sign (const uint8_t * buf, int len, uint8_t * signature) const
{
GetEd25519 ()->Sign (m_ExpandedPrivateKey, m_PublicKeyEncoded, buf, len, signature);
}
#if OPENSSL_EDDSA
EDDSA25519Signer::EDDSA25519Signer (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey):
m_Pkey (nullptr), m_Fallback (nullptr)
{
m_Pkey = EVP_PKEY_new_raw_private_key (EVP_PKEY_ED25519, NULL, signingPrivateKey, 32);
uint8_t publicKey[EDDSA25519_PUBLIC_KEY_LENGTH];
size_t len = EDDSA25519_PUBLIC_KEY_LENGTH;
EVP_PKEY_get_raw_public_key (m_Pkey, publicKey, &len);
if (signingPublicKey && memcmp (publicKey, signingPublicKey, EDDSA25519_PUBLIC_KEY_LENGTH))
{
LogPrint (eLogWarning, "EdDSA public key mismatch. Fallback");
m_Fallback = new EDDSA25519SignerCompat (signingPrivateKey, signingPublicKey);
EVP_PKEY_free (m_Pkey);
m_Pkey = nullptr;
}
}
EDDSA25519Signer::~EDDSA25519Signer ()
{
if (m_Fallback) delete m_Fallback;
if (m_Pkey) EVP_PKEY_free (m_Pkey);
}
void EDDSA25519Signer::Sign (const uint8_t * buf, int len, uint8_t * signature) const
{
if (m_Fallback)
return m_Fallback->Sign (buf, len, signature);
else if (m_Pkey)
{
EVP_MD_CTX * ctx = EVP_MD_CTX_create ();
size_t l = 64;
uint8_t sig[64]; // temporary buffer for signature. openssl issue #7232
EVP_DigestSignInit (ctx, NULL, NULL, NULL, m_Pkey);
if (!EVP_DigestSign (ctx, sig, &l, buf, len))
LogPrint (eLogError, "EdDSA signing failed");
memcpy (signature, sig, 64);
EVP_MD_CTX_destroy (ctx);
}
else
LogPrint (eLogError, "EdDSA signing key is not set");
}
#endif
}
}