Mirrors/i2pd
2
0
Fork 0
mirror of https://github.com/PurpleI2P/i2pd.git synced 2025-04-28 11:47:48 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

correct param set for GOST R 34.10 verification

Browse source
This commit is contained in:
orignal 2017-03-10 11:55:30 -05:00
parent 084e48d6dd
commit ba89c60b6d
3 changed files with 62 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files

56
Signature.cpp
View file

@ -532,6 +532,13 @@ namespace crypto
return EC_POINT_get_affine_coordinates_GFp (m_Group, p, x, y, nullptr);
}
EC_POINT * CreatePoint (const BIGNUM * x, const BIGNUM * y) const
{
EC_POINT * p = EC_POINT_new (m_Group);
EC_POINT_set_affine_coordinates_GFp (m_Group, p, x, y, nullptr);
return p;
}
void Sign (const BIGNUM * priv, const BIGNUM * digest, BIGNUM * r, BIGNUM * s)
{
BN_CTX * ctx = BN_CTX_new ();
@ -551,6 +558,31 @@ namespace crypto
BN_CTX_free (ctx);
}
bool Verify (const EC_POINT * pub, const BIGNUM * digest, const BIGNUM * r, const BIGNUM * s)
{
BN_CTX * ctx = BN_CTX_new ();
BN_CTX_start (ctx);
BIGNUM * q = BN_CTX_get (ctx);
EC_GROUP_get_order(m_Group, q, ctx);
BIGNUM * h = BN_CTX_get (ctx);
BN_mod (h, digest, q, ctx); // h = digest % q
BN_mod_inverse (h, h, q, ctx); // 1/h mod q
BIGNUM * z1 = BN_CTX_get (ctx);
BN_mod_mul (z1, s, h, q, ctx); // z1 = s/h
BIGNUM * z2 = BN_CTX_get (ctx);
BN_sub (z2, q, r); // z2 = -r
BN_mod_mul (z2, z2, h, q, ctx); // z2 = -r/h
EC_POINT * C = EC_POINT_new (m_Group);
EC_POINT_mul (m_Group, C, z1, pub, z2, ctx); // z1*P + z2*pub
BIGNUM * x = BN_CTX_get (ctx);
GetXY (C, x, nullptr); // Cx
BN_mod (x, x, q, ctx); // Cx % q
bool ret = !BN_cmp (x, r); // Cx = r ?
EC_POINT_free (C);
BN_CTX_end (ctx);
BN_CTX_free (ctx);
return ret;
}
private:
@ -614,14 +646,34 @@ namespace crypto
return g_GOSTR3410Curves[paramSet];
}
GOSTR3410Verifier::GOSTR3410Verifier (GOSTR3410ParamSet paramSet, const uint8_t * signingKey):
m_ParamSet (paramSet)
{
BIGNUM * x = BN_bin2bn (signingKey, GOSTR3410_PUBLIC_KEY_LENGTH/2, NULL);
BIGNUM * y = BN_bin2bn (signingKey + GOSTR3410_PUBLIC_KEY_LENGTH/2, GOSTR3410_PUBLIC_KEY_LENGTH/2, NULL);
m_PublicKey = GetGOSTR3410Curve (m_ParamSet)->CreatePoint (x, y);
BN_free (x); BN_free (y);
}
bool GOSTR3410Verifier::Verify (const uint8_t * buf, size_t len, const uint8_t * signature) const
{
uint8_t digest[32];
GOSTR3411 (buf, len, digest);
BIGNUM * d = BN_bin2bn (digest, 32, nullptr);
BIGNUM * r = BN_bin2bn (signature, GetSignatureLen ()/2, NULL);
BIGNUM * s = BN_bin2bn (signature + GetSignatureLen ()/2, GetSignatureLen ()/2, NULL);
bool ret = GetGOSTR3410Curve (m_ParamSet)->Verify (m_PublicKey, d, r, s);
BN_free (d); BN_free (r); BN_free (s);
return ret;
}
void GOSTR3410Signer::Sign (const uint8_t * buf, int len, uint8_t * signature) const
{
uint8_t digest[32];
GOSTR3411 (buf, len, digest);
BIGNUM * d = BN_bin2bn (digest, 32, nullptr);
BIGNUM * r = BN_new (), * s = BN_new ();
const auto& curve = GetGOSTR3410Curve (m_ParamSet);
curve->Sign (m_PrivateKey, d, r, s);
GetGOSTR3410Curve (m_ParamSet)->Sign (m_PrivateKey, d, r, s);
bn2buf (r, signature, GOSTR3410_SIGNATURE_LENGTH/2);
bn2buf (s, signature + GOSTR3410_SIGNATURE_LENGTH/2, GOSTR3410_SIGNATURE_LENGTH/2);
BN_free (d); BN_free (r); BN_free (s);