/*
* Do an RSA operation and check the message digest
*/
int rsa_pkcs1_verify( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig )
{
switch( ctx->padding )
{
case RSA_PKCS_V15:
return rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode,
hash_id, hashlen, hash, sig );
#if defined(POLARSSL_PKCS1_V21)
case RSA_PKCS_V21:
return rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, hash_id,
hashlen, hash, sig );
#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING );
}
}
int EsSign::RsaVerify(const u8* hash, const u8* modulus, const u8* signature)
{
static const u8 public_exponent[3] = { 0x01, 0x00, 0x01 };
int ret;
EsSignType type;
rsa_context rsa;
int hash_id = 0;
int hash_len = 0;
rsa_init(&rsa, RSA_PKCS_V15, hash_id);
if (hash == NULL || modulus == NULL || signature == NULL) return 1;
// get signature type
type = (EsSignType)be_word(*((u32*)(signature)));
switch (type)
{
case(ES_SIGN_RSA4096_SHA1) :
case(ES_SIGN_RSA4096_SHA256) :
{
rsa.len = Crypto::kRsa4096Size;
hash_id = (type == ES_SIGN_RSA4096_SHA1) ? SIG_RSA_SHA1 : SIG_RSA_SHA256;
hash_len = (type == ES_SIGN_RSA4096_SHA1) ? Crypto::kSha1HashLen : Crypto::kSha256HashLen;
break;
}
case(ES_SIGN_RSA2048_SHA1) :
case(ES_SIGN_RSA2048_SHA256) :
{
rsa.len = Crypto::kRsa2048Size;
hash_id = (type == ES_SIGN_RSA2048_SHA1) ? SIG_RSA_SHA1 : SIG_RSA_SHA256;
hash_len = (type == ES_SIGN_RSA2048_SHA1) ? Crypto::kSha1HashLen : Crypto::kSha256HashLen;
break;
}
default:
return 1;
}
mpi_read_binary(&rsa.E, public_exponent, sizeof(public_exponent));
mpi_read_binary(&rsa.N, modulus, rsa.len);
ret = rsa_rsassa_pkcs1_v15_verify(&rsa, RSA_PRIVATE, hash_id, hash_len, hash, signature + 4);
rsa_free(&rsa);
return ret;
}
int Crypto::VerifyRsa2048Sha256(const u8 modulus[kRsa2048Size], const u8 hash[kSha256HashLen], const u8 signature[kRsa2048Size])
{
static const u8 public_exponent[3] = { 0x01, 0x00, 0x01 };
int ret;
rsa_context ctx;
rsa_init(&ctx, RSA_PKCS_V15, 0);
ctx.len = kRsa2048Size;
mpi_read_binary(&ctx.E, public_exponent, sizeof(public_exponent));
mpi_read_binary(&ctx.N, modulus, ctx.len);
ret = rsa_rsassa_pkcs1_v15_verify(&ctx, RSA_PUBLIC, SIG_RSA_SHA256, kSha256HashLen, hash, signature);
rsa_free(&ctx);
return ret;
}
