static feeReturn ECDSA_decode(
feeSigFormat format, // Signature format DER 9.62 / RAW
unsigned groupBytesLen,
const unsigned char *sigData,
size_t sigDataLen,
giant *c, // alloc'd & RETURNED
giant *d, // alloc'd & RETURNED
unsigned *sigVersion) // RETURNED
{
#if CRYPTKIT_DER_ENABLE
feeReturn frtn;
if (format==FSF_RAW) {
frtn = feeRAWDecodeECDSASignature(groupBytesLen, sigData, sigDataLen, c, d);
} else {
frtn = feeDERDecodeECDSASignature(sigData, sigDataLen, c, d);
}
if(frtn == FR_Success) {
*sigVersion = FEE_ECDSA_VERSION;
}
return frtn;
#else
int magic;
int minVersion;
int rtn;
rtn = byteRepToSig(sigData,
sigDataLen,
FEE_ECDSA_VERSION,
&magic,
(int *)sigVersion,
&minVersion,
c,
d);
if(rtn == 0) {
return FR_BadSignatureFormat;
}
switch(magic) {
case FEE_ECDSA_MAGIC:
return FR_Success;
case FEE_SIG_MAGIC: // ElGamal sig!
return FR_WrongSignatureType;
default:
return FR_BadSignatureFormat;
}
#endif
}
/*
* Obtain a feeSig object by parsing an existing signature block.
* Note that if Pm is used to salt a hash of the signed data, this must
* function must be called prior to hashing.
*/
feeReturn feeSigParse(const unsigned char *sigData,
size_t sigDataLen,
feeSig *sig) // RETURNED
{
sigInst *sinst = NULL;
feeReturn frtn;
#if !CRYPTKIT_DER_ENABLE
int version;
int magic;
int minVersion;
int rtn;
#endif
sinst = sinstAlloc();
#if CRYPTKIT_DER_ENABLE
frtn = feeDERDecodeElGamalSignature(sigData, sigDataLen, &sinst->u, &sinst->PmX);
if(frtn) {
goto abort;
}
#else
rtn = byteRepToSig(sigData,
sigDataLen,
FEE_SIG_VERSION,
&magic,
&version,
&minVersion,
&sinst->u,
&sinst->PmX);
if(rtn == 0) {
frtn = FR_BadSignatureFormat;
goto abort;
}
switch(magic) {
case FEE_ECDSA_MAGIC:
frtn = FR_WrongSignatureType; // ECDSA!
goto abort;
case FEE_SIG_MAGIC:
break; // proceed
default:
frtn = FR_BadSignatureFormat;
goto abort;
}
#endif /* CRYPTKIT_DER_ENABLE */
#if SIG_DEBUG
if(sigDebug) {
printf("sigParse: \n");
printf("u: ");
printGiant(sinst->u);
}
#endif // SIG_DEBUG
*sig = sinst;
return FR_Success;
abort:
if(sinst) {
feeSigFree(sinst);
}
return frtn;
}