// sign a hash of input using private key
void sign (void)
{
char *p;
// initialize crypto API
if (open_crypt())
{
// import our private key
if (open_key (RSA_PRIVATE_BIN))
{
// hash the input
if (open_hash ())
{
// obtain size of signature
CryptSignHash (hHash, AT_SIGNATURE, NULL, 0, NULL, &dwSigLen);
pbSignature=xmalloc (dwSigLen);
// sign the hash to obtain signature
if (CryptSignHash (hHash, AT_SIGNATURE, NULL, 0, pbSignature, &dwSigLen))
{
p=sig2hex();
if (p)
{
printf (" [ signature is: %i::%s\n", lstrlen(p), p);
}
xfree (pbSignature);
} else {
xstrerror ("CryptSignHash()");
}
close_hash();
} else {
xstrerror ("open_hash()");
}
close_key();
} else {
xstrerror ("open_key()");
}
close_crypt();
} else {
xstrerror ("open_crypt()");
}
}
// verify a signature using public key
BOOL verify(void)
{
BOOL bStatus = FALSE;
// initialize crypto API
if (open_crypt()) {
// import public key
if (open_key(DSA_PUBLIC_BIN)) {
// hash the input
if (open_hash()) {
// convert signature to binary
sig2bin();
if (pbSignature != NULL) {
// verify signature
bStatus = CryptVerifySignature(hHash, pbSignature,
dwSigLen, hKey, NULL, 0);
printf(" [ signature is %s\n",
bStatus ? "valid" : "invalid");
xfree(pbSignature);
}
close_hash();
} else {
printf("open_hash()");
}
close_key();
} else {
printf("open_key()");
}
close_crypt();
} else {
printf("open_crypt()");
}
return bStatus;
}
