//Hardcoding this test code for PSS-SHA1
void RsaPssVerification(unsigned int uKeySize, const unsigned char* pMsg, const unsigned char* pSign,
unsigned int E, const unsigned char* pN, const unsigned char* pD)
{
RSA* pRsaKey = NULL;
const unsigned char* pDigest = NULL;
size_t uDigestLen = 20;
unsigned char EM[512];
unsigned char signature[512];
unsigned int uLen = 0;
int status = 0;
// Generate an RSA key pair
pRsaKey = GetRsaKey(E, pN, pD);
if (pRsaKey) {
//Use the already hashed input message and compute the PSS padded data with max salt size
pDigest = pMsg;
printbin("HASH", pDigest, 20);
status = RSA_padding_add_PKCS1_PSS(pRsaKey, EM, pDigest, EVP_sha1(), -2);
printbin("EM", EM, uKeySize);
if (status == 1) {
//Now do Rsa Signature (RSA private encrypt)
status = RSA_private_encrypt(uKeySize, EM, signature, pRsaKey, RSA_NO_PADDING);
printbin("Sign", signature, uKeySize);
if (status != -1) {
//Now its time to verify the signature using RSA public decryption
//We could directly use signature, but we are here to verify the signature generated by HW KM1
uLen = hex2bin(signature, pSign);
//assert(uLen == uKeySize)
printbin("Sign", signature, uLen);
status = RSA_public_decrypt(uKeySize, signature, EM, pRsaKey, RSA_NO_PADDING);
printbin("EM", EM, uKeySize);
if (status != -1) {
//Verify the data against the message with expecting max salt length from ssignature
status = RSA_verify_PKCS1_PSS(pRsaKey, pDigest, EVP_sha1(), EM, -2);
if (status == 1) {
printf("GREAT: Signature verification successful\n");
} else {
printf("RSA_verify_PKCS1_PSS failed with error %s\n", ERR_error_string(ERR_get_error(), NULL));
}
} else {
printf("RSA_public_decrypt failed with error %s\n", ERR_error_string(ERR_get_error(), NULL));
}
} else {
printf("RSA_private_encrypt failed with error %s\n", ERR_error_string(ERR_get_error(), NULL));
}
} else {
printf("RSA_padding_add_PKCS1_PSS failed with error %s\n", ERR_error_string(ERR_get_error(), NULL));
}
}
if (pRsaKey) {
RSA_free(pRsaKey);
}
}
int main(char **args)
{
unsigned int x;
printf("number to print in binary: \n");
scanf("%x",&x);
printf("The binary format for %x is %s\n",
x, printbin((unsigned char)x));
//printf("the for %s\n", printbin((unsigned char)x));
return 0;
}
static void
printhdr(uint8_t *hdr, int len)
{
int i, j;
j = 0;
for(i = 0; i < len; ++i) {
printbin(hdr[i], 8);
printf(" (0x%0x), ", hdr[i]);
++j;
if(j == 10) {
printf("\n");
j = 0;
}
}
if(j != 0) {
printf("\n");
}
}
