Visual Basic Cryptography Question
- by Glenn Sullivan
I am trying to mimic the results of some C code that uses the OpenSSL library using the system.security.crytography library in the .net 3.5 world, and I can't seem to get it right. I need some help... part of the issue is my understanding of crytography in general.
Here's what is supposed to happen:
I send a request for authentication to a device.
It returns a challenge digest, which I then need to sign with a known key and return
The device returns a "success" or "Fail" message.
I have the following code snippet that I am trying to "copy":
//Seed the PRNG
//Cheating here - the PRNG will be seeded when we create a key pair
//The key pair is discarded only doing this to seed the PRNG.
DSA *temp_dsa = DSA_new();
if(!temp_dsa)
{
printf("Error: The client had an error with the DSA API\n");
exit(0);
}
unsigned char seed[20] = "Our Super Secret Key";
temp_dsa = DSA_generate_parameters(128, seed, sizeof(seed), NULL, NULL, NULL, NULL);
DSA_free(temp_dsa);
//A pointer to the private key.
p = (unsigned char *)&priv_key;
//Create and allocate a DSA structure from the private key.
DSA *priv_dsa = NULL;
priv_dsa = d2i_DSAPrivateKey(NULL, &p, sizeof(priv_key));
if(!priv_dsa)
{
printf("Error: The client had an error with the DSA API\n");
exit(0);
}
//Allocate memory for the to be computed signature.
sigret = OPENSSL_malloc(DSA_size(priv_dsa));
//Sign the challenge digest recieved from the ISC.
retval = DSA_sign(0, pResp->data, pResp->data_length, sigret, &siglen, priv_dsa);
A few more bits of information:
priv_key is a 252 element character array of hex characters that is included.
The end result is a 512 (or less) array of characters to send back for validation to the device.
Rasmus asked to see the key array. Here it is:
unsigned char priv_key[] = {0x30, 0x81, 0xf9, 0x02, 0x01, 0x00,
0x02, 0x41, 0x00, 0xfe, 0xca,
0x97, 0x55, 0x1f, 0xc0, 0xb7,
0x1f, 0xad, 0xf0, 0x93, 0xec,
0x4b, 0x31, 0x94, 0x78, 0x86,
0x82, 0x1b, 0xab, 0xc4, 0x9e,
0x5c, 0x40, 0xd9, 0x89, 0x7d,
0xde, 0x43, 0x38, 0x06, 0x4f,
0x1b, 0x2b, 0xef, 0x5c, 0xb7,
0xff, 0x21, 0xb1, 0x11, 0xe6,
0x9a, 0x81, 0x9a, 0x2b, 0xef,
0x3a, 0xbb, 0x5c, 0xea, 0x76,
0xae, 0x3a, 0x8b, 0x92, 0xd2,
0x7c, 0xf1, 0x89, 0x8e, 0x4d,
0x3f, 0x0d, 0x02, 0x15, 0x00,
0x88, 0x16, 0x1b, 0xf5, 0xda,
0x43, 0xee, 0x4b, 0x58, 0xbb,
0x93, 0xea, 0x4e, 0x2b, 0xda,
0xb9, 0x17, 0xd1, 0xff, 0x21,
0x02, 0x41, 0x00, 0xf6, 0xbb,
0x45, 0xea, 0xda, 0x72, 0x39,
0x4f, 0xc1, 0xdd, 0x02, 0xb4,
0xf3, 0xaa, 0xe5, 0xe2, 0x76,
0xc7, 0xdc, 0x34, 0xb2, 0x0a,
0xd8, 0x69, 0x63, 0xc3, 0x40,
0x2c, 0x58, 0xea, 0xa6, 0xbd,
0x24, 0x8b, 0x6b, 0xaa, 0x4b,
0x41, 0xfc, 0x5f, 0x21, 0x02,
0x3c, 0x27, 0xa9, 0xc7, 0x7a,
0xc8, 0x59, 0xcd, 0x5b, 0xdd,
0x6c, 0x44, 0x48, 0x86, 0xd1,
0x34, 0x46, 0xb0, 0x89, 0x55,
0x50, 0x87, 0x02, 0x41, 0x00,
0x80, 0x29, 0xc6, 0x4a, 0x08,
0x3e, 0x30, 0x54, 0x71, 0x9b,
0x95, 0x49, 0x55, 0x17, 0x70,
0xc7, 0x96, 0x65, 0xc8, 0xc2,
0xe2, 0x8a, 0xe0, 0x5d, 0x9f,
0xe4, 0xb2, 0x1f, 0x20, 0x83,
0x70, 0xbc, 0x88, 0x36, 0x03,
0x29, 0x59, 0xcd, 0xc7, 0xcd,
0xd9, 0x4a, 0xa8, 0x65, 0x24,
0x6a, 0x77, 0x8a, 0x10, 0x88,
0x0d, 0x2f, 0x15, 0x4b, 0xbe,
0xba, 0x13, 0x23, 0xa1, 0x73,
0xa3, 0x04, 0x37, 0xc9, 0x02,
0x14, 0x06, 0x8e, 0xc1, 0x41,
0x40, 0xf1, 0xf6, 0xe1, 0xfa,
0xfb, 0x64, 0x28, 0x02, 0x15,
0xce, 0x47, 0xaa, 0xce, 0x6e,
0xfe};
Can anyone help me translate this code to it's VB.net crypto equivalent?
TIA,
Glenn
