Setting Up pQCee SPP toolkit

To use SPP toolkit Windows target, you can do the following:

1. Have Microsoft Visual Studio 2017 installed

2. Open a “x64 Native Tools Command Prompt”

3. Copy all files into a directory

   • sha256.h

   • sha256.c

   • pqspp.h

   • main.c

   • pqspp_sdk.dll.lib

4. Compile the code using “cl main.c sha256.c pqspp_sdk.dll.lib”. It will result in main.exe created.

5. Execute main.exe, and expect to see the following output:

   Generated a secret key and a public key (DER encoded of length 91)!

   Signed a message; got a pq_proof of size 210982 bytes

   Successfully verified the signature and the preimage proof!

pQCee main.c Code Sample

// This is pQCee's main.c code sample
#include "pqspp.h"
#include "sha256.h"

#include <stdio.h>
#include <stdlib.h>

int main() {

uint8_t *sk = NULL;
uint8_t *pk = NULL;
int pk_len = -1;

// call PQSPP_keygen to generate a secret key, public key and the length of each key
int ret = PQSPP_keygen(&sk, &pk, &pk_len);
if (ret != PQSPP_OK) {
    printf("Error in keygen: %d\n", ret);
    return -1;
}
printf(
    "Generated a secret key and a public key (DER encoded of length %d)!\n",
    pk_len);

// your message digest
uint8_t message[4] = {0x01, 0x02, 0x03, 0x04};

// hash the message digest
unsigned char hash[32];
SHA256_CTX ctx;

sha256_init(&ctx);
sha256_update(&ctx,message,sizeof(message));
sha256_final(&ctx,hash);

uint8_t *ec_sig = NULL;
int ec_sig_len = -1;
uint8_t *pip = NULL;
int pip_len = -1;

// call PQSPP_sign_digest to sign the hashed message
ret =
    PQSPP_sign_digest(sk, hash,sizeof(hash), &ec_sig, &ec_sig_len, &pip, &pip_len);
if (ret != PQSPP_OK) {
    printf("Error in sign: %d\n", ret);
    PQSPP_free_memory(sk);
    PQSPP_free_memory(pk);
    return -2;
}
printf("Signed a message; got a pq_proof of size %d bytes\n", pip_len);

// call PQSPP_verify_digest to verify the hashed message against its signature
ret = PQSPP_verify_digest(pk, pk_len, hash, sizeof(hash), ec_sig, ec_sig_len, pip,
    pip_len);
if (ret != PQSPP_OK) {
    printf("Error in verify: %d\n", ret);
    PQSPP_free_memory(sk);
    PQSPP_free_memory(pk);
    PQSPP_free_memory(ec_sig);
    PQSPP_free_memory(pip);
    return -3;
}

printf("Successfully verified the signature and the preimage proof!\n");

// call PQSPP_free_memory to free memories used during the signing process
PQSPP_free_memory(sk);
PQSPP_free_memory(pk);
PQSPP_free_memory(ec_sig);
PQSPP_free_memory(pip);

return 0;
}