wolfssl-examples/ecc/ecc-sign.c

163 lines
3.7 KiB
C

#include <wolfssl/options.h>
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/sha256.h>
#include <wolfssl/wolfcrypt/ecc.h>
#include <wolfssl/wolfcrypt/random.h>
static const int gFwLen = (1024 * 1024);
static const int gFwChunkLen = 128;
static byte gFwBuf[gFwLen];
static ecc_key gMyKey;
static int gMyKeyInit = 0;
static const int gSignTimes = 10;
//#define ENABLE_BUF_PRINT
#define ECC_KEY_SIZE 48
#define ECC_KEY_CURVE ECC_SECP384R1
#ifdef ENABLE_BUF_PRINT
static void PrintBuffer(const byte* buffer, word32 length)
{
#define LINE_LEN 16
word32 i;
char line[80];
if (!buffer) {
printf("\tNULL");
return;
}
sprintf(line, "\t");
for (i = 0; i < LINE_LEN; i++) {
if (i < length)
sprintf(line + 1 + i * 3,"%02x ", buffer[i]);
else
sprintf(line + 1 + i * 3, " ");
}
sprintf(line + 1 + LINE_LEN * 3, "| ");
for (i = 0; i < LINE_LEN; i++)
if (i < length)
sprintf(line + 3 + LINE_LEN * 3 + i,
"%c", 31 < buffer[i] && buffer[i] < 127 ? buffer[i] : '.');
puts(line);
if (length > LINE_LEN)
PrintBuffer(buffer + LINE_LEN, length - LINE_LEN);
}
#endif
static int HashFirmware(byte* hashBuf)
{
int ret;
Sha256 sha;
int idx = 0, len = gFwLen, sz;
ret = wc_InitSha256(&sha);
if (ret != 0)
return ret;
/* loop through each chunk of firmware */
while (len > 0) {
/* determine hash update size */
sz = len;
if (sz > gFwChunkLen)
sz = gFwChunkLen;
/* update hash */
ret = wc_Sha256Update(&sha, &gFwBuf[idx], (word32)sz);
if (ret != 0)
break;
len -= sz;
idx += sz;
}
if (ret == 0) {
ret = wc_Sha256Final(&sha, hashBuf);
}
wc_Sha256Free(&sha);
return ret;
}
static int SignFirmware(byte* hashBuf, word32 hashLen, byte* sigBuf, word32* sigLen)
{
int ret = 0;
WC_RNG rng;
ret = wc_InitRng(&rng);
if (ret != 0)
return ret;
/* generate key for testing if one hasn't been created */
if (gMyKeyInit == 0) {
ret = wc_ecc_init(&gMyKey);
if (ret == 0) {
ret = wc_ecc_make_key_ex(&rng, ECC_KEY_SIZE, &gMyKey, ECC_KEY_CURVE);
if (ret == 0) {
gMyKeyInit = 1;
printf("KeyGen Done\n");
}
}
}
/* sign hash */
if (ret == 0) {
ret = wc_ecc_sign_hash(hashBuf, hashLen, sigBuf, sigLen, &rng, &gMyKey);
printf("Sign ret %d, sigLen %d\n", ret, *sigLen);
}
if (ret == 0) {
int is_valid_sig = 0;
ret = wc_ecc_verify_hash(sigBuf, *sigLen, hashBuf, hashLen,
&is_valid_sig, &gMyKey);
printf("Verify ret %d, is_valid_sig %d\n", ret, is_valid_sig);
}
wc_FreeRng(&rng);
return ret;
}
int main(void)
{
int ret;
byte hashBuf[SHA256_DIGEST_SIZE];
word32 hashLen = SHA256_DIGEST_SIZE;
byte sigBuf[ECC_MAX_SIG_SIZE];
word32 sigLen = ECC_MAX_SIG_SIZE;
int i;
/* init bogus firmware */
for (i=0; i<gFwLen; i++) {
gFwBuf[i] = (byte)i;
}
/* try perofrming signature a few times */
for (i=0; i < gSignTimes; i++) {
memset(hashBuf, 0, hashLen);
ret = HashFirmware(hashBuf);
if (ret == 0) {
sigLen = ECC_MAX_SIG_SIZE;
memset(sigBuf, 0, sigLen);
ret = SignFirmware(hashBuf, hashLen, sigBuf, &sigLen);
}
printf("Firmware Signature %d: Ret %d, HashLen %d, SigLen %d\n", i, ret, hashLen, sigLen);
#ifdef ENABLE_BUF_PRINT
PrintBuffer(hashBuf, hashLen);
printf("\n");
PrintBuffer(sigBuf, sigLen);
#endif
}
return ret;
}