wolfssl-examples/pk/ecc/ecc_sign.c

359 lines
10 KiB
C

/* ecc_sign.c
*
* Copyright (C) 2006-2020 wolfSSL Inc.
*
* This file is part of wolfSSL. (formerly known as CyaSSL)
*
* wolfSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/* Example to demonstrate SHA-256 hashing and ECC Sign */
/*
./configure CFLAGS="-DWOLFSSL_PUBLIC_MP" && make && sudo make install
gcc -lwolfssl -o ecc_sign ecc_sign.c
*/
#ifndef WOLFSSL_USER_SETTINGS
#include <wolfssl/options.h>
#endif
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/sha256.h>
#include <wolfssl/wolfcrypt/ecc.h>
#include <wolfssl/wolfcrypt/integer.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#include <wolfssl/wolfcrypt/logging.h>
#include <stdint.h>
#include <stdio.h>
#define ECC_CURVE_SZ 32 /* SECP256R1 curve size in bytes */
#define ECC_CURVE_ID ECC_SECP256R1
#ifdef WOLFSSL_PUBLIC_MP
/* Test Vector */
/* NIST P-256, SHA256 ECC Test Vector */
static const uint8_t kMsg[] = {
0x69, 0xbc, 0x9f, 0xce, 0x68, 0x17, 0xc2, 0x10, 0xea, 0xfc, 0x10, 0x65, 0x67, 0x52, 0xed, 0x78,
0x6e, 0xb8, 0x83, 0x9c, 0x9a, 0xb4, 0x56, 0x0d, 0xc1, 0x0d, 0x1f, 0x78, 0x6e, 0x75, 0xd7, 0xbe,
0x92, 0x6b, 0x12, 0xf6, 0x76, 0x60, 0x8e, 0xb1, 0xf4, 0x19, 0x0c, 0x81, 0xe7, 0x54, 0x5e, 0xbc,
0xe0, 0xae, 0xc2, 0x7d, 0x1b, 0xc4, 0x6e, 0xec, 0xb1, 0x99, 0x6c, 0xbf, 0x0e, 0x38, 0xa8, 0x01,
0xa6, 0x9a, 0x48, 0x12, 0xe4, 0xc9, 0x3b, 0xf0, 0x63, 0x46, 0x15, 0xb4, 0x61, 0xa8, 0x1a, 0x60,
0x71, 0x87, 0x98, 0xd7, 0x6f, 0x98, 0x7b, 0x2d, 0xb9, 0x19, 0x1b, 0x21, 0x9c, 0x70, 0x58, 0xe8,
0x0d, 0x0f, 0xe9, 0x2d, 0x9a, 0x9a, 0xf1, 0x55, 0xa0, 0x4c, 0xd3, 0x07, 0xbd, 0x97, 0x48, 0xec,
0x88, 0x0a, 0xaf, 0xb3, 0x80, 0x78, 0xa4, 0x59, 0x43, 0x57, 0xd3, 0xa7, 0x01, 0x66, 0x0e, 0xfc
};
static const uint8_t kPrivKey[] = {
/* d */
0x1e, 0xe7, 0x70, 0x07, 0xd3, 0x30, 0x94, 0x39,
0x28, 0x90, 0xdf, 0x23, 0x88, 0x2c, 0x4a, 0x34,
0x15, 0xdb, 0x4c, 0x43, 0xcd, 0xfa, 0xe5, 0x1f,
0x3d, 0x4c, 0x37, 0xfe, 0x59, 0x3b, 0x96, 0xd8
};
static const uint8_t kPubKey[] = {
/* Qx */
0x96, 0x93, 0x1c, 0x53, 0x0b, 0x43, 0x6c, 0x42,
0x0c, 0x52, 0x90, 0xe4, 0xa7, 0xec, 0x98, 0xb1,
0xaf, 0xd4, 0x14, 0x49, 0xd8, 0xc1, 0x42, 0x82,
0x04, 0x78, 0xd1, 0x90, 0xae, 0xa0, 0x6c, 0x07,
/* Qy */
0xf2, 0x3a, 0xb5, 0x10, 0x32, 0x8d, 0xce, 0x9e,
0x76, 0xa0, 0xd2, 0x8c, 0xf3, 0xfc, 0xa9, 0x94,
0x43, 0x24, 0xe6, 0x82, 0x00, 0x40, 0xc6, 0xdb,
0x1c, 0x2f, 0xcd, 0x38, 0x4b, 0x60, 0xdd, 0x61
};
#ifndef NO_SHA256
/* perform hashing block by block */
int crypto_sha256(const uint8_t *buf, uint32_t len, uint8_t *hash,
uint32_t hashSz, uint32_t blkSz)
{
int ret;
uint32_t i = 0, chunk;
wc_Sha256 sha256;
/* validate arguments */
if ((buf == NULL && len > 0) || hash == NULL ||
hashSz < WC_SHA256_DIGEST_SIZE || blkSz == 0)
{
return BAD_FUNC_ARG;
}
/* Init Sha256 structure */
ret = wc_InitSha256(&sha256);
if (ret != 0) {
return ret;
}
while (i < len) {
chunk = blkSz;
if ((chunk + i) > len)
chunk = len - i;
/* Perform chunked update */
ret = wc_Sha256Update(&sha256, (buf + i), chunk);
if (ret != 0) {
break;
}
i += chunk;
}
if (ret == 0) {
/* Get final digest result */
ret = wc_Sha256Final(&sha256, hash);
}
return ret;
}
#endif
#ifdef HAVE_ECC
#ifdef HAVE_ECC_VERIFY
/* perform verify of signature and hash using public key */
/* key is public Qx + public Qy */
/* sig is r + s */
int crypto_ecc_verify(const uint8_t *key, uint32_t keySz,
const uint8_t *hash, uint32_t hashSz, const uint8_t *sig, uint32_t sigSz,
int curveSz, int curveId)
{
int ret, verify_res = 0;
mp_int r, s;
ecc_key ecc;
/* validate arguments */
if (key == NULL || hash == NULL || sig == NULL || curveSz == 0 ||
hashSz == 0 || keySz < (curveSz*2) || sigSz < (curveSz*2))
{
return BAD_FUNC_ARG;
}
/* Setup the ECC key */
ret = wc_ecc_init(&ecc);
if (ret < 0) {
return ret;
}
/* Setup the signature r/s variables */
ret = mp_init(&r);
if (ret != MP_OKAY) {
wc_ecc_free(&ecc);
return ret;
}
ret = mp_init(&s);
if (ret != MP_OKAY) {
mp_clear(&r);
wc_ecc_free(&ecc);
return ret;
}
/* Import public key x/y */
ret = wc_ecc_import_unsigned(
&ecc,
(byte*)key, /* Public "x" Coordinate */
(byte*)(key + curveSz), /* Public "y" Coordinate */
NULL, /* Private "d" (optional) */
curveId /* ECC Curve Id */
);
/* Make sure it was a public key imported */
if (ret == 0 && ecc.type != ECC_PUBLICKEY) {
ret = ECC_BAD_ARG_E;
}
/* Import signature r/s */
if (ret == 0) {
ret = mp_read_unsigned_bin(&r, sig, curveSz);
}
if (ret == 0) {
ret = mp_read_unsigned_bin(&s, sig + curveSz, curveSz);
}
/* Verify ECC Signature */
if (ret == 0) {
ret = wc_ecc_verify_hash_ex(
&r, &s, /* r/s as mp_int */
hash, hashSz, /* computed hash digest */
&verify_res, /* verification result 1=success */
&ecc
);
}
/* check verify result */
if (ret == 0 && verify_res == 0) {
ret = SIG_VERIFY_E;
}
mp_clear(&r);
mp_clear(&s);
wc_ecc_free(&ecc);
return ret;
}
#endif /* HAVE_ECC_VERIFY */
#ifdef HAVE_ECC_SIGN
/* perform signature operation against hash using private key */
int crypto_ecc_sign(const uint8_t *key, uint32_t keySz,
const uint8_t *hash, uint32_t hashSz, uint8_t *sig, uint32_t* sigSz,
int curveSz, int curveId)
{
int ret;
mp_int r, s;
ecc_key ecc;
WC_RNG rng;
/* validate arguments */
if (key == NULL || hash == NULL || sig == NULL || sigSz == NULL ||
curveSz == 0 || hashSz == 0 || keySz < curveSz || *sigSz < (curveSz*2))
{
return BAD_FUNC_ARG;
}
/* Initialize signature result */
memset(sig, 0, curveSz*2);
/* Setup the RNG */
ret = wc_InitRng(&rng);
if (ret < 0) {
return ret;
}
/* Setup the ECC key */
ret = wc_ecc_init(&ecc);
if (ret < 0) {
wc_FreeRng(&rng);
return ret;
}
/* Setup the signature r/s variables */
ret = mp_init(&r);
if (ret != MP_OKAY) {
wc_ecc_free(&ecc);
wc_FreeRng(&rng);
return ret;
}
ret = mp_init(&s);
if (ret != MP_OKAY) {
mp_clear(&r);
wc_ecc_free(&ecc);
wc_FreeRng(&rng);
return ret;
}
/* Import private key "k" */
ret = wc_ecc_import_private_key_ex(
key, keySz, /* private key "d" */
NULL, 0, /* public (optional) */
&ecc,
curveId /* ECC Curve Id */
);
if (ret == 0) {
/* Verify ECC Signature */
ret = wc_ecc_sign_hash_ex(
hash, hashSz, /* computed hash digest */
&rng, &ecc, /* random and key context */
&r, &s /* r/s as mp_int */
);
/* export r/s */
mp_to_unsigned_bin(&r, sig);
mp_to_unsigned_bin(&s, sig + curveSz);
}
mp_clear(&r);
mp_clear(&s);
wc_ecc_free(&ecc);
wc_FreeRng(&rng);
return ret;
}
#endif /* HAVE_ECC_SIGN */
#endif /* HAVE_ECC */
static void print_hex(uint8_t* data, int sz)
{
int i;
for (i = 0; i < sz; i++) {
printf("%02X ", data[i]);
if (i > 0 && ((i+1) % 16) == 0)
printf("\n");
}
printf("\n");
}
#endif /* WOLFSSL_PUBLIC_MP */
int main()
{
#if defined(HAVE_ECC) && defined(HAVE_ECC_SIGN) && defined(HAVE_ECC_VERIFY) && \
!defined(NO_SHA256) && defined(WOLFSSL_PUBLIC_MP)
int ret;
uint8_t hash[WC_SHA256_DIGEST_SIZE];
uint8_t sig[ECC_CURVE_SZ*2];
uint32_t sigSz = 0;
#ifdef DEBUG_WOLFSSL
wolfSSL_Debugging_ON();
#endif
printf("Running NIST P-256,SHA-256 Sign Test\n");
memset(sig, 0, sizeof(sig));
ret = crypto_sha256(
kMsg, sizeof(kMsg), /* input message */
hash, sizeof(hash), /* hash digest result */
32 /* configurable block / chunk size */
);
if (ret == 0) {
/* Sign hash using private key */
/* Note: result of an ECC sign varies for each call even with same
private key and hash. This is because a new random public key is
used for each operation. */
sigSz = sizeof(sig);
ret = crypto_ecc_sign(
kPrivKey, sizeof(kPrivKey), /* private key */
hash, sizeof(hash), /* computed hash digest */
sig, &sigSz, /* signature r/s */
ECC_CURVE_SZ, /* SECP256R1 curve size in bytes */
ECC_CURVE_ID /* curve id */
);
}
if (ret == 0) {
/* Verify generated signature is valid */
ret = crypto_ecc_verify(
kPubKey, sizeof(kPubKey), /* public key point x/y */
hash, sizeof(hash), /* computed hash digest */
sig, sigSz, /* signature r/s */
ECC_CURVE_SZ, /* curve size in bytes */
ECC_CURVE_ID /* curve id */
);
}
if (ret == 0) {
printf("Signature %d\n", sigSz);
print_hex(sig, sigSz);
printf("Success\n");
}
else {
printf("Failure %d: %s\n", ret, wc_GetErrorString(ret));
ret = -1;
}
return ret;
#else
printf("wolfSSL requires ECC and SHA256 and WOLFSSL_PUBLIC_MP\n");
return -1;
#endif
}