wolfssl-examples/pk/ecdh_generate_secret/ecdh_gen_secret.c

299 lines
7.8 KiB
C

/* ecdh_gen_secret.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
*/
#include <stdio.h>
#include <wolfssl/options.h>
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/random.h>
#include <wolfssl/wolfcrypt/ecc.h>
#include <wolfssl/wolfcrypt/curve25519.h>
#include <wolfssl/wolfcrypt/curve448.h>
#define ECC_256_BIT_FIELD 32 // 256-bit curve field
#define ECC_448_BIT_FIELD 56 // 448-bit curve field
void print_secret(char* who, byte* s, int sLen);
void Usage(int* curveChoice);
int do_ecc(void);
int do_25519(void);
int do_448(void);
int main(int argc, char** argv)
{
int curveChoice = 0;
int ret;
if (argc < 2)
Usage(&curveChoice);
else
sscanf(argv[1], "%d", &curveChoice);
if (curveChoice == 1) {
ret = do_ecc();
}
else if (curveChoice == 2) {
ret = do_25519();
}
else {
ret = do_448();
}
return ret;
}
int do_ecc(void)
{
int ret;
#ifdef HAVE_ECC
WC_RNG rng;
ecc_key AliceKey, BobKey;
byte AliceSecret[ECC_256_BIT_FIELD] = {0};
byte BobSecret[ECC_256_BIT_FIELD] = {0};
word32 secretLen = 0;
ret = wc_InitRng(&rng);
if (ret != 0)
return ret;
ret = wc_ecc_init(&AliceKey);
if (ret != 0)
goto only_rng;
ret = wc_ecc_init(&BobKey);
if (ret != 0)
goto alice_and_rng;
ret = wc_ecc_make_key(&rng, ECC_256_BIT_FIELD, &AliceKey);
if (ret != 0)
goto all_three;
#ifdef ECC_TIMING_RESISTANT
ret = wc_ecc_set_rng(&AliceKey, &rng);
if (ret != 0)
goto all_three;
#endif
ret = wc_ecc_make_key(&rng, ECC_256_BIT_FIELD, &BobKey);
if (ret != 0)
goto all_three;
#ifdef ECC_TIMING_RESISTANT
ret = wc_ecc_set_rng(&BobKey, &rng);
if (ret != 0)
goto all_three;
#endif
secretLen = ECC_256_BIT_FIELD; /* explicit set */
wc_ecc_set_rng(&AliceKey, &rng);
ret = wc_ecc_shared_secret(&AliceKey, &BobKey, AliceSecret, &secretLen);
if (ret != 0)
goto all_three;
secretLen = ECC_256_BIT_FIELD; /* explicit reset for best practice */
wc_ecc_set_rng(&BobKey, &rng);
ret = wc_ecc_shared_secret(&BobKey, &AliceKey, BobSecret, &secretLen);
if (ret == 0) {
if (XMEMCMP(AliceSecret, BobSecret, secretLen))
printf("Failed to generate a common secret\n");
} else {
goto all_three;
}
printf("Successfully generated a common secret\n");
print_secret("Alice", AliceSecret, (int) secretLen);
print_secret("Bob", BobSecret, (int) secretLen);
all_three:
wc_ecc_free(&BobKey);
alice_and_rng:
wc_ecc_free(&AliceKey);
only_rng:
wc_FreeRng(&rng);
#else
printf("Configure wolfSSL with --enable-ecc and try again\n");
ret = -1;
#endif
return ret;
}
int do_25519(void)
{
int ret;
#ifdef HAVE_CURVE25519
WC_RNG rng;
curve25519_key AliceKey, BobKey;
byte AliceSecret[ECC_256_BIT_FIELD] = {0};
byte BobSecret[ECC_256_BIT_FIELD] = {0};
word32 secretLen = 0;
ret = wc_InitRng(&rng);
if (ret != 0)
return ret;
ret = wc_curve25519_init(&AliceKey);
if (ret != 0)
goto only_rng;
ret = wc_curve25519_init(&BobKey);
if (ret != 0)
goto alice_and_rng;
ret = wc_curve25519_make_key(&rng, ECC_256_BIT_FIELD, &AliceKey);
if (ret != 0)
goto all_three;
ret = wc_curve25519_make_key(&rng, ECC_256_BIT_FIELD, &BobKey);
if (ret != 0)
goto all_three;
secretLen = ECC_256_BIT_FIELD; /* explicit set */
ret = wc_curve25519_shared_secret(&AliceKey, &BobKey, AliceSecret, &secretLen);
if (ret != 0)
goto all_three;
secretLen = ECC_256_BIT_FIELD; /* explicit reset for best practice */
ret = wc_curve25519_shared_secret(&BobKey, &AliceKey, BobSecret, &secretLen);
if (ret == 0) {
if (XMEMCMP(AliceSecret, BobSecret, secretLen))
printf("Failed to generate a common secret\n");
} else {
goto all_three;
}
printf("Successfully generated a common 25519 secret\n");
print_secret("Alice", AliceSecret, (int) secretLen);
print_secret("Bob", BobSecret, (int) secretLen);
all_three:
wc_curve25519_free(&BobKey);
alice_and_rng:
wc_curve25519_free(&AliceKey);
only_rng:
wc_FreeRng(&rng);
#else
printf("Configure wolfssl with --enable-curve25519 and try again\n");
ret = -1;
#endif
return ret;
}
int do_448(void)
{
int ret;
#ifdef HAVE_CURVE448
WC_RNG rng;
curve448_key AliceKey, BobKey;
byte AliceSecret[ECC_448_BIT_FIELD] = {0};
byte BobSecret[ECC_448_BIT_FIELD] = {0};
word32 secretLen = 0;
ret = wc_InitRng(&rng);
if (ret != 0)
return ret;
ret = wc_curve448_init(&AliceKey);
if (ret != 0)
goto only_rng;
ret = wc_curve448_init(&BobKey);
if (ret != 0)
goto alice_and_rng;
ret = wc_curve448_make_key(&rng, ECC_448_BIT_FIELD, &AliceKey);
if (ret != 0)
goto all_three;
ret = wc_curve448_make_key(&rng, ECC_448_BIT_FIELD, &BobKey);
if (ret != 0)
goto all_three;
secretLen = ECC_448_BIT_FIELD; /* explicit set */
ret = wc_curve448_shared_secret(&AliceKey, &BobKey, AliceSecret, &secretLen);
if (ret != 0)
goto all_three;
secretLen = ECC_448_BIT_FIELD; /* explicit reset for best practice */
ret = wc_curve448_shared_secret(&BobKey, &AliceKey, BobSecret, &secretLen);
if (ret == 0) {
if (XMEMCMP(AliceSecret, BobSecret, secretLen))
printf("Failed to generate a common secret\n");
} else {
goto all_three;
}
printf("Successfully generated a common 448 secret\n");
print_secret("Alice", AliceSecret, (int) secretLen);
print_secret("Bob", BobSecret, (int) secretLen);
all_three:
wc_curve448_free(&BobKey);
alice_and_rng:
wc_curve448_free(&AliceKey);
only_rng:
wc_FreeRng(&rng);
#else
printf("Configure wolfssl with --enable-curve448 and try again\n");
ret = -1;
#endif
return ret;
}
void print_secret(char* who, byte* s, int sLen)
{
int i;
printf("%ss' Secret: ", who);
for (i = 0; i < sLen; i++)
printf("%02x", s[i]);
printf("\n");
}
void Usage(int* curveChoice)
{
char answer = 0;
char input[10];
printf("Optional, specify a curve:\n");
printf("1) ECC SECP256R1\n"
"2) Curve25519\n\n"
"3) Curve448\n\n"
"Contact support@wolfssl.com if you'd like to see other options\n\n"
"Example usage:\n"
"./ecdh_gen_secret 1\n"
"./ecdh_gen_secret 2\n\n"
"Selecting no (n) will default to option 1, SECP256R1\n"
"Would you like to select a curve now? (y/n) > "
);
answer = getchar();
if (answer == 'y') {
printf("\nEnter an option from the above curve list > ");
scanf("%s", input);
printf("You entered: %s\n", input);
sscanf(input, "%d", curveChoice);
if (*curveChoice != 1 && *curveChoice != 2) {
printf("Invalid choice, select either: 1 or 2\n");
exit(-1);
}
} else
*curveChoice = 1;
printf("curveChoice indicated: %d\n", *curveChoice);
}