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#include <openssl/opensslconf.h>
#ifdef OPENSSL_NO_SRP
# include <stdio.h>
int main(int argc, char *argv[])
{
printf("No SRP support\n");
return (0);
}
#else
# include <openssl/srp.h>
# include <openssl/rand.h>
# include <openssl/err.h>
static void showbn(const char *name, const BIGNUM *bn)
{
fputs(name, stdout);
fputs(" = ", stdout);
BN_print_fp(stdout, bn);
putc('\n', stdout);
}
# define RANDOM_SIZE 32 /* use 256 bits on each side */
static int run_srp(const char *username, const char *client_pass,
const char *server_pass)
{
int ret = -1;
BIGNUM *s = NULL;
BIGNUM *v = NULL;
BIGNUM *a = NULL;
BIGNUM *b = NULL;
BIGNUM *u = NULL;
BIGNUM *x = NULL;
BIGNUM *Apub = NULL;
BIGNUM *Bpub = NULL;
BIGNUM *Kclient = NULL;
BIGNUM *Kserver = NULL;
unsigned char rand_tmp[RANDOM_SIZE];
/* use builtin 1024-bit params */
SRP_gN *GN = SRP_get_default_gN("1024");
if (GN == NULL) {
fprintf(stderr, "Failed to get SRP parameters\n");
return -1;
}
/* Set up server's password entry */
if (!SRP_create_verifier_BN(username, server_pass, &s, &v, GN->N, GN->g)) {
fprintf(stderr, "Failed to create SRP verifier\n");
return -1;
}
showbn("N", GN->N);
showbn("g", GN->g);
showbn("Salt", s);
showbn("Verifier", v);
/* Server random */
RAND_pseudo_bytes(rand_tmp, sizeof(rand_tmp));
b = BN_bin2bn(rand_tmp, sizeof(rand_tmp), NULL);
/* TODO - check b != 0 */
showbn("b", b);
/* Server's first message */
Bpub = SRP_Calc_B(b, GN->N, GN->g, v);
showbn("B", Bpub);
if (!SRP_Verify_B_mod_N(Bpub, GN->N)) {
fprintf(stderr, "Invalid B\n");
return -1;
}
/* Client random */
RAND_pseudo_bytes(rand_tmp, sizeof(rand_tmp));
a = BN_bin2bn(rand_tmp, sizeof(rand_tmp), NULL);
/* TODO - check a != 0 */
showbn("a", a);
/* Client's response */
Apub = SRP_Calc_A(a, GN->N, GN->g);
showbn("A", Apub);
if (!SRP_Verify_A_mod_N(Apub, GN->N)) {
fprintf(stderr, "Invalid A\n");
return -1;
}
/* Both sides calculate u */
u = SRP_Calc_u(Apub, Bpub, GN->N);
/* Client's key */
x = SRP_Calc_x(s, username, client_pass);
Kclient = SRP_Calc_client_key(GN->N, Bpub, GN->g, x, a, u);
showbn("Client's key", Kclient);
/* Server's key */
Kserver = SRP_Calc_server_key(Apub, v, u, b, GN->N);
showbn("Server's key", Kserver);
if (BN_cmp(Kclient, Kserver) == 0) {
ret = 0;
} else {
fprintf(stderr, "Keys mismatch\n");
ret = 1;
}
BN_clear_free(Kclient);
BN_clear_free(Kserver);
BN_clear_free(x);
BN_free(u);
BN_free(Apub);
BN_clear_free(a);
BN_free(Bpub);
BN_clear_free(b);
BN_free(s);
BN_clear_free(v);
return ret;
}
int main(int argc, char **argv)
{
BIO *bio_err;
bio_err = BIO_new_fp(stderr, BIO_NOCLOSE);
CRYPTO_malloc_debug_init();
CRYPTO_dbg_set_options(V_CRYPTO_MDEBUG_ALL);
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);
ERR_load_crypto_strings();
/* "Negative" test, expect a mismatch */
if (run_srp("alice", "password1", "password2") == 0) {
fprintf(stderr, "Mismatched SRP run failed\n");
return 1;
}
/* "Positive" test, should pass */
if (run_srp("alice", "password", "password") != 0) {
fprintf(stderr, "Plain SRP run failed\n");
return 1;
}
CRYPTO_cleanup_all_ex_data();
ERR_remove_thread_state(NULL);
ERR_free_strings();
CRYPTO_mem_leaks(bio_err);
return 0;
}
#endif
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