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-rw-r--r--lib/lib5.c138
-rw-r--r--lib/lib5.h22
-rw-r--r--set5/task36.c31
3 files changed, 150 insertions, 41 deletions
diff --git a/lib/lib5.c b/lib/lib5.c
index 60b0836..f637469 100644
--- a/lib/lib5.c
+++ b/lib/lib5.c
@@ -176,86 +176,142 @@ void dh_mitm(struct dh_param *dh)
dh_get_session_key(dh);
}
-void srp_compute_x(int salt, unsigned char *password, char *sha1_hash)
+void srp_context_init(struct srp_context *s)
+{
+ s->salt = BN_new();
+ s->v = BN_new();
+ s->g = BN_new();
+ s->N = BN_new();
+ s->a = BN_new();
+ s->u = BN_new();
+ s->k = BN_new();
+ s->b = BN_new();
+ s->A = BN_new();
+ s->B = BN_new();
+
+ char *N_str = "ffffffffffffffffc90fdaa22168c234c4c6628b80dc1cd129024"
+ "e088a67cc74020bbea63b139b22514a08798e3404ddef9519b3cd"
+ "3a431b302b0a6df25f14374fe1356d6d51c245e485b576625e7ec"
+ "6f44c42e9a637ed6b0bff5cb6f406b7edee386bfb5a899fa5ae9f"
+ "24117c4b1fe649286651ece45b3dc2007cb8a163bf0598da48361"
+ "c55d39a69163fa8fd24cf5f83655d23dca3ad961c62f356208552"
+ "bb9ed529077096966d670c354e4abc9804f1746c08ca237327fff"
+ "fffffffffffff";
+ unsigned char *res = malloc(strlen(N_str));
+ int len_dec = decode_hex_string(N_str, res);
+
+ BN_bin2bn(res, len_dec, s->N);
+ BN_set_word(s->g, 2);
+ BN_set_word(s->k, 3);
+}
+
+void srp_compute_x(BIGNUM *salt, unsigned char *password, char *sha1_hash)
{
unsigned char *to_hash;
SHA1Context sha1;
+ to_hash = malloc(strlen(password) + BN_num_bytes(salt));
- to_hash = malloc(strlen(password) + sizeof(int));
-
- memcpy(to_hash, &salt, sizeof(int));
- memcpy(&to_hash[sizeof(int)], password, strlen(password));
+ BN_bn2bin(salt, to_hash);
+ memcpy(&to_hash[BN_num_bytes(salt)-1], password, strlen(password));
SHA1Reset(&sha1);
SHA1Input(&sha1, to_hash, strlen(to_hash));
SHA1Result(&sha1);
-
memcpy(sha1_hash, &(sha1.Message_Digest), 20);
}
-void srp_server_init(char *email, char *password, char *g, char *N)
+void srp_server_init(char *email, char *password, struct srp_context *srpc)
{
- int salt;
char sha1_hash[20];
- mpz_t sha1_as_number;
- mpz_t v;
+ BIGNUM *x = BN_new();
- generate_random_bytes((char *)&salt, sizeof(int));
+ BN_pseudo_rand(srpc->salt, 256, -1, -1);
- srp_compute_x(salt, password, sha1_hash);
- modexp_bignums(g, sha1_hash, N, 16, &v);
+ srp_compute_x(srpc->salt, password, sha1_hash);
+ BN_bin2bn(sha1_hash, 20, x);
+ BN_mod_exp(srpc->v, srpc->g, x, srpc->N, ctx);
}
-void srp_client_send1(char *g)
+void srp_client_send1(char *email, struct srp_context *srpc)
{
- // send email
-
- // compute public key A
- //char *a
+ BN_pseudo_rand(srpc->a, 1024, -1, -1);
+ BN_mod_exp(srpc->A, srpc->g, srpc->a, srpc->N, ctx);
}
-void srp_server_send1()
+void srp_server_send1(struct srp_context *srpc)
{
- // send salt
-
- // compute public key B
+ BIGNUM *t = BN_new();
+ BIGNUM *t2 = BN_new();
+ BN_pseudo_rand(srpc->b, 1024, -1, -1);
+ BN_mod_exp(t, srpc->g, srpc->b, srpc->N, ctx);
+ BN_mod_mul(t2, srpc->k, srpc->v, srpc->N, ctx);
+ BN_mod_add(srpc->B, t, t2, srpc->N, ctx);
}
-void srp_compute_uH(unsigned char *A, unsigned char *B)
+void srp_compute_uH(struct srp_context *srpc)
{
SHA1Context sha1;
unsigned char uH[20];
- mpz_t u;
- unsigned char *res = malloc(strlen(A) + strlen(B));
-
- memcpy(res, A, strlen(A));
- memcpy(&res[strlen(A)], B, strlen(B));
+ unsigned char *res = malloc(BN_num_bytes(srpc->A) + BN_num_bytes(srpc->B));
+ BN_bn2bin(srpc->A, res);
+ BN_bn2bin(srpc->B, &res[BN_num_bytes(srpc->A)-1]);
SHA1Reset(&sha1);
- SHA1Input(&sha1, res, (strlen(A) + strlen(B)));
+ SHA1Input(&sha1, res, BN_num_bytes(srpc->A) + BN_num_bytes(srpc->B));
SHA1Result(&sha1);
memcpy(uH, &(sha1.Message_Digest), 20);
- mpz_init_set_str(u, uH, 16);
+ BN_bin2bn(uH, 20, srpc->u);
}
-/*
-void srp_client(unsigned char *salt, unsigned char *password, unsigned char *g,
- unsigned char *N, unsigned char *B, unsigned char *k)
+
+void srp_client_prepare_k(struct srp_context *srpc, char *password)
{
+ SHA1Context sha1;
+ BIGNUM *x = BN_new();
+ char K[20];
char sha1_hash[20];
- mpz_t g_mp, N_mp, B_mp, k_mp, tmp_mp;
- srp_compute_x(salt, password, sha1_hash);
+ srp_compute_x(srpc->salt, password, sha1_hash);
+ BN_bin2bn(sha1_hash, 20, x);
+
+ BIGNUM *S = BN_new();
+ BIGNUM *tmp = BN_new();
+ BIGNUM *tmp1 = BN_new();
+ BIGNUM *left= BN_new();
+ BN_mod_exp(tmp1, srpc->g, x, srpc->N, ctx);
+ BN_mod_mul(tmp, srpc->k, tmp1, srpc->N, ctx);
+ BN_mod_sub(left, srpc->B, tmp, srpc->N, ctx);
- mpz_init_set_str(g_mp, g, 16);
- mpz_init_set_str(N_mp, N, 16);
- mpz_init_set_str(B_mp, B, 16);
- mpz_init_set_str(k_mp, k, 16);
+ BN_mod_mul(tmp, srpc->u, x, srpc->N, ctx);
+ BN_mod_add(tmp, tmp, srpc->a, srpc->N, ctx);
+ BN_mod_exp(S, left, tmp, srpc->N, ctx);
- mpz_pow_
+ char *s_str = malloc(BN_num_bytes(S));
+ BN_bn2bin(S, s_str);
+ SHA1Reset(&sha1);
+ SHA1Input(&sha1, s_str, BN_num_bytes(S));
+ SHA1Result(&sha1);
+ memcpy(srpc->client_K, &(sha1.Message_Digest), 20);
+}
+
+void srp_server_prepare_k(struct srp_context *srpc)
+{
+ BIGNUM *S = BN_new();
+ BIGNUM *tmp = BN_new();
+ char K[20];
+ SHA1Context sha1;
+
+ BN_mod_exp(tmp, srpc->v, srpc->u, srpc->N, ctx);
+ BN_mod_mul(tmp, tmp, srpc->A, srpc->N, ctx);
+ BN_mod_exp(S, tmp, srpc->b, srpc->N, ctx);
+ char *s_str = malloc(BN_num_bytes(S));
+ BN_bn2bin(S, s_str);
+ SHA1Reset(&sha1);
+ SHA1Input(&sha1, s_str, BN_num_bytes(S));
+ SHA1Result(&sha1);
+ memcpy(srpc->server_K, &(sha1.Message_Digest), 20);
}
-*/
/**
* in C the % operator is more the remainder than the modulo
diff --git a/lib/lib5.h b/lib/lib5.h
index da3868d..4aaa7d6 100644
--- a/lib/lib5.h
+++ b/lib/lib5.h
@@ -30,6 +30,21 @@ struct dh_param_bignum {
BIGNUM *s2;
};
+struct srp_context {
+ BIGNUM *salt;
+ BIGNUM *v;
+ BIGNUM *g;
+ BIGNUM *N;
+ BIGNUM *a;
+ BIGNUM *u;
+ BIGNUM *k;
+ BIGNUM *b;
+ BIGNUM *B;
+ BIGNUM *A;
+ char client_K[20];
+ char server_K[20];
+};
+
// global openssl context for auxaliry results
BN_CTX *ctx;
BIO *out;
@@ -94,4 +109,11 @@ int check_co_prime(int a, int b);
int __chinese_remainder_theorem(int *a, int *n, int len);
int nth_root_bignum(BIGNUM *res, BIGNUM *number, BIGNUM *n);
double nth_root_wr(double x, int n);
+void srp_server_init(char *email, char *password, struct srp_context *srpc);
+void srp_client_send1(char *email, struct srp_context *srpc);
+void srp_server_send1(struct srp_context *srpc);
+void srp_compute_uH(struct srp_context *srpc);
+void srp_client_prepare_k(struct srp_context *srpc, char *password);
+void srp_server_prepare_k(struct srp_context *srpc);
+void srp_context_init(struct srp_context *s);
#endif
diff --git a/set5/task36.c b/set5/task36.c
new file mode 100644
index 0000000..5fc05af
--- /dev/null
+++ b/set5/task36.c
@@ -0,0 +1,31 @@
+#include "../lib/lib.h"
+#include "../lib/lib2.h"
+#include "../lib/lib3.h"
+#include "../lib/lib4.h"
+#include "../lib/lib5.h"
+#include <time.h>
+
+int main()
+{
+ struct srp_context srpc;
+ char *email = "test@example.com";
+ char *password = "123456";
+ char sK[41];
+ char cK[41];
+ out = BIO_new(BIO_s_file());
+ BIO_set_fp(out, stdout, BIO_NOCLOSE);
+
+ ctx = BN_CTX_new();
+
+ srp_context_init(&srpc);
+ srp_server_init(email, password, &srpc);
+ srp_client_send1(email, &srpc);
+ srp_server_send1(&srpc);
+ srp_compute_uH(&srpc);
+ srp_client_prepare_k(&srpc, password);
+ srp_server_prepare_k(&srpc);
+ hex_binary_to_string(srpc.client_K, cK, 20);
+ hex_binary_to_string(srpc.server_K, sK, 20);
+ printf("cK: %s\n", cK);
+ printf("sK: %s\n", sK);
+}
generated by cgit v1.2.3-70-g09d2 (git 2.52.0) at 2025-12-08 17:36:51 +0000