Abstract bignum API.
Этот коммит содержится в:
Simon Josefsson
родитель
51b9ff0f16
Коммит
c9d40afa14
86
src/kex.c
86
src/kex.c
@ -65,29 +65,29 @@
|
||||
/* {{{ libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange
|
||||
* Diffie Hellman Key Exchange, Group Agnostic
|
||||
*/
|
||||
static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_SESSION *session, BIGNUM *g, BIGNUM *p, int group_order,
|
||||
static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_SESSION *session, _libssh2_bn *g, _libssh2_bn *p, int group_order,
|
||||
unsigned char packet_type_init, unsigned char packet_type_reply,
|
||||
unsigned char *midhash, unsigned long midhash_len)
|
||||
{
|
||||
unsigned char *e_packet = NULL, *s_packet = NULL, *tmp, h_sig_comp[SHA_DIGEST_LENGTH], c;
|
||||
unsigned long e_packet_len, s_packet_len, tmp_len;
|
||||
int ret = 0;
|
||||
BN_CTX *ctx = BN_CTX_new();
|
||||
BIGNUM *x = BN_new(); /* Random from client */
|
||||
BIGNUM *e = BN_new(); /* g^x mod p */
|
||||
BIGNUM *f = BN_new(); /* g^(Random from server) mod p */
|
||||
BIGNUM *k = BN_new(); /* The shared secret: f^x mod p */
|
||||
_libssh2_bn_ctx *ctx = _libssh2_bn_ctx_new();
|
||||
_libssh2_bn *x = _libssh2_bn_init(); /* Random from client */
|
||||
_libssh2_bn *e = _libssh2_bn_init(); /* g^x mod p */
|
||||
_libssh2_bn *f = _libssh2_bn_init(); /* g^(Random from server) mod p */
|
||||
_libssh2_bn *k = _libssh2_bn_init(); /* The shared secret: f^x mod p */
|
||||
unsigned char *s, *f_value, *k_value = NULL, *h_sig;
|
||||
unsigned long f_value_len, k_value_len, h_sig_len;
|
||||
libssh2_sha1_ctx exchange_hash;
|
||||
|
||||
/* Generate x and e */
|
||||
BN_rand(x, group_order, 0, -1);
|
||||
BN_mod_exp(e, g, x, p, ctx);
|
||||
_libssh2_bn_rand(x, group_order, 0, -1);
|
||||
_libssh2_bn_mod_exp(e, g, x, p, ctx);
|
||||
|
||||
/* Send KEX init */
|
||||
e_packet_len = BN_num_bytes(e) + 6; /* packet_type(1) + String Length(4) + leading 0(1) */
|
||||
if (BN_num_bits(e) % 8) {
|
||||
e_packet_len = _libssh2_bn_bytes(e) + 6; /* packet_type(1) + String Length(4) + leading 0(1) */
|
||||
if (_libssh2_bn_bits(e) % 8) {
|
||||
/* Leading 00 not needed */
|
||||
e_packet_len--;
|
||||
}
|
||||
@ -99,11 +99,11 @@ static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_S
|
||||
}
|
||||
e_packet[0] = packet_type_init;
|
||||
libssh2_htonu32(e_packet + 1, e_packet_len - 5);
|
||||
if (BN_num_bits(e) % 8) {
|
||||
BN_bn2bin(e, e_packet + 5);
|
||||
if (_libssh2_bn_bits(e) % 8) {
|
||||
_libssh2_bn_to_bin(e, e_packet + 5);
|
||||
} else {
|
||||
e_packet[5] = 0;
|
||||
BN_bn2bin(e, e_packet + 6);
|
||||
_libssh2_bn_to_bin(e, e_packet + 6);
|
||||
}
|
||||
|
||||
#ifdef LIBSSH2_DEBUG_KEX
|
||||
@ -203,15 +203,15 @@ static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_S
|
||||
|
||||
f_value_len = libssh2_ntohu32(s); s += 4;
|
||||
f_value = s; s += f_value_len;
|
||||
BN_bin2bn(f_value, f_value_len, f);
|
||||
_libssh2_bn_from_bin(f, f_value_len, f_value);
|
||||
|
||||
h_sig_len = libssh2_ntohu32(s); s += 4;
|
||||
h_sig = s;
|
||||
|
||||
/* Compute the shared secret */
|
||||
BN_mod_exp(k, f, x, p, ctx);
|
||||
k_value_len = BN_num_bytes(k) + 5;
|
||||
if (BN_num_bits(k) % 8) {
|
||||
_libssh2_bn_mod_exp(k, f, x, p, ctx);
|
||||
k_value_len = _libssh2_bn_bytes(k) + 5;
|
||||
if (_libssh2_bn_bits(k) % 8) {
|
||||
/* don't need leading 00 */
|
||||
k_value_len--;
|
||||
}
|
||||
@ -222,11 +222,11 @@ static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_S
|
||||
goto clean_exit;
|
||||
}
|
||||
libssh2_htonu32(k_value, k_value_len - 4);
|
||||
if (BN_num_bits(k) % 8) {
|
||||
BN_bn2bin(k, k_value + 4);
|
||||
if (_libssh2_bn_bits(k) % 8) {
|
||||
_libssh2_bn_to_bin(k, k_value + 4);
|
||||
} else {
|
||||
k_value[4] = 0;
|
||||
BN_bn2bin(k, k_value + 5);
|
||||
_libssh2_bn_to_bin(k, k_value + 5);
|
||||
}
|
||||
|
||||
libssh2_sha1_init(&exchange_hash);
|
||||
@ -436,11 +436,11 @@ static int libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(LIBSSH2_S
|
||||
#endif
|
||||
|
||||
clean_exit:
|
||||
BN_clear_free(x);
|
||||
BN_clear_free(e);
|
||||
BN_clear_free(f);
|
||||
BN_clear_free(k);
|
||||
BN_CTX_free(ctx);
|
||||
_libssh2_bn_free(x);
|
||||
_libssh2_bn_free(e);
|
||||
_libssh2_bn_free(f);
|
||||
_libssh2_bn_free(k);
|
||||
_libssh2_bn_ctx_free(ctx);
|
||||
|
||||
if (e_packet) {
|
||||
LIBSSH2_FREE(session, e_packet);
|
||||
@ -486,21 +486,21 @@ static int libssh2_kex_method_diffie_hellman_group1_sha1_key_exchange(LIBSSH2_SE
|
||||
0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
||||
/* g == 2 */
|
||||
BIGNUM *p = BN_new(); /* SSH2 defined value (p_value) */
|
||||
BIGNUM *g = BN_new(); /* SSH2 defined value (2) */
|
||||
_libssh2_bn *p = _libssh2_bn_init(); /* SSH2 defined value (p_value) */
|
||||
_libssh2_bn *g = _libssh2_bn_init(); /* SSH2 defined value (2) */
|
||||
int ret;
|
||||
|
||||
/* Initialize P and G */
|
||||
BN_set_word(g, 2);
|
||||
BN_bin2bn(p_value, 128, p);
|
||||
_libssh2_bn_set_word(g, 2);
|
||||
_libssh2_bn_from_bin(p, 128, p_value);
|
||||
|
||||
#ifdef LIBSSH2_DEBUG_KEX
|
||||
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Initiating Diffie-Hellman Group1 Key Exchange");
|
||||
#endif
|
||||
ret = libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(session, g, p, 128, SSH_MSG_KEXDH_INIT, SSH_MSG_KEXDH_REPLY, NULL, 0);
|
||||
|
||||
BN_clear_free(p);
|
||||
BN_clear_free(g);
|
||||
_libssh2_bn_free(p);
|
||||
_libssh2_bn_free(g);
|
||||
|
||||
return ret;
|
||||
}
|
||||
@ -545,21 +545,21 @@ static int libssh2_kex_method_diffie_hellman_group14_sha1_key_exchange(LIBSSH2_S
|
||||
0x15, 0x72, 0x8E, 0x5A, 0x8A, 0xAC, 0xAA, 0x68,
|
||||
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
|
||||
/* g == 2 */
|
||||
BIGNUM *p = BN_new(); /* SSH2 defined value (p_value) */
|
||||
BIGNUM *g = BN_new(); /* SSH2 defined value (2) */
|
||||
_libssh2_bn *p = _libssh2_bn_init(); /* SSH2 defined value (p_value) */
|
||||
_libssh2_bn *g = _libssh2_bn_init(); /* SSH2 defined value (2) */
|
||||
int ret;
|
||||
|
||||
/* Initialize P and G */
|
||||
BN_set_word(g, 2);
|
||||
BN_bin2bn(p_value, 256, p);
|
||||
_libssh2_bn_set_word(g, 2);
|
||||
_libssh2_bn_from_bin(p, 256, p_value);
|
||||
|
||||
#ifdef LIBSSH2_DEBUG_KEX
|
||||
_libssh2_debug(session, LIBSSH2_DBG_KEX, "Initiating Diffie-Hellman Group14 Key Exchange");
|
||||
#endif
|
||||
ret = libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(session, g, p, 256, SSH_MSG_KEXDH_INIT, SSH_MSG_KEXDH_REPLY, NULL, 0);
|
||||
|
||||
BN_clear_free(p);
|
||||
BN_clear_free(g);
|
||||
_libssh2_bn_free(p);
|
||||
_libssh2_bn_free(g);
|
||||
|
||||
return ret;
|
||||
}
|
||||
@ -573,8 +573,8 @@ static int libssh2_kex_method_diffie_hellman_group_exchange_sha1_key_exchange(LI
|
||||
{
|
||||
unsigned char request[13], *s, *data;
|
||||
unsigned long data_len, p_len, g_len, request_len;
|
||||
BIGNUM *p = BN_new();
|
||||
BIGNUM *g = BN_new();
|
||||
_libssh2_bn *p = _libssh2_bn_init ();
|
||||
_libssh2_bn *g = _libssh2_bn_init ();
|
||||
int ret;
|
||||
|
||||
/* Ask for a P and G pair */
|
||||
@ -610,18 +610,18 @@ static int libssh2_kex_method_diffie_hellman_group_exchange_sha1_key_exchange(LI
|
||||
|
||||
s = data + 1;
|
||||
p_len = libssh2_ntohu32(s); s += 4;
|
||||
BN_bin2bn(s, p_len, p); s += p_len;
|
||||
_libssh2_bn_from_bin(p, p_len, s); s += p_len;
|
||||
|
||||
g_len = libssh2_ntohu32(s); s += 4;
|
||||
BN_bin2bn(s, g_len, g); s += g_len;
|
||||
_libssh2_bn_from_bin(g, g_len, s); s += g_len;
|
||||
|
||||
ret = libssh2_kex_method_diffie_hellman_groupGP_sha1_key_exchange(session, g, p, p_len, SSH_MSG_KEX_DH_GEX_INIT, SSH_MSG_KEX_DH_GEX_REPLY, data + 1, data_len - 1);
|
||||
|
||||
LIBSSH2_FREE(session, data);
|
||||
|
||||
dh_gex_clean_exit:
|
||||
BN_clear_free(g);
|
||||
BN_clear_free(p);
|
||||
_libssh2_bn_free(g);
|
||||
_libssh2_bn_free(p);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
@ -180,3 +180,17 @@ int _libssh2_cipher_crypt(_libssh2_cipher_ctx *ctx,
|
||||
unsigned char *block);
|
||||
|
||||
#define _libssh2_cipher_dtor(ctx) gcry_cipher_close(*(ctx))
|
||||
|
||||
#define _libssh2_bn struct gcry_mpi
|
||||
#define _libssh2_bn_ctx int
|
||||
#define _libssh2_bn_ctx_new() 0
|
||||
#define _libssh2_bn_ctx_free(bnctx) 0
|
||||
#define _libssh2_bn_init() gcry_mpi_new(0)
|
||||
#define _libssh2_bn_rand(bn, bits, top, bottom) gcry_mpi_randomize (bn, bits, GCRY_WEAK_RANDOM)
|
||||
#define _libssh2_bn_mod_exp(r, a, p, m, ctx) gcry_mpi_powm (r, a, p, m)
|
||||
#define _libssh2_bn_set_word(bn, val) gcry_mpi_set_ui(bn, val)
|
||||
#define _libssh2_bn_from_bin(bn, len, val) gcry_mpi_scan(&((bn)), GCRYMPI_FMT_USG, val, len, NULL)
|
||||
#define _libssh2_bn_to_bin(bn, val) gcry_mpi_print (GCRYMPI_FMT_USG, val, _libssh2_bn_bytes(bn), NULL, bn)
|
||||
#define _libssh2_bn_bytes(bn) (gcry_mpi_get_nbits (bn) / 8 + ((gcry_mpi_get_nbits (bn) % 8 == 0) ? 0 : 1))
|
||||
#define _libssh2_bn_bits(bn) gcry_mpi_get_nbits (bn)
|
||||
#define _libssh2_bn_free(bn) gcry_mpi_release(bn)
|
||||
|
||||
@ -203,3 +203,17 @@ int _libssh2_cipher_crypt(_libssh2_cipher_ctx *ctx,
|
||||
unsigned char *block);
|
||||
|
||||
#define _libssh2_cipher_dtor(ctx) EVP_CIPHER_CTX_cleanup(ctx)
|
||||
|
||||
#define _libssh2_bn BIGNUM
|
||||
#define _libssh2_bn_ctx BN_CTX
|
||||
#define _libssh2_bn_ctx_new() BN_CTX_new()
|
||||
#define _libssh2_bn_ctx_free(bnctx) BN_CTX_free(bnctx)
|
||||
#define _libssh2_bn_init() BN_new()
|
||||
#define _libssh2_bn_rand(bn, bits, top, bottom) BN_rand(bn, bits, top, bottom)
|
||||
#define _libssh2_bn_mod_exp(r, a, p, m, ctx) BN_mod_exp(r, a, p, m, ctx)
|
||||
#define _libssh2_bn_set_word(bn, val) BN_set_word(bn, val)
|
||||
#define _libssh2_bn_from_bin(bn, len, val) BN_bin2bn(val, len, bn)
|
||||
#define _libssh2_bn_to_bin(bn, val) BN_bn2bin(bn, val)
|
||||
#define _libssh2_bn_bytes(bn) BN_num_bytes(bn)
|
||||
#define _libssh2_bn_bits(bn) BN_num_bits(bn)
|
||||
#define _libssh2_bn_free(bn) BN_clear_free(bn)
|
||||
|
||||
Загрузка…
x
Ссылка в новой задаче
Block a user