int s2n_dhe_server_key_recv_parse_data(struct s2n_connection *conn, union s2n_kex_raw_server_data *raw_server_data)
{
struct s2n_dhe_raw_server_points dhe_data = raw_server_data->dhe_data;
/* Copy the DH details */
GUARD(s2n_dh_p_g_Ys_to_dh_params(&conn->secure.server_dh_params, &dhe_data.p, &dhe_data.g, &dhe_data.Ys));
return 0;
}
static int s2n_dhe_server_key_recv(struct s2n_connection *conn)
{
struct s2n_hash_state signature_hash;
struct s2n_stuffer *in = &conn->handshake.io;
struct s2n_blob p, g, Ys, serverDHparams, signature;
uint16_t p_length;
uint16_t g_length;
uint16_t Ys_length;
uint16_t signature_length;
/* Keep a copy to the start of the whole structure for the signature check */
serverDHparams.data = s2n_stuffer_raw_read(in, 0);
notnull_check(serverDHparams.data);
/* Read each of the three elements in */
GUARD(s2n_stuffer_read_uint16(in, &p_length));
p.size = p_length;
p.data = s2n_stuffer_raw_read(in, p.size);
notnull_check(p.data);
GUARD(s2n_stuffer_read_uint16(in, &g_length));
g.size = g_length;
g.data = s2n_stuffer_raw_read(in, g.size);
notnull_check(g.data);
GUARD(s2n_stuffer_read_uint16(in, &Ys_length));
Ys.size = Ys_length;
Ys.data = s2n_stuffer_raw_read(in, Ys.size);
notnull_check(Ys.data);
/* Now we know the total size of the structure */
serverDHparams.size = 2 + p_length + 2 + g_length + 2 + Ys_length;
GUARD(s2n_hash_init(&signature_hash, conn->secure.signature_digest_alg));
if (conn->actual_protocol_version == S2N_TLS12) {
uint8_t hash_algorithm;
uint8_t signature_algorithm;
GUARD(s2n_stuffer_read_uint8(in, &hash_algorithm));
GUARD(s2n_stuffer_read_uint8(in, &signature_algorithm));
if (signature_algorithm != TLS_SIGNATURE_ALGORITHM_RSA) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
switch(hash_algorithm) {
case TLS_HASH_ALGORITHM_MD5:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_MD5));
break;
case TLS_HASH_ALGORITHM_SHA1:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA1));
break;
case TLS_HASH_ALGORITHM_SHA224:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA224));
break;
case TLS_HASH_ALGORITHM_SHA256:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA256));
break;
case TLS_HASH_ALGORITHM_SHA384:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA384));
break;
case TLS_HASH_ALGORITHM_SHA512:
GUARD(s2n_hash_init(&signature_hash, S2N_HASH_SHA512));
break;
default:
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
}
GUARD(s2n_hash_update(&signature_hash, conn->secure.client_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, conn->secure.server_random, S2N_TLS_RANDOM_DATA_LEN));
GUARD(s2n_hash_update(&signature_hash, serverDHparams.data, serverDHparams.size));
GUARD(s2n_stuffer_read_uint16(in, &signature_length));
signature.size = signature_length;
signature.data = s2n_stuffer_raw_read(in, signature.size);
notnull_check(signature.data);
gt_check(signature_length, 0);
if (s2n_rsa_verify(&conn->secure.server_rsa_public_key, &signature_hash, &signature) < 0) {
S2N_ERROR(S2N_ERR_BAD_MESSAGE);
}
/* We don't need the key any more, so free it */
GUARD(s2n_rsa_public_key_free(&conn->secure.server_rsa_public_key));
/* Copy the DH details */
GUARD(s2n_dh_p_g_Ys_to_dh_params(&conn->secure.server_dh_params, &p, &g, &Ys));
return 0;
}
