mirror of
https://github.com/openssl/openssl.git
synced 2025-01-30 14:01:55 +08:00
Rewrite ssl3_send_client_key_exchange to support extms.
Rewrite ssl3_send_client_key_exchange to retain the premaster secret instead of using it immediately. This is needed because the premaster secret is used after the client key exchange message has been sent to compute the extended master secret. Reviewed-by: Tim Hudson <tjh@openssl.org> Reviewed-by: Matt Caswell <matt@openssl.org>
This commit is contained in:
Dr. Stephen Henson
parent
48fbcbacd2
commit
c660ec63a8
190
ssl/s3_clnt.c
190
ssl/s3_clnt.c
@ -2338,6 +2338,8 @@ int ssl3_send_client_key_exchange(SSL *s)
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int encoded_pt_len = 0;
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BN_CTX *bn_ctx = NULL;
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#endif
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unsigned char *pms = NULL;
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size_t pmslen = 0;
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if (s->state == SSL3_ST_CW_KEY_EXCH_A) {
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p = ssl_handshake_start(s);
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@ -2350,7 +2352,10 @@ int ssl3_send_client_key_exchange(SSL *s)
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#ifndef OPENSSL_NO_RSA
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else if (alg_k & SSL_kRSA) {
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RSA *rsa;
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unsigned char tmp_buf[SSL_MAX_MASTER_KEY_LENGTH];
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pmslen = SSL_MAX_MASTER_KEY_LENGTH;
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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if (s->session->sess_cert == NULL) {
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/*
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@ -2378,19 +2383,16 @@ int ssl3_send_client_key_exchange(SSL *s)
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EVP_PKEY_free(pkey);
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}
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tmp_buf[0] = s->client_version >> 8;
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tmp_buf[1] = s->client_version & 0xff;
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if (RAND_bytes(&(tmp_buf[2]), sizeof tmp_buf - 2) <= 0)
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pms[0] = s->client_version >> 8;
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pms[1] = s->client_version & 0xff;
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if (RAND_bytes(pms + 2, pmslen - 2) <= 0)
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goto err;
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s->session->master_key_length = sizeof tmp_buf;
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q = p;
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/* Fix buf for TLS and beyond */
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if (s->version > SSL3_VERSION)
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p += 2;
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n = RSA_public_encrypt(sizeof tmp_buf,
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tmp_buf, p, rsa, RSA_PKCS1_PADDING);
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n = RSA_public_encrypt(pmslen, pms, p, rsa, RSA_PKCS1_PADDING);
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# ifdef PKCS1_CHECK
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if (s->options & SSL_OP_PKCS1_CHECK_1)
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p[1]++;
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@ -2408,14 +2410,6 @@ int ssl3_send_client_key_exchange(SSL *s)
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s2n(n, q);
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n += 2;
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}
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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tmp_buf,
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sizeof tmp_buf);
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OPENSSL_cleanse(tmp_buf, sizeof tmp_buf);
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}
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#endif
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#ifndef OPENSSL_NO_KRB5
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@ -2505,9 +2499,14 @@ int ssl3_send_client_key_exchange(SSL *s)
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n += 2;
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}
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tmp_buf[0] = s->client_version >> 8;
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tmp_buf[1] = s->client_version & 0xff;
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if (RAND_bytes(&(tmp_buf[2]), sizeof tmp_buf - 2) <= 0)
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pmslen = SSL_MAX_MASTER_KEY_LENGTH;
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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pms[0] = s->client_version >> 8;
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pms[1] = s->client_version & 0xff;
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if (RAND_bytes(pms + 2, pmslen - 2) <= 0)
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goto err;
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/*-
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@ -2520,8 +2519,7 @@ int ssl3_send_client_key_exchange(SSL *s)
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memset(iv, 0, sizeof iv); /* per RFC 1510 */
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EVP_EncryptInit_ex(&ciph_ctx, enc, NULL, kssl_ctx->key, iv);
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EVP_EncryptUpdate(&ciph_ctx, epms, &outl, tmp_buf,
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sizeof tmp_buf);
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EVP_EncryptUpdate(&ciph_ctx, epms, &outl, pms, pmslen);
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EVP_EncryptFinal_ex(&ciph_ctx, &(epms[outl]), &padl);
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outl += padl;
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if (outl > (int)sizeof epms) {
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@ -2536,15 +2534,6 @@ int ssl3_send_client_key_exchange(SSL *s)
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memcpy(p, epms, outl);
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p += outl;
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n += outl + 2;
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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tmp_buf,
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sizeof tmp_buf);
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OPENSSL_cleanse(tmp_buf, sizeof tmp_buf);
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OPENSSL_cleanse(epms, outl);
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}
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#endif
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@ -2603,12 +2592,17 @@ int ssl3_send_client_key_exchange(SSL *s)
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}
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}
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pmslen = DH_size(dh_clnt);
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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/*
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* use the 'p' output buffer for the DH key, but make sure to
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* clear it out afterwards
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*/
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n = DH_compute_key(p, dh_srvr->pub_key, dh_clnt);
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n = DH_compute_key(pms, dh_srvr->pub_key, dh_clnt);
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if (scert->peer_dh_tmp == NULL)
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DH_free(dh_srvr);
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@ -2618,15 +2612,6 @@ int ssl3_send_client_key_exchange(SSL *s)
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goto err;
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}
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/* generate master key from the result */
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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p, n);
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/* clean up */
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memset(p, 0, n);
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if (s->s3->flags & TLS1_FLAGS_SKIP_CERT_VERIFY)
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n = 0;
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else {
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@ -2758,22 +2743,16 @@ int ssl3_send_client_key_exchange(SSL *s)
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_ECDH_LIB);
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goto err;
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}
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n = ECDH_compute_key(p, (field_size + 7) / 8, srvr_ecpoint,
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clnt_ecdh, NULL);
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if (n <= 0) {
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pmslen = (field_size + 7) / 8;
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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n = ECDH_compute_key(pms, pmslen, srvr_ecpoint, clnt_ecdh, NULL);
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if (n <= 0 || pmslen != (size_t)n) {
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_ECDH_LIB);
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goto err;
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}
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/* generate master key from the result */
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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p, n);
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memset(p, 0, n); /* clean up */
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if (ecdh_clnt_cert) {
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/* Send empty client key exch message */
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n = 0;
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@ -2828,10 +2807,15 @@ int ssl3_send_client_key_exchange(SSL *s)
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size_t msglen;
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unsigned int md_len;
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int keytype;
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unsigned char premaster_secret[32], shared_ukm[32], tmp[256];
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unsigned char shared_ukm[32], tmp[256];
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EVP_MD_CTX *ukm_hash;
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EVP_PKEY *pub_key;
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pmslen = 32;
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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/*
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* Get server sertificate PKEY and create ctx from it
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*/
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@ -2861,7 +2845,7 @@ int ssl3_send_client_key_exchange(SSL *s)
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EVP_PKEY_encrypt_init(pkey_ctx);
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/* Generate session key */
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RAND_bytes(premaster_secret, 32);
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RAND_bytes(pms, pmslen);
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/*
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* If we have client certificate, use its secret as peer key
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*/
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@ -2901,8 +2885,7 @@ int ssl3_send_client_key_exchange(SSL *s)
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*/
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*(p++) = V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED;
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msglen = 255;
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if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, premaster_secret, 32)
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< 0) {
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if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) < 0) {
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
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SSL_R_LIBRARY_BUG);
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goto err;
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@ -2923,12 +2906,6 @@ int ssl3_send_client_key_exchange(SSL *s)
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s->s3->flags |= TLS1_FLAGS_SKIP_CERT_VERIFY;
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}
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EVP_PKEY_CTX_free(pkey_ctx);
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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premaster_secret,
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32);
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EVP_PKEY_free(pub_key);
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}
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@ -2953,15 +2930,6 @@ int ssl3_send_client_key_exchange(SSL *s)
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ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if ((s->session->master_key_length =
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SRP_generate_client_master_secret(s,
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s->session->master_key)) <
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0) {
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
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ERR_R_INTERNAL_ERROR);
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goto err;
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}
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}
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#endif
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#ifndef OPENSSL_NO_PSK
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@ -2974,8 +2942,7 @@ int ssl3_send_client_key_exchange(SSL *s)
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char identity[PSK_MAX_IDENTITY_LEN + 2];
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size_t identity_len;
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unsigned char *t = NULL;
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unsigned char psk_or_pre_ms[PSK_MAX_PSK_LEN * 2 + 4];
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unsigned int pre_ms_len = 0, psk_len = 0;
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unsigned int psk_len = 0;
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int psk_err = 1;
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n = 0;
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@ -2986,10 +2953,15 @@ int ssl3_send_client_key_exchange(SSL *s)
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}
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memset(identity, 0, sizeof(identity));
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/* Allocate maximum size buffer */
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pmslen = PSK_MAX_PSK_LEN * 2 + 4;
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pms = OPENSSL_malloc(pmslen);
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if (!pms)
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goto memerr;
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psk_len = s->psk_client_callback(s, s->ctx->psk_identity_hint,
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identity, sizeof(identity) - 1,
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psk_or_pre_ms,
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sizeof(psk_or_pre_ms));
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pms, pmslen);
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if (psk_len > PSK_MAX_PSK_LEN) {
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
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ERR_R_INTERNAL_ERROR);
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@ -2999,6 +2971,8 @@ int ssl3_send_client_key_exchange(SSL *s)
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SSL_R_PSK_IDENTITY_NOT_FOUND);
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goto psk_err;
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}
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/* Change pmslen to real length */
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pmslen = 2 + psk_len + 2 + psk_len;
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identity[PSK_MAX_IDENTITY_LEN + 1] = '\0';
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identity_len = strlen(identity);
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if (identity_len > PSK_MAX_IDENTITY_LEN) {
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@ -3007,9 +2981,8 @@ int ssl3_send_client_key_exchange(SSL *s)
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goto psk_err;
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}
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/* create PSK pre_master_secret */
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pre_ms_len = 2 + psk_len + 2 + psk_len;
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t = psk_or_pre_ms;
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memmove(psk_or_pre_ms + psk_len + 4, psk_or_pre_ms, psk_len);
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t = pms;
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memmove(pms + psk_len + 4, pms, psk_len);
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s2n(psk_len, t);
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memset(t, 0, psk_len);
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t += psk_len;
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@ -3035,19 +3008,12 @@ int ssl3_send_client_key_exchange(SSL *s)
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goto psk_err;
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}
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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psk_or_pre_ms,
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pre_ms_len);
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s2n(identity_len, p);
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memcpy(p, identity, identity_len);
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n = 2 + identity_len;
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psk_err = 0;
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psk_err:
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OPENSSL_cleanse(identity, sizeof(identity));
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OPENSSL_cleanse(psk_or_pre_ms, sizeof(psk_or_pre_ms));
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if (psk_err != 0) {
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ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
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goto err;
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@ -3065,8 +3031,60 @@ int ssl3_send_client_key_exchange(SSL *s)
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}
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/* SSL3_ST_CW_KEY_EXCH_B */
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return ssl_do_write(s);
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n = ssl_do_write(s);
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#ifndef OPENSSL_NO_SRP
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/* Check for SRP */
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if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
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/*
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* If everything written generate master key: no need to save PMS as
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* SRP_generate_client_master_secret generates it internally.
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*/
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if (n > 0) {
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if ((s->session->master_key_length =
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SRP_generate_client_master_secret(s,
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s->session->master_key)) <
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0) {
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
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ERR_R_INTERNAL_ERROR);
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goto err;
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}
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}
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} else
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#endif
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/* If we haven't written everything save PMS */
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if (n <= 0) {
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s->cert->pms = pms;
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s->cert->pmslen = pmslen;
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} else {
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/* If we don't have a PMS restore */
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if (pms == NULL) {
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pms = s->cert->pms;
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pmslen = s->cert->pmslen;
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}
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if (pms == NULL) {
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ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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s->session->master_key_length =
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s->method->ssl3_enc->generate_master_secret(s,
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s->
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session->master_key,
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pms, pmslen);
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OPENSSL_cleanse(pms, pmslen);
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OPENSSL_free(pms);
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s->cert->pms = NULL;
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}
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return n;
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memerr:
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ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
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SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
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err:
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if (pms) {
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OPENSSL_cleanse(pms, pmslen);
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OPENSSL_free(pms);
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s->cert->pms = NULL;
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}
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#ifndef OPENSSL_NO_ECDH
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BN_CTX_free(bn_ctx);
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if (encodedPoint != NULL)
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@ -476,6 +476,11 @@ void ssl_cert_free(CERT *c)
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custom_exts_free(&c->cli_ext);
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custom_exts_free(&c->srv_ext);
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#endif
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if (c->pms) {
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OPENSSL_cleanse(c->pms, c->pmslen);
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OPENSSL_free(c->pms);
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c->pms = NULL;
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}
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OPENSSL_free(c);
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}
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@ -1679,6 +1679,9 @@ typedef struct cert_st {
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*/
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unsigned char *ctypes;
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size_t ctype_num;
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/* Temporary storage for premaster secret */
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unsigned char *pms;
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size_t pmslen;
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/*
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* signature algorithms peer reports: e.g. supported signature algorithms
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* extension for server or as part of a certificate request for client.
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