| /* |
| * DTLS implementation written by Nagendra Modadugu |
| * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. |
| */ |
| /* ==================================================================== |
| * Copyright (c) 1999-2007 The OpenSSL Project. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. All advertising materials mentioning features or use of this |
| * software must display the following acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" |
| * |
| * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| * endorse or promote products derived from this software without |
| * prior written permission. For written permission, please contact |
| * openssl-core@OpenSSL.org. |
| * |
| * 5. Products derived from this software may not be called "OpenSSL" |
| * nor may "OpenSSL" appear in their names without prior written |
| * permission of the OpenSSL Project. |
| * |
| * 6. Redistributions of any form whatsoever must retain the following |
| * acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This product includes cryptographic software written by Eric Young |
| * (eay@cryptsoft.com). This product includes software written by Tim |
| * Hudson (tjh@cryptsoft.com). |
| * |
| */ |
| /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| * All rights reserved. |
| * |
| * This package is an SSL implementation written |
| * by Eric Young (eay@cryptsoft.com). |
| * The implementation was written so as to conform with Netscapes SSL. |
| * |
| * This library is free for commercial and non-commercial use as long as |
| * the following conditions are aheared to. The following conditions |
| * apply to all code found in this distribution, be it the RC4, RSA, |
| * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| * included with this distribution is covered by the same copyright terms |
| * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| * |
| * Copyright remains Eric Young's, and as such any Copyright notices in |
| * the code are not to be removed. |
| * If this package is used in a product, Eric Young should be given attribution |
| * as the author of the parts of the library used. |
| * This can be in the form of a textual message at program startup or |
| * in documentation (online or textual) provided with the package. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * "This product includes cryptographic software written by |
| * Eric Young (eay@cryptsoft.com)" |
| * The word 'cryptographic' can be left out if the rouines from the library |
| * being used are not cryptographic related :-). |
| * 4. If you include any Windows specific code (or a derivative thereof) from |
| * the apps directory (application code) you must include an acknowledgement: |
| * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| * The licence and distribution terms for any publically available version or |
| * derivative of this code cannot be changed. i.e. this code cannot simply be |
| * copied and put under another distribution licence |
| * [including the GNU Public Licence.] |
| */ |
| |
| #include <assert.h> |
| #include <stdio.h> |
| |
| #include <openssl/bn.h> |
| #include <openssl/buf.h> |
| #include <openssl/dh.h> |
| #include <openssl/evp.h> |
| #include <openssl/md5.h> |
| #include <openssl/obj.h> |
| #include <openssl/rand.h> |
| #include <openssl/x509.h> |
| |
| #include "ssl_locl.h" |
| |
| |
| static int dtls1_send_hello_verify_request(SSL *s); |
| |
| int dtls1_accept(SSL *s) { |
| BUF_MEM *buf = NULL; |
| void (*cb)(const SSL *ssl, int type, int val) = NULL; |
| unsigned long alg_a; |
| int ret = -1; |
| int new_state, state, skip = 0; |
| |
| assert(s->handshake_func == dtls1_accept); |
| assert(s->server); |
| assert(SSL_IS_DTLS(s)); |
| |
| ERR_clear_error(); |
| ERR_clear_system_error(); |
| |
| if (s->info_callback != NULL) { |
| cb = s->info_callback; |
| } else if (s->ctx->info_callback != NULL) { |
| cb = s->ctx->info_callback; |
| } |
| |
| s->in_handshake++; |
| |
| if (s->cert == NULL) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_accept, SSL_R_NO_CERTIFICATE_SET); |
| return -1; |
| } |
| |
| for (;;) { |
| state = s->state; |
| |
| switch (s->state) { |
| case SSL_ST_RENEGOTIATE: |
| s->renegotiate = 1; |
| /* s->state=SSL_ST_ACCEPT; */ |
| |
| case SSL_ST_ACCEPT: |
| case SSL_ST_BEFORE | SSL_ST_ACCEPT: |
| if (cb != NULL) { |
| cb(s, SSL_CB_HANDSHAKE_START, 1); |
| } |
| |
| if (s->init_buf == NULL) { |
| buf = BUF_MEM_new(); |
| if (buf == NULL || !BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) { |
| ret = -1; |
| goto end; |
| } |
| s->init_buf = buf; |
| buf = NULL; |
| } |
| |
| if (!ssl3_setup_buffers(s)) { |
| ret = -1; |
| goto end; |
| } |
| |
| s->init_num = 0; |
| |
| if (s->state != SSL_ST_RENEGOTIATE) { |
| if (!ssl_init_wbio_buffer(s, 1)) { |
| ret = -1; |
| goto end; |
| } |
| |
| if (!ssl3_init_finished_mac(s)) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_accept, ERR_R_INTERNAL_ERROR); |
| ret = -1; |
| goto end; |
| } |
| |
| s->state = SSL3_ST_SR_CLNT_HELLO_A; |
| s->ctx->stats.sess_accept++; |
| } else { |
| /* s->state == SSL_ST_RENEGOTIATE, * we will just send a |
| * HelloRequest */ |
| s->ctx->stats.sess_accept_renegotiate++; |
| s->state = SSL3_ST_SW_HELLO_REQ_A; |
| } |
| |
| break; |
| |
| case SSL3_ST_SW_HELLO_REQ_A: |
| case SSL3_ST_SW_HELLO_REQ_B: |
| s->shutdown = 0; |
| dtls1_clear_record_buffer(s); |
| dtls1_start_timer(s); |
| ret = ssl3_send_hello_request(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A; |
| s->state = SSL3_ST_SW_FLUSH; |
| s->init_num = 0; |
| |
| if (!ssl3_init_finished_mac(s)) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_accept, ERR_R_INTERNAL_ERROR); |
| ret = -1; |
| goto end; |
| } |
| break; |
| |
| case SSL3_ST_SW_HELLO_REQ_C: |
| s->state = SSL_ST_OK; |
| break; |
| |
| case SSL3_ST_SR_CLNT_HELLO_A: |
| case SSL3_ST_SR_CLNT_HELLO_B: |
| case SSL3_ST_SR_CLNT_HELLO_C: |
| case SSL3_ST_SR_CLNT_HELLO_D: |
| s->shutdown = 0; |
| ret = ssl3_get_client_hello(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| dtls1_stop_timer(s); |
| |
| if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE)) { |
| s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A; |
| } else { |
| s->state = SSL3_ST_SW_SRVR_HELLO_A; |
| } |
| |
| s->init_num = 0; |
| break; |
| |
| case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A: |
| case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B: |
| ret = dtls1_send_hello_verify_request(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SW_FLUSH; |
| s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A; |
| |
| /* HelloVerifyRequest resets Finished MAC */ |
| if (!ssl3_init_finished_mac(s)) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_accept, ERR_R_INTERNAL_ERROR); |
| ret = -1; |
| goto end; |
| } |
| break; |
| |
| case SSL3_ST_SW_SRVR_HELLO_A: |
| case SSL3_ST_SW_SRVR_HELLO_B: |
| s->renegotiate = 2; |
| dtls1_start_timer(s); |
| ret = ssl3_send_server_hello(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| |
| if (s->hit) { |
| if (s->tlsext_ticket_expected) { |
| s->state = SSL3_ST_SW_SESSION_TICKET_A; |
| } else { |
| s->state = SSL3_ST_SW_CHANGE_A; |
| } |
| } else { |
| s->state = SSL3_ST_SW_CERT_A; |
| } |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_CERT_A: |
| case SSL3_ST_SW_CERT_B: |
| if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher)) { |
| dtls1_start_timer(s); |
| ret = ssl3_send_server_certificate(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| if (s->s3->tmp.certificate_status_expected) { |
| s->state = SSL3_ST_SW_CERT_STATUS_A; |
| } else { |
| s->state = SSL3_ST_SW_KEY_EXCH_A; |
| } |
| } else { |
| skip = 1; |
| s->state = SSL3_ST_SW_KEY_EXCH_A; |
| } |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_KEY_EXCH_A: |
| case SSL3_ST_SW_KEY_EXCH_B: |
| alg_a = s->s3->tmp.new_cipher->algorithm_auth; |
| |
| /* Send a ServerKeyExchange message if: |
| * - The key exchange is ephemeral or anonymous |
| * Diffie-Hellman. |
| * - There is a PSK identity hint. |
| * |
| * TODO(davidben): This logic is currently duplicated |
| * in s3_srvr.c. Fix this. In the meantime, keep them |
| * in sync. */ |
| if (ssl_cipher_requires_server_key_exchange(s->s3->tmp.new_cipher) || |
| ((alg_a & SSL_aPSK) && s->psk_identity_hint)) { |
| dtls1_start_timer(s); |
| ret = ssl3_send_server_key_exchange(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| } else { |
| skip = 1; |
| } |
| |
| s->state = SSL3_ST_SW_CERT_REQ_A; |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_CERT_REQ_A: |
| case SSL3_ST_SW_CERT_REQ_B: |
| if (/* don't request cert unless asked for it: */ |
| !(s->verify_mode & SSL_VERIFY_PEER) || |
| /* if SSL_VERIFY_CLIENT_ONCE is set, |
| * don't request cert during re-negotiation: */ |
| ((s->session->peer != NULL) && |
| (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) || |
| /* never request cert in anonymous ciphersuites |
| * (see section "Certificate request" in SSL 3 drafts |
| * and in RFC 2246): */ |
| ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) && |
| /* ... except when the application insists on verification |
| * (against the specs, but s3_clnt.c accepts this for SSL 3) */ |
| !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) || |
| /* With normal PSK Certificates and |
| * Certificate Requests are omitted */ |
| (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) { |
| /* no cert request */ |
| skip = 1; |
| s->s3->tmp.cert_request = 0; |
| s->state = SSL3_ST_SW_SRVR_DONE_A; |
| } else { |
| s->s3->tmp.cert_request = 1; |
| dtls1_start_timer(s); |
| ret = ssl3_send_certificate_request(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SW_SRVR_DONE_A; |
| s->init_num = 0; |
| } |
| break; |
| |
| case SSL3_ST_SW_SRVR_DONE_A: |
| case SSL3_ST_SW_SRVR_DONE_B: |
| dtls1_start_timer(s); |
| ret = ssl3_send_server_done(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->s3->tmp.next_state = SSL3_ST_SR_CERT_A; |
| s->state = SSL3_ST_SW_FLUSH; |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_FLUSH: |
| s->rwstate = SSL_WRITING; |
| if (BIO_flush(s->wbio) <= 0) { |
| /* If the write error was fatal, stop trying */ |
| if (!BIO_should_retry(s->wbio)) { |
| s->rwstate = SSL_NOTHING; |
| s->state = s->s3->tmp.next_state; |
| } |
| |
| ret = -1; |
| goto end; |
| } |
| s->rwstate = SSL_NOTHING; |
| s->state = s->s3->tmp.next_state; |
| break; |
| |
| case SSL3_ST_SR_CERT_A: |
| case SSL3_ST_SR_CERT_B: |
| if (s->s3->tmp.cert_request) { |
| ret = ssl3_get_client_certificate(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| } |
| s->init_num = 0; |
| s->state = SSL3_ST_SR_KEY_EXCH_A; |
| break; |
| |
| case SSL3_ST_SR_KEY_EXCH_A: |
| case SSL3_ST_SR_KEY_EXCH_B: |
| ret = ssl3_get_client_key_exchange(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SR_CERT_VRFY_A; |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SR_CERT_VRFY_A: |
| case SSL3_ST_SR_CERT_VRFY_B: |
| ret = ssl3_get_cert_verify(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SR_FINISHED_A; |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SR_FINISHED_A: |
| case SSL3_ST_SR_FINISHED_B: |
| s->d1->change_cipher_spec_ok = 1; |
| ret = |
| ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A, SSL3_ST_SR_FINISHED_B); |
| if (ret <= 0) { |
| goto end; |
| } |
| dtls1_stop_timer(s); |
| if (s->hit) { |
| s->state = SSL_ST_OK; |
| } else if (s->tlsext_ticket_expected) { |
| s->state = SSL3_ST_SW_SESSION_TICKET_A; |
| } else { |
| s->state = SSL3_ST_SW_CHANGE_A; |
| } |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_SESSION_TICKET_A: |
| case SSL3_ST_SW_SESSION_TICKET_B: |
| ret = ssl3_send_new_session_ticket(s); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SW_CHANGE_A; |
| s->init_num = 0; |
| break; |
| |
| case SSL3_ST_SW_CHANGE_A: |
| case SSL3_ST_SW_CHANGE_B: |
| s->session->cipher = s->s3->tmp.new_cipher; |
| if (!s->enc_method->setup_key_block(s)) { |
| ret = -1; |
| goto end; |
| } |
| |
| ret = dtls1_send_change_cipher_spec(s, SSL3_ST_SW_CHANGE_A, |
| SSL3_ST_SW_CHANGE_B); |
| |
| if (ret <= 0) { |
| goto end; |
| } |
| |
| s->state = SSL3_ST_SW_FINISHED_A; |
| s->init_num = 0; |
| |
| if (!s->enc_method->change_cipher_state( |
| s, SSL3_CHANGE_CIPHER_SERVER_WRITE)) { |
| ret = -1; |
| goto end; |
| } |
| |
| dtls1_reset_seq_numbers(s, SSL3_CC_WRITE); |
| break; |
| |
| case SSL3_ST_SW_FINISHED_A: |
| case SSL3_ST_SW_FINISHED_B: |
| ret = |
| ssl3_send_finished(s, SSL3_ST_SW_FINISHED_A, SSL3_ST_SW_FINISHED_B, |
| s->enc_method->server_finished_label, |
| s->enc_method->server_finished_label_len); |
| if (ret <= 0) { |
| goto end; |
| } |
| s->state = SSL3_ST_SW_FLUSH; |
| if (s->hit) { |
| s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A; |
| } else { |
| s->s3->tmp.next_state = SSL_ST_OK; |
| } |
| s->init_num = 0; |
| break; |
| |
| case SSL_ST_OK: |
| ssl3_cleanup_key_block(s); |
| |
| /* remove buffering on output */ |
| ssl_free_wbio_buffer(s); |
| |
| s->init_num = 0; |
| |
| if (s->renegotiate == 2) { |
| /* skipped if we just sent a HelloRequest */ |
| s->renegotiate = 0; |
| s->new_session = 0; |
| |
| ssl_update_cache(s, SSL_SESS_CACHE_SERVER); |
| |
| s->ctx->stats.sess_accept_good++; |
| |
| if (cb != NULL) { |
| cb(s, SSL_CB_HANDSHAKE_DONE, 1); |
| } |
| } |
| |
| ret = 1; |
| |
| /* done handshaking, next message is client hello */ |
| s->d1->handshake_read_seq = 0; |
| /* next message is server hello */ |
| s->d1->handshake_write_seq = 0; |
| s->d1->next_handshake_write_seq = 0; |
| goto end; |
| |
| default: |
| OPENSSL_PUT_ERROR(SSL, dtls1_accept, SSL_R_UNKNOWN_STATE); |
| ret = -1; |
| goto end; |
| } |
| |
| if (!s->s3->tmp.reuse_message && !skip) { |
| if (cb != NULL && s->state != state) { |
| new_state = s->state; |
| s->state = state; |
| cb(s, SSL_CB_ACCEPT_LOOP, 1); |
| s->state = new_state; |
| } |
| } |
| skip = 0; |
| } |
| |
| end: |
| s->in_handshake--; |
| if (buf != NULL) { |
| BUF_MEM_free(buf); |
| } |
| if (cb != NULL) { |
| cb(s, SSL_CB_ACCEPT_EXIT, ret); |
| } |
| return ret; |
| } |
| |
| int dtls1_send_hello_verify_request(SSL *s) { |
| uint8_t *msg, *p; |
| |
| if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) { |
| msg = p = ssl_handshake_start(s); |
| /* Always use DTLS 1.0 version: see RFC 6347 */ |
| *(p++) = DTLS1_VERSION >> 8; |
| *(p++) = DTLS1_VERSION & 0xFF; |
| |
| /* Inform the callback how much space is in the |
| * cookie's buffer. */ |
| s->d1->cookie_len = sizeof(s->d1->cookie); |
| |
| if (s->ctx->app_gen_cookie_cb == NULL || |
| s->ctx->app_gen_cookie_cb(s, s->d1->cookie, &(s->d1->cookie_len)) == |
| 0) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_send_hello_verify_request, |
| ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| *(p++) = (uint8_t)s->d1->cookie_len; |
| memcpy(p, s->d1->cookie, s->d1->cookie_len); |
| p += s->d1->cookie_len; |
| |
| ssl_set_handshake_header(s, DTLS1_MT_HELLO_VERIFY_REQUEST, p - msg); |
| s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B; |
| } |
| |
| /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */ |
| return ssl_do_write(s); |
| } |
