/* $OpenBSD: d1_srvr.c,v 1.68 2016/11/04 18:30:21 guenther Exp $ */ /* * 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 #include "ssl_locl.h" #include #include #include #include #include #include #include static const SSL_METHOD *dtls1_get_server_method(int ver); static int dtls1_send_hello_verify_request(SSL *s); static const SSL_METHOD DTLSv1_server_method_data = { .version = DTLS1_VERSION, .ssl_new = dtls1_new, .ssl_clear = dtls1_clear, .ssl_free = dtls1_free, .ssl_accept = dtls1_accept, .ssl_connect = ssl_undefined_function, .ssl_read = ssl3_read, .ssl_peek = ssl3_peek, .ssl_write = ssl3_write, .ssl_shutdown = dtls1_shutdown, .ssl_renegotiate = ssl3_renegotiate, .ssl_renegotiate_check = ssl3_renegotiate_check, .ssl_get_message = dtls1_get_message, .ssl_read_bytes = dtls1_read_bytes, .ssl_write_bytes = dtls1_write_app_data_bytes, .ssl_dispatch_alert = dtls1_dispatch_alert, .ssl_ctrl = dtls1_ctrl, .ssl_ctx_ctrl = ssl3_ctx_ctrl, .get_cipher_by_char = ssl3_get_cipher_by_char, .put_cipher_by_char = ssl3_put_cipher_by_char, .ssl_pending = ssl3_pending, .num_ciphers = ssl3_num_ciphers, .get_cipher = dtls1_get_cipher, .get_ssl_method = dtls1_get_server_method, .get_timeout = dtls1_default_timeout, .ssl3_enc = &DTLSv1_enc_data, .ssl_version = ssl_undefined_void_function, .ssl_callback_ctrl = ssl3_callback_ctrl, .ssl_ctx_callback_ctrl = ssl3_ctx_callback_ctrl, }; const SSL_METHOD * DTLSv1_server_method(void) { return &DTLSv1_server_method_data; } static const SSL_METHOD * dtls1_get_server_method(int ver) { if (ver == DTLS1_VERSION) return (DTLSv1_server_method()); return (NULL); } int dtls1_accept(SSL *s) { void (*cb)(const SSL *ssl, int type, int val) = NULL; unsigned long alg_k; int ret = -1; int new_state, state, skip = 0; int listen; ERR_clear_error(); errno = 0; if (s->info_callback != NULL) cb = s->info_callback; else if (s->ctx->info_callback != NULL) cb = s->ctx->info_callback; listen = s->d1->listen; /* init things to blank */ s->in_handshake++; if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); s->d1->listen = listen; if (s->cert == NULL) { SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET); ret = -1; goto end; } for (;;) { state = s->state; switch (s->state) { case SSL_ST_RENEGOTIATE: s->renegotiate = 1; /* s->state=SSL_ST_ACCEPT; */ case SSL_ST_BEFORE: case SSL_ST_ACCEPT: case SSL_ST_BEFORE|SSL_ST_ACCEPT: case SSL_ST_OK|SSL_ST_ACCEPT: s->server = 1; if (cb != NULL) cb(s, SSL_CB_HANDSHAKE_START, 1); if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) { SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } s->type = SSL_ST_ACCEPT; if (!ssl3_setup_init_buffer(s)) { ret = -1; goto end; } if (!ssl3_setup_buffers(s)) { ret = -1; goto end; } s->init_num = 0; if (s->state != SSL_ST_RENEGOTIATE) { /* Ok, we now need to push on a buffering BIO so that * the output is sent in a way that TCP likes :-) * ...but not with SCTP :-) */ if (!ssl_init_wbio_buffer(s, 1)) { ret = -1; goto end; } if (!tls1_init_finished_mac(s)) { 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 (!tls1_init_finished_mac(s)) { 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: 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; /* Reflect ClientHello sequence to remain stateless while listening */ if (listen) { memcpy(s->s3->write_sequence, s->s3->read_sequence, sizeof(s->s3->write_sequence)); } /* If we're just listening, stop here */ if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) { ret = 2; s->d1->listen = 0; /* Set expected sequence numbers * to continue the handshake. */ s->d1->handshake_read_seq = 2; s->d1->handshake_write_seq = 1; s->d1->next_handshake_write_seq = 1; goto end; } 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 (!tls1_init_finished_mac(s)) { 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: /* Check if it is anon DH. */ if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)) { dtls1_start_timer(s); ret = dtls1_send_server_certificate(s); if (ret <= 0) goto end; if (s->tlsext_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_k = s->s3->tmp.new_cipher->algorithm_mkey; /* Only send if using a DH key exchange. */ if (alg_k & (SSL_kDHE|SSL_kECDHE)) { 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: /* * Determine whether or not we need to request a * certificate. * * Do not request a certificate if: * * - We did not ask for it (SSL_VERIFY_PEER is unset). * * - SSL_VERIFY_CLIENT_ONCE is set and we are * renegotiating. * * - We are using an anonymous ciphersuites * (see section "Certificate request" in SSL 3 drafts * and in RFC 2246) ... except when the application * insists on verification (against the specs, but * s3_clnt.c accepts this for SSL 3). */ if (!(s->verify_mode & SSL_VERIFY_PEER) || ((s->session->peer != NULL) && (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) || ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) && !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) { /* 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; if (ret == 2) { /* For the ECDH ciphersuites when * the client sends its ECDH pub key in * a certificate, the CertificateVerify * message is not sent. */ s->state = SSL3_ST_SR_FINISHED_A; s->init_num = 0; } else if (SSL_USE_SIGALGS(s)) { s->state = SSL3_ST_SR_CERT_VRFY_A; s->init_num = 0; if (!s->session->peer) break; /* * For sigalgs freeze the handshake buffer * at this point and digest cached records. */ if (!s->s3->handshake_buffer) { SSLerr(SSL_F_SSL3_ACCEPT, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE; if (!tls1_digest_cached_records(s)) { ret = -1; goto end; } } else { s->state = SSL3_ST_SR_CERT_VRFY_A; s->init_num = 0; /* We need to get hashes here so if there is * a client cert, it can be verified */ s->method->ssl3_enc->cert_verify_mac(s, NID_md5, &(s->s3->tmp.cert_verify_md[0])); s->method->ssl3_enc->cert_verify_mac(s, NID_sha1, &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH])); } break; case SSL3_ST_SR_CERT_VRFY_A: case SSL3_ST_SR_CERT_VRFY_B: s->d1->change_cipher_spec_ok = 1; /* we should decide if we expected this one */ 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_newsession_ticket(s); if (ret <= 0) goto end; s->state = SSL3_ST_SW_CHANGE_A; s->init_num = 0; break; case SSL3_ST_SW_CERT_STATUS_A: case SSL3_ST_SW_CERT_STATUS_B: ret = ssl3_send_cert_status(s); if (ret <= 0) goto end; s->state = SSL3_ST_SW_KEY_EXCH_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->method->ssl3_enc->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->method->ssl3_enc->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->method->ssl3_enc->server_finished_label, s->method->ssl3_enc->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: /* clean a few things up */ tls1_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++; /* s->server=1; */ s->handshake_func = dtls1_accept; 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; /* break; */ default: SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE); ret = -1; goto end; /* break; */ } if (!s->s3->tmp.reuse_message && !skip) { if (s->debug) { if ((ret = BIO_flush(s->wbio)) <= 0) goto end; } 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: /* BIO_flush(s->wbio); */ s->in_handshake--; if (cb != NULL) cb(s, SSL_CB_ACCEPT_EXIT, ret); return (ret); } int dtls1_send_hello_verify_request(SSL *s) { unsigned char *d, *p; if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) { d = p = ssl3_handshake_msg_start(s, DTLS1_MT_HELLO_VERIFY_REQUEST); *(p++) = s->version >> 8; *(p++) = s->version & 0xFF; if (s->ctx->app_gen_cookie_cb == NULL || s->ctx->app_gen_cookie_cb(s, s->d1->cookie, &(s->d1->cookie_len)) == 0) { SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST, ERR_R_INTERNAL_ERROR); return 0; } *(p++) = (unsigned char) s->d1->cookie_len; memcpy(p, s->d1->cookie, s->d1->cookie_len); p += s->d1->cookie_len; ssl3_handshake_msg_finish(s, p - d); s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B; } /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */ return (ssl3_handshake_write(s)); } int dtls1_send_server_certificate(SSL *s) { unsigned long l; X509 *x; if (s->state == SSL3_ST_SW_CERT_A) { x = ssl_get_server_send_cert(s); if (x == NULL) { SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR); return (0); } l = dtls1_output_cert_chain(s, x); s->state = SSL3_ST_SW_CERT_B; s->init_num = (int)l; s->init_off = 0; /* buffer the message to handle re-xmits */ dtls1_buffer_message(s, 0); } /* SSL3_ST_SW_CERT_B */ return (dtls1_do_write(s, SSL3_RT_HANDSHAKE)); }