/* $OpenBSD: d1_srvr.c,v 1.88 2017/05/07 04:22:24 beck 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 int dtls1_send_hello_verify_request(SSL *s); static const SSL_METHOD_INTERNAL DTLSv1_server_method_internal_data = { .version = DTLS1_VERSION, .min_version = DTLS1_VERSION, .max_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_pending = ssl3_pending, .get_ssl_method = dtls1_get_server_method, .get_timeout = dtls1_default_timeout, .ssl_version = ssl_undefined_void_function, .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, .ssl3_enc = &DTLSv1_enc_data, }; static const SSL_METHOD DTLSv1_server_method_data = { .ssl_dispatch_alert = dtls1_dispatch_alert, .num_ciphers = ssl3_num_ciphers, .get_cipher = dtls1_get_cipher, .get_cipher_by_char = ssl3_get_cipher_by_char, .put_cipher_by_char = ssl3_put_cipher_by_char, .internal = &DTLSv1_server_method_internal_data, }; const SSL_METHOD * DTLSv1_server_method(void) { return &DTLSv1_server_method_data; } 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->internal->info_callback != NULL) cb = s->internal->info_callback; else if (s->ctx->internal->info_callback != NULL) cb = s->ctx->internal->info_callback; listen = D1I(s)->listen; /* init things to blank */ s->internal->in_handshake++; if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); D1I(s)->listen = listen; if (s->cert == NULL) { SSLerror(s, SSL_R_NO_CERTIFICATE_SET); ret = -1; goto end; } for (;;) { state = S3I(s)->hs.state; switch (S3I(s)->hs.state) { case SSL_ST_RENEGOTIATE: s->internal->renegotiate = 1; /* S3I(s)->hs.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)) { SSLerror(s, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } s->internal->type = SSL_ST_ACCEPT; if (!ssl3_setup_init_buffer(s)) { ret = -1; goto end; } if (!ssl3_setup_buffers(s)) { ret = -1; goto end; } s->internal->init_num = 0; if (S3I(s)->hs.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; } S3I(s)->hs.state = SSL3_ST_SR_CLNT_HELLO_A; s->ctx->internal->stats.sess_accept++; } else { /* S3I(s)->hs.state == SSL_ST_RENEGOTIATE, * we will just send a HelloRequest */ s->ctx->internal->stats.sess_accept_renegotiate++; S3I(s)->hs.state = SSL3_ST_SW_HELLO_REQ_A; } break; case SSL3_ST_SW_HELLO_REQ_A: case SSL3_ST_SW_HELLO_REQ_B: s->internal->shutdown = 0; dtls1_clear_record_buffer(s); dtls1_start_timer(s); ret = ssl3_send_hello_request(s); if (ret <= 0) goto end; S3I(s)->hs.next_state = SSL3_ST_SR_CLNT_HELLO_A; S3I(s)->hs.state = SSL3_ST_SW_FLUSH; s->internal->init_num = 0; if (!tls1_init_finished_mac(s)) { ret = -1; goto end; } break; case SSL3_ST_SW_HELLO_REQ_C: S3I(s)->hs.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->internal->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)) S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A; else S3I(s)->hs.state = SSL3_ST_SW_SRVR_HELLO_A; s->internal->init_num = 0; /* Reflect ClientHello sequence to remain stateless while listening */ if (listen) { memcpy(S3I(s)->write_sequence, S3I(s)->read_sequence, sizeof(S3I(s)->write_sequence)); } /* If we're just listening, stop here */ if (listen && S3I(s)->hs.state == SSL3_ST_SW_SRVR_HELLO_A) { ret = 2; D1I(s)->listen = 0; /* Set expected sequence numbers * to continue the handshake. */ D1I(s)->handshake_read_seq = 2; D1I(s)->handshake_write_seq = 1; D1I(s)->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; S3I(s)->hs.state = SSL3_ST_SW_FLUSH; S3I(s)->hs.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->internal->renegotiate = 2; dtls1_start_timer(s); ret = ssl3_send_server_hello(s); if (ret <= 0) goto end; if (s->internal->hit) { if (s->internal->tlsext_ticket_expected) S3I(s)->hs.state = SSL3_ST_SW_SESSION_TICKET_A; else S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A; } else S3I(s)->hs.state = SSL3_ST_SW_CERT_A; s->internal->init_num = 0; break; case SSL3_ST_SW_CERT_A: case SSL3_ST_SW_CERT_B: /* Check if it is anon DH. */ if (!(S3I(s)->hs.new_cipher->algorithm_auth & SSL_aNULL)) { dtls1_start_timer(s); ret = ssl3_send_server_certificate(s); if (ret <= 0) goto end; if (s->internal->tlsext_status_expected) S3I(s)->hs.state = SSL3_ST_SW_CERT_STATUS_A; else S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A; } else { skip = 1; S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A; } s->internal->init_num = 0; break; case SSL3_ST_SW_KEY_EXCH_A: case SSL3_ST_SW_KEY_EXCH_B: alg_k = S3I(s)->hs.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; S3I(s)->hs.state = SSL3_ST_SW_CERT_REQ_A; s->internal->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)) || ((S3I(s)->hs.new_cipher->algorithm_auth & SSL_aNULL) && !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) { /* no cert request */ skip = 1; S3I(s)->tmp.cert_request = 0; S3I(s)->hs.state = SSL3_ST_SW_SRVR_DONE_A; } else { S3I(s)->tmp.cert_request = 1; dtls1_start_timer(s); ret = ssl3_send_certificate_request(s); if (ret <= 0) goto end; S3I(s)->hs.state = SSL3_ST_SW_SRVR_DONE_A; s->internal->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; S3I(s)->hs.next_state = SSL3_ST_SR_CERT_A; S3I(s)->hs.state = SSL3_ST_SW_FLUSH; s->internal->init_num = 0; break; case SSL3_ST_SW_FLUSH: s->internal->rwstate = SSL_WRITING; if (BIO_flush(s->wbio) <= 0) { /* If the write error was fatal, stop trying */ if (!BIO_should_retry(s->wbio)) { s->internal->rwstate = SSL_NOTHING; S3I(s)->hs.state = S3I(s)->hs.next_state; } ret = -1; goto end; } s->internal->rwstate = SSL_NOTHING; S3I(s)->hs.state = S3I(s)->hs.next_state; break; case SSL3_ST_SR_CERT_A: case SSL3_ST_SR_CERT_B: if (S3I(s)->tmp.cert_request) { ret = ssl3_get_client_certificate(s); if (ret <= 0) goto end; } s->internal->init_num = 0; S3I(s)->hs.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; S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A; s->internal->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. */ S3I(s)->hs.state = SSL3_ST_SR_FINISHED_A; s->internal->init_num = 0; } else if (SSL_USE_SIGALGS(s)) { S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A; s->internal->init_num = 0; if (!s->session->peer) break; /* * For sigalgs freeze the handshake buffer * at this point and digest cached records. */ if (!S3I(s)->handshake_buffer) { SSLerror(s, 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 { S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A; s->internal->init_num = 0; /* * We need to get hashes here so if there is * a client cert, it can be verified. */ if (S3I(s)->handshake_buffer) { if (!tls1_digest_cached_records(s)) { ret = -1; goto end; } } if (!tls1_handshake_hash_value(s, S3I(s)->tmp.cert_verify_md, sizeof(S3I(s)->tmp.cert_verify_md), NULL)) { ret = -1; goto end; } } break; case SSL3_ST_SR_CERT_VRFY_A: case SSL3_ST_SR_CERT_VRFY_B: D1I(s)->change_cipher_spec_ok = 1; /* we should decide if we expected this one */ ret = ssl3_get_cert_verify(s); if (ret <= 0) goto end; S3I(s)->hs.state = SSL3_ST_SR_FINISHED_A; s->internal->init_num = 0; break; case SSL3_ST_SR_FINISHED_A: case SSL3_ST_SR_FINISHED_B: D1I(s)->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->internal->hit) S3I(s)->hs.state = SSL_ST_OK; else if (s->internal->tlsext_ticket_expected) S3I(s)->hs.state = SSL3_ST_SW_SESSION_TICKET_A; else S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A; s->internal->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; S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A; s->internal->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; S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A; s->internal->init_num = 0; break; case SSL3_ST_SW_CHANGE_A: case SSL3_ST_SW_CHANGE_B: s->session->cipher = S3I(s)->hs.new_cipher; if (!tls1_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; S3I(s)->hs.state = SSL3_ST_SW_FINISHED_A; s->internal->init_num = 0; if (!tls1_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, TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE); if (ret <= 0) goto end; S3I(s)->hs.state = SSL3_ST_SW_FLUSH; if (s->internal->hit) { S3I(s)->hs.next_state = SSL3_ST_SR_FINISHED_A; } else { S3I(s)->hs.next_state = SSL_ST_OK; } s->internal->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->internal->init_num = 0; if (s->internal->renegotiate == 2) /* skipped if we just sent a HelloRequest */ { s->internal->renegotiate = 0; s->internal->new_session = 0; ssl_update_cache(s, SSL_SESS_CACHE_SERVER); s->ctx->internal->stats.sess_accept_good++; /* s->server=1; */ s->internal->handshake_func = dtls1_accept; if (cb != NULL) cb(s, SSL_CB_HANDSHAKE_DONE, 1); } ret = 1; /* done handshaking, next message is client hello */ D1I(s)->handshake_read_seq = 0; /* next message is server hello */ D1I(s)->handshake_write_seq = 0; D1I(s)->next_handshake_write_seq = 0; goto end; /* break; */ default: SSLerror(s, SSL_R_UNKNOWN_STATE); ret = -1; goto end; /* break; */ } if (!S3I(s)->tmp.reuse_message && !skip) { if (s->internal->debug) { if ((ret = BIO_flush(s->wbio)) <= 0) goto end; } if ((cb != NULL) && (S3I(s)->hs.state != state)) { new_state = S3I(s)->hs.state; S3I(s)->hs.state = state; cb(s, SSL_CB_ACCEPT_LOOP, 1); S3I(s)->hs.state = new_state; } } skip = 0; } end: /* BIO_flush(s->wbio); */ s->internal->in_handshake--; if (cb != NULL) cb(s, SSL_CB_ACCEPT_EXIT, ret); return (ret); } int dtls1_send_hello_verify_request(SSL *s) { CBB cbb, verify, cookie; memset(&cbb, 0, sizeof(cbb)); if (S3I(s)->hs.state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) { if (s->ctx->internal->app_gen_cookie_cb == NULL || s->ctx->internal->app_gen_cookie_cb(s, D1I(s)->cookie, &(D1I(s)->cookie_len)) == 0) { SSLerror(s, ERR_R_INTERNAL_ERROR); return 0; } if (!ssl3_handshake_msg_start_cbb(s, &cbb, &verify, DTLS1_MT_HELLO_VERIFY_REQUEST)) goto err; if (!CBB_add_u16(&verify, s->version)) goto err; if (!CBB_add_u8_length_prefixed(&verify, &cookie)) goto err; if (!CBB_add_bytes(&cookie, D1I(s)->cookie, D1I(s)->cookie_len)) goto err; if (!ssl3_handshake_msg_finish_cbb(s, &cbb)) goto err; S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B; } /* S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */ return (ssl3_handshake_write(s)); err: CBB_cleanup(&cbb); return (-1); }