/* * 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 #include #include #include #include #include #include #include #include "ssl_locl.h" static const SSL_METHOD *dtls1_get_server_method(int ver); static int dtls1_send_hello_verify_request(SSL *s); static const SSL_METHOD *dtls1_get_server_method(int ver) { if (ver == DTLS1_VERSION) return(DTLSv1_server_method()); else if (ver == DTLS1_2_VERSION) return(DTLSv1_2_server_method()); else return(NULL); } IMPLEMENT_dtls1_meth_func(DTLS1_VERSION, DTLSv1_server_method, dtls1_accept, ssl_undefined_function, dtls1_get_server_method, DTLSv1_enc_data) IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION, DTLSv1_2_server_method, dtls1_accept, ssl_undefined_function, dtls1_get_server_method, DTLSv1_2_enc_data) IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION, DTLS_server_method, dtls1_accept, ssl_undefined_function, dtls1_get_server_method, DTLSv1_2_enc_data) int dtls1_accept(SSL *s) { BUF_MEM *buf; void (*cb)(const SSL *ssl,int type,int val)=NULL; unsigned long alg_a; int ret= -1; int new_state,state,skip=0; int listen; 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; 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) { 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_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)) { OPENSSL_PUT_ERROR(SSL, dtls1_accept, ERR_R_INTERNAL_ERROR); return -1; } s->type=SSL_ST_ACCEPT; if (s->init_buf == NULL) { if ((buf=BUF_MEM_new()) == NULL) { ret= -1; goto end; } if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH)) { ret= -1; goto end; } s->init_buf=buf; } 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; } ssl3_init_finished_mac(s); 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; ssl3_init_finished_mac(s); 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; /* 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 */ ssl3_init_finished_mac(s); 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 or normal PSK */ if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) { dtls1_start_timer(s); ret=ssl3_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_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->session->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; #ifndef NETSCAPE_HANG_BUG s->state=SSL3_ST_SW_SRVR_DONE_A; #else s->state=SSL3_ST_SW_FLUSH; s->s3->tmp.next_state=SSL3_ST_SR_CERT_A; #endif 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: /* Check for second client hello (MS SGC) */ ret = ssl3_check_client_hello(s); if (ret <= 0) goto end; if (ret == 2) { dtls1_stop_timer(s); s->state = SSL3_ST_SR_CLNT_HELLO_C; } else { 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; /* TODO(davidben): These two blocks are different * between SSL and DTLS. Resolve the difference and code * duplication. */ if (SSL_USE_SIGALGS(s)) { if (!s->session->peer) break; /* For sigalgs freeze the handshake buffer * at this point and digest cached records. */ if (!s->s3->handshake_buffer) { OPENSSL_PUT_ERROR(SSL, dtls1_accept, ERR_R_INTERNAL_ERROR); return -1; } s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE; if (!ssl3_digest_cached_records(s)) return -1; } else { /* 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 */ ssl3_cleanup_key_block(s); #if 0 BUF_MEM_free(s->init_buf); s->init_buf=NULL; #endif /* 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: OPENSSL_PUT_ERROR(SSL, 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 int msg_len; unsigned char *msg, *buf, *p; if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) { buf = (unsigned char *)s->init_buf->data; msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]); /* Always use DTLS 1.0 version: see RFC 6347 */ *(p++) = DTLS1_VERSION >> 8; *(p++) = DTLS1_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) { OPENSSL_PUT_ERROR(SSL, 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; msg_len = p - msg; dtls1_set_message_header(s, buf, DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len); s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B; /* number of bytes to write */ s->init_num=p-buf; s->init_off=0; } /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */ return(dtls1_do_write(s,SSL3_RT_HANDSHAKE)); }