/* $OpenBSD: s23_srvr.c,v 1.47 2016/07/16 04:42:35 beck Exp $ */ /* 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.] */ /* ==================================================================== * Copyright (c) 1998-2006 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). * */ #include #include "ssl_locl.h" #include #include #include int ssl23_get_client_hello(SSL *s); int ssl23_accept(SSL *s) { void (*cb)(const SSL *ssl, int type, int val) = NULL; int ret = -1; int new_state, state; 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; s->in_handshake++; if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); for (;;) { state = s->state; switch (s->state) { 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); /* s->version=SSL3_VERSION; */ s->type = SSL_ST_ACCEPT; if (!ssl3_setup_init_buffer(s)) { ret = -1; goto end; } if (!tls1_init_finished_mac(s)) { ret = -1; goto end; } s->state = SSL23_ST_SR_CLNT_HELLO_A; s->ctx->stats.sess_accept++; s->init_num = 0; break; case SSL23_ST_SR_CLNT_HELLO_A: case SSL23_ST_SR_CLNT_HELLO_B: s->shutdown = 0; ret = ssl23_get_client_hello(s); if (ret >= 0) cb = NULL; goto end; /* break; */ default: SSLerr(SSL_F_SSL23_ACCEPT, SSL_R_UNKNOWN_STATE); ret = -1; goto end; /* break; */ } if ((cb != NULL) && (s->state != state)) { new_state = s->state; s->state = state; cb(s, SSL_CB_ACCEPT_LOOP, 1); s->state = new_state; } } end: s->in_handshake--; if (cb != NULL) cb(s, SSL_CB_ACCEPT_EXIT, ret); return (ret); } int ssl23_get_client_hello(SSL *s) { char buf[11]; /* * sizeof(buf) == 11, because we'll need to request this many bytes in * the initial read. * We can detect SSL 3.0/TLS 1.0 Client Hellos ('type == 3') correctly * only when the following is in a single record, which is not * guaranteed by the protocol specification: * Byte Content * 0 type \ * 1/2 version > record header * 3/4 length / * 5 msg_type \ * 6-8 length > Client Hello message * 9/10 client_version / */ unsigned char *p, *d, *d_len, *dd; unsigned int i; unsigned int csl, sil, cl; int n = 0, j; int type = 0; int v[2]; if (s->state == SSL23_ST_SR_CLNT_HELLO_A) { /* read the initial header */ v[0] = v[1] = 0; if (!ssl3_setup_buffers(s)) return -1; n = ssl23_read_bytes(s, sizeof buf); if (n != sizeof buf) return(n); p = s->packet; memcpy(buf, p, n); if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) { /* * SSLv2 header */ if ((p[3] == 0x00) && (p[4] == 0x02)) { /* SSLv2 support has been removed */ goto unsupported; } else if (p[3] == SSL3_VERSION_MAJOR) { v[0] = p[3]; v[1] = p[4]; /* SSLv3/TLS */ if (p[4] >= TLS1_VERSION_MINOR) { if (p[4] >= TLS1_2_VERSION_MINOR && !(s->options & SSL_OP_NO_TLSv1_2)) { s->version = TLS1_2_VERSION; s->state = SSL23_ST_SR_CLNT_HELLO_B; } else if (p[4] >= TLS1_1_VERSION_MINOR && !(s->options & SSL_OP_NO_TLSv1_1)) { s->version = TLS1_1_VERSION; /* type=2; */ /* done later to survive restarts */ s->state = SSL23_ST_SR_CLNT_HELLO_B; } else if (!(s->options & SSL_OP_NO_TLSv1)) { s->version = TLS1_VERSION; /* type=2; */ /* done later to survive restarts */ s->state = SSL23_ST_SR_CLNT_HELLO_B; } else { goto unsupported; } } else { /* SSLv3 support has been removed */ goto unsupported; } } } else if ((p[0] == SSL3_RT_HANDSHAKE) && (p[1] == SSL3_VERSION_MAJOR) && (p[5] == SSL3_MT_CLIENT_HELLO) && ((p[3] == 0 && p[4] < 5 /* silly record length? */) || (p[9] >= p[1]))) { /* * SSLv3 or tls1 header */ v[0] = p[1]; /* major version (= SSL3_VERSION_MAJOR) */ /* We must look at client_version inside the Client Hello message * to get the correct minor version. * However if we have only a pathologically small fragment of the * Client Hello message, this would be difficult, and we'd have * to read more records to find out. * No known SSL 3.0 client fragments ClientHello like this, * so we simply reject such connections to avoid * protocol version downgrade attacks. */ if (p[3] == 0 && p[4] < 6) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_SMALL); return -1; } /* if major version number > 3 set minor to a value * which will use the highest version 3 we support. * If TLS 2.0 ever appears we will need to revise * this.... */ if (p[9] > SSL3_VERSION_MAJOR) v[1] = 0xff; else v[1] = p[10]; /* minor version according to client_version */ if (v[1] >= TLS1_VERSION_MINOR) { if (v[1] >= TLS1_2_VERSION_MINOR && !(s->options & SSL_OP_NO_TLSv1_2)) { s->version = TLS1_2_VERSION; type = 3; } else if (v[1] >= TLS1_1_VERSION_MINOR && !(s->options & SSL_OP_NO_TLSv1_1)) { s->version = TLS1_1_VERSION; type = 3; } else if (!(s->options & SSL_OP_NO_TLSv1)) { s->version = TLS1_VERSION; type = 3; } else { goto unsupported; } } else { /* SSLv3 */ if (!(s->options & SSL_OP_NO_TLSv1)) { /* we won't be able to use TLS of course, * but this will send an appropriate alert */ s->version = TLS1_VERSION; type = 3; } else { goto unsupported; } } } else if ((strncmp("GET ", (char *)p, 4) == 0) || (strncmp("POST ",(char *)p, 5) == 0) || (strncmp("HEAD ",(char *)p, 5) == 0) || (strncmp("PUT ", (char *)p, 4) == 0)) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTP_REQUEST); return -1; } else if (strncmp("CONNECT", (char *)p, 7) == 0) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTPS_PROXY_REQUEST); return -1; } } if (s->state == SSL23_ST_SR_CLNT_HELLO_B) { /* we have SSLv3/TLSv1 in an SSLv2 header * (other cases skip this state) */ /* * Limit the support of "backward compatible" headers * only to "backward" versions of TLS. If we have moved * on to modernity, just say no. */ if (s->options & SSL_OP_NO_TLSv1) goto unsupported; type = 2; p = s->packet; v[0] = p[3]; /* == SSL3_VERSION_MAJOR */ v[1] = p[4]; /* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2 * header is sent directly on the wire, not wrapped as a TLS * record. It's format is: * Byte Content * 0-1 msg_length * 2 msg_type * 3-4 version * 5-6 cipher_spec_length * 7-8 session_id_length * 9-10 challenge_length * ... ... */ n = ((p[0] & 0x7f) << 8) | p[1]; if (n > (1024 * 4)) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_LARGE); return -1; } if (n < 9) { SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_LENGTH_MISMATCH); return -1; } j = ssl23_read_bytes(s, n + 2); if (j != n + 2) return -1; tls1_finish_mac(s, s->packet + 2, s->packet_length - 2); if (s->msg_callback) s->msg_callback(0, SSL2_VERSION, 0, s->packet + 2, s->packet_length - 2, s, s->msg_callback_arg); p = s->packet; p += 5; n2s(p, csl); n2s(p, sil); n2s(p, cl); d = (unsigned char *)s->init_buf->data; if ((csl + sil + cl + 11) != s->packet_length) { /* * We can't have TLS extensions in SSL 2.0 format * Client Hello, can we ? Error condition should be * '>' otherwise */ SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_LENGTH_MISMATCH); return -1; } /* record header: msg_type ... */ *(d++) = SSL3_MT_CLIENT_HELLO; /* ... and length (actual value will be written later) */ d_len = d; d += 3; /* client_version */ *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */ *(d++) = v[1]; /* lets populate the random area */ /* get the challenge_length */ i = (cl > SSL3_RANDOM_SIZE) ? SSL3_RANDOM_SIZE : cl; memset(d, 0, SSL3_RANDOM_SIZE); memcpy(&(d[SSL3_RANDOM_SIZE - i]), &(p[csl + sil]), i); d += SSL3_RANDOM_SIZE; /* no session-id reuse */ *(d++) = 0; /* ciphers */ j = 0; dd = d; d += 2; for (i = 0; i < csl; i += 3) { if (p[i] != 0) continue; *(d++) = p[i + 1]; *(d++) = p[i + 2]; j += 2; } s2n(j, dd); /* add in (no) COMPRESSION */ *(d++) = 1; *(d++) = 0; i = (d - (unsigned char *)s->init_buf->data) - 4; l2n3((long)i, d_len); /* get the data reused from the init_buf */ s->s3->tmp.reuse_message = 1; s->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO; s->s3->tmp.message_size = i; } /* imaginary new state (for program structure): */ /* s->state = SSL23_SR_CLNT_HELLO_C */ if (type == 2 || type == 3) { /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */ if (!ssl_init_wbio_buffer(s, 1)) return -1; /* we are in this state */ s->state = SSL3_ST_SR_CLNT_HELLO_A; if (type == 3) { /* put the 'n' bytes we have read into the input buffer * for SSLv3 */ s->rstate = SSL_ST_READ_HEADER; s->packet_length = n; if (s->s3->rbuf.buf == NULL) if (!ssl3_setup_read_buffer(s)) return -1; s->packet = &(s->s3->rbuf.buf[0]); memcpy(s->packet, buf, n); s->s3->rbuf.left = n; s->s3->rbuf.offset = 0; } else { s->packet_length = 0; s->s3->rbuf.left = 0; s->s3->rbuf.offset = 0; } if (s->version == TLS1_2_VERSION) s->method = TLSv1_2_server_method(); else if (s->version == TLS1_1_VERSION) s->method = TLSv1_1_server_method(); else if (s->version == TLS1_VERSION) s->method = TLSv1_server_method(); else goto unsupported; s->handshake_func = s->method->ssl_accept; } else { /* bad, very bad */ SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL); return -1; } s->init_num = 0; return (SSL_accept(s)); unsupported: SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL); return -1; }