Import LibreSSL v2.4.2 to vendor branch

[dragonfly.git] / crypto / libressl / ssl / s23_srvr.c

/* $OpenBSD: s23_srvr.c,v 1.46 2015/10/25 15:49:04 doug 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 <stdio.h>

#include "ssl_locl.h"

#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/objects.h>

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;
}