/* ssl/s23_srvr.c */

/* 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/rand.h>

#include <openssl/objects.h>

#include <openssl/evp.h>

#ifdef OPENSSL_FIPS

# include <openssl/fips.h>

#endif

static const SSL_METHOD *ssl23_get_server_method(int ver);

int ssl23_get_client_hello(SSL *s);

static const SSL_METHOD *ssl23_get_server_method(int ver)

{

#ifndef OPENSSL_NO_SSL2

    if (ver == SSL2_VERSION)

        return (SSLv2_server_method());

#endif

#ifndef OPENSSL_NO_SSL3

    if (ver == SSL3_VERSION)

        return (SSLv3_server_method());

#endif

    if (ver == TLS1_VERSION)

        return (TLSv1_server_method());

    else if (ver == TLS1_1_VERSION)

        return (TLSv1_1_server_method());

    else if (ver == TLS1_2_VERSION)

        return (TLSv1_2_server_method());

    else

        return (NULL);

}

IMPLEMENT_ssl23_meth_func(SSLv23_server_method,

                          ssl23_accept,

                          ssl_undefined_function, ssl23_get_server_method)

int ssl23_accept(SSL *s)

{

    BUF_MEM *buf;

    unsigned long Time = (unsigned long)time(NULL);

    void (*cb) (const SSL *ssl, int type, int val) = NULL;

    int ret = -1;

    int new_state, state;

    RAND_add(&Time, sizeof(Time), 0);

    ERR_clear_error();

    clear_sys_error();

    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 (s->init_buf == NULL) {

                if ((buf = BUF_MEM_new()) == NULL) {

                    ret = -1;

                    goto end;

                }

                if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {

                    BUF_MEM_free(buf);

                    ret = -1;

                    goto end;

                }

                s->init_buf = buf;

            }

            if (!ssl3_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)

{

    /*-

     * Request this many bytes in 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  /

     */

    char buf_space[11];

    char *buf = &(buf_space[0]);

    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))

            goto err;

        n = ssl23_read_bytes(s, sizeof buf_space);

        if (n != sizeof buf_space)

            return (n);         /* n == -1 || n == 0 */

        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)) {

                v[0] = p[3];

                v[1] = p[4];

                /* SSLv2 */

                if (!(s->options & SSL_OP_NO_SSLv2))

                    type = 1;

            } else if (p[3] == SSL3_VERSION_MAJOR) {

                v[0] = p[3];

                v[1] = p[4];

                /* SSLv3/TLSv1 */

                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 if (!(s->options & SSL_OP_NO_SSLv3)) {

                        s->version = SSL3_VERSION;

                        /* type=2; */

                        s->state = SSL23_ST_SR_CLNT_HELLO_B;

                    } else if (!(s->options & SSL_OP_NO_SSLv2)) {

                        type = 1;

                    }

                } else if (!(s->options & SSL_OP_NO_SSLv3)) {

                    s->version = SSL3_VERSION;

                    /* type=2; */

                    s->state = SSL23_ST_SR_CLNT_HELLO_B;

                } else if (!(s->options & SSL_OP_NO_SSLv2))

                    type = 1;

            }

        }

        /* p[4] < 5 ... silly record length? */

        else if ((p[0] == SSL3_RT_HANDSHAKE) &&

                 (p[1] == SSL3_VERSION_MAJOR) &&

                 (p[5] == SSL3_MT_CLIENT_HELLO) && ((p[3] == 0 && p[4] < 5)

                                                    || (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);

                goto err;

            }

            /*

             * 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 if (!(s->options & SSL_OP_NO_SSLv3)) {

                    s->version = SSL3_VERSION;

                    type = 3;

                }

            } else {

                /* client requests SSL 3.0 */

                if (!(s->options & SSL_OP_NO_SSLv3)) {

                    s->version = SSL3_VERSION;

                    type = 3;

                } else 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 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);

            goto err;

        } else if (strncmp("CONNECT", (char *)p, 7) == 0) {

            SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTPS_PROXY_REQUEST);

            goto err;

        }

    }

    /* ensure that TLS_MAX_VERSION is up-to-date */

    OPENSSL_assert(s->version <= TLS_MAX_VERSION);

    if (s->version < TLS1_2_VERSION && tls1_suiteb(s)) {

        SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,

               SSL_R_ONLY_TLS_1_2_ALLOWED_IN_SUITEB_MODE);

        goto err;

    }

#ifdef OPENSSL_FIPS

    if (FIPS_mode() && (s->version < TLS1_VERSION)) {

        SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,

               SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);

        goto err;

    }

#endif

    if (s->state == SSL23_ST_SR_CLNT_HELLO_B) {

        /*

         * we have SSLv3/TLSv1 in an SSLv2 header (other cases skip this

         * state)

         */

        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);

            goto err;

        }

        if (n < 9) {

            SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,

                   SSL_R_RECORD_LENGTH_MISMATCH);

            goto err;

        }

        j = ssl23_read_bytes(s, n + 2);

        /*

         * We previously read 11 bytes, so if j > 0, we must have j == n+2 ==

         * s->packet_length. We have at least 11 valid packet bytes.

         */

        if (j <= 0)

            return (j);

        ssl3_finish_mac(s, s->packet + 2, s->packet_length - 2);

        /* CLIENT-HELLO */

        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 * '>'

                                                          * otherweise */

            SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,

                   SSL_R_RECORD_LENGTH_MISMATCH);

            goto err;

        }

        /* 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);

        /* COMPRESSION */

        *(d++) = 1;

        *(d++) = 0;

#if 0

        /* copy any remaining data with may be extensions */

        p = p + csl + sil + cl;

        while (p < s->packet + s->packet_length) {

            *(d++) = *(p++);

        }

#endif

        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 == 1) {

#ifdef OPENSSL_NO_SSL2

        SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);

        goto err;

#else

        /* we are talking sslv2 */

        /*

         * we need to clean up the SSLv3/TLSv1 setup and put in the sslv2

         * stuff.

         */

        if (s->s2 == NULL) {

            if (!ssl2_new(s))

                goto err;

        } else

            ssl2_clear(s);

        if (s->s3 != NULL)

            ssl3_free(s);

        if (!BUF_MEM_grow_clean(s->init_buf,

                                SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) {

            goto err;

        }

        s->state = SSL2_ST_GET_CLIENT_HELLO_A;

        if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)

            s->s2->ssl2_rollback = 0;

        else

            /*

             * reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0

             * (SSL 3.0 draft/RFC 2246, App. E.2)

             */

            s->s2->ssl2_rollback = 1;

        /*

         * setup the n bytes we have read so we get them from the sslv2

         * buffer

         */

        s->rstate = SSL_ST_READ_HEADER;

        s->packet_length = n;

        s->packet = &(s->s2->rbuf[0]);

        memcpy(s->packet, buf, n);

        s->s2->rbuf_left = n;

        s->s2->rbuf_offs = 0;

        s->method = SSLv2_server_method();

        s->handshake_func = s->method->ssl_accept;

#endif

    }

    if ((type == 2) || (type == 3)) {

        /*

         * we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style)

         */

        const SSL_METHOD *new_method;

        new_method = ssl23_get_server_method(s->version);

        if (new_method == NULL) {

            SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);

            goto err;

        }

        s->method = new_method;

        if (!ssl_init_wbio_buffer(s, 1))

            goto err;

        /* 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))

                    goto err;

            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 0                           /* ssl3_get_client_hello does this */

        s->client_version = (v[0] << 8) | v[1];

#endif

        s->handshake_func = s->method->ssl_accept;

    }

    if ((type < 1) || (type > 3)) {

        /* bad, very bad */

        SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);

        goto err;

    }

    s->init_num = 0;

    if (buf != buf_space)

        OPENSSL_free(buf);

    return (SSL_accept(s));

 err:

    if (buf != buf_space)

        OPENSSL_free(buf);

    return (-1);

}