Add a constant time flag to one of the bignums to avoid a timing leak.

[thirdparty/openssl.git] / ssl / s2_lib.c

/* ssl/s2_lib.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) 1998-2007 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).
 *
 */

#include "ssl_locl.h"
#ifndef OPENSSL_NO_SSL2
# include <stdio.h>
# include <openssl/objects.h>
# include <openssl/evp.h>
# include <openssl/md5.h>

const char ssl2_version_str[] = "SSLv2" OPENSSL_VERSION_PTEXT;

# define SSL2_NUM_CIPHERS (sizeof(ssl2_ciphers)/sizeof(SSL_CIPHER))

/* list of available SSLv2 ciphers (sorted by id) */
OPENSSL_GLOBAL const SSL_CIPHER ssl2_ciphers[] = {
# if 0
/* NULL_WITH_MD5 v3 */
    {
     1,
     SSL2_TXT_NULL_WITH_MD5,
     SSL2_CK_NULL_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_eNULL,
     SSL_MD5,
     SSL_SSLV2,
     SSL_EXPORT | SSL_EXP40 | SSL_STRONG_NONE,
     0,
     0,
     0,
     },
# endif

/* RC4_128_WITH_MD5 */
    {
     1,
     SSL2_TXT_RC4_128_WITH_MD5,
     SSL2_CK_RC4_128_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_RC4,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_MEDIUM,
     0,
     128,
     128,
     },

# if 0
/* RC4_128_EXPORT40_WITH_MD5 */
    {
     1,
     SSL2_TXT_RC4_128_EXPORT40_WITH_MD5,
     SSL2_CK_RC4_128_EXPORT40_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_RC4,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_EXPORT | SSL_EXP40,
     SSL2_CF_5_BYTE_ENC,
     40,
     128,
     },
# endif

/* RC2_128_CBC_WITH_MD5 */
    {
     1,
     SSL2_TXT_RC2_128_CBC_WITH_MD5,
     SSL2_CK_RC2_128_CBC_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_RC2,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_MEDIUM,
     0,
     128,
     128,
     },

# if 0
/* RC2_128_CBC_EXPORT40_WITH_MD5 */
    {
     1,
     SSL2_TXT_RC2_128_CBC_EXPORT40_WITH_MD5,
     SSL2_CK_RC2_128_CBC_EXPORT40_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_RC2,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_EXPORT | SSL_EXP40,
     SSL2_CF_5_BYTE_ENC,
     40,
     128,
     },
# endif

# ifndef OPENSSL_NO_IDEA
/* IDEA_128_CBC_WITH_MD5 */
    {
     1,
     SSL2_TXT_IDEA_128_CBC_WITH_MD5,
     SSL2_CK_IDEA_128_CBC_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_IDEA,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_MEDIUM,
     0,
     128,
     128,
     },
# endif

# if 0
/* DES_64_CBC_WITH_MD5 */
    {
     1,
     SSL2_TXT_DES_64_CBC_WITH_MD5,
     SSL2_CK_DES_64_CBC_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_DES,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_LOW,
     0,
     56,
     56,
     },
# endif

/* DES_192_EDE3_CBC_WITH_MD5 */
    {
     1,
     SSL2_TXT_DES_192_EDE3_CBC_WITH_MD5,
     SSL2_CK_DES_192_EDE3_CBC_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_3DES,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_MEDIUM,
     0,
     112,
     168,
     },

# if 0
/* RC4_64_WITH_MD5 */
    {
     1,
     SSL2_TXT_RC4_64_WITH_MD5,
     SSL2_CK_RC4_64_WITH_MD5,
     SSL_kRSA,
     SSL_aRSA,
     SSL_RC4,
     SSL_MD5,
     SSL_SSLV2,
     SSL_NOT_DEFAULT | SSL_NOT_EXP | SSL_LOW,
     SSL2_CF_8_BYTE_ENC,
     64,
     64,
     },
# endif

# if 0
/* NULL SSLeay (testing) */
    {
     0,
     SSL2_TXT_NULL,
     SSL2_CK_NULL,
     0,
     0,
     0,
     0,
     SSL_SSLV2,
     SSL_STRONG_NONE,
     0,
     0,
     0,
     },
# endif

/* end of list :-) */
};

long ssl2_default_timeout(void)
{
    return (300);
}

int ssl2_num_ciphers(void)
{
    return (SSL2_NUM_CIPHERS);
}

const SSL_CIPHER *ssl2_get_cipher(unsigned int u)
{
    if (u < SSL2_NUM_CIPHERS)
        return (&(ssl2_ciphers[SSL2_NUM_CIPHERS - 1 - u]));
    else
        return (NULL);
}

int ssl2_pending(const SSL *s)
{
    return SSL_in_init(s) ? 0 : s->s2->ract_data_length;
}

int ssl2_new(SSL *s)
{
    SSL2_STATE *s2;

    if ((s2 = OPENSSL_malloc(sizeof(*s2))) == NULL)
        goto err;
    memset(s2, 0, sizeof(*s2));

# if SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER + 3 > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2
#  error "assertion failed"
# endif

    if ((s2->rbuf =
         OPENSSL_malloc(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2)) == NULL)
        goto err;
    /*
     * wbuf needs one byte more because when using two-byte headers, we leave
     * the first byte unused in do_ssl_write (s2_pkt.c)
     */
    if ((s2->wbuf =
         OPENSSL_malloc(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 3)) == NULL)
        goto err;
    s->s2 = s2;

    ssl2_clear(s);
    return (1);
 err:
    if (s2 != NULL) {
        if (s2->wbuf != NULL)
            OPENSSL_free(s2->wbuf);
        if (s2->rbuf != NULL)
            OPENSSL_free(s2->rbuf);
        OPENSSL_free(s2);
    }
    return (0);
}

void ssl2_free(SSL *s)
{
    SSL2_STATE *s2;

    if (s == NULL)
        return;

    s2 = s->s2;
    if (s2->rbuf != NULL)
        OPENSSL_free(s2->rbuf);
    if (s2->wbuf != NULL)
        OPENSSL_free(s2->wbuf);
    OPENSSL_cleanse(s2, sizeof(*s2));
    OPENSSL_free(s2);
    s->s2 = NULL;
}

void ssl2_clear(SSL *s)
{
    SSL2_STATE *s2;
    unsigned char *rbuf, *wbuf;

    s2 = s->s2;

    rbuf = s2->rbuf;
    wbuf = s2->wbuf;

    memset(s2, 0, sizeof(*s2));

    s2->rbuf = rbuf;
    s2->wbuf = wbuf;
    s2->clear_text = 1;
    s->packet = s2->rbuf;
    s->version = SSL2_VERSION;
    s->packet_length = 0;
}

long ssl2_ctrl(SSL *s, int cmd, long larg, void *parg)
{
    int ret = 0;

    switch (cmd) {
    case SSL_CTRL_GET_SESSION_REUSED:
        ret = s->hit;
        break;
    case SSL_CTRL_CHECK_PROTO_VERSION:
        return ssl3_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, larg, parg);
    default:
        break;
    }
    return (ret);
}

long ssl2_callback_ctrl(SSL *s, int cmd, void (*fp) (void))
{
    return (0);
}

long ssl2_ctx_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg)
{
    return (0);
}

long ssl2_ctx_callback_ctrl(SSL_CTX *ctx, int cmd, void (*fp) (void))
{
    return (0);
}

/*
 * This function needs to check if the ciphers required are actually
 * available
 */
const SSL_CIPHER *ssl2_get_cipher_by_char(const unsigned char *p)
{
    SSL_CIPHER c;
    const SSL_CIPHER *cp;
    unsigned long id;

    id = 0x02000000L | ((unsigned long)p[0] << 16L) |
        ((unsigned long)p[1] << 8L) | (unsigned long)p[2];
    c.id = id;
    cp = OBJ_bsearch_ssl_cipher_id(&c, ssl2_ciphers, SSL2_NUM_CIPHERS);
    return cp;
}

int ssl2_put_cipher_by_char(const SSL_CIPHER *c, unsigned char *p)
{
    long l;

    if (p != NULL) {
        l = c->id;
        if ((l & 0xff000000) != 0x02000000 && l != SSL3_CK_FALLBACK_SCSV)
            return (0);
        p[0] = ((unsigned char)(l >> 16L)) & 0xFF;
        p[1] = ((unsigned char)(l >> 8L)) & 0xFF;
        p[2] = ((unsigned char)(l)) & 0xFF;
    }
    return (3);
}

int ssl2_generate_key_material(SSL *s)
{
    unsigned int i;
    EVP_MD_CTX ctx;
    unsigned char *km;
    unsigned char c = '0';
    const EVP_MD *md5;
    int md_size;

    md5 = EVP_md5();

# ifdef CHARSET_EBCDIC
    c = os_toascii['0'];        /* Must be an ASCII '0', not EBCDIC '0', see
                                 * SSLv2 docu */
# endif
    EVP_MD_CTX_init(&ctx);
    km = s->s2->key_material;

    if (s->session->master_key_length < 0 ||
        s->session->master_key_length > (int)sizeof(s->session->master_key)) {
        SSLerr(SSL_F_SSL2_GENERATE_KEY_MATERIAL, ERR_R_INTERNAL_ERROR);
        return 0;
    }
    md_size = EVP_MD_size(md5);
    if (md_size < 0)
        return 0;
    for (i = 0; i < s->s2->key_material_length; i += md_size) {
        if (((km - s->s2->key_material) + md_size) >
            (int)sizeof(s->s2->key_material)) {
            /*
             * EVP_DigestFinal_ex() below would write beyond buffer
             */
            SSLerr(SSL_F_SSL2_GENERATE_KEY_MATERIAL, ERR_R_INTERNAL_ERROR);
            return 0;
        }

        EVP_DigestInit_ex(&ctx, md5, NULL);

        OPENSSL_assert(s->session->master_key_length >= 0
                       && s->session->master_key_length
                       <= (int)sizeof(s->session->master_key));
        EVP_DigestUpdate(&ctx, s->session->master_key,
                         s->session->master_key_length);
        EVP_DigestUpdate(&ctx, &c, 1);
        c++;
        EVP_DigestUpdate(&ctx, s->s2->challenge, s->s2->challenge_length);
        EVP_DigestUpdate(&ctx, s->s2->conn_id, s->s2->conn_id_length);
        EVP_DigestFinal_ex(&ctx, km, NULL);
        km += md_size;
    }

    EVP_MD_CTX_cleanup(&ctx);
    return 1;
}

void ssl2_return_error(SSL *s, int err)
{
    if (!s->error) {
        s->error = 3;
        s->error_code = err;

        ssl2_write_error(s);
    }
}

void ssl2_write_error(SSL *s)
{
    unsigned char buf[3];
    int i, error;

    buf[0] = SSL2_MT_ERROR;
    buf[1] = (s->error_code >> 8) & 0xff;
    buf[2] = (s->error_code) & 0xff;

/*      state=s->rwstate;*/

    error = s->error;           /* number of bytes left to write */
    s->error = 0;
    OPENSSL_assert(error >= 0 && error <= (int)sizeof(buf));
    i = ssl2_write(s, &(buf[3 - error]), error);

/*      if (i == error) s->rwstate=state; */

    if (i < 0)
        s->error = error;
    else {
        s->error = error - i;

        if (s->error == 0)
            if (s->msg_callback) {
                /* ERROR */
                s->msg_callback(1, s->version, 0, buf, 3, s,
                                s->msg_callback_arg);
            }
    }
}

int ssl2_shutdown(SSL *s)
{
    s->shutdown = (SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
    return (1);
}
#else                           /* !OPENSSL_NO_SSL2 */

# if PEDANTIC
static void *dummy = &dummy;
# endif

#endif