/* ssl/t1_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) 1998-2006 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).

 *

 */

/*

 * DTLS code by Eric Rescorla <ekr@rtfm.com>

 *

 * Copyright (C) 2006, Network Resonance, Inc. Copyright (C) 2011, RTFM, Inc.

 */

#include <stdio.h>

#include <openssl/objects.h>

#include "ssl_locl.h"

#include "srtp.h"

#ifndef OPENSSL_NO_SRTP

static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {

    {

     "SRTP_AES128_CM_SHA1_80",

     SRTP_AES128_CM_SHA1_80,

     },

    {

     "SRTP_AES128_CM_SHA1_32",

     SRTP_AES128_CM_SHA1_32,

     },

# if 0

    {

     "SRTP_NULL_SHA1_80",

     SRTP_NULL_SHA1_80,

     },

    {

     "SRTP_NULL_SHA1_32",

     SRTP_NULL_SHA1_32,

     },

# endif

    {0}

};

static int find_profile_by_name(char *profile_name,

                                SRTP_PROTECTION_PROFILE **pptr, unsigned len)

{

    SRTP_PROTECTION_PROFILE *p;

    p = srtp_known_profiles;

    while (p->name) {

        if ((len == strlen(p->name)) && !strncmp(p->name, profile_name, len)) {

            *pptr = p;

            return 0;

        }

        p++;

    }

    return 1;

}

static int ssl_ctx_make_profiles(const char *profiles_string,

                                 STACK_OF(SRTP_PROTECTION_PROFILE) **out)

{

    STACK_OF(SRTP_PROTECTION_PROFILE) *profiles;

    char *col;

    char *ptr = (char *)profiles_string;

    SRTP_PROTECTION_PROFILE *p;

    if (!(profiles = sk_SRTP_PROTECTION_PROFILE_new_null())) {

        SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,

               SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);

        return 1;

    }

    do {

        col = strchr(ptr, ':');

        if (!find_profile_by_name(ptr, &p,

                                  col ? col - ptr : (int)strlen(ptr))) {

            if (sk_SRTP_PROTECTION_PROFILE_find(profiles, p) >= 0) {

                SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,

                       SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

                sk_SRTP_PROTECTION_PROFILE_free(profiles);

                return 1;

            }

            sk_SRTP_PROTECTION_PROFILE_push(profiles, p);

        } else {

            SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,

                   SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);

            sk_SRTP_PROTECTION_PROFILE_free(profiles);

            return 1;

        }

        if (col)

            ptr = col + 1;

    } while (col);

    *out = profiles;

    return 0;

}

int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)

{

    return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);

}

int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)

{

    return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);

}

STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)

{

    if (s != NULL) {

        if (s->srtp_profiles != NULL) {

            return s->srtp_profiles;

        } else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {

            return s->ctx->srtp_profiles;

        }

    }

    return NULL;

}

SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)

{

    return s->srtp_profile;

}

/*

 * Note: this function returns 0 length if there are no profiles specified

 */

int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,

                                     int maxlen)

{

    int ct = 0;

    int i;

    STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;

    SRTP_PROTECTION_PROFILE *prof;

    clnt = SSL_get_srtp_profiles(s);

    ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */

    if (p) {

        if (ct == 0) {

            SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,

                   SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);

            return 1;

        }

        if ((2 + ct * 2 + 1) > maxlen) {

            SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,

                   SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);

            return 1;

        }

        /* Add the length */

        s2n(ct * 2, p);

        for (i = 0; i < ct; i++) {

            prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);

            s2n(prof->id, p);

        }

        /* Add an empty use_mki value */

        *p++ = 0;

    }

    *len = 2 + ct * 2 + 1;

    return 0;

}

int ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len,

                                       int *al)

{

    SRTP_PROTECTION_PROFILE *sprof;

    STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;

    int ct;

    int mki_len;

    int i, srtp_pref;

    unsigned int id;

    /* Length value + the MKI length */

    if (len < 3) {

        SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    /* Pull off the length of the cipher suite list */

    n2s(d, ct);

    len -= 2;

    /* Check that it is even */

    if (ct % 2) {

        SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    /* Check that lengths are consistent */

    if (len < (ct + 1)) {

        SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    srvr = SSL_get_srtp_profiles(s);

    s->srtp_profile = NULL;

    /* Search all profiles for a match initially */

    srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);

    while (ct) {

        n2s(d, id);

        ct -= 2;

        len -= 2;

        /*

         * Only look for match in profiles of higher preference than

         * current match.

         * If no profiles have been have been configured then this

         * does nothing.

         */

        for (i = 0; i < srtp_pref; i++) {

            sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);

            if (sprof->id == id) {

                s->srtp_profile = sprof;

                srtp_pref = i;

                break;

            }

        }

    }

    /*

     * Now extract the MKI value as a sanity check, but discard it for now

     */

    mki_len = *d;

    d++;

    len--;

    if (mki_len != len) {

        SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_MKI_VALUE);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    return 0;

}

int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,

                                     int maxlen)

{

    if (p) {

        if (maxlen < 5) {

            SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,

                   SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);

            return 1;

        }

        if (s->srtp_profile == 0) {

            SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,

                   SSL_R_USE_SRTP_NOT_NEGOTIATED);

            return 1;

        }

        s2n(2, p);

        s2n(s->srtp_profile->id, p);

        *p++ = 0;

    }

    *len = 5;

    return 0;

}

int ssl_parse_serverhello_use_srtp_ext(SSL *s, unsigned char *d, int len,

                                       int *al)

{

    unsigned id;

    int i;

    int ct;

    STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;

    SRTP_PROTECTION_PROFILE *prof;

    if (len != 5) {

        SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    n2s(d, ct);

    if (ct != 2) {

        SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    n2s(d, id);

    if (*d) {                   /* Must be no MKI, since we never offer one */

        SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,

               SSL_R_BAD_SRTP_MKI_VALUE);

        *al = SSL_AD_ILLEGAL_PARAMETER;

        return 1;

    }

    clnt = SSL_get_srtp_profiles(s);

    /* Throw an error if the server gave us an unsolicited extension */

    if (clnt == NULL) {

        SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,

               SSL_R_NO_SRTP_PROFILES);

        *al = SSL_AD_DECODE_ERROR;

        return 1;

    }

    /*

     * Check to see if the server gave us something we support (and

     * presumably offered)

     */

    for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {

        prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);

        if (prof->id == id) {

            s->srtp_profile = prof;

            *al = 0;

            return 0;

        }

    }

    SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,

           SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);

    *al = SSL_AD_DECODE_ERROR;

    return 1;

}

#endif