d1_srtp.c

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/* ssl/t1_lib.c */
/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * 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 ([email protected]).
 * 
 * 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 ([email protected])"
 *    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 ([email protected])"
 * 
 * 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
 *    [email protected].
 *
 * 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
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */
/*
  DTLS code by Eric Rescorla <[email protected]>

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

#ifndef OPENSSL_NO_SRTP

#include <stdio.h>
#include <openssl/objects.h>
#include "ssl_locl.h"
#include "srtp.h"


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 find_profile_by_num(unsigned profile_num,
                   SRTP_PROTECTION_PROFILE **pptr)
    {
    SRTP_PROTECTION_PROFILE *p;

    p=srtp_known_profiles;
    while(p->name)
        {
        if(p->id == profile_num)
            {
            *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)))
            {
            sk_SRTP_PROTECTION_PROFILE_push(profiles,p);
            }
        else
            {
            SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
            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 *cprof,*sprof;
    STACK_OF(SRTP_PROTECTION_PROFILE) *clnt=0,*srvr;
        int ct;
        int mki_len;
    int i,j;
    int id;
    int ret;

         /* 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;
        }

        
    clnt=sk_SRTP_PROTECTION_PROFILE_new_null();

    while(ct)
        {
        n2s(d,id);
        ct-=2;
                len-=2;

        if(!find_profile_by_num(id,&cprof))
            {
            sk_SRTP_PROTECTION_PROFILE_push(clnt,cprof);
            }
        else
            {
            ; /* Ignore */
            }
        }

        /* 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;
        }

    srvr=SSL_get_srtp_profiles(s);

    /* Pick our most preferred profile. If no profiles have been
     configured then the outer loop doesn't run 
     (sk_SRTP_PROTECTION_PROFILE_num() = -1)
     and so we just return without doing anything */
    for(i=0;i<sk_SRTP_PROTECTION_PROFILE_num(srvr);i++)
        {
        sprof=sk_SRTP_PROTECTION_PROFILE_value(srvr,i);

        for(j=0;j<sk_SRTP_PROTECTION_PROFILE_num(clnt);j++)
            {
            cprof=sk_SRTP_PROTECTION_PROFILE_value(clnt,j);
            
            if(cprof->id==sprof->id)
                {
                s->srtp_profile=sprof;
                *al=0;
                ret=0;
                goto done;
                }
            }
        }

    ret=0;
    
done:
    if(clnt) sk_SRTP_PROTECTION_PROFILE_free(clnt);

    return ret;
    }

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