openssl/ssl/s3_enc.c
2001-07-30 23:57:25 +00:00

616 lines
17 KiB
C

/* ssl/s3_enc.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.]
*/
#include <stdio.h>
#include <openssl/evp.h>
#include "ssl_locl.h"
#include <openssl/md5.h>
static unsigned char ssl3_pad_1[48]={
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36,
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36,
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36,
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36,
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36,
0x36,0x36,0x36,0x36,0x36,0x36,0x36,0x36 };
static unsigned char ssl3_pad_2[48]={
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,
0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c,0x5c };
static int ssl3_handshake_mac(SSL *s, EVP_MD_CTX *in_ctx,
const char *sender, int len, unsigned char *p);
static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
{
EVP_MD_CTX m5;
EVP_MD_CTX s1;
unsigned char buf[16],smd[SHA_DIGEST_LENGTH];
unsigned char c='A';
int i,j,k;
#ifdef CHARSET_EBCDIC
c = os_toascii[c]; /*'A' in ASCII */
#endif
k=0;
EVP_MD_CTX_init(&m5);
EVP_MD_CTX_init(&s1);
for (i=0; i<num; i+=MD5_DIGEST_LENGTH)
{
k++;
if (k > sizeof buf)
{
/* bug: 'buf' is too small for this ciphersuite */
SSLerr(SSL_F_SSL3_GENERATE_KEY_BLOCK, ERR_R_INTERNAL_ERROR);
return 0;
}
for (j=0; j<k; j++)
buf[j]=c;
c++;
EVP_DigestInit(&s1,EVP_sha1());
EVP_DigestUpdate(&s1,buf,k);
EVP_DigestUpdate(&s1,s->session->master_key,
s->session->master_key_length);
EVP_DigestUpdate(&s1,s->s3->server_random,SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&s1,s->s3->client_random,SSL3_RANDOM_SIZE);
EVP_DigestFinal(&s1,smd,NULL);
EVP_DigestInit(&m5,EVP_md5());
EVP_DigestUpdate(&m5,s->session->master_key,
s->session->master_key_length);
EVP_DigestUpdate(&m5,smd,SHA_DIGEST_LENGTH);
if ((i+MD5_DIGEST_LENGTH) > num)
{
EVP_DigestFinal(&m5,smd,NULL);
memcpy(km,smd,(num-i));
}
else
EVP_DigestFinal(&m5,km,NULL);
km+=MD5_DIGEST_LENGTH;
}
memset(smd,0,SHA_DIGEST_LENGTH);
EVP_MD_CTX_cleanup(&m5);
EVP_MD_CTX_cleanup(&s1);
return 1;
}
int ssl3_change_cipher_state(SSL *s, int which)
{
unsigned char *p,*key_block,*mac_secret;
unsigned char exp_key[EVP_MAX_KEY_LENGTH];
unsigned char exp_iv[EVP_MAX_KEY_LENGTH];
unsigned char *ms,*key,*iv,*er1,*er2;
EVP_CIPHER_CTX *dd;
const EVP_CIPHER *c;
COMP_METHOD *comp;
const EVP_MD *m;
EVP_MD_CTX md;
int exp,n,i,j,k,cl;
exp=SSL_C_IS_EXPORT(s->s3->tmp.new_cipher);
c=s->s3->tmp.new_sym_enc;
m=s->s3->tmp.new_hash;
if (s->s3->tmp.new_compression == NULL)
comp=NULL;
else
comp=s->s3->tmp.new_compression->method;
key_block=s->s3->tmp.key_block;
if (which & SSL3_CC_READ)
{
if ((s->enc_read_ctx == NULL) &&
((s->enc_read_ctx=(EVP_CIPHER_CTX *)
OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
goto err;
dd= s->enc_read_ctx;
s->read_hash=m;
/* COMPRESS */
if (s->expand != NULL)
{
COMP_CTX_free(s->expand);
s->expand=NULL;
}
if (comp != NULL)
{
s->expand=COMP_CTX_new(comp);
if (s->expand == NULL)
{
SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,SSL_R_COMPRESSION_LIBRARY_ERROR);
goto err2;
}
if (s->s3->rrec.comp == NULL)
s->s3->rrec.comp=(unsigned char *)
OPENSSL_malloc(SSL3_RT_MAX_PLAIN_LENGTH);
if (s->s3->rrec.comp == NULL)
goto err;
}
memset(&(s->s3->read_sequence[0]),0,8);
mac_secret= &(s->s3->read_mac_secret[0]);
}
else
{
if ((s->enc_write_ctx == NULL) &&
((s->enc_write_ctx=(EVP_CIPHER_CTX *)
OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL))
goto err;
dd= s->enc_write_ctx;
s->write_hash=m;
/* COMPRESS */
if (s->compress != NULL)
{
COMP_CTX_free(s->compress);
s->compress=NULL;
}
if (comp != NULL)
{
s->compress=COMP_CTX_new(comp);
if (s->compress == NULL)
{
SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,SSL_R_COMPRESSION_LIBRARY_ERROR);
goto err2;
}
}
memset(&(s->s3->write_sequence[0]),0,8);
mac_secret= &(s->s3->write_mac_secret[0]);
}
EVP_CIPHER_CTX_init(dd);
p=s->s3->tmp.key_block;
i=EVP_MD_size(m);
cl=EVP_CIPHER_key_length(c);
j=exp ? (cl < SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher) ?
cl : SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher)) : cl;
/* Was j=(exp)?5:EVP_CIPHER_key_length(c); */
k=EVP_CIPHER_iv_length(c);
if ( (which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
(which == SSL3_CHANGE_CIPHER_SERVER_READ))
{
ms= &(p[ 0]); n=i+i;
key= &(p[ n]); n+=j+j;
iv= &(p[ n]); n+=k+k;
er1= &(s->s3->client_random[0]);
er2= &(s->s3->server_random[0]);
}
else
{
n=i;
ms= &(p[ n]); n+=i+j;
key= &(p[ n]); n+=j+k;
iv= &(p[ n]); n+=k;
er1= &(s->s3->server_random[0]);
er2= &(s->s3->client_random[0]);
}
if (n > s->s3->tmp.key_block_length)
{
SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,ERR_R_INTERNAL_ERROR);
goto err2;
}
EVP_MD_CTX_init(&md);
memcpy(mac_secret,ms,i);
if (exp)
{
/* In here I set both the read and write key/iv to the
* same value since only the correct one will be used :-).
*/
EVP_DigestInit(&md,EVP_md5());
EVP_DigestUpdate(&md,key,j);
EVP_DigestUpdate(&md,er1,SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md,er2,SSL3_RANDOM_SIZE);
EVP_DigestFinal(&md,&(exp_key[0]),NULL);
key= &(exp_key[0]);
if (k > 0)
{
EVP_DigestInit(&md,EVP_md5());
EVP_DigestUpdate(&md,er1,SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md,er2,SSL3_RANDOM_SIZE);
EVP_DigestFinal(&md,&(exp_iv[0]),NULL);
iv= &(exp_iv[0]);
}
}
s->session->key_arg_length=0;
EVP_CipherInit(dd,c,key,iv,(which & SSL3_CC_WRITE));
memset(&(exp_key[0]),0,sizeof(exp_key));
memset(&(exp_iv[0]),0,sizeof(exp_iv));
EVP_MD_CTX_cleanup(&md);
return(1);
err:
SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,ERR_R_MALLOC_FAILURE);
err2:
return(0);
}
int ssl3_setup_key_block(SSL *s)
{
unsigned char *p;
const EVP_CIPHER *c;
const EVP_MD *hash;
int num;
SSL_COMP *comp;
if (s->s3->tmp.key_block_length != 0)
return(1);
if (!ssl_cipher_get_evp(s->session,&c,&hash,&comp))
{
SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK,SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
return(0);
}
s->s3->tmp.new_sym_enc=c;
s->s3->tmp.new_hash=hash;
s->s3->tmp.new_compression=comp;
num=EVP_CIPHER_key_length(c)+EVP_MD_size(hash)+EVP_CIPHER_iv_length(c);
num*=2;
ssl3_cleanup_key_block(s);
if ((p=OPENSSL_malloc(num)) == NULL)
goto err;
s->s3->tmp.key_block_length=num;
s->s3->tmp.key_block=p;
return ssl3_generate_key_block(s,p,num);
err:
SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK,ERR_R_MALLOC_FAILURE);
return(0);
}
void ssl3_cleanup_key_block(SSL *s)
{
if (s->s3->tmp.key_block != NULL)
{
memset(s->s3->tmp.key_block,0,
s->s3->tmp.key_block_length);
OPENSSL_free(s->s3->tmp.key_block);
s->s3->tmp.key_block=NULL;
}
s->s3->tmp.key_block_length=0;
}
int ssl3_enc(SSL *s, int send)
{
SSL3_RECORD *rec;
EVP_CIPHER_CTX *ds;
unsigned long l;
int bs,i;
const EVP_CIPHER *enc;
if (send)
{
ds=s->enc_write_ctx;
rec= &(s->s3->wrec);
if (s->enc_write_ctx == NULL)
enc=NULL;
else
enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
}
else
{
ds=s->enc_read_ctx;
rec= &(s->s3->rrec);
if (s->enc_read_ctx == NULL)
enc=NULL;
else
enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
}
if ((s->session == NULL) || (ds == NULL) ||
(enc == NULL))
{
memmove(rec->data,rec->input,rec->length);
rec->input=rec->data;
}
else
{
l=rec->length;
bs=EVP_CIPHER_block_size(ds->cipher);
/* COMPRESS */
if ((bs != 1) && send)
{
i=bs-((int)l%bs);
/* we need to add 'i-1' padding bytes */
l+=i;
rec->length+=i;
rec->input[l-1]=(i-1);
}
if (!send)
{
if (l == 0 || l%bs != 0)
{
SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPT_ERROR);
return(0);
}
}
EVP_Cipher(ds,rec->data,rec->input,l);
if ((bs != 1) && !send)
{
i=rec->data[l-1]+1;
/* SSL 3.0 bounds the number of padding bytes by the block size;
* padding bytes (except that last) are arbitrary */
if (i > bs)
{
SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPT_ERROR);
return(0);
}
rec->length-=i;
}
}
return(1);
}
void ssl3_init_finished_mac(SSL *s)
{
EVP_DigestInit(&(s->s3->finish_dgst1),s->ctx->md5);
EVP_DigestInit(&(s->s3->finish_dgst2),s->ctx->sha1);
}
void ssl3_finish_mac(SSL *s, const unsigned char *buf, int len)
{
EVP_DigestUpdate(&(s->s3->finish_dgst1),buf,len);
EVP_DigestUpdate(&(s->s3->finish_dgst2),buf,len);
}
int ssl3_cert_verify_mac(SSL *s, EVP_MD_CTX *ctx, unsigned char *p)
{
return(ssl3_handshake_mac(s,ctx,NULL,0,p));
}
int ssl3_final_finish_mac(SSL *s, EVP_MD_CTX *ctx1, EVP_MD_CTX *ctx2,
const char *sender, int len, unsigned char *p)
{
int ret;
ret=ssl3_handshake_mac(s,ctx1,sender,len,p);
p+=ret;
ret+=ssl3_handshake_mac(s,ctx2,sender,len,p);
return(ret);
}
static int ssl3_handshake_mac(SSL *s, EVP_MD_CTX *in_ctx,
const char *sender, int len, unsigned char *p)
{
unsigned int ret;
int npad,n;
unsigned int i;
unsigned char md_buf[EVP_MAX_MD_SIZE];
EVP_MD_CTX ctx;
EVP_MD_CTX_init(&ctx);
EVP_MD_CTX_copy(&ctx,in_ctx);
n=EVP_MD_CTX_size(&ctx);
npad=(48/n)*n;
if (sender != NULL)
EVP_DigestUpdate(&ctx,sender,len);
EVP_DigestUpdate(&ctx,s->session->master_key,
s->session->master_key_length);
EVP_DigestUpdate(&ctx,ssl3_pad_1,npad);
EVP_DigestFinal(&ctx,md_buf,&i);
EVP_DigestInit(&ctx,EVP_MD_CTX_md(&ctx));
EVP_DigestUpdate(&ctx,s->session->master_key,
s->session->master_key_length);
EVP_DigestUpdate(&ctx,ssl3_pad_2,npad);
EVP_DigestUpdate(&ctx,md_buf,i);
EVP_DigestFinal(&ctx,p,&ret);
EVP_MD_CTX_cleanup(&ctx);
return((int)ret);
}
int ssl3_mac(SSL *ssl, unsigned char *md, int send)
{
SSL3_RECORD *rec;
unsigned char *mac_sec,*seq;
EVP_MD_CTX md_ctx;
const EVP_MD *hash;
unsigned char *p,rec_char;
unsigned int md_size;
int npad,i;
if (send)
{
rec= &(ssl->s3->wrec);
mac_sec= &(ssl->s3->write_mac_secret[0]);
seq= &(ssl->s3->write_sequence[0]);
hash=ssl->write_hash;
}
else
{
rec= &(ssl->s3->rrec);
mac_sec= &(ssl->s3->read_mac_secret[0]);
seq= &(ssl->s3->read_sequence[0]);
hash=ssl->read_hash;
}
md_size=EVP_MD_size(hash);
npad=(48/md_size)*md_size;
/* Chop the digest off the end :-) */
EVP_MD_CTX_init(&md_ctx);
EVP_DigestInit( &md_ctx,hash);
EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad);
EVP_DigestUpdate(&md_ctx,seq,8);
rec_char=rec->type;
EVP_DigestUpdate(&md_ctx,&rec_char,1);
p=md;
s2n(rec->length,p);
EVP_DigestUpdate(&md_ctx,md,2);
EVP_DigestUpdate(&md_ctx,rec->input,rec->length);
EVP_DigestFinal( &md_ctx,md,NULL);
EVP_DigestInit( &md_ctx,hash);
EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad);
EVP_DigestUpdate(&md_ctx,md,md_size);
EVP_DigestFinal( &md_ctx,md,&md_size);
EVP_MD_CTX_cleanup(&md_ctx);
for (i=7; i>=0; i--)
{
++seq[i];
if (seq[i] != 0) break;
}
return(md_size);
}
int ssl3_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p,
int len)
{
static const unsigned char *salt[3]={
#ifndef CHARSET_EBCDIC
(const unsigned char *)"A",
(const unsigned char *)"BB",
(const unsigned char *)"CCC",
#else
(const unsigned char *)"\x41",
(const unsigned char *)"\x42\x42",
(const unsigned char *)"\x43\x43\x43",
#endif
};
unsigned char buf[EVP_MAX_MD_SIZE];
EVP_MD_CTX ctx;
int i,ret=0;
unsigned int n;
EVP_MD_CTX_init(&ctx);
for (i=0; i<3; i++)
{
EVP_DigestInit(&ctx,s->ctx->sha1);
EVP_DigestUpdate(&ctx,salt[i],strlen((const char *)salt[i]));
EVP_DigestUpdate(&ctx,p,len);
EVP_DigestUpdate(&ctx,&(s->s3->client_random[0]),
SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&ctx,&(s->s3->server_random[0]),
SSL3_RANDOM_SIZE);
EVP_DigestFinal(&ctx,buf,&n);
EVP_DigestInit(&ctx,s->ctx->md5);
EVP_DigestUpdate(&ctx,p,len);
EVP_DigestUpdate(&ctx,buf,n);
EVP_DigestFinal(&ctx,out,&n);
out+=n;
ret+=n;
}
EVP_MD_CTX_cleanup(&ctx);
return(ret);
}
int ssl3_alert_code(int code)
{
switch (code)
{
case SSL_AD_CLOSE_NOTIFY: return(SSL3_AD_CLOSE_NOTIFY);
case SSL_AD_UNEXPECTED_MESSAGE: return(SSL3_AD_UNEXPECTED_MESSAGE);
case SSL_AD_BAD_RECORD_MAC: return(SSL3_AD_BAD_RECORD_MAC);
case SSL_AD_DECRYPTION_FAILED: return(SSL3_AD_BAD_RECORD_MAC);
case SSL_AD_RECORD_OVERFLOW: return(SSL3_AD_BAD_RECORD_MAC);
case SSL_AD_DECOMPRESSION_FAILURE:return(SSL3_AD_DECOMPRESSION_FAILURE);
case SSL_AD_HANDSHAKE_FAILURE: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_NO_CERTIFICATE: return(SSL3_AD_NO_CERTIFICATE);
case SSL_AD_BAD_CERTIFICATE: return(SSL3_AD_BAD_CERTIFICATE);
case SSL_AD_UNSUPPORTED_CERTIFICATE:return(SSL3_AD_UNSUPPORTED_CERTIFICATE);
case SSL_AD_CERTIFICATE_REVOKED:return(SSL3_AD_CERTIFICATE_REVOKED);
case SSL_AD_CERTIFICATE_EXPIRED:return(SSL3_AD_CERTIFICATE_EXPIRED);
case SSL_AD_CERTIFICATE_UNKNOWN:return(SSL3_AD_CERTIFICATE_UNKNOWN);
case SSL_AD_ILLEGAL_PARAMETER: return(SSL3_AD_ILLEGAL_PARAMETER);
case SSL_AD_UNKNOWN_CA: return(SSL3_AD_BAD_CERTIFICATE);
case SSL_AD_ACCESS_DENIED: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_DECODE_ERROR: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_DECRYPT_ERROR: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_EXPORT_RESTRICTION: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_PROTOCOL_VERSION: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_INSUFFICIENT_SECURITY:return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_INTERNAL_ERROR: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_USER_CANCELLED: return(SSL3_AD_HANDSHAKE_FAILURE);
case SSL_AD_NO_RENEGOTIATION: return(-1); /* Don't send it :-) */
default: return(-1);
}
}