There are a few showstoppers. Unfortunately, I only remember one. Please fill this in.
[openssl.git] / ssl / s3_enc.c
index 6d9f986d58e003b6ee614636b5aedd99680ae283..6d92050bb17b270b1c8dcc21d86f84cbba09dd45 100644 (file)
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2002 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 <openssl/evp.h>
 #include "ssl_locl.h"
+#include <openssl/evp.h>
 #include <openssl/md5.h>
 
 static unsigned char ssl3_pad_1[48]={
@@ -86,7 +139,7 @@ static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
        EVP_MD_CTX s1;
        unsigned char buf[16],smd[SHA_DIGEST_LENGTH];
        unsigned char c='A';
-       int i,j,k;
+       unsigned int i,j,k;
 
 #ifdef CHARSET_EBCDIC
        c = os_toascii[c]; /*'A' in ASCII */
@@ -94,7 +147,7 @@ static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
        k=0;
        EVP_MD_CTX_init(&m5);
        EVP_MD_CTX_init(&s1);
-       for (i=0; i<num; i+=MD5_DIGEST_LENGTH)
+       for (i=0; (int)i<num; i+=MD5_DIGEST_LENGTH)
                {
                k++;
                if (k > sizeof buf)
@@ -119,7 +172,7 @@ static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
                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)
+               if ((int)(i+MD5_DIGEST_LENGTH) > num)
                        {
                        EVP_DigestFinal_ex(&m5,smd,NULL);
                        memcpy(km,smd,(num-i));
@@ -129,7 +182,7 @@ static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
 
                km+=MD5_DIGEST_LENGTH;
                }
-       memset(smd,0,SHA_DIGEST_LENGTH);
+       OPENSSL_cleanse(smd,SHA_DIGEST_LENGTH);
        EVP_MD_CTX_cleanup(&m5);
        EVP_MD_CTX_cleanup(&s1);
        return 1;
@@ -139,17 +192,17 @@ 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 exp_iv[EVP_MAX_IV_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;
+       int is_exp,n,i,j,k,cl;
        int reuse_dd = 0;
 
-       exp=SSL_C_IS_EXPORT(s->s3->tmp.new_cipher);
+       is_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)
@@ -223,9 +276,9 @@ int ssl3_change_cipher_state(SSL *s, int which)
        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) ?
+       j=is_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); */
+       /* Was j=(is_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))
@@ -254,7 +307,7 @@ int ssl3_change_cipher_state(SSL *s, int which)
 
        EVP_MD_CTX_init(&md);
        memcpy(mac_secret,ms,i);
-       if (exp)
+       if (is_exp)
                {
                /* In here I set both the read and write key/iv to the
                 * same value since only the correct one will be used :-).
@@ -280,8 +333,8 @@ int ssl3_change_cipher_state(SSL *s, int which)
 
        EVP_CipherInit_ex(dd,c,NULL,key,iv,(which & SSL3_CC_WRITE));
 
-       memset(&(exp_key[0]),0,sizeof(exp_key));
-       memset(&(exp_iv[0]),0,sizeof(exp_iv));
+       OPENSSL_cleanse(&(exp_key[0]),sizeof(exp_key));
+       OPENSSL_cleanse(&(exp_iv[0]),sizeof(exp_iv));
        EVP_MD_CTX_cleanup(&md);
        return(1);
 err:
@@ -296,6 +349,7 @@ int ssl3_setup_key_block(SSL *s)
        const EVP_CIPHER *c;
        const EVP_MD *hash;
        int num;
+       int ret = 0;
        SSL_COMP *comp;
 
        if (s->s3->tmp.key_block_length != 0)
@@ -322,8 +376,29 @@ int ssl3_setup_key_block(SSL *s)
        s->s3->tmp.key_block_length=num;
        s->s3->tmp.key_block=p;
 
-       return ssl3_generate_key_block(s,p,num);
+       ret = ssl3_generate_key_block(s,p,num);
 
+       if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
+               {
+               /* enable vulnerability countermeasure for CBC ciphers with
+                * known-IV problem (http://www.openssl.org/~bodo/tls-cbc.txt)
+                */
+               s->s3->need_empty_fragments = 1;
+
+               if (s->session->cipher != NULL)
+                       {
+                       if ((s->session->cipher->algorithms & SSL_ENC_MASK) == SSL_eNULL)
+                               s->s3->need_empty_fragments = 0;
+                       
+#ifndef OPENSSL_NO_RC4
+                       if ((s->session->cipher->algorithms & SSL_ENC_MASK) == SSL_RC4)
+                               s->s3->need_empty_fragments = 0;
+#endif
+                       }
+               }
+
+       return ret;
+               
 err:
        SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK,ERR_R_MALLOC_FAILURE);
        return(0);
@@ -333,7 +408,7 @@ void ssl3_cleanup_key_block(SSL *s)
        {
        if (s->s3->tmp.key_block != NULL)
                {
-               memset(s->s3->tmp.key_block,0,
+               OPENSSL_cleanse(s->s3->tmp.key_block,
                        s->s3->tmp.key_block_length);
                OPENSSL_free(s->s3->tmp.key_block);
                s->s3->tmp.key_block=NULL;
@@ -399,6 +474,7 @@ int ssl3_enc(SSL *s, int send)
                                ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
                                return 0;
                                }
+                       /* otherwise, rec->length >= bs */
                        }
                
                EVP_Cipher(ds,rec->data,rec->input,l);
@@ -407,7 +483,7 @@ int ssl3_enc(SSL *s, int 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 */
+                        * padding bytes (except the last one) are arbitrary */
                        if (i > bs)
                                {
                                /* Incorrect padding. SSLerr() and ssl3_alert are done
@@ -416,6 +492,7 @@ int ssl3_enc(SSL *s, int send)
                                 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
                                return -1;
                                }
+                       /* now i <= bs <= rec->length */
                        rec->length-=i;
                        }
                }
@@ -492,7 +569,7 @@ int ssl3_mac(SSL *ssl, unsigned char *md, int send)
        const EVP_MD *hash;
        unsigned char *p,rec_char;
        unsigned int md_size;
-       int npad,i;
+       int npad;
 
        if (send)
                {
@@ -535,13 +612,19 @@ int ssl3_mac(SSL *ssl, unsigned char *md, int send)
 
        EVP_MD_CTX_cleanup(&md_ctx);
 
+       ssl3_record_sequence_update(seq);
+       return(md_size);
+       }
+
+void ssl3_record_sequence_update(unsigned char *seq)
+       {
+       int i;
+
        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,