OpenSSL Security Advisory [30 July 2002]
[openssl.git] / ssl / s2_srvr.c
index 3bd83793b71ed00031e24018e7d35b6cecd7627a..391287bfcd2b05b76747c170e48a0ee4d74cb5d2 100644 (file)
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2001 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 <openssl/rand.h>
 #include <openssl/objects.h>
 #include <openssl/evp.h>
+#include "cryptlib.h"
 
 static SSL_METHOD *ssl2_get_server_method(int ver);
 static int get_client_master_key(SSL *s);
@@ -106,7 +160,7 @@ int ssl2_accept(SSL *s)
        BUF_MEM *buf=NULL;
        int ret= -1;
        long num1;
-       void (*cb)()=NULL;
+       void (*cb)(const SSL *ssl,int type,int val)=NULL;
        int new_state,state;
 
        RAND_add(&l,sizeof(l),0);
@@ -119,8 +173,8 @@ int ssl2_accept(SSL *s)
                cb=s->ctx->info_callback;
 
        /* init things to blank */
-       if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
        s->in_handshake++;
+       if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 
        if (s->cert == NULL)
                {
@@ -322,6 +376,7 @@ end:
 static int get_client_master_key(SSL *s)
        {
        int is_export,i,n,keya,ek;
+       unsigned long len;
        unsigned char *p;
        SSL_CIPHER *cp;
        const EVP_CIPHER *c;
@@ -334,6 +389,8 @@ static int get_client_master_key(SSL *s)
 
                if (i < (10-s->init_num))
                        return(ssl2_part_read(s,SSL_F_GET_CLIENT_MASTER_KEY,i));
+               s->init_num = 10;
+
                if (*(p++) != SSL2_MT_CLIENT_MASTER_KEY)
                        {
                        if (p[-1] != SSL2_MT_ERROR)
@@ -361,16 +418,31 @@ static int get_client_master_key(SSL *s)
                n2s(p,i); s->s2->tmp.clear=i;
                n2s(p,i); s->s2->tmp.enc=i;
                n2s(p,i); s->session->key_arg_length=i;
+               if(s->session->key_arg_length > SSL_MAX_KEY_ARG_LENGTH)
+                       {
+                       SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
+                                  SSL_R_KEY_ARG_TOO_LONG);
+                       return -1;
+                       }
                s->state=SSL2_ST_GET_CLIENT_MASTER_KEY_B;
-               s->init_num=0;
                }
 
        /* SSL2_ST_GET_CLIENT_MASTER_KEY_B */
        p=(unsigned char *)s->init_buf->data;
+       die(s->init_buf->length >= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER);
        keya=s->session->key_arg_length;
-       n=s->s2->tmp.clear+s->s2->tmp.enc+keya - s->init_num;
-       i=ssl2_read(s,(char *)&(p[s->init_num]),n);
+       len = 10 + (unsigned long)s->s2->tmp.clear + (unsigned long)s->s2->tmp.enc + (unsigned long)keya;
+       if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
+               {
+               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_MESSAGE_TOO_LONG);
+               return -1;
+               }
+       n = (int)len - s->init_num;
+       i = ssl2_read(s,(char *)&(p[s->init_num]),n);
        if (i != n) return(ssl2_part_read(s,SSL_F_GET_CLIENT_MASTER_KEY,i));
+       if (s->msg_callback)
+               s->msg_callback(0, s->version, 0, p, (size_t)len, s, s->msg_callback_arg); /* CLIENT-MASTER-KEY */
+       p += 10;
 
        memcpy(s->session->key_arg,&(p[s->s2->tmp.clear+s->s2->tmp.enc]),
                (unsigned int)keya);
@@ -408,8 +480,8 @@ static int get_client_master_key(SSL *s)
         * random master secret (Bleichenbacher attack) */
        if ((i < 0) ||
                ((!is_export && (i != EVP_CIPHER_key_length(c)))
-               || (is_export && ((i != ek) || (s->s2->tmp.clear+i !=
-                       EVP_CIPHER_key_length(c))))))
+               || (is_export && ((i != ek) || (s->s2->tmp.clear+(unsigned int)i !=
+                       (unsigned int)EVP_CIPHER_key_length(c))))))
                {
                ERR_clear_error();
                if (is_export)
@@ -440,6 +512,7 @@ static int get_client_master_key(SSL *s)
 #endif
 
        if (is_export) i+=s->s2->tmp.clear;
+       die(i <= SSL_MAX_MASTER_KEY_LENGTH);
        s->session->master_key_length=i;
        memcpy(s->session->master_key,p,(unsigned int)i);
        return(1);
@@ -448,6 +521,7 @@ static int get_client_master_key(SSL *s)
 static int get_client_hello(SSL *s)
        {
        int i,n;
+       unsigned long len;
        unsigned char *p;
        STACK_OF(SSL_CIPHER) *cs; /* a stack of SSL_CIPHERS */
        STACK_OF(SSL_CIPHER) *cl; /* the ones we want to use */
@@ -468,6 +542,7 @@ static int get_client_hello(SSL *s)
                i=ssl2_read(s,(char *)&(p[s->init_num]),9-s->init_num);
                if (i < (9-s->init_num)) 
                        return(ssl2_part_read(s,SSL_F_GET_CLIENT_HELLO,i));
+               s->init_num = 9;
        
                if (*(p++) != SSL2_MT_CLIENT_HELLO)
                        {
@@ -492,15 +567,22 @@ static int get_client_hello(SSL *s)
                        return(-1);
                        }
                s->state=SSL2_ST_GET_CLIENT_HELLO_C;
-               s->init_num=0;
                }
 
        /* SSL2_ST_GET_CLIENT_HELLO_C */
        p=(unsigned char *)s->init_buf->data;
-       n=s->s2->tmp.cipher_spec_length+s->s2->challenge_length+
-               s->s2->tmp.session_id_length-s->init_num;
-       i=ssl2_read(s,(char *)&(p[s->init_num]),n);
+       len = 9 + (unsigned long)s->s2->tmp.cipher_spec_length + (unsigned long)s->s2->challenge_length + (unsigned long)s->s2->tmp.session_id_length;
+       if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
+               {
+               SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_MESSAGE_TOO_LONG);
+               return -1;
+               }
+       n = (int)len - s->init_num;
+       i = ssl2_read(s,(char *)&(p[s->init_num]),n);
        if (i != n) return(ssl2_part_read(s,SSL_F_GET_CLIENT_HELLO,i));
+       if (s->msg_callback)
+               s->msg_callback(0, s->version, 0, p, (size_t)len, s, s->msg_callback_arg); /* CLIENT-HELLO */
+       p += 9;
 
        /* get session-id before cipher stuff so we can get out session
         * structure if it is cached */
@@ -597,6 +679,7 @@ static int get_client_hello(SSL *s)
        p+=s->s2->tmp.session_id_length;
 
        /* challenge */
+       die(s->s2->challenge_length <= sizeof s->s2->challenge);
        memcpy(s->s2->challenge,p,(unsigned int)s->s2->challenge_length);
        return(1);
 mem_err:
@@ -722,7 +805,8 @@ static int server_hello(SSL *s)
 static int get_client_finished(SSL *s)
        {
        unsigned char *p;
-       int i;
+       int i, n;
+       unsigned long len;
 
        p=(unsigned char *)s->init_buf->data;
        if (s->state == SSL2_ST_GET_CLIENT_FINISHED_A)
@@ -730,6 +814,7 @@ static int get_client_finished(SSL *s)
                i=ssl2_read(s,(char *)&(p[s->init_num]),1-s->init_num);
                if (i < 1-s->init_num)
                        return(ssl2_part_read(s,SSL_F_GET_CLIENT_FINISHED,i));
+               s->init_num += i;
 
                if (*p != SSL2_MT_CLIENT_FINISHED)
                        {
@@ -739,19 +824,29 @@ static int get_client_finished(SSL *s)
                                SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_READ_WRONG_PACKET_TYPE);
                                }
                        else
+                               {
                                SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_PEER_ERROR);
+                               /* try to read the error message */
+                               i=ssl2_read(s,(char *)&(p[s->init_num]),3-s->init_num);
+                               return ssl2_part_read(s,SSL_F_GET_SERVER_VERIFY,i);
+                               }
                        return(-1);
                        }
-               s->init_num=0;
                s->state=SSL2_ST_GET_CLIENT_FINISHED_B;
                }
 
        /* SSL2_ST_GET_CLIENT_FINISHED_B */
-       i=ssl2_read(s,(char *)&(p[s->init_num]),s->s2->conn_id_length-s->init_num);
-       if (i < (int)s->s2->conn_id_length-s->init_num)
+       die(s->s2->conn_id_length <= sizeof s->s2->conn_id);
+       len = 1 + (unsigned long)s->s2->conn_id_length;
+       n = (int)len - s->init_num;
+       i = ssl2_read(s,(char *)&(p[s->init_num]),n);
+       if (i < n)
                {
                return(ssl2_part_read(s,SSL_F_GET_CLIENT_FINISHED,i));
                }
+       if (s->msg_callback)
+               s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* CLIENT-FINISHED */
+       p += 1;
        if (memcmp(p,s->s2->conn_id,(unsigned int)s->s2->conn_id_length) != 0)
                {
                ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
@@ -769,6 +864,7 @@ static int server_verify(SSL *s)
                {
                p=(unsigned char *)s->init_buf->data;
                *(p++)=SSL2_MT_SERVER_VERIFY;
+               die(s->s2->challenge_length <= sizeof s->s2->challenge);
                memcpy(p,s->s2->challenge,(unsigned int)s->s2->challenge_length);
                /* p+=s->s2->challenge_length; */
 
@@ -788,6 +884,8 @@ static int server_finish(SSL *s)
                p=(unsigned char *)s->init_buf->data;
                *(p++)=SSL2_MT_SERVER_FINISHED;
 
+               die(s->session->session_id_length
+                   <= sizeof s->session->session_id);
                memcpy(p,s->session->session_id,
                        (unsigned int)s->session->session_id_length);
                /* p+=s->session->session_id_length; */
@@ -807,6 +905,7 @@ static int request_certificate(SSL *s)
        unsigned char *p,*p2,*buf2;
        unsigned char *ccd;
        int i,j,ctype,ret= -1;
+       unsigned long len;
        X509 *x509=NULL;
        STACK_OF(X509) *sk=NULL;
 
@@ -840,16 +939,31 @@ static int request_certificate(SSL *s)
        if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_C)
                {
                p=(unsigned char *)s->init_buf->data;
-               i=ssl2_read(s,(char *)&(p[s->init_num]),6-s->init_num);
-               if (i < 3)
+               i=ssl2_read(s,(char *)&(p[s->init_num]),6-s->init_num); /* try to read 6 octets ... */
+               if (i < 3-s->init_num) /* ... but don't call ssl2_part_read now if we got at least 3
+                                       * (probably NO-CERTIFICATE-ERROR) */
                        {
                        ret=ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE,i);
                        goto end;
                        }
+               s->init_num += i;
 
-               if ((*p == SSL2_MT_ERROR) && (i >= 3))
+               if ((s->init_num >= 3) && (p[0] == SSL2_MT_ERROR))
                        {
                        n2s(p,i);
+                       if (i != SSL2_PE_NO_CERTIFICATE)
+                               {
+                               /* not the error message we expected -- let ssl2_part_read handle it */
+                               s->init_num -= 3;
+                               ret = ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE, 3);
+                               goto end;
+                               }
+
+                       if (s->msg_callback)
+                               s->msg_callback(0, s->version, 0, p, 3, s, s->msg_callback_arg); /* ERROR */
+
+                       /* this is the one place where we can recover from an SSL 2.0 error */
+
                        if (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)
                                {
                                ssl2_return_error(s,SSL2_PE_BAD_CERTIFICATE);
@@ -859,12 +973,18 @@ static int request_certificate(SSL *s)
                        ret=1;
                        goto end;
                        }
-               if ((*(p++) != SSL2_MT_CLIENT_CERTIFICATE) || (i < 6))
+               if ((*(p++) != SSL2_MT_CLIENT_CERTIFICATE) || (s->init_num < 6))
                        {
                        ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
                        SSLerr(SSL_F_REQUEST_CERTIFICATE,SSL_R_SHORT_READ);
                        goto end;
                        }
+               if (s->init_num != 6)
+                       {
+                       SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_INTERNAL_ERROR);
+                       goto end;
+                       }
+               
                /* ok we have a response */
                /* certificate type, there is only one right now. */
                ctype= *(p++);
@@ -877,18 +997,26 @@ static int request_certificate(SSL *s)
                n2s(p,i); s->s2->tmp.clen=i;
                n2s(p,i); s->s2->tmp.rlen=i;
                s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_D;
-               s->init_num=0;
                }
 
        /* SSL2_ST_SEND_REQUEST_CERTIFICATE_D */
        p=(unsigned char *)s->init_buf->data;
-       j=s->s2->tmp.clen+s->s2->tmp.rlen-s->init_num;
-       i=ssl2_read(s,(char *)&(p[s->init_num]),j);
+       len = 6 + (unsigned long)s->s2->tmp.clen + (unsigned long)s->s2->tmp.rlen;
+       if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
+               {
+               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_MESSAGE_TOO_LONG);
+               goto end;
+               }
+       j = (int)len - s->init_num;
+       i = ssl2_read(s,(char *)&(p[s->init_num]),j);
        if (i < j) 
                {
                ret=ssl2_part_read(s,SSL_F_REQUEST_CERTIFICATE,i);
                goto end;
                }
+       if (s->msg_callback)
+               s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* CLIENT-CERTIFICATE */
+       p += 6;
 
        x509=(X509 *)d2i_X509(NULL,&p,(long)s->s2->tmp.clen);
        if (x509 == NULL)
@@ -911,7 +1039,7 @@ static int request_certificate(SSL *s)
                EVP_PKEY *pkey=NULL;
 
                EVP_MD_CTX_init(&ctx);
-               EVP_VerifyInit(&ctx,s->ctx->rsa_md5);
+               EVP_VerifyInit_ex(&ctx,s->ctx->rsa_md5, NULL);
                EVP_VerifyUpdate(&ctx,s->s2->key_material,
                        (unsigned int)s->s2->key_material_length);
                EVP_VerifyUpdate(&ctx,ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);