Assorted bugfixes:
[openssl.git] / ssl / s2_srvr.c
index e219ae5e325f843bc5ff3094eda91f571f9ebbcb..bc885e8e7f6dbc440001b025d8a3315df759152b 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).
+ *
+ */
 
-#ifndef NO_RSA
+#include "ssl_locl.h"
+#ifndef OPENSSL_NO_SSL2
 #include <stdio.h>
 #include <openssl/bio.h>
 #include <openssl/rand.h>
 #include <openssl/objects.h>
-#include "ssl_locl.h"
 #include <openssl/evp.h>
 
-static SSL_METHOD *ssl2_get_server_method(int ver);
+static const SSL_METHOD *ssl2_get_server_method(int ver);
 static int get_client_master_key(SSL *s);
 static int get_client_hello(SSL *s);
 static int server_hello(SSL *s); 
@@ -76,7 +129,7 @@ static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
        unsigned char *to,int padding);
 #define BREAK  break
 
-static SSL_METHOD *ssl2_get_server_method(int ver)
+static const SSL_METHOD *ssl2_get_server_method(int ver)
        {
        if (ver == SSL2_VERSION)
                return(SSLv2_server_method());
@@ -84,32 +137,21 @@ static SSL_METHOD *ssl2_get_server_method(int ver)
                return(NULL);
        }
 
-SSL_METHOD *SSLv2_server_method(void)
-       {
-       static int init=1;
-       static SSL_METHOD SSLv2_server_data;
-
-       if (init)
-               {
-               memcpy((char *)&SSLv2_server_data,(char *)sslv2_base_method(),
-                       sizeof(SSL_METHOD));
-               SSLv2_server_data.ssl_accept=ssl2_accept;
-               SSLv2_server_data.get_ssl_method=ssl2_get_server_method;
-               init=0;
-               }
-       return(&SSLv2_server_data);
-       }
+IMPLEMENT_ssl2_meth_func(SSLv2_server_method,
+                       ssl2_accept,
+                       ssl_undefined_function,
+                       ssl2_get_server_method)
 
 int ssl2_accept(SSL *s)
        {
-       unsigned long l=time(NULL);
+       unsigned long l=(unsigned long)time(NULL);
        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_seed(&l,sizeof(l));
+       RAND_add(&l,sizeof(l),0);
        ERR_clear_error();
        clear_sys_error();
 
@@ -119,8 +161,8 @@ 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)
                {
@@ -225,7 +267,7 @@ int ssl2_accept(SSL *s)
                case SSL2_ST_SEND_SERVER_VERIFY_C:
                        /* get the number of bytes to write */
                        num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
-                       if (num1 != 0)
+                       if (num1 > 0)
                                {
                                s->rwstate=SSL_WRITING;
                                num1=BIO_flush(s->wbio);
@@ -322,8 +364,9 @@ 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 SSL_CIPHER *cp;
        const EVP_CIPHER *c;
        const EVP_MD *md;
 
@@ -334,6 +377,8 @@ 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)
@@ -342,8 +387,7 @@ static int get_client_master_key(SSL *s)
                                SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_READ_WRONG_PACKET_TYPE);
                                }
                        else
-                               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
-                                       SSL_R_PEER_ERROR);
+                               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_PEER_ERROR);
                        return(-1);
                        }
 
@@ -351,8 +395,7 @@ static int get_client_master_key(SSL *s)
                if (cp == NULL)
                        {
                        ssl2_return_error(s,SSL2_PE_NO_CIPHER);
-                       SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
-                               SSL_R_NO_CIPHER_MATCH);
+                       SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_CIPHER_MATCH);
                        return(-1);
                        }
                s->session->cipher= cp;
@@ -360,17 +403,39 @@ static int get_client_master_key(SSL *s)
                p+=3;
                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;
+               n2s(p,i);
+               if(i > SSL_MAX_KEY_ARG_LENGTH)
+                       {
+                       ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+                       SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_KEY_ARG_TOO_LONG);
+                       return -1;
+                       }
+               s->session->key_arg_length=i;
                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;
+       if (s->init_buf->length < SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, ERR_R_INTERNAL_ERROR);
+               return -1;
+               }
        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)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               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);
@@ -387,7 +452,7 @@ static int get_client_master_key(SSL *s)
 
        is_export=SSL_C_IS_EXPORT(s->session->cipher);
        
-       if (!ssl_cipher_get_evp(s->session,&c,&md,NULL))
+       if (!ssl_cipher_get_evp(s->session,&c,&md,NULL,NULL,NULL))
                {
                ssl2_return_error(s,SSL2_PE_NO_CIPHER);
                SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
@@ -405,17 +470,19 @@ static int get_client_master_key(SSL *s)
        /* bad decrypt */
 #if 1
        /* If a bad decrypt, continue with protocol but with a
-        * dud master secret */
+        * 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)
                        i=ek;
                else
                        i=EVP_CIPHER_key_length(c);
-               RAND_bytes(p,i);
+               if (RAND_pseudo_bytes(p,i) <= 0)
+                       return 0;
                }
 #else
        if (i < 0)
@@ -439,6 +506,13 @@ static int get_client_master_key(SSL *s)
 #endif
 
        if (is_export) i+=s->s2->tmp.clear;
+
+       if (i > SSL_MAX_MASTER_KEY_LENGTH)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, ERR_R_INTERNAL_ERROR);
+               return -1;
+               }
        s->session->master_key_length=i;
        memcpy(s->session->master_key,p,(unsigned int)i);
        return(1);
@@ -447,9 +521,11 @@ 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 */
+       STACK_OF(SSL_CIPHER) *prio, *allow;
        int z;
 
        /* This is a bit of a hack to check for the correct packet
@@ -466,6 +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)
                        {
@@ -486,19 +563,28 @@ static int get_client_hello(SSL *s)
                if (    (i < SSL2_MIN_CHALLENGE_LENGTH) ||
                        (i > SSL2_MAX_CHALLENGE_LENGTH))
                        {
+                       ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
                        SSLerr(SSL_F_GET_CLIENT_HELLO,SSL_R_INVALID_CHALLENGE_LENGTH);
                        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)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               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 */
@@ -522,7 +608,7 @@ static int get_client_hello(SSL *s)
        else
                {
                i=ssl_get_prev_session(s,&(p[s->s2->tmp.cipher_spec_length]),
-                       s->s2->tmp.session_id_length);
+                       s->s2->tmp.session_id_length, NULL);
                if (i == 1)
                        { /* previous session */
                        s->hit=1;
@@ -555,21 +641,37 @@ static int get_client_hello(SSL *s)
                        &s->session->ciphers);
                if (cs == NULL) goto mem_err;
 
-               cl=ssl_get_ciphers_by_id(s);
+               cl=SSL_get_ciphers(s);
 
-               for (z=0; z<sk_SSL_CIPHER_num(cs); z++)
+               if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE)
+                   {
+                   prio=sk_SSL_CIPHER_dup(cl);
+                   if (prio == NULL) goto mem_err;
+                   allow = cs;
+                   }
+               else
+                   {
+                   prio = cs;
+                   allow = cl;
+                   }
+               for (z=0; z<sk_SSL_CIPHER_num(prio); z++)
                        {
-                       if (sk_SSL_CIPHER_find(cl,sk_SSL_CIPHER_value(cs,z)) < 0)
+                       if (sk_SSL_CIPHER_find(allow,sk_SSL_CIPHER_value(prio,z)) < 0)
                                {
-                               sk_SSL_CIPHER_delete(cs,z);
+                               (void)sk_SSL_CIPHER_delete(prio,z);
                                z--;
                                }
                        }
-
+               if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE)
+                   {
+                   sk_SSL_CIPHER_free(s->session->ciphers);
+                   s->session->ciphers = prio;
+                   }
                /* s->session->ciphers should now have a list of
                 * ciphers that are on both the client and server.
                 * This list is ordered by the order the client sent
-                * the ciphers.
+                * the ciphers or in the order of the server's preference
+                * if SSL_OP_CIPHER_SERVER_PREFERENCE was set.
                 */
                }
        p+=s->s2->tmp.cipher_spec_length;
@@ -579,6 +681,12 @@ static int get_client_hello(SSL *s)
        p+=s->s2->tmp.session_id_length;
 
        /* challenge */
+       if (s->s2->challenge_length > sizeof s->s2->challenge)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               SSLerr(SSL_F_GET_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
+               return -1;
+               }
        memcpy(s->s2->challenge,p,(unsigned int)s->s2->challenge_length);
        return(1);
 mem_err:
@@ -590,7 +698,6 @@ static int server_hello(SSL *s)
        {
        unsigned char *p,*d;
        int n,hit;
-       STACK_OF(SSL_CIPHER) *sk;
 
        p=(unsigned char *)s->init_buf->data;
        if (s->state == SSL2_ST_SEND_SERVER_HELLO_A)
@@ -671,8 +778,7 @@ static int server_hello(SSL *s)
                        
                        /* lets send out the ciphers we like in the
                         * prefered order */
-                       sk= s->session->ciphers;
-                       n=ssl_cipher_list_to_bytes(s,s->session->ciphers,d);
+                       n=ssl_cipher_list_to_bytes(s,s->session->ciphers,d,0);
                        d+=n;
                        s2n(n,p);               /* add cipher length */
                        }
@@ -680,7 +786,8 @@ static int server_hello(SSL *s)
                /* make and send conn_id */
                s2n(SSL2_CONNECTION_ID_LENGTH,p);       /* add conn_id length */
                s->s2->conn_id_length=SSL2_CONNECTION_ID_LENGTH;
-               RAND_bytes(s->s2->conn_id,(int)s->s2->conn_id_length);
+               if (RAND_pseudo_bytes(s->s2->conn_id,(int)s->s2->conn_id_length) <= 0)
+                       return -1;
                memcpy(d,s->s2->conn_id,SSL2_CONNECTION_ID_LENGTH);
                d+=SSL2_CONNECTION_ID_LENGTH;
 
@@ -689,7 +796,7 @@ static int server_hello(SSL *s)
                s->init_off=0;
                }
        /* SSL2_ST_SEND_SERVER_HELLO_B */
-       /* If we are using TCP/IP, the performace is bad if we do 2
+       /* If we are using TCP/IP, the performance is bad if we do 2
         * writes without a read between them.  This occurs when
         * Session-id reuse is used, so I will put in a buffering module
         */
@@ -704,7 +811,8 @@ 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)
@@ -712,6 +820,7 @@ 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)
                        {
@@ -721,20 +830,35 @@ 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)
+       if (s->s2->conn_id_length > sizeof s->s2->conn_id)
+               {
+               ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
+               SSLerr(SSL_F_GET_CLIENT_FINISHED, ERR_R_INTERNAL_ERROR);
+               return -1;
+               }
+       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 (memcmp(p,s->s2->conn_id,(unsigned int)s->s2->conn_id_length) != 0)
+       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,s->s2->conn_id_length) != 0)
                {
                ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
                SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_CONNECTION_ID_IS_DIFFERENT);
@@ -751,6 +875,11 @@ static int server_verify(SSL *s)
                {
                p=(unsigned char *)s->init_buf->data;
                *(p++)=SSL2_MT_SERVER_VERIFY;
+               if (s->s2->challenge_length > sizeof s->s2->challenge)
+                       {
+                       SSLerr(SSL_F_SERVER_VERIFY, ERR_R_INTERNAL_ERROR);
+                       return -1;
+                       }
                memcpy(p,s->s2->challenge,(unsigned int)s->s2->challenge_length);
                /* p+=s->s2->challenge_length; */
 
@@ -770,8 +899,12 @@ static int server_finish(SSL *s)
                p=(unsigned char *)s->init_buf->data;
                *(p++)=SSL2_MT_SERVER_FINISHED;
 
-               memcpy(p,s->session->session_id,
-                       (unsigned int)s->session->session_id_length);
+               if (s->session->session_id_length > sizeof s->session->session_id)
+                       {
+                       SSLerr(SSL_F_SERVER_FINISH, ERR_R_INTERNAL_ERROR);
+                       return -1;
+                       }
+               memcpy(p,s->session->session_id, (unsigned int)s->session->session_id_length);
                /* p+=s->session->session_id_length; */
 
                s->state=SSL2_ST_SEND_SERVER_FINISHED_B;
@@ -786,9 +919,11 @@ static int server_finish(SSL *s)
 /* send the request and check the response */
 static int request_certificate(SSL *s)
        {
+       const unsigned char *cp;
        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;
 
@@ -798,7 +933,8 @@ static int request_certificate(SSL *s)
                p=(unsigned char *)s->init_buf->data;
                *(p++)=SSL2_MT_REQUEST_CERTIFICATE;
                *(p++)=SSL2_AT_MD5_WITH_RSA_ENCRYPTION;
-               RAND_bytes(ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
+               if (RAND_pseudo_bytes(ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH) <= 0)
+                       return -1;
                memcpy(p,ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
 
                s->state=SSL2_ST_SEND_REQUEST_CERTIFICATE_B;
@@ -822,16 +958,31 @@ 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);
@@ -841,12 +992,18 @@ 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++);
@@ -859,20 +1016,29 @@ 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_REQUEST_CERTIFICATE,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);
+       cp = p;
+       x509=(X509 *)d2i_X509(NULL,&cp,(long)s->s2->tmp.clen);
        if (x509 == NULL)
                {
                SSLerr(SSL_F_REQUEST_CERTIFICATE,ERR_R_X509_LIB);
@@ -887,18 +1053,19 @@ static int request_certificate(SSL *s)
 
        i=ssl_verify_cert_chain(s,sk);
 
-       if (i)  /* we like the packet, now check the chksum */
+       if (i > 0)      /* we like the packet, now check the chksum */
                {
                EVP_MD_CTX ctx;
                EVP_PKEY *pkey=NULL;
 
-               EVP_VerifyInit(&ctx,s->ctx->rsa_md5);
+               EVP_MD_CTX_init(&ctx);
+               EVP_VerifyInit_ex(&ctx,s->ctx->rsa_md5, NULL);
                EVP_VerifyUpdate(&ctx,s->s2->key_material,
-                       (unsigned int)s->s2->key_material_length);
+                                s->s2->key_material_length);
                EVP_VerifyUpdate(&ctx,ccd,SSL2_MIN_CERT_CHALLENGE_LENGTH);
 
                i=i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,NULL);
-               buf2=(unsigned char *)Malloc((unsigned int)i);
+               buf2=OPENSSL_malloc((unsigned int)i);
                if (buf2 == NULL)
                        {
                        SSLerr(SSL_F_REQUEST_CERTIFICATE,ERR_R_MALLOC_FAILURE);
@@ -907,15 +1074,15 @@ static int request_certificate(SSL *s)
                p2=buf2;
                i=i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509,&p2);
                EVP_VerifyUpdate(&ctx,buf2,(unsigned int)i);
-               Free(buf2);
+               OPENSSL_free(buf2);
 
                pkey=X509_get_pubkey(x509);
                if (pkey == NULL) goto end;
-               i=EVP_VerifyFinal(&ctx,p,s->s2->tmp.rlen,pkey);
+               i=EVP_VerifyFinal(&ctx,cp,s->s2->tmp.rlen,pkey);
                EVP_PKEY_free(pkey);
-               memset(&ctx,0,sizeof(ctx));
+               EVP_MD_CTX_cleanup(&ctx);
 
-               if (i
+               if (i > 0)
                        {
                        if (s->session->peer != NULL)
                                X509_free(s->session->peer);
@@ -966,7 +1133,7 @@ static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
                SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT,ERR_R_RSA_LIB);
        return(i);
        }
-#else /* !NO_RSA */
+#else /* !OPENSSL_NO_SSL2 */
 
 # if PEDANTIC
 static void *dummy=&dummy;