From cf82191d77a0a8f77894a65185b6f7a4b3855d6c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Bodo=20M=C3=B6ller?= <bodo@openssl.org>
Date: Sat, 10 Nov 2001 01:16:28 +0000
Subject: [PATCH] Implement msg_callback for SSL 2.0.

Important SSL 2.0 bugfixes (bugs found while implementing msg_callback).
---
 CHANGES        |   5 +-
 ssl/s23_clnt.c |   7 ++-
 ssl/s23_srvr.c |   4 +-
 ssl/s2_clnt.c  | 123 ++++++++++++++++++++++++++++++++--------
 ssl/s2_lib.c   |  10 +++-
 ssl/s2_pkt.c   |  39 ++++++++-----
 ssl/s2_srvr.c  | 149 ++++++++++++++++++++++++++++++++++++++++++-------
 ssl/ssl.h      |   1 +
 ssl/ssl2.h     |   6 +-
 ssl/ssl_err.c  |   1 +
 10 files changed, 279 insertions(+), 66 deletions(-)

diff --git a/CHANGES b/CHANGES
index 8f282ff4e2..437c07ec6a 100644
--- a/CHANGES
+++ b/CHANGES
@@ -111,8 +111,11 @@
 
      'openssl s_client' and 'openssl s_server' have new '-msg' options
      to enable a callback that displays all protocol messages.
+     [Bodo Moeller]
 
-     TODO: SSL 2.0, doc/ssl/, doc/apps/
+  *) Change ssl/s2_clnt.c and ssl/s3_srvr.c so that received handshake
+     messages are stored in a single piece (fixed-length part and
+     variable-length part) and fix various bugs found on the way.
      [Bodo Moeller]
 
   *) In ssl3_get_client_hello (ssl/s3_srvr.c), generate a fatal alert
diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c
index dd2562af15..d74245384a 100644
--- a/ssl/s23_clnt.c
+++ b/ssl/s23_clnt.c
@@ -211,6 +211,7 @@ static int ssl23_client_hello(SSL *s)
 	unsigned char *buf;
 	unsigned char *p,*d;
 	int i,ch_len;
+	int ret;
 
 	buf=(unsigned char *)s->init_buf->data;
 	if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
@@ -302,7 +303,11 @@ static int ssl23_client_hello(SSL *s)
 		}
 
 	/* SSL3_ST_CW_CLNT_HELLO_B */
-	return(ssl23_write_bytes(s));
+	ret = ssl23_write_bytes(s);
+	if (ret >= 2)
+		if (s->msg_callback)
+			s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
+	return ret;
 	}
 
 static int ssl23_get_server_hello(SSL *s)
diff --git a/ssl/s23_srvr.c b/ssl/s23_srvr.c
index f2e1dc4173..bcf8e51c5d 100644
--- a/ssl/s23_srvr.c
+++ b/ssl/s23_srvr.c
@@ -420,7 +420,9 @@ int ssl23_get_client_hello(SSL *s)
 		j=ssl23_read_bytes(s,n+2);
 		if (j <= 0) return(j);
 
-		ssl3_finish_mac(s,&(s->packet[2]),s->packet_length-2);
+		ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
+		if (s->msg_callback)
+			s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
 
 		p=s->packet;
 		p+=5;
diff --git a/ssl/s2_clnt.c b/ssl/s2_clnt.c
index 8cb7388ef9..3a990e42cc 100644
--- a/ssl/s2_clnt.c
+++ b/ssl/s2_clnt.c
@@ -55,6 +55,59 @@
  * 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
@@ -287,6 +340,7 @@ static int get_server_hello(SSL *s)
 	unsigned char *buf;
 	unsigned char *p;
 	int i,j;
+	unsigned long len;
 	STACK_OF(SSL_CIPHER) *sk=NULL,*cl, *prio, *allow;
 
 	buf=(unsigned char *)s->init_buf->data;
@@ -296,6 +350,7 @@ static int get_server_hello(SSL *s)
 		i=ssl2_read(s,(char *)&(buf[s->init_num]),11-s->init_num);
 		if (i < (11-s->init_num)) 
 			return(ssl2_part_read(s,SSL_F_GET_SERVER_HELLO,i));
+		s->init_num = 11;
 
 		if (*(p++) != SSL2_MT_SERVER_HELLO)
 			{
@@ -324,18 +379,24 @@ static int get_server_hello(SSL *s)
 		n2s(p,i); s->s2->tmp.csl=i;
 		n2s(p,i); s->s2->tmp.conn_id_length=i;
 		s->state=SSL2_ST_GET_SERVER_HELLO_B;
-		s->init_num=0;
 		}
 
 	/* SSL2_ST_GET_SERVER_HELLO_B */
-	j=s->s2->tmp.cert_length+s->s2->tmp.csl+s->s2->tmp.conn_id_length
-		- s->init_num;
-	i=ssl2_read(s,(char *)&(buf[s->init_num]),j);
+	len = 11 + (unsigned long)s->s2->tmp.cert_length + (unsigned long)s->s2->tmp.csl + (unsigned long)s->s2->tmp.conn_id_length;
+	if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
+		{
+		SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_MESSAGE_TOO_LONG);
+		return -1;
+		}
+	j = (int)len - s->init_num;
+	i = ssl2_read(s,(char *)&(buf[s->init_num]),j);
 	if (i != j) return(ssl2_part_read(s,SSL_F_GET_SERVER_HELLO,i));
+	if (s->msg_callback)
+		s->msg_callback(0, s->version, 0, buf, (size_t)len, s, s->msg_callback_arg); /* SERVER-HELLO */
 
 	/* things are looking good */
 
-	p=buf;
+	p = buf + 11;
 	if (s->hit)
 		{
 		if (s->s2->tmp.cert_length != 0) 
@@ -661,11 +722,10 @@ static int client_certificate(SSL *s)
 	unsigned char *p,*d;
 	int i;
 	unsigned int n;
-	int cert_ch_len=0;
+	int cert_ch_len;
 	unsigned char *cert_ch;
 
 	buf=(unsigned char *)s->init_buf->data;
-	cert_ch= &(buf[2]);
 
 	/* We have a cert associated with the SSL, so attach it to
 	 * the session if it does not have one */
@@ -676,6 +736,9 @@ static int client_certificate(SSL *s)
 			SSL2_MAX_CERT_CHALLENGE_LENGTH+1-s->init_num);
 		if (i<(SSL2_MIN_CERT_CHALLENGE_LENGTH+1-s->init_num))
 			return(ssl2_part_read(s,SSL_F_CLIENT_CERTIFICATE,i));
+		s->init_num += i;
+		if (s->msg_callback)
+			s->msg_callback(0, s->version, 0, buf, (size_t)s->init_num, s, s->msg_callback_arg); /* REQUEST-CERTIFICATE */
 
 		/* type=buf[0]; */
 		/* type eq x509 */
@@ -685,7 +748,6 @@ static int client_certificate(SSL *s)
 			SSLerr(SSL_F_CLIENT_CERTIFICATE,SSL_R_BAD_AUTHENTICATION_TYPE);
 			return(-1);
 			}
-		cert_ch_len=i-1;
 
 		if ((s->cert == NULL) ||
 			(s->cert->key->x509 == NULL) ||
@@ -697,6 +759,9 @@ static int client_certificate(SSL *s)
 			s->state=SSL2_ST_SEND_CLIENT_CERTIFICATE_C;
 		}
 
+	cert_ch = buf + 2;
+	cert_ch_len = s->init_num - 2;
+
 	if (s->state == SSL2_ST_X509_GET_CLIENT_CERTIFICATE)
 		{
 		X509 *x509=NULL;
@@ -803,17 +868,17 @@ static int client_certificate(SSL *s)
 static int get_server_verify(SSL *s)
 	{
 	unsigned char *p;
-	int i;
+	int i, n, len;
 
 	p=(unsigned char *)s->init_buf->data;
 	if (s->state == SSL2_ST_GET_SERVER_VERIFY_A)
 		{
-		i=ssl2_read(s,(char *)&(p[s->init_num]),1-s->init_num);
-		if (i < (1-s->init_num)) 
+		i=ssl2_read(s,(char *)&(p[s->init_num]),3-s->init_num);
+		if (i < (3-s->init_num)) 
 			return(ssl2_part_read(s,SSL_F_GET_SERVER_VERIFY,i));
+		s->init_num += i;
 
 		s->state= SSL2_ST_GET_SERVER_VERIFY_B;
-		s->init_num=0;
 		if (*p != SSL2_MT_SERVER_VERIFY)
 			{
 			if (p[0] != SSL2_MT_ERROR)
@@ -830,10 +895,15 @@ static int get_server_verify(SSL *s)
 		}
 	
 	p=(unsigned char *)s->init_buf->data;
-	i=ssl2_read(s,(char *)&(p[s->init_num]),
-		(unsigned int)s->s2->challenge_length-s->init_num);
-	if (i < ((int)s->s2->challenge_length-s->init_num))
+	len = 1 + s->s2->challenge_length;
+	n =  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_SERVER_VERIFY,i));
+	if (s->msg_callback)
+		s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* SERVER-VERIFY */
+	p += 1;
+
 	if (memcmp(p,s->s2->challenge,(unsigned int)s->s2->challenge_length) != 0)
 		{
 		ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
@@ -847,16 +917,17 @@ static int get_server_finished(SSL *s)
 	{
 	unsigned char *buf;
 	unsigned char *p;
-	int i;
+	int i, n, len;
 
 	buf=(unsigned char *)s->init_buf->data;
 	p=buf;
 	if (s->state == SSL2_ST_GET_SERVER_FINISHED_A)
 		{
-		i=ssl2_read(s,(char *)&(buf[s->init_num]),1-s->init_num);
-		if (i < (1-s->init_num))
+		i=ssl2_read(s,(char *)&(buf[s->init_num]),3-s->init_num);
+		if (i < (3-s->init_num))
 			return(ssl2_part_read(s,SSL_F_GET_SERVER_FINISHED,i));
-		s->init_num=i;
+		s->init_num += i;
+
 		if (*p == SSL2_MT_REQUEST_CERTIFICATE)
 			{
 			s->state=SSL2_ST_SEND_CLIENT_CERTIFICATE_A;
@@ -873,14 +944,17 @@ static int get_server_finished(SSL *s)
 				SSLerr(SSL_F_GET_SERVER_FINISHED,SSL_R_PEER_ERROR);
 			return(-1);
 			}
-		s->state=SSL_ST_OK;
-		s->init_num=0;
+		s->state=SSL2_ST_GET_SERVER_FINISHED_B;
 		}
 
-	i=ssl2_read(s,(char *)&(buf[s->init_num]),
-		SSL2_SSL_SESSION_ID_LENGTH-s->init_num);
-	if (i < (SSL2_SSL_SESSION_ID_LENGTH-s->init_num))
+	len = 1 + SSL2_SSL_SESSION_ID_LENGTH;
+	n = len - s->init_num;
+	i = ssl2_read(s,(char *)&(buf[s->init_num]), n);
+	if (i < n) /* XXX could be shorter than SSL2_SSL_SESSION_ID_LENGTH, that's the maximum */
 		return(ssl2_part_read(s,SSL_F_GET_SERVER_FINISHED,i));
+	s->init_num += i;
+	if (s->msg_callback)
+		s->msg_callback(0, s->version, 0, buf, (size_t)s->init_num, s, s->msg_callback_arg); /* SERVER-FINISHED */
 
 	if (!s->hit) /* new session */
 		{
@@ -904,6 +978,7 @@ static int get_server_finished(SSL *s)
 				}
 			}
 		}
+	s->state = SSL_ST_OK;
 	return(1);
 	}
 
diff --git a/ssl/s2_lib.c b/ssl/s2_lib.c
index aaca270fc6..bce2b4e83f 100644
--- a/ssl/s2_lib.c
+++ b/ssl/s2_lib.c
@@ -470,10 +470,14 @@ void ssl2_write_error(SSL *s)
 
 	if (i < 0)
 		s->error=error;
-	else if (i != s->error)
+	else
+		{
 		s->error=error-i;
-	/* else
-		s->error=0; */
+
+		if (s->error == 0)
+			if (s->msg_callback)
+				s->msg_callback(1, s->version, 0, buf, 3, s, s->msg_callback_arg); /* ERROR */
+		}
 	}
 
 int ssl2_shutdown(SSL *s)
diff --git a/ssl/s2_pkt.c b/ssl/s2_pkt.c
index 1bb0ef1e8f..cf0aee2bd6 100644
--- a/ssl/s2_pkt.c
+++ b/ssl/s2_pkt.c
@@ -56,7 +56,7 @@
  * [including the GNU Public Licence.]
  */
 /* ====================================================================
- * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
+ * 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
@@ -651,27 +651,36 @@ int ssl2_part_read(SSL *s, unsigned long f, int i)
 	unsigned char *p;
 	int j;
 
-	/* check for error */
-	if ((s->init_num == 0) && (i >= 3))
-		{
-		p=(unsigned char *)s->init_buf->data;
-		if (p[0] == SSL2_MT_ERROR)
-			{
-			j=(p[1]<<8)|p[2];
-			SSLerr((int)f,ssl_mt_error(j));
-			}
-		}
-
 	if (i < 0)
 		{
 		/* ssl2_return_error(s); */
 		/* for non-blocking io,
-		 * this is not fatal */
+		 * this is not necessarily fatal */
 		return(i);
 		}
 	else
 		{
 		s->init_num+=i;
+
+		/* Check for error.  While there are recoverable errors,
+		 * this function is not called when those must be expected;
+		 * any error detected here is fatal. */
+		if (s->init_num >= 3)
+			{
+			p=(unsigned char *)s->init_buf->data;
+			if (p[0] == SSL2_MT_ERROR)
+				{
+				j=(p[1]<<8)|p[2];
+				SSLerr((int)f,ssl_mt_error(j));
+				s->init_num -= 3;
+				if (s->init_num > 0)
+					memmove(p, p+3, s->init_num);
+				}
+			}
+
+		/* If it's not an error message, we have some error anyway --
+		 * the message was shorter than expected.  This too is treated
+		 * as fatal (at least if SSL_get_error is asked for its opinion). */
 		return(0);
 		}
 	}
@@ -682,7 +691,11 @@ int ssl2_do_write(SSL *s)
 
 	ret=ssl2_write(s,&s->init_buf->data[s->init_off],s->init_num);
 	if (ret == s->init_num)
+		{
+		if (s->msg_callback)
+			s->msg_callback(1, s->version, 0, s->init_buf->data, (size_t)(s->init_off + s->init_num), s, s->msg_callback_arg);
 		return(1);
+		}
 	if (ret < 0)
 		return(-1);
 	s->init_off+=ret;
diff --git a/ssl/s2_srvr.c b/ssl/s2_srvr.c
index f849e2b32a..ea07852d1a 100644
--- a/ssl/s2_srvr.c
+++ b/ssl/s2_srvr.c
@@ -55,6 +55,59 @@
  * 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
@@ -322,6 +375,7 @@ 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 +388,8 @@ 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)
@@ -362,15 +418,23 @@ static int get_client_master_key(SSL *s)
 		n2s(p,i); s->s2->tmp.enc=i;
 		n2s(p,i); 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;
 	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);
@@ -448,6 +512,7 @@ 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 +533,7 @@ 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 +558,22 @@ 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 */
@@ -722,14 +795,16 @@ 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)
 		{
-		i=ssl2_read(s,(char *)&(p[s->init_num]),1-s->init_num);
-		if (i < 1-s->init_num)
+		i=ssl2_read(s,(char *)&(p[s->init_num]),3-s->init_num);
+		if (i < 3-s->init_num)
 			return(ssl2_part_read(s,SSL_F_GET_CLIENT_FINISHED,i));
+		s->init_num = 3;
 
 		if (*p != SSL2_MT_CLIENT_FINISHED)
 			{
@@ -742,16 +817,20 @@ static int get_client_finished(SSL *s)
 				SSLerr(SSL_F_GET_CLIENT_FINISHED,SSL_R_PEER_ERROR);
 			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)
+	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);
@@ -807,6 +886,7 @@ 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 +920,31 @@ 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 +954,18 @@ 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 +978,26 @@ 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)
diff --git a/ssl/ssl.h b/ssl/ssl.h
index b366281e8e..611a260c7b 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -1593,6 +1593,7 @@ void ERR_load_SSL_strings(void);
 #define SSL_R_LENGTH_TOO_SHORT				 160
 #define SSL_R_LIBRARY_BUG				 274
 #define SSL_R_LIBRARY_HAS_NO_CIPHERS			 161
+#define SSL_R_MESSAGE_TOO_LONG				 1111
 #define SSL_R_MISSING_DH_DSA_CERT			 162
 #define SSL_R_MISSING_DH_KEY				 163
 #define SSL_R_MISSING_DH_RSA_CERT			 164
diff --git a/ssl/ssl2.h b/ssl/ssl2.h
index a979c355f8..99a52ea0dd 100644
--- a/ssl/ssl2.h
+++ b/ssl/ssl2.h
@@ -208,11 +208,11 @@ typedef struct ssl2_state_st
 		unsigned int conn_id_length;
 		unsigned int cert_type;	
 		unsigned int cert_length;
-		int csl; 
-		int clear;
+		unsigned int csl; 
+		unsigned int clear;
 		unsigned int enc; 
 		unsigned char ccl[SSL2_MAX_CERT_CHALLENGE_LENGTH];
-		int cipher_spec_length;
+		unsigned int cipher_spec_length;
 		unsigned int session_id_length;
 		unsigned int clen;
 		unsigned int rlen;
diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
index 0fdd38dd24..c32c4ef6e9 100644
--- a/ssl/ssl_err.c
+++ b/ssl/ssl_err.c
@@ -290,6 +290,7 @@ static ERR_STRING_DATA SSL_str_reasons[]=
 {SSL_R_LENGTH_TOO_SHORT                  ,"length too short"},
 {SSL_R_LIBRARY_BUG                       ,"library bug"},
 {SSL_R_LIBRARY_HAS_NO_CIPHERS            ,"library has no ciphers"},
+{SSL_R_MESSAGE_TOO_LONG                  ,"message too long"},
 {SSL_R_MISSING_DH_DSA_CERT               ,"missing dh dsa cert"},
 {SSL_R_MISSING_DH_KEY                    ,"missing dh key"},
 {SSL_R_MISSING_DH_RSA_CERT               ,"missing dh rsa cert"},
-- 
2.25.1