Fix for Netscape "hang" bug.
[openssl.git] / ssl / s3_pkt.c
index 85b929cb9ce039a336e0e5ca0be07657dce14dd9..2f56df3e32430719336e933b887a8b6eb76fd757 100644 (file)
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-1999 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 <errno.h>
@@ -71,104 +124,97 @@ static int ssl3_get_record(SSL *s);
 static int do_compress(SSL *ssl);
 static int do_uncompress(SSL *ssl);
 static int do_change_cipher_spec(SSL *ssl);
+
 static int ssl3_read_n(SSL *s, int n, int max, int extend)
        {
+       /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
+        * packet by another n bytes.
+        * The packet will be in the sub-array of s->s3->rbuf.buf specified
+        * by s->packet and s->packet_length.
+        * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
+        * [plus s->packet_length bytes if extend == 1].)
+        */
        int i,off,newb;
 
-       /* if there is stuff still in the buffer from a previous read,
-        * and there is more than we want, take some. */
+       if (!extend)
+               {
+               /* start with empty packet ... */
+               if (s->s3->rbuf.left == 0)
+                       s->s3->rbuf.offset = 0;
+               s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset;
+               s->packet_length = 0;
+               /* ... now we can act as if 'extend' was set */
+               }
+
+       /* if there is enough in the buffer from a previous read, take some */
        if (s->s3->rbuf.left >= (int)n)
                {
-               if (extend)
-                       s->packet_length+=n;
-               else
-                       {
-                       s->packet= &(s->s3->rbuf.buf[s->s3->rbuf.offset]);
-                       s->packet_length=n;
-                       }
+               s->packet_length+=n;
                s->s3->rbuf.left-=n;
                s->s3->rbuf.offset+=n;
                return(n);
                }
 
        /* else we need to read more data */
-       if (!s->read_ahead) max=n;
-       if (max > SSL3_RT_MAX_PACKET_SIZE)
-               max=SSL3_RT_MAX_PACKET_SIZE;
-
-       /* First check if there is some left or we want to extend */
-       off=0;
-       if (    (s->s3->rbuf.left != 0) ||
-               ((s->packet_length != 0) && extend))
-               {
-               newb=s->s3->rbuf.left;
-               if (extend)
-                       {
-                       /* Copy bytes back to the front of the buffer 
-                        * Take the bytes already pointed to by 'packet'
-                        * and take the extra ones on the end. */
-                       off=s->packet_length;
-                       if (s->packet != s->s3->rbuf.buf)
-                               memcpy(s->s3->rbuf.buf,s->packet,newb+off);
-                       }
-               else if (s->s3->rbuf.offset != 0)
-                       { /* so the data is not at the start of the buffer */
-                       memcpy(s->s3->rbuf.buf,
-                               &(s->s3->rbuf.buf[s->s3->rbuf.offset]),newb);
-                       s->s3->rbuf.offset=0;
-                       }
+       if (!s->read_ahead)
+               max=n;
 
-               s->s3->rbuf.left=0;
+       {
+               /* avoid buffer overflow */
+               int max_max = SSL3_RT_MAX_PACKET_SIZE - s->packet_length;
+               if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
+                       max_max += SSL3_RT_MAX_EXTRA;
+               if (max > max_max)
+                       max = max_max;
+       }
+       if (n > max) /* does not happen */
+               {
+               SSLerr(SSL_F_SSL3_READ_N,SSL_R_INTERNAL_ERROR);
+               return -1;
                }
-       else
-               newb=0;
-
-       /* So we now have 'newb' bytes at the front of 
-        * s->s3->rbuf.buf and need to read some more in on the end
-        * We start reading into the buffer at 's->s3->rbuf.offset'
-        */
-       s->packet=s->s3->rbuf.buf;
 
+       off = s->packet_length;
+       newb = s->s3->rbuf.left;
+       /* Move any available bytes to front of buffer:
+        * 'off' bytes already pointed to by 'packet',
+        * 'newb' extra ones at the end */
+       if (s->packet != s->s3->rbuf.buf)
+               {
+               /*  off > 0 */
+               memmove(s->s3->rbuf.buf, s->packet, off+newb);
+               s->packet = s->s3->rbuf.buf;
+               }
+       
        while (newb < n)
                {
+               /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need
+                * to read in more until we have off+n (up to off+max if possible) */
+
                clear_sys_error();
                if (s->rbio != NULL)
                        {
                        s->rwstate=SSL_READING;
-                       i=BIO_read(s->rbio,
-                               (char *)&(s->s3->rbuf.buf[off+newb]),
-                               max-newb);
+                       i=BIO_read(s->rbio,     &(s->s3->rbuf.buf[off+newb]), max-newb);
                        }
                else
                        {
                        SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
-                       i= -1;
+                       i = -1;
                        }
 
                if (i <= 0)
                        {
-                       s->s3->rbuf.left+=newb;
+                       s->s3->rbuf.left = newb;
                        return(i);
                        }
                newb+=i;
                }
 
-       /* record used data read */
-       if (newb > n)
-               {
-               s->s3->rbuf.offset=n+off;
-               s->s3->rbuf.left=newb-n;
-               }
-       else
-               {
-               s->s3->rbuf.offset=0;
-               s->s3->rbuf.left=0;
-               }
-
-       if (extend)
-               s->packet_length+=n;
-       else
-               s->packet_length+=n;
+       /* done reading, now the book-keeping */
+       s->s3->rbuf.offset = off + n;
+       s->s3->rbuf.left = newb - n;
+       s->packet_length += n;
+       s->rwstate=SSL_NOTHING;
        return(n);
        }
 
@@ -176,8 +222,8 @@ static int ssl3_read_n(SSL *s, int n, int max, int extend)
  * It will return <= 0 if more data is needed, normally due to an error
  * or non-blocking IO.
  * When it finishes, one packet has been decoded and can be found in
- * ssl->s3->rrec.type  - is the type of record
- * ssl->s3->rrec.data,         - data
+ * ssl->s3->rrec.type    - is the type of record
+ * ssl->s3->rrec.data,          - data
  * ssl->s3->rrec.length, - number of bytes
  */
 static int ssl3_get_record(SSL *s)
@@ -253,27 +299,26 @@ again:
                        goto f_err;
                        }
 
-               s->rstate=SSL_ST_READ_BODY;
+               /* now s->rstate == SSL_ST_READ_BODY */
                }
 
-       /* get and decode the data */
-       if (s->rstate == SSL_ST_READ_BODY)
+       /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
+
+       if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
                {
-               if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
-                       {
-                       i=rr->length;
-                       /*-(s->packet_length-SSL3_RT_HEADER_LENGTH); */
-                       n=ssl3_read_n(s,i,i,1);
-                       if (n <= 0) return(n); /* error or non-blocking io */
-                       }
-               s->rstate=SSL_ST_READ_HEADER;
+               /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
+               i=rr->length;
+               n=ssl3_read_n(s,i,i,1);
+               if (n <= 0) return(n); /* error or non-blocking io */
+               /* now n == rr->length,
+                * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
                }
 
-       /* At this point, we have the data in s->packet and there should be
-        * s->packet_length bytes, we must not 'overrun' this buffer :-)
-        * One of the following functions will copy the data from the
-        * s->packet buffer */
+       s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 
+       /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
+        * and we have that many bytes in s->packet
+        */
        rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 
        /* ok, we can now read from 's->packet' data into 'rr'
@@ -283,13 +328,10 @@ again:
         * When the data is 'copied' into the rr->data buffer,
         * rr->input will be pointed at the new buffer */ 
 
-       /* Set the state for the following operations */
-       s->rstate=SSL_ST_READ_HEADER;
-
        /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
         * rr->length bytes of encrypted compressed stuff. */
 
-       /* check is not needed I belive */
+       /* check is not needed I believe */
        if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
                {
                al=SSL_AD_RECORD_OVERFLOW;
@@ -326,7 +368,7 @@ printf("\n");
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
                        goto f_err;
                        }
-               /* check MAC for rr->input' */
+               /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
                if (rr->length < mac_size)
                        {
                        al=SSL_AD_DECODE_ERROR;
@@ -426,12 +468,12 @@ static int do_compress(SSL *ssl)
        return(1);
        }
 
-/* Call this to write data
+/* Call this to write data in records of type 'type'
  * It will return <= 0 if not all data has been sent or non-blocking IO.
  */
-int ssl3_write_bytes(SSL *s, int type, const void *_buf, int len)
+int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
        {
-       const unsigned char *buf=_buf;
+       const unsigned char *buf=buf_;
        unsigned int tot,n,nw;
        int i;
 
@@ -503,7 +545,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                /* if it went, fall through and send more stuff */
                }
 
-       if (len <= 0) return(len);
+       if (len == 0) return(len);
        
        wr= &(s->s3->wrec);
        wb= &(s->s3->wbuf);
@@ -645,7 +687,7 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len)
        void (*cb)()=NULL;
        BIO *bio;
 
-       if (s->s3->rbuf.buf == NULL) /* Not initialize yet */
+       if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
                if (!ssl3_setup_buffers(s))
                        return(-1);
 
@@ -662,10 +704,10 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len)
 start:
        s->rwstate=SSL_NOTHING;
 
-       /* s->s3->rrec.type     - is the type of record
-        * s->s3->rrec.data,    - data
-        * s->s3->rrec.off,     - ofset into 'data' for next read
-        * s->s3->rrec.length,  - number of bytes. */
+       /* s->s3->rrec.type         - is the type of record
+        * s->s3->rrec.data,    - data
+        * s->s3->rrec.off,     - offset into 'data' for next read
+        * s->s3->rrec.length,  - number of bytes. */
        rr= &(s->s3->rrec);
 
        /* get new packet */
@@ -692,16 +734,16 @@ start:
                return(0);
                }
 
-       /* Check for an incoming 'Client Request' message */
+       /* Check for an incoming 'Hello Request' message from client */
        if ((rr->type == SSL3_RT_HANDSHAKE) && (rr->length == 4) &&
-               (rr->data[0] == SSL3_MT_CLIENT_REQUEST) &&
+               (rr->data[0] == SSL3_MT_HELLO_REQUEST) &&
                (s->session != NULL) && (s->session->cipher != NULL))
                {
                if ((rr->data[1] != 0) || (rr->data[2] != 0) ||
                        (rr->data[3] != 0))
                        {
                        al=SSL_AD_DECODE_ERROR;
-                       SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CLIENT_REQUEST);
+                       SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
                        goto err;
                        }
 
@@ -755,7 +797,7 @@ start:
                                cb(s,SSL_CB_READ_ALERT,j);
                                }
 
-                       if (i == 1)
+                       if (i == 1) /* warning */
                                {
                                s->s3->warn_alert=n;
                                if (n == SSL_AD_CLOSE_NOTIFY)
@@ -764,7 +806,7 @@ start:
                                        return(0);
                                        }
                                }
-                       else if (i == 2)
+                       else if (i == 2) /* fatal */
                                {
                                char tmp[16];
 
@@ -895,8 +937,11 @@ start:
                                goto f_err;
                                }
                        }
+               /* not reached */
                }
 
+       /* rr->type == type */
+
        /* make sure that we are not getting application data when we
         * are doing a handshake for the first time */
        if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
@@ -917,7 +962,7 @@ start:
        memcpy(buf,&(rr->data[rr->off]),(unsigned int)n);
        rr->length-=n;
        rr->off+=n;
-       if (rr->length <= 0)
+       if (rr->length == 0)
                {
                s->rstate=SSL_ST_READ_HEADER;
                rr->off=0;
@@ -966,14 +1011,15 @@ static int do_change_cipher_spec(SSL *s)
                slen=s->method->ssl3_enc->client_finished_label_len;
                }
 
-       s->method->ssl3_enc->final_finish_mac(s,
+       s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
                &(s->s3->finish_dgst1),
                &(s->s3->finish_dgst2),
-               sender,slen,&(s->s3->tmp.finish_md[0]));
+               sender,slen,s->s3->tmp.peer_finish_md);
 
        return(1);
        }
 
+/* send s->init_buf in records of type 'type' */
 int ssl3_do_write(SSL *s, int type)
        {
        int ret;
@@ -1038,4 +1084,3 @@ int ssl3_dispatch_alert(SSL *s)
                }
        return(i);
        }
-