Massive constification.

[thirdparty/openssl.git] / ssl / s3_pkt.c

/* ssl/s3_pkt.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <errno.h>
#define USE_SOCKETS
#include "evp.h"
#include "buffer.h"
#include "ssl_locl.h"

/* SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_PEER_ERROR_NO_CIPHER);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_PEER_ERROR_NO_CERTIFICATE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_PEER_ERROR_CERTIFICATE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_UNKNOWN_REMOTE_ERROR_TYPE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_BAD_RECORD_MAC);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_NO_CERTIFICATE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_BAD_CERTIFICATE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_DECRYPTION_FAILED);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_RECORD_OVERFLOW);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_UNKNOWN_CA);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_ACCESS_DENIED);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_DECODE_ERROR);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_DECRYPT_ERROR);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_EXPORT_RESTRICION);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_PROTOCOL_VERSION);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_INTERNAL_ERROR);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_USER_CANCLED);
 * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_TLSV1_ALERT_NO_RENEGOTIATION);
 */

#ifndef NOPROTO
static int do_ssl3_write(SSL *s, int type, const char *buf, unsigned int len);
static int ssl3_write_pending(SSL *s, int type, const char *buf,
                              unsigned int len);
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);
#else
static int do_ssl3_write();
static int ssl3_write_pending();
static int ssl3_get_record();
static int do_compress();
static int do_uncompress();
static int do_change_cipher_spec();
#endif

static int ssl3_read_n(s,n,max,extend)
SSL *s;
int n;
int max;
int extend;
        {
        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 (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->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;
                        }

                s->s3->rbuf.left=0;
                }
        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;

        while (newb < n)
                {
                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);
                        }
                else
                        {
                        SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
                        i= -1;
                        }

                if (i <= 0)
                        {
                        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;
        return(n);
        }

/* Call this to get a new input record.
 * 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.length, - number of bytes
 */
static int ssl3_get_record(s)
SSL *s;
        {
        int ssl_major,ssl_minor,al;
        int n,i,ret= -1;
        SSL3_BUFFER *rb;
        SSL3_RECORD *rr;
        SSL_SESSION *sess;
        unsigned char *p;
        unsigned char md[EVP_MAX_MD_SIZE];
        short version;
        unsigned int mac_size;
        int clear=0,extra;

        rr= &(s->s3->rrec);
        rb= &(s->s3->rbuf);
        sess=s->session;

        if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
                extra=SSL3_RT_MAX_EXTRA;
        else
                extra=0;

again:
        /* check if we have the header */
        if (    (s->rstate != SSL_ST_READ_BODY) ||
                (s->packet_length < SSL3_RT_HEADER_LENGTH)) 
                {
                n=ssl3_read_n(s,SSL3_RT_HEADER_LENGTH,
                        SSL3_RT_MAX_PACKET_SIZE,0);
                if (n <= 0) return(n); /* error or non-blocking */
                s->rstate=SSL_ST_READ_BODY;

                p=s->packet;

                /* Pull apart the header into the SSL3_RECORD */
                rr->type= *(p++);
                ssl_major= *(p++);
                ssl_minor= *(p++);
                version=(ssl_major<<8)|ssl_minor;
                n2s(p,rr->length);

                /* Lets check version */
                if (s->first_packet)
                        {
                        s->first_packet=0;
                        }
                else
                        {
                        if (version != s->version)
                                {
                                SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
                                /* Send back error using their
                                 * version number :-) */
                                s->version=version;
                                al=SSL_AD_PROTOCOL_VERSION;
                                goto f_err;
                                }
                        }

                if ((version>>8) != SSL3_VERSION_MAJOR)
                        {
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
                        goto err;
                        }

                if (rr->length > 
                        (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
                        {
                        al=SSL_AD_RECORD_OVERFLOW;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
                        goto f_err;
                        }

                s->rstate=SSL_ST_READ_BODY;
                }

        /* get and decode the data */
        if (s->rstate == SSL_ST_READ_BODY)
                {
                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;
                }

        /* 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 */

        rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);

        /* ok, we can now read from 's->packet' data into 'rr'
         * rr->input points at rr->length bytes, which
         * need to be copied into rr->data by either
         * the decryption or by the decompression
         * 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 */
        if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
                {
                al=SSL_AD_RECORD_OVERFLOW;
                SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
                goto f_err;
                }

        /* decrypt in place in 'rr->input' */
        rr->data=rr->input;

        if (!s->method->ssl3_enc->enc(s,0))
                {
                al=SSL_AD_DECRYPT_ERROR;
                goto f_err;
                }
#ifdef TLS_DEBUG
printf("dec %d\n",rr->length);
{ unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
printf("\n");
#endif
        /* r->length is now the compressed data plus mac */
        if (    (sess == NULL) ||
                (s->enc_read_ctx == NULL) ||
                (s->read_hash == NULL))
                clear=1;

        if (!clear)
                {
                mac_size=EVP_MD_size(s->read_hash);

                if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
                        {
                        al=SSL_AD_RECORD_OVERFLOW;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
                        goto f_err;
                        }
                /* check MAC for rr->input' */
                if (rr->length < mac_size)
                        {
                        al=SSL_AD_DECODE_ERROR;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
                        goto f_err;
                        }
                rr->length-=mac_size;
                i=s->method->ssl3_enc->mac(s,md,0);
                if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
                        {
                        al=SSL_AD_BAD_RECORD_MAC;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_MAC_DECODE);
                        ret= -1;
                        goto f_err;
                        }
                }

        /* r->length is now just compressed */
        if (s->expand != NULL)
                {
                if (rr->length > 
                        (unsigned int)SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
                        {
                        al=SSL_AD_RECORD_OVERFLOW;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
                        goto f_err;
                        }
                if (!do_uncompress(s))
                        {
                        al=SSL_AD_DECOMPRESSION_FAILURE;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
                        goto f_err;
                        }
                }

        if (rr->length > (unsigned int)SSL3_RT_MAX_PLAIN_LENGTH+extra)
                {
                al=SSL_AD_RECORD_OVERFLOW;
                SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
                goto f_err;
                }

        rr->off=0;
        /* So at this point the following is true
         * ssl->s3->rrec.type   is the type of record
         * ssl->s3->rrec.length == number of bytes in record
         * ssl->s3->rrec.off    == offset to first valid byte
         * ssl->s3->rrec.data   == where to take bytes from, increment
         *                         after use :-).
         */

        /* we have pulled in a full packet so zero things */
        s->packet_length=0;

        /* just read a 0 length packet */
        if (rr->length == 0) goto again;

        return(1);
f_err:
        ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
        return(ret);
        }

static int do_uncompress(ssl)
SSL *ssl;
        {
        int i;
        SSL3_RECORD *rr;

        rr= &(ssl->s3->rrec);
        i=COMP_expand_block(ssl->expand,rr->comp,
                SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
        if (i < 0)
                return(0);
        else
                rr->length=i;
        rr->data=rr->comp;

        return(1);
        }

static int do_compress(ssl)
SSL *ssl;
        {
        int i;
        SSL3_RECORD *wr;

        wr= &(ssl->s3->wrec);
        i=COMP_compress_block(ssl->compress,wr->data,
                SSL3_RT_MAX_COMPRESSED_LENGTH,
                wr->input,(int)wr->length);
        if (i < 0)
                return(0);
        else
                wr->length=i;

        wr->input=wr->data;
        return(1);
        }

/* Call this to write data
 * It will return <= 0 if not all data has been sent or non-blocking IO.
 */
int ssl3_write_bytes(s,type,buf,len)
SSL *s;
int type;
const char *buf;
int len;
        {
        unsigned int tot,n,nw;
        int i;

        s->rwstate=SSL_NOTHING;
        tot=s->s3->wnum;
        s->s3->wnum=0;

        if (SSL_in_init(s) && !s->in_handshake)
                {
                i=s->handshake_func(s);
                if (i < 0) return(i);
                if (i == 0)
                        {
                        SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
                        return(-1);
                        }
                }

        n=(len-tot);
        for (;;)
                {
                if (n > SSL3_RT_MAX_PLAIN_LENGTH)
                        nw=SSL3_RT_MAX_PLAIN_LENGTH;
                else
                        nw=n;
                        
                i=do_ssl3_write(s,type,&(buf[tot]),nw);
                if (i <= 0)
                        {
                        s->s3->wnum=tot;
                        return(i);
                        }

                if (type == SSL3_RT_HANDSHAKE)
                        ssl3_finish_mac(s,&(buf[tot]),i);

                if (i == (int)n) return(tot+i);

                n-=i;
                tot+=i;
                }
        }

static int do_ssl3_write(s,type,buf,len)
SSL *s;
int type;
const char *buf;
unsigned int len;
        {
        unsigned char *p,*plen;
        int i,mac_size,clear=0;
        SSL3_RECORD *wr;
        SSL3_BUFFER *wb;
        SSL_SESSION *sess;

        /* first check is there is a SSL3_RECORD still being written
         * out.  This will happen with non blocking IO */
        if (s->s3->wbuf.left != 0)
                return(ssl3_write_pending(s,type,buf,len));

        /* If we have an alert to send, lets send it */
        if (s->s3->alert_dispatch)
                {
                i=ssl3_dispatch_alert(s);
                if (i <= 0)
                        return(i);
                /* if it went, fall through and send more stuff */
                }

        if (len <= 0) return(len);
        
        wr= &(s->s3->wrec);
        wb= &(s->s3->wbuf);
        sess=s->session;

        if (    (sess == NULL) ||
                (s->enc_write_ctx == NULL) ||
                (s->write_hash == NULL))
                clear=1;

        if (clear)
                mac_size=0;
        else
                mac_size=EVP_MD_size(s->write_hash);

        p=wb->buf;

        /* write the header */
        *(p++)=type&0xff;
        wr->type=type;

        *(p++)=(s->version>>8);
        *(p++)=s->version&0xff;
        
        /* record where we are to write out packet length */
        plen=p; 
        p+=2;
        
        /* lets setup the record stuff. */
        wr->data=p;
        wr->length=(int)len;
        wr->input=(unsigned char *)buf;

        /* we now 'read' from wr->input, wr->length bytes into
         * wr->data */

        /* first we compress */
        if (s->compress != NULL)
                {
                if (!do_compress(s))
                        {
                        SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
                        goto err;
                        }
                }
        else
                {
                memcpy(wr->data,wr->input,wr->length);
                wr->input=wr->data;
                }

        /* we should still have the output to wr->data and the input
         * from wr->input.  Length should be wr->length.
         * wr->data still points in the wb->buf */

        if (mac_size != 0)
                {
                s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
                wr->length+=mac_size;
                wr->input=p;
                wr->data=p;
                }

        /* ssl3_enc can only have an error on read */
        s->method->ssl3_enc->enc(s,1);

        /* record length after mac and block padding */
        s2n(wr->length,plen);

        /* we should now have
         * wr->data pointing to the encrypted data, which is
         * wr->length long */
        wr->type=type; /* not needed but helps for debugging */
        wr->length+=SSL3_RT_HEADER_LENGTH;

        /* Now lets setup wb */
        wb->left=wr->length;
        wb->offset=0;

        s->s3->wpend_tot=len;
        s->s3->wpend_buf=buf;
        s->s3->wpend_type=type;
        s->s3->wpend_ret=len;

        /* we now just need to write the buffer */
        return(ssl3_write_pending(s,type,buf,len));
err:
        return(-1);
        }

/* if s->s3->wbuf.left != 0, we need to call this */
static int ssl3_write_pending(s,type,buf,len)
SSL *s;
int type;
const char *buf;
unsigned int len;
        {
        int i;

/* XXXX */
        if ((s->s3->wpend_tot > (int)len) || (s->s3->wpend_buf != buf)
                || (s->s3->wpend_type != type))
                {
                SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
                return(-1);
                }

        for (;;)
                {
                clear_sys_error();
                if (s->wbio != NULL)
                        {
                        s->rwstate=SSL_WRITING;
                        i=BIO_write(s->wbio,
                                (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
                                (unsigned int)s->s3->wbuf.left);
                        }
                else
                        {
                        SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
                        i= -1;
                        }
                if (i == s->s3->wbuf.left)
                        {
                        s->s3->wbuf.left=0;
                        s->rwstate=SSL_NOTHING;
                        return(s->s3->wpend_ret);
                        }
                else if (i <= 0)
                        return(i);
                s->s3->wbuf.offset+=i;
                s->s3->wbuf.left-=i;
                }
        }

int ssl3_read_bytes(s,type,buf,len)
SSL *s;
int type;
char *buf;
int len;
        {
        int al,i,j,n,ret;
        SSL3_RECORD *rr;
        void (*cb)()=NULL;
        BIO *bio;

        if (s->s3->rbuf.buf == NULL) /* Not initialize yet */
                if (!ssl3_setup_buffers(s))
                        return(-1);

        if (!s->in_handshake && SSL_in_init(s))
                {
                i=s->handshake_func(s);
                if (i < 0) return(i);
                if (i == 0)
                        {
                        SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
                        return(-1);
                        }
                }
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. */
        rr= &(s->s3->rrec);

        /* get new packet */
        if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
                {
                ret=ssl3_get_record(s);
                if (ret <= 0) return(ret);
                }

        /* we now have a packet which can be read and processed */

        if (s->s3->change_cipher_spec && (rr->type != SSL3_RT_HANDSHAKE))
                {
                al=SSL_AD_UNEXPECTED_MESSAGE;
                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
                goto err;
                }

        /* If the other end has shutdown, throw anything we read away */
        if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
                {
                rr->length=0;
                s->rwstate=SSL_NOTHING;
                return(0);
                }

        /* Check for an incoming 'Client Request' message */
        if ((rr->type == SSL3_RT_HANDSHAKE) && (rr->length == 4) &&
                (rr->data[0] == SSL3_MT_CLIENT_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);
                        goto err;
                        }

                if (SSL_is_init_finished(s) &&
                        !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
                        !s->s3->renegotiate)
                        {
                        ssl3_renegotiate(s);
                        if (ssl3_renegotiate_check(s))
                                {
                                n=s->handshake_func(s);
                                if (n < 0) return(n);
                                if (n == 0)
                                        {
                                        SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
                                        return(-1);
                                        }
                                }
                        }
                rr->length=0;
/* ZZZ */       goto start;
                }

        /* if it is not the type we want, or we have shutdown and want
         * the peer shutdown */
        if ((rr->type != type) || (s->shutdown & SSL_SENT_SHUTDOWN))
                {
                if (rr->type == SSL3_RT_ALERT)
                        {
                        if ((rr->length != 2) || (rr->off != 0))
                                {
                                al=SSL_AD_DECODE_ERROR;
                                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_ALERT_RECORD);
                                goto f_err;
                                }

                        i=rr->data[0];
                        n=rr->data[1];

                        /* clear from buffer */
                        rr->length=0;

                        if (s->info_callback != NULL)
                                cb=s->info_callback;
                        else if (s->ctx->info_callback != NULL)
                                cb=s->ctx->info_callback;

                        if (cb != NULL)
                                {
                                j=(i<<8)|n;
                                cb(s,SSL_CB_READ_ALERT,j);
                                }

                        if (i == 1)
                                {
                                s->s3->warn_alert=n;
                                if (n == SSL_AD_CLOSE_NOTIFY)
                                        {
                                        s->shutdown|=SSL_RECEIVED_SHUTDOWN;
                                        return(0);
                                        }
                                }
                        else if (i == 2)
                                {
                                char tmp[16];

                                s->rwstate=SSL_NOTHING;
                                s->s3->fatal_alert=n;
                                SSLerr(SSL_F_SSL3_READ_BYTES,
                                        SSL_AD_REASON_OFFSET+n);
                                sprintf(tmp,"%d",n);
                                ERR_add_error_data(2,"SSL alert number ",tmp);
                                s->shutdown|=SSL_RECEIVED_SHUTDOWN;
                                SSL_CTX_remove_session(s->ctx,s->session);
                                return(0);
                                }
                        else
                                {
                                al=SSL_AD_ILLEGAL_PARAMETER;
                                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
                                goto f_err;
                                }

                        rr->length=0;
                        goto start;
                        }

                if (s->shutdown & SSL_SENT_SHUTDOWN)
                        {
                        s->rwstate=SSL_NOTHING;
                        rr->length=0;
                        return(0);
                        }

                if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
                        {
                        if (    (rr->length != 1) || (rr->off != 0) ||
                                (rr->data[0] != SSL3_MT_CCS))
                                {
                                i=SSL_AD_ILLEGAL_PARAMETER;
                                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
                                goto err;
                                }

                        rr->length=0;
                        s->s3->change_cipher_spec=1;
                        if (!do_change_cipher_spec(s))
                                goto err;
                        else
                                goto start;
                        }

                /* else we have a handshake */
                if ((rr->type == SSL3_RT_HANDSHAKE) &&
                        !s->in_handshake)
                        {
                        if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
                                !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
                                {
                                s->state=SSL_ST_BEFORE|(s->server)
                                                ?SSL_ST_ACCEPT
                                                :SSL_ST_CONNECT;
                                s->new_session=1;
                                }
                        n=s->handshake_func(s);
                        if (n < 0) return(n);
                        if (n == 0)
                                {
                                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
                                return(-1);
                                }

                        /* In the case where we try to read application data
                         * the first time, but we trigger an SSL handshake, we
                         * return -1 with the retry option set.  I do this
                         * otherwise renegotiation can cause nasty problems 
                         * in the non-blocking world */

                        s->rwstate=SSL_READING;
                        bio=SSL_get_rbio(s);
                        BIO_clear_retry_flags(bio);
                        BIO_set_retry_read(bio);
                        return(-1);
                        }

                switch (rr->type)
                        {
                default:
#ifndef NO_TLS
                        /* TLS just ignores unknown message types */
                        if (s->version == TLS1_VERSION)
                                {
                                goto start;
                                }
#endif
                case SSL3_RT_CHANGE_CIPHER_SPEC:
                case SSL3_RT_ALERT:
                case SSL3_RT_HANDSHAKE:
                        al=SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
                        goto f_err;
                case SSL3_RT_APPLICATION_DATA:
                        /* At this point, we were expecting something else,
                         * but have application data.  What we do is set the
                         * error, and return -1.  On the way out, if the
                         * library was running inside ssl3_read() and it makes
                         * sense to read application data at this point, we
                         * will indulge it.  This will mostly happen during
                         * session renegotiation.
                         */
                        if (s->s3->in_read_app_data &&
                                (s->s3->total_renegotiations != 0) &&
                                ((
                                  (s->state & SSL_ST_CONNECT) &&
                                  (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
                                  (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
                                 ) || (
                                  (s->state & SSL_ST_ACCEPT) &&
                                  (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
                                  (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
                                 )
                                ))
                                {
                                s->s3->in_read_app_data=0;
                                return(-1);
                                }
                        else
                                {
                                al=SSL_AD_UNEXPECTED_MESSAGE;
                                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
                                goto f_err;
                                }
                        }
                }

        /* 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) &&
                (s->enc_read_ctx == NULL))
                {
                al=SSL_AD_UNEXPECTED_MESSAGE;
                SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
                goto f_err;
                }

        if (len <= 0) return(len);

        if ((unsigned int)len > rr->length)
                n=rr->length;
        else
                n=len;

        memcpy(buf,&(rr->data[rr->off]),(unsigned int)n);
        rr->length-=n;
        rr->off+=n;
        if (rr->length <= 0)
                {
                s->rstate=SSL_ST_READ_HEADER;
                rr->off=0;
                }

        if (type == SSL3_RT_HANDSHAKE)
                ssl3_finish_mac(s,buf,n);
        return(n);
f_err:
        ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
        return(-1);
        }

static int do_change_cipher_spec(s)
SSL *s;
        {
        int i;
        unsigned char *sender;
        int slen;

        if (s->state & SSL_ST_ACCEPT)
                i=SSL3_CHANGE_CIPHER_SERVER_READ;
        else
                i=SSL3_CHANGE_CIPHER_CLIENT_READ;

        if (s->s3->tmp.key_block == NULL)
                {
                s->session->cipher=s->s3->tmp.new_cipher;
                if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
                }

        if (!s->method->ssl3_enc->change_cipher_state(s,i))
                return(0);

        /* we have to record the message digest at
         * this point so we can get it before we read
         * the finished message */
        if (s->state & SSL_ST_CONNECT)
                {
                sender=s->method->ssl3_enc->server_finished;
                slen=s->method->ssl3_enc->server_finished_len;
                }
        else
                {
                sender=s->method->ssl3_enc->client_finished;
                slen=s->method->ssl3_enc->client_finished_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]));

        return(1);
        }

int ssl3_do_write(s,type)
SSL *s;
int type;
        {
        int ret;

        ret=ssl3_write_bytes(s,type,(char *)
                &(s->init_buf->data[s->init_off]),s->init_num);
        if (ret == s->init_num)
                return(1);
        if (ret < 0) return(-1);
        s->init_off+=ret;
        s->init_num-=ret;
        return(0);
        }

void ssl3_send_alert(s,level,desc)
SSL *s;
int level;
int desc;
        {
        /* Map tls/ssl alert value to correct one */
        desc=s->method->ssl3_enc->alert_value(desc);
        if (desc < 0) return;
        /* If a fatal one, remove from cache */
        if ((level == 2) && (s->session != NULL))
                SSL_CTX_remove_session(s->ctx,s->session);

        s->s3->alert_dispatch=1;
        s->s3->send_alert[0]=level;
        s->s3->send_alert[1]=desc;
        if (s->s3->wbuf.left == 0) /* data still being written out */
                ssl3_dispatch_alert(s);
        /* else data is still being written out, we will get written
         * some time in the future */
        }

int ssl3_dispatch_alert(s)
SSL *s;
        {
        int i,j;
        void (*cb)()=NULL;

        s->s3->alert_dispatch=0;
        i=do_ssl3_write(s,SSL3_RT_ALERT,&(s->s3->send_alert[0]),2);
        if (i <= 0)
                {
                s->s3->alert_dispatch=1;
                }
        else
                {
                /* If it is important, send it now.  If the message
                 * does not get sent due to non-blocking IO, we will
                 * not worry too much. */
                if (s->s3->send_alert[0] == SSL3_AL_FATAL)
                        BIO_flush(s->wbio);

                if (s->info_callback != NULL)
                        cb=s->info_callback;
                else if (s->ctx->info_callback != NULL)
                        cb=s->ctx->info_callback;
                
                if (cb != NULL)
                        {
                        j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
                        cb(s,SSL_CB_WRITE_ALERT,j);
                        }
                }
        return(i);
        }