s2_pkt.c revision 296341
1/* ssl/s2_pkt.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58/* ====================================================================
59 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 *    notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 *    notice, this list of conditions and the following disclaimer in
70 *    the documentation and/or other materials provided with the
71 *    distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 *    software must display the following acknowledgment:
75 *    "This product includes software developed by the OpenSSL Project
76 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 *    endorse or promote products derived from this software without
80 *    prior written permission. For written permission, please contact
81 *    openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 *    nor may "OpenSSL" appear in their names without prior written
85 *    permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 *    acknowledgment:
89 *    "This product includes software developed by the OpenSSL Project
90 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com).  This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111
112#include "ssl_locl.h"
113#ifndef OPENSSL_NO_SSL2
114# include <stdio.h>
115# include <errno.h>
116# define USE_SOCKETS
117
118static int read_n(SSL *s, unsigned int n, unsigned int max,
119                  unsigned int extend);
120static int n_do_ssl_write(SSL *s, const unsigned char *buf, unsigned int len);
121static int write_pending(SSL *s, const unsigned char *buf, unsigned int len);
122static int ssl_mt_error(int n);
123
124/*
125 * SSL 2.0 imlementation for SSL_read/SSL_peek - This routine will return 0
126 * to len bytes, decrypted etc if required.
127 */
128static int ssl2_read_internal(SSL *s, void *buf, int len, int peek)
129{
130    int n;
131    unsigned char mac[MAX_MAC_SIZE];
132    unsigned char *p;
133    int i;
134    int mac_size;
135
136 ssl2_read_again:
137    if (SSL_in_init(s) && !s->in_handshake) {
138        n = s->handshake_func(s);
139        if (n < 0)
140            return (n);
141        if (n == 0) {
142            SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_SSL_HANDSHAKE_FAILURE);
143            return (-1);
144        }
145    }
146
147    clear_sys_error();
148    s->rwstate = SSL_NOTHING;
149    if (len <= 0)
150        return (len);
151
152    if (s->s2->ract_data_length != 0) { /* read from buffer */
153        if (len > s->s2->ract_data_length)
154            n = s->s2->ract_data_length;
155        else
156            n = len;
157
158        memcpy(buf, s->s2->ract_data, (unsigned int)n);
159        if (!peek) {
160            s->s2->ract_data_length -= n;
161            s->s2->ract_data += n;
162            if (s->s2->ract_data_length == 0)
163                s->rstate = SSL_ST_READ_HEADER;
164        }
165
166        return (n);
167    }
168
169    /*
170     * s->s2->ract_data_length == 0 Fill the buffer, then goto
171     * ssl2_read_again.
172     */
173
174    if (s->rstate == SSL_ST_READ_HEADER) {
175        if (s->first_packet) {
176            n = read_n(s, 5, SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2, 0);
177            if (n <= 0)
178                return (n);     /* error or non-blocking */
179            s->first_packet = 0;
180            p = s->packet;
181            if (!((p[0] & 0x80) && ((p[2] == SSL2_MT_CLIENT_HELLO) ||
182                                    (p[2] == SSL2_MT_SERVER_HELLO)))) {
183                SSLerr(SSL_F_SSL2_READ_INTERNAL,
184                       SSL_R_NON_SSLV2_INITIAL_PACKET);
185                return (-1);
186            }
187        } else {
188            n = read_n(s, 2, SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2, 0);
189            if (n <= 0)
190                return (n);     /* error or non-blocking */
191        }
192        /* part read stuff */
193
194        s->rstate = SSL_ST_READ_BODY;
195        p = s->packet;
196        /* Do header */
197        /*
198         * s->s2->padding=0;
199         */
200        s->s2->escape = 0;
201        s->s2->rlength = (((unsigned int)p[0]) << 8) | ((unsigned int)p[1]);
202        if ((p[0] & TWO_BYTE_BIT)) { /* Two byte header? */
203            s->s2->three_byte_header = 0;
204            s->s2->rlength &= TWO_BYTE_MASK;
205        } else {
206            s->s2->three_byte_header = 1;
207            s->s2->rlength &= THREE_BYTE_MASK;
208
209            /* security >s2->escape */
210            s->s2->escape = ((p[0] & SEC_ESC_BIT)) ? 1 : 0;
211        }
212    }
213
214    if (s->rstate == SSL_ST_READ_BODY) {
215        n = s->s2->rlength + 2 + s->s2->three_byte_header;
216        if (n > (int)s->packet_length) {
217            n -= s->packet_length;
218            i = read_n(s, (unsigned int)n, (unsigned int)n, 1);
219            if (i <= 0)
220                return (i);     /* ERROR */
221        }
222
223        p = &(s->packet[2]);
224        s->rstate = SSL_ST_READ_HEADER;
225        if (s->s2->three_byte_header)
226            s->s2->padding = *(p++);
227        else
228            s->s2->padding = 0;
229
230        /* Data portion */
231        if (s->s2->clear_text) {
232            mac_size = 0;
233            s->s2->mac_data = p;
234            s->s2->ract_data = p;
235            if (s->s2->padding) {
236                SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_ILLEGAL_PADDING);
237                return (-1);
238            }
239        } else {
240            mac_size = EVP_MD_CTX_size(s->read_hash);
241            if (mac_size < 0)
242                return -1;
243            OPENSSL_assert(mac_size <= MAX_MAC_SIZE);
244            s->s2->mac_data = p;
245            s->s2->ract_data = &p[mac_size];
246            if (s->s2->padding + mac_size > s->s2->rlength) {
247                SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_ILLEGAL_PADDING);
248                return (-1);
249            }
250        }
251
252        s->s2->ract_data_length = s->s2->rlength;
253        /*
254         * added a check for length > max_size in case encryption was not
255         * turned on yet due to an error
256         */
257        if ((!s->s2->clear_text) &&
258            (s->s2->rlength >= (unsigned int)mac_size)) {
259            if (!ssl2_enc(s, 0)) {
260                SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_DECRYPTION_FAILED);
261                return (-1);
262            }
263            s->s2->ract_data_length -= mac_size;
264            ssl2_mac(s, mac, 0);
265            s->s2->ract_data_length -= s->s2->padding;
266            if ((CRYPTO_memcmp(mac, s->s2->mac_data, mac_size) != 0) ||
267                (s->s2->rlength %
268                 EVP_CIPHER_CTX_block_size(s->enc_read_ctx) != 0)) {
269                SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_BAD_MAC_DECODE);
270                return (-1);
271            }
272        }
273        INC32(s->s2->read_sequence); /* expect next number */
274        /* s->s2->ract_data is now available for processing */
275
276        /*
277         * Possibly the packet that we just read had 0 actual data bytes.
278         * (SSLeay/OpenSSL itself never sends such packets; see ssl2_write.)
279         * In this case, returning 0 would be interpreted by the caller as
280         * indicating EOF, so it's not a good idea.  Instead, we just
281         * continue reading; thus ssl2_read_internal may have to process
282         * multiple packets before it can return. [Note that using select()
283         * for blocking sockets *never* guarantees that the next SSL_read
284         * will not block -- the available data may contain incomplete
285         * packets, and except for SSL 2, renegotiation can confuse things
286         * even more.]
287         */
288
289        goto ssl2_read_again;   /* This should really be "return
290                                 * ssl2_read(s,buf,len)", but that would
291                                 * allow for denial-of-service attacks if a C
292                                 * compiler is used that does not recognize
293                                 * end-recursion. */
294    } else {
295        SSLerr(SSL_F_SSL2_READ_INTERNAL, SSL_R_BAD_STATE);
296        return (-1);
297    }
298}
299
300int ssl2_read(SSL *s, void *buf, int len)
301{
302    return ssl2_read_internal(s, buf, len, 0);
303}
304
305int ssl2_peek(SSL *s, void *buf, int len)
306{
307    return ssl2_read_internal(s, buf, len, 1);
308}
309
310static int read_n(SSL *s, unsigned int n, unsigned int max,
311                  unsigned int extend)
312{
313    int i, off, newb;
314
315    /*
316     * if there is stuff still in the buffer from a previous read, and there
317     * is more than we want, take some.
318     */
319    if (s->s2->rbuf_left >= (int)n) {
320        if (extend)
321            s->packet_length += n;
322        else {
323            s->packet = &(s->s2->rbuf[s->s2->rbuf_offs]);
324            s->packet_length = n;
325        }
326        s->s2->rbuf_left -= n;
327        s->s2->rbuf_offs += n;
328        return (n);
329    }
330
331    if (!s->read_ahead)
332        max = n;
333    if (max > (unsigned int)(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2))
334        max = SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2;
335
336    /*
337     * Else we want more than we have. First, if there is some left or we
338     * want to extend
339     */
340    off = 0;
341    if ((s->s2->rbuf_left != 0) || ((s->packet_length != 0) && extend)) {
342        newb = s->s2->rbuf_left;
343        if (extend) {
344            off = s->packet_length;
345            if (s->packet != s->s2->rbuf)
346                memcpy(s->s2->rbuf, s->packet, (unsigned int)newb + off);
347        } else if (s->s2->rbuf_offs != 0) {
348            memcpy(s->s2->rbuf, &(s->s2->rbuf[s->s2->rbuf_offs]),
349                   (unsigned int)newb);
350            s->s2->rbuf_offs = 0;
351        }
352        s->s2->rbuf_left = 0;
353    } else
354        newb = 0;
355
356    /*
357     * off is the offset to start writing too. r->s2->rbuf_offs is the
358     * 'unread data', now 0. newb is the number of new bytes so far
359     */
360    s->packet = s->s2->rbuf;
361    while (newb < (int)n) {
362        clear_sys_error();
363        if (s->rbio != NULL) {
364            s->rwstate = SSL_READING;
365            i = BIO_read(s->rbio, (char *)&(s->s2->rbuf[off + newb]),
366                         max - newb);
367        } else {
368            SSLerr(SSL_F_READ_N, SSL_R_READ_BIO_NOT_SET);
369            i = -1;
370        }
371# ifdef PKT_DEBUG
372        if (s->debug & 0x01)
373            sleep(1);
374# endif
375        if (i <= 0) {
376            s->s2->rbuf_left += newb;
377            return (i);
378        }
379        newb += i;
380    }
381
382    /* record unread data */
383    if (newb > (int)n) {
384        s->s2->rbuf_offs = n + off;
385        s->s2->rbuf_left = newb - n;
386    } else {
387        s->s2->rbuf_offs = 0;
388        s->s2->rbuf_left = 0;
389    }
390    if (extend)
391        s->packet_length += n;
392    else
393        s->packet_length = n;
394    s->rwstate = SSL_NOTHING;
395    return (n);
396}
397
398int ssl2_write(SSL *s, const void *_buf, int len)
399{
400    const unsigned char *buf = _buf;
401    unsigned int n, tot;
402    int i;
403
404    if (SSL_in_init(s) && !s->in_handshake) {
405        i = s->handshake_func(s);
406        if (i < 0)
407            return (i);
408        if (i == 0) {
409            SSLerr(SSL_F_SSL2_WRITE, SSL_R_SSL_HANDSHAKE_FAILURE);
410            return (-1);
411        }
412    }
413
414    if (s->error) {
415        ssl2_write_error(s);
416        if (s->error)
417            return (-1);
418    }
419
420    clear_sys_error();
421    s->rwstate = SSL_NOTHING;
422    if (len <= 0)
423        return (len);
424
425    tot = s->s2->wnum;
426    s->s2->wnum = 0;
427
428    n = (len - tot);
429    for (;;) {
430        i = n_do_ssl_write(s, &(buf[tot]), n);
431        if (i <= 0) {
432            s->s2->wnum = tot;
433            return (i);
434        }
435        if ((i == (int)n) || (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)) {
436            return (tot + i);
437        }
438
439        n -= i;
440        tot += i;
441    }
442}
443
444static int write_pending(SSL *s, const unsigned char *buf, unsigned int len)
445{
446    int i;
447
448    /* s->s2->wpend_len != 0 MUST be true. */
449
450    /*
451     * check that they have given us the same buffer to write
452     */
453    if ((s->s2->wpend_tot > (int)len) ||
454        ((s->s2->wpend_buf != buf) &&
455         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))) {
456        SSLerr(SSL_F_WRITE_PENDING, SSL_R_BAD_WRITE_RETRY);
457        return (-1);
458    }
459
460    for (;;) {
461        clear_sys_error();
462        if (s->wbio != NULL) {
463            s->rwstate = SSL_WRITING;
464            i = BIO_write(s->wbio,
465                          (char *)&(s->s2->write_ptr[s->s2->wpend_off]),
466                          (unsigned int)s->s2->wpend_len);
467        } else {
468            SSLerr(SSL_F_WRITE_PENDING, SSL_R_WRITE_BIO_NOT_SET);
469            i = -1;
470        }
471# ifdef PKT_DEBUG
472        if (s->debug & 0x01)
473            sleep(1);
474# endif
475        if (i == s->s2->wpend_len) {
476            s->s2->wpend_len = 0;
477            s->rwstate = SSL_NOTHING;
478            return (s->s2->wpend_ret);
479        } else if (i <= 0)
480            return (i);
481        s->s2->wpend_off += i;
482        s->s2->wpend_len -= i;
483    }
484}
485
486static int n_do_ssl_write(SSL *s, const unsigned char *buf, unsigned int len)
487{
488    unsigned int j, k, olen, p, bs;
489    int mac_size;
490    register unsigned char *pp;
491
492    olen = len;
493
494    /*
495     * first check if there is data from an encryption waiting to be sent -
496     * it must be sent because the other end is waiting. This will happen
497     * with non-blocking IO.  We print it and then return.
498     */
499    if (s->s2->wpend_len != 0)
500        return (write_pending(s, buf, len));
501
502    /* set mac_size to mac size */
503    if (s->s2->clear_text)
504        mac_size = 0;
505    else {
506        mac_size = EVP_MD_CTX_size(s->write_hash);
507        if (mac_size < 0)
508            return -1;
509    }
510
511    /* lets set the pad p */
512    if (s->s2->clear_text) {
513        if (len > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
514            len = SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
515        p = 0;
516        s->s2->three_byte_header = 0;
517        /* len=len; */
518    } else {
519        bs = EVP_CIPHER_CTX_block_size(s->enc_read_ctx);
520        j = len + mac_size;
521        /*
522         * Two-byte headers allow for a larger record length than three-byte
523         * headers, but we can't use them if we need padding or if we have to
524         * set the escape bit.
525         */
526        if ((j > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) && (!s->s2->escape)) {
527            if (j > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
528                j = SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
529            /*
530             * set k to the max number of bytes with 2 byte header
531             */
532            k = j - (j % bs);
533            /* how many data bytes? */
534            len = k - mac_size;
535            s->s2->three_byte_header = 0;
536            p = 0;
537        } else if ((bs <= 1) && (!s->s2->escape)) {
538            /*-
539             * j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER, thus
540             * j < SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER
541             */
542            s->s2->three_byte_header = 0;
543            p = 0;
544        } else {                /* we may have to use a 3 byte header */
545
546            /*-
547             * If s->s2->escape is not set, then
548             * j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER, and thus
549             * j < SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER.
550             */
551            p = (j % bs);
552            p = (p == 0) ? 0 : (bs - p);
553            if (s->s2->escape) {
554                s->s2->three_byte_header = 1;
555                if (j > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)
556                    j = SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER;
557            } else
558                s->s2->three_byte_header = (p == 0) ? 0 : 1;
559        }
560    }
561
562    /*-
563     * Now
564     *      j <= SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER
565     * holds, and if s->s2->three_byte_header is set, then even
566     *      j <= SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER.
567     */
568
569    /*
570     * mac_size is the number of MAC bytes len is the number of data bytes we
571     * are going to send p is the number of padding bytes (if it is a
572     * two-byte header, then p == 0)
573     */
574
575    s->s2->wlength = len;
576    s->s2->padding = p;
577    s->s2->mac_data = &(s->s2->wbuf[3]);
578    s->s2->wact_data = &(s->s2->wbuf[3 + mac_size]);
579
580    /*
581     * It would be clearer to write this as follows:
582     *     if (mac_size + len + p > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
583     * However |len| is user input that could in theory be very large. We
584     * know |mac_size| and |p| are small, so to avoid any possibility of
585     * overflow we write it like this.
586     *
587     * In theory this should never fail because the logic above should have
588     * modified |len| if it is too big. But we are being cautious.
589     */
590    if (len > (SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER - (mac_size + p))) {
591        return -1;
592    }
593    /* we copy the data into s->s2->wbuf */
594    memcpy(s->s2->wact_data, buf, len);
595    if (p)
596        memset(&(s->s2->wact_data[len]), 0, p); /* arbitrary padding */
597
598    if (!s->s2->clear_text) {
599        s->s2->wact_data_length = len + p;
600        ssl2_mac(s, s->s2->mac_data, 1);
601        s->s2->wlength += p + mac_size;
602        if (ssl2_enc(s, 1) < 1)
603            return -1;
604    }
605
606    /* package up the header */
607    s->s2->wpend_len = s->s2->wlength;
608    if (s->s2->three_byte_header) { /* 3 byte header */
609        pp = s->s2->mac_data;
610        pp -= 3;
611        pp[0] = (s->s2->wlength >> 8) & (THREE_BYTE_MASK >> 8);
612        if (s->s2->escape)
613            pp[0] |= SEC_ESC_BIT;
614        pp[1] = s->s2->wlength & 0xff;
615        pp[2] = s->s2->padding;
616        s->s2->wpend_len += 3;
617    } else {
618        pp = s->s2->mac_data;
619        pp -= 2;
620        pp[0] = ((s->s2->wlength >> 8) & (TWO_BYTE_MASK >> 8)) | TWO_BYTE_BIT;
621        pp[1] = s->s2->wlength & 0xff;
622        s->s2->wpend_len += 2;
623    }
624    s->s2->write_ptr = pp;
625
626    INC32(s->s2->write_sequence); /* expect next number */
627
628    /* lets try to actually write the data */
629    s->s2->wpend_tot = olen;
630    s->s2->wpend_buf = buf;
631
632    s->s2->wpend_ret = len;
633
634    s->s2->wpend_off = 0;
635    return (write_pending(s, buf, olen));
636}
637
638int ssl2_part_read(SSL *s, unsigned long f, int i)
639{
640    unsigned char *p;
641    int j;
642
643    if (i < 0) {
644        /* ssl2_return_error(s); */
645        /*
646         * for non-blocking io, this is not necessarily fatal
647         */
648        return (i);
649    } else {
650        s->init_num += i;
651
652        /*
653         * Check for error.  While there are recoverable errors, this
654         * function is not called when those must be expected; any error
655         * detected here is fatal.
656         */
657        if (s->init_num >= 3) {
658            p = (unsigned char *)s->init_buf->data;
659            if (p[0] == SSL2_MT_ERROR) {
660                j = (p[1] << 8) | p[2];
661                SSLerr((int)f, ssl_mt_error(j));
662                s->init_num -= 3;
663                if (s->init_num > 0)
664                    memmove(p, p + 3, s->init_num);
665            }
666        }
667
668        /*
669         * If it's not an error message, we have some error anyway -- the
670         * message was shorter than expected.  This too is treated as fatal
671         * (at least if SSL_get_error is asked for its opinion).
672         */
673        return (0);
674    }
675}
676
677int ssl2_do_write(SSL *s)
678{
679    int ret;
680
681    ret = ssl2_write(s, &s->init_buf->data[s->init_off], s->init_num);
682    if (ret == s->init_num) {
683        if (s->msg_callback)
684            s->msg_callback(1, s->version, 0, s->init_buf->data,
685                            (size_t)(s->init_off + s->init_num), s,
686                            s->msg_callback_arg);
687        return (1);
688    }
689    if (ret < 0)
690        return (-1);
691    s->init_off += ret;
692    s->init_num -= ret;
693    return (0);
694}
695
696static int ssl_mt_error(int n)
697{
698    int ret;
699
700    switch (n) {
701    case SSL2_PE_NO_CIPHER:
702        ret = SSL_R_PEER_ERROR_NO_CIPHER;
703        break;
704    case SSL2_PE_NO_CERTIFICATE:
705        ret = SSL_R_PEER_ERROR_NO_CERTIFICATE;
706        break;
707    case SSL2_PE_BAD_CERTIFICATE:
708        ret = SSL_R_PEER_ERROR_CERTIFICATE;
709        break;
710    case SSL2_PE_UNSUPPORTED_CERTIFICATE_TYPE:
711        ret = SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE;
712        break;
713    default:
714        ret = SSL_R_UNKNOWN_REMOTE_ERROR_TYPE;
715        break;
716    }
717    return (ret);
718}
719#else                           /* !OPENSSL_NO_SSL2 */
720
721# if PEDANTIC
722static void *dummy = &dummy;
723# endif
724
725#endif
726