encode.c revision 299068 
1/* crypto/evp/encode.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#include <stdio.h>
60#include <limits.h>
61#include "cryptlib.h"
62#include <openssl/evp.h>
63
64#ifndef CHARSET_EBCDIC
65# define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
66# define conv_ascii2bin(a)       (data_ascii2bin[(a)&0x7f])
67#else
68/*
69 * We assume that PEM encoded files are EBCDIC files (i.e., printable text
70 * files). Convert them here while decoding. When encoding, output is EBCDIC
71 * (text) format again. (No need for conversion in the conv_bin2ascii macro,
72 * as the underlying textstring data_bin2ascii[] is already EBCDIC)
73 */
74# define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
75# define conv_ascii2bin(a)       (data_ascii2bin[os_toascii[a]&0x7f])
76#endif
77
78/*-
79 * 64 char lines
80 * pad input with 0
81 * left over chars are set to =
82 * 1 byte  => xx==
83 * 2 bytes => xxx=
84 * 3 bytes => xxxx
85 */
86#define BIN_PER_LINE    (64/4*3)
87#define CHUNKS_PER_LINE (64/4)
88#define CHAR_PER_LINE   (64+1)
89
90static unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
91abcdefghijklmnopqrstuvwxyz0123456789+/";
92
93/*-
94 * 0xF0 is a EOLN
95 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
96 * 0xF2 is EOF
97 * 0xE0 is ignore at start of line.
98 * 0xFF is error
99 */
100
101#define B64_EOLN                0xF0
102#define B64_CR                  0xF1
103#define B64_EOF                 0xF2
104#define B64_WS                  0xE0
105#define B64_ERROR               0xFF
106#define B64_NOT_BASE64(a)       (((a)|0x13) == 0xF3)
107
108static unsigned char data_ascii2bin[128] = {
109    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
110    0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
111    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
112    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
113    0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
114    0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
115    0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
116    0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
117    0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
118    0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
119    0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
120    0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
121    0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
122    0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
123    0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
124    0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
125};
126
127void EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
128{
129    ctx->length = 48;
130    ctx->num = 0;
131    ctx->line_num = 0;
132}
133
134void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
135                      const unsigned char *in, int inl)
136{
137    int i, j;
138    size_t total = 0;
139
140    *outl = 0;
141    if (inl == 0)
142        return;
143    OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
144    if (ctx->length - ctx->num > inl) {
145        memcpy(&(ctx->enc_data[ctx->num]), in, inl);
146        ctx->num += inl;
147        return;
148    }
149    if (ctx->num != 0) {
150        i = ctx->length - ctx->num;
151        memcpy(&(ctx->enc_data[ctx->num]), in, i);
152        in += i;
153        inl -= i;
154        j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
155        ctx->num = 0;
156        out += j;
157        *(out++) = '\n';
158        *out = '\0';
159        total = j + 1;
160    }
161    while (inl >= ctx->length && total <= INT_MAX) {
162        j = EVP_EncodeBlock(out, in, ctx->length);
163        in += ctx->length;
164        inl -= ctx->length;
165        out += j;
166        *(out++) = '\n';
167        *out = '\0';
168        total += j + 1;
169    }
170    if (total > INT_MAX) {
171        /* Too much output data! */
172        *outl = 0;
173        return;
174    }
175    if (inl != 0)
176        memcpy(&(ctx->enc_data[0]), in, inl);
177    ctx->num = inl;
178    *outl = total;
179}
180
181void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
182{
183    unsigned int ret = 0;
184
185    if (ctx->num != 0) {
186        ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
187        out[ret++] = '\n';
188        out[ret] = '\0';
189        ctx->num = 0;
190    }
191    *outl = ret;
192}
193
194int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
195{
196    int i, ret = 0;
197    unsigned long l;
198
199    for (i = dlen; i > 0; i -= 3) {
200        if (i >= 3) {
201            l = (((unsigned long)f[0]) << 16L) |
202                (((unsigned long)f[1]) << 8L) | f[2];
203            *(t++) = conv_bin2ascii(l >> 18L);
204            *(t++) = conv_bin2ascii(l >> 12L);
205            *(t++) = conv_bin2ascii(l >> 6L);
206            *(t++) = conv_bin2ascii(l);
207        } else {
208            l = ((unsigned long)f[0]) << 16L;
209            if (i == 2)
210                l |= ((unsigned long)f[1] << 8L);
211
212            *(t++) = conv_bin2ascii(l >> 18L);
213            *(t++) = conv_bin2ascii(l >> 12L);
214            *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
215            *(t++) = '=';
216        }
217        ret += 4;
218        f += 3;
219    }
220
221    *t = '\0';
222    return (ret);
223}
224
225void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
226{
227    ctx->length = 30;
228    ctx->num = 0;
229    ctx->line_num = 0;
230    ctx->expect_nl = 0;
231}
232
233/*-
234 * -1 for error
235 *  0 for last line
236 *  1 for full line
237 */
238int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
239                     const unsigned char *in, int inl)
240{
241    int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
242    unsigned char *d;
243
244    n = ctx->num;
245    d = ctx->enc_data;
246    ln = ctx->line_num;
247    exp_nl = ctx->expect_nl;
248
249    /* last line of input. */
250    if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
251        rv = 0;
252        goto end;
253    }
254
255    /* We parse the input data */
256    for (i = 0; i < inl; i++) {
257        /* If the current line is > 80 characters, scream alot */
258        if (ln >= 80) {
259            rv = -1;
260            goto end;
261        }
262
263        /* Get char and put it into the buffer */
264        tmp = *(in++);
265        v = conv_ascii2bin(tmp);
266        /* only save the good data :-) */
267        if (!B64_NOT_BASE64(v)) {
268            OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
269            d[n++] = tmp;
270            ln++;
271        } else if (v == B64_ERROR) {
272            rv = -1;
273            goto end;
274        }
275
276        /*
277         * have we seen a '=' which is 'definitly' the last input line.  seof
278         * will point to the character that holds it. and eof will hold how
279         * many characters to chop off.
280         */
281        if (tmp == '=') {
282            if (seof == -1)
283                seof = n;
284            eof++;
285        }
286
287        if (v == B64_CR) {
288            ln = 0;
289            if (exp_nl)
290                continue;
291        }
292
293        /* eoln */
294        if (v == B64_EOLN) {
295            ln = 0;
296            if (exp_nl) {
297                exp_nl = 0;
298                continue;
299            }
300        }
301        exp_nl = 0;
302
303        /*
304         * If we are at the end of input and it looks like a line, process
305         * it.
306         */
307        if (((i + 1) == inl) && (((n & 3) == 0) || eof)) {
308            v = B64_EOF;
309            /*
310             * In case things were given us in really small records (so two
311             * '=' were given in separate updates), eof may contain the
312             * incorrect number of ending bytes to skip, so let's redo the
313             * count
314             */
315            eof = 0;
316            if (d[n - 1] == '=')
317                eof++;
318            if (d[n - 2] == '=')
319                eof++;
320            /* There will never be more than two '=' */
321        }
322
323        if ((v == B64_EOF && (n & 3) == 0) || (n >= 64)) {
324            /*
325             * This is needed to work correctly on 64 byte input lines.  We
326             * process the line and then need to accept the '\n'
327             */
328            if ((v != B64_EOF) && (n >= 64))
329                exp_nl = 1;
330            if (n > 0) {
331                v = EVP_DecodeBlock(out, d, n);
332                n = 0;
333                if (v < 0) {
334                    rv = 0;
335                    goto end;
336                }
337                if (eof > v) {
338                    rv = -1;
339                    goto end;
340                }
341                ret += (v - eof);
342            } else {
343                eof = 1;
344                v = 0;
345            }
346
347            /*
348             * This is the case where we have had a short but valid input
349             * line
350             */
351            if ((v < ctx->length) && eof) {
352                rv = 0;
353                goto end;
354            } else
355                ctx->length = v;
356
357            if (seof >= 0) {
358                rv = 0;
359                goto end;
360            }
361            out += v;
362        }
363    }
364    rv = 1;
365 end:
366    *outl = ret;
367    ctx->num = n;
368    ctx->line_num = ln;
369    ctx->expect_nl = exp_nl;
370    return (rv);
371}
372
373int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
374{
375    int i, ret = 0, a, b, c, d;
376    unsigned long l;
377
378    /* trim white space from the start of the line. */
379    while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
380        f++;
381        n--;
382    }
383
384    /*
385     * strip off stuff at the end of the line ascii2bin values B64_WS,
386     * B64_EOLN, B64_EOLN and B64_EOF
387     */
388    while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
389        n--;
390
391    if (n % 4 != 0)
392        return (-1);
393
394    for (i = 0; i < n; i += 4) {
395        a = conv_ascii2bin(*(f++));
396        b = conv_ascii2bin(*(f++));
397        c = conv_ascii2bin(*(f++));
398        d = conv_ascii2bin(*(f++));
399        if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80))
400            return (-1);
401        l = ((((unsigned long)a) << 18L) |
402             (((unsigned long)b) << 12L) |
403             (((unsigned long)c) << 6L) | (((unsigned long)d)));
404        *(t++) = (unsigned char)(l >> 16L) & 0xff;
405        *(t++) = (unsigned char)(l >> 8L) & 0xff;
406        *(t++) = (unsigned char)(l) & 0xff;
407        ret += 3;
408    }
409    return (ret);
410}
411
412int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
413{
414    int i;
415
416    *outl = 0;
417    if (ctx->num != 0) {
418        i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
419        if (i < 0)
420            return (-1);
421        ctx->num = 0;
422        *outl = i;
423        return (1);
424    } else
425        return (1);
426}
427
428#ifdef undef
429int EVP_DecodeValid(unsigned char *buf, int len)
430{
431    int i, num = 0, bad = 0;
432
433    if (len == 0)
434        return (-1);
435    while (conv_ascii2bin(*buf) == B64_WS) {
436        buf++;
437        len--;
438        if (len == 0)
439            return (-1);
440    }
441
442    for (i = len; i >= 4; i -= 4) {
443        if ((conv_ascii2bin(buf[0]) >= 0x40) ||
444            (conv_ascii2bin(buf[1]) >= 0x40) ||
445            (conv_ascii2bin(buf[2]) >= 0x40) ||
446            (conv_ascii2bin(buf[3]) >= 0x40))
447            return (-1);
448        buf += 4;
449        num += 1 + (buf[2] != '=') + (buf[3] != '=');
450    }
451    if ((i == 1) && (conv_ascii2bin(buf[0]) == B64_EOLN))
452        return (num);
453    if ((i == 2) && (conv_ascii2bin(buf[0]) == B64_EOLN) &&
454        (conv_ascii2bin(buf[0]) == B64_EOLN))
455        return (num);
456    return (1);
457}
458#endif
459