encode.c revision 296465 
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 "cryptlib.h"
61#include <openssl/evp.h>
62
63#ifndef CHARSET_EBCDIC
64# define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
65# define conv_ascii2bin(a)       (data_ascii2bin[(a)&0x7f])
66#else
67/*
68 * We assume that PEM encoded files are EBCDIC files (i.e., printable text
69 * files). Convert them here while decoding. When encoding, output is EBCDIC
70 * (text) format again. (No need for conversion in the conv_bin2ascii macro,
71 * as the underlying textstring data_bin2ascii[] is already EBCDIC)
72 */
73# define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
74# define conv_ascii2bin(a)       (data_ascii2bin[os_toascii[a]&0x7f])
75#endif
76
77/*-
78 * 64 char lines
79 * pad input with 0
80 * left over chars are set to =
81 * 1 byte  => xx==
82 * 2 bytes => xxx=
83 * 3 bytes => xxxx
84 */
85#define BIN_PER_LINE    (64/4*3)
86#define CHUNKS_PER_LINE (64/4)
87#define CHAR_PER_LINE   (64+1)
88
89static unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
90abcdefghijklmnopqrstuvwxyz0123456789+/";
91
92/*-
93 * 0xF0 is a EOLN
94 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
95 * 0xF2 is EOF
96 * 0xE0 is ignore at start of line.
97 * 0xFF is error
98 */
99
100#define B64_EOLN                0xF0
101#define B64_CR                  0xF1
102#define B64_EOF                 0xF2
103#define B64_WS                  0xE0
104#define B64_ERROR               0xFF
105#define B64_NOT_BASE64(a)       (((a)|0x13) == 0xF3)
106
107static unsigned char data_ascii2bin[128] = {
108    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
109    0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
110    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
111    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
112    0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
113    0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
114    0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
115    0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
116    0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
117    0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
118    0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
119    0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
120    0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
121    0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
122    0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
123    0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
124};
125
126void EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
127{
128    ctx->length = 48;
129    ctx->num = 0;
130    ctx->line_num = 0;
131}
132
133void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
134                      const unsigned char *in, int inl)
135{
136    int i, j;
137    unsigned int total = 0;
138
139    *outl = 0;
140    if (inl == 0)
141        return;
142    OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
143    if ((ctx->num + inl) < ctx->length) {
144        memcpy(&(ctx->enc_data[ctx->num]), in, inl);
145        ctx->num += inl;
146        return;
147    }
148    if (ctx->num != 0) {
149        i = ctx->length - ctx->num;
150        memcpy(&(ctx->enc_data[ctx->num]), in, i);
151        in += i;
152        inl -= i;
153        j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
154        ctx->num = 0;
155        out += j;
156        *(out++) = '\n';
157        *out = '\0';
158        total = j + 1;
159    }
160    while (inl >= ctx->length) {
161        j = EVP_EncodeBlock(out, in, ctx->length);
162        in += ctx->length;
163        inl -= ctx->length;
164        out += j;
165        *(out++) = '\n';
166        *out = '\0';
167        total += j + 1;
168    }
169    if (inl != 0)
170        memcpy(&(ctx->enc_data[0]), in, inl);
171    ctx->num = inl;
172    *outl = total;
173}
174
175void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
176{
177    unsigned int ret = 0;
178
179    if (ctx->num != 0) {
180        ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
181        out[ret++] = '\n';
182        out[ret] = '\0';
183        ctx->num = 0;
184    }
185    *outl = ret;
186}
187
188int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
189{
190    int i, ret = 0;
191    unsigned long l;
192
193    for (i = dlen; i > 0; i -= 3) {
194        if (i >= 3) {
195            l = (((unsigned long)f[0]) << 16L) |
196                (((unsigned long)f[1]) << 8L) | f[2];
197            *(t++) = conv_bin2ascii(l >> 18L);
198            *(t++) = conv_bin2ascii(l >> 12L);
199            *(t++) = conv_bin2ascii(l >> 6L);
200            *(t++) = conv_bin2ascii(l);
201        } else {
202            l = ((unsigned long)f[0]) << 16L;
203            if (i == 2)
204                l |= ((unsigned long)f[1] << 8L);
205
206            *(t++) = conv_bin2ascii(l >> 18L);
207            *(t++) = conv_bin2ascii(l >> 12L);
208            *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
209            *(t++) = '=';
210        }
211        ret += 4;
212        f += 3;
213    }
214
215    *t = '\0';
216    return (ret);
217}
218
219void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
220{
221    ctx->length = 30;
222    ctx->num = 0;
223    ctx->line_num = 0;
224    ctx->expect_nl = 0;
225}
226
227/*-
228 * -1 for error
229 *  0 for last line
230 *  1 for full line
231 */
232int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
233                     const unsigned char *in, int inl)
234{
235    int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
236    unsigned char *d;
237
238    n = ctx->num;
239    d = ctx->enc_data;
240    ln = ctx->line_num;
241    exp_nl = ctx->expect_nl;
242
243    /* last line of input. */
244    if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
245        rv = 0;
246        goto end;
247    }
248
249    /* We parse the input data */
250    for (i = 0; i < inl; i++) {
251        /* If the current line is > 80 characters, scream alot */
252        if (ln >= 80) {
253            rv = -1;
254            goto end;
255        }
256
257        /* Get char and put it into the buffer */
258        tmp = *(in++);
259        v = conv_ascii2bin(tmp);
260        /* only save the good data :-) */
261        if (!B64_NOT_BASE64(v)) {
262            OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
263            d[n++] = tmp;
264            ln++;
265        } else if (v == B64_ERROR) {
266            rv = -1;
267            goto end;
268        }
269
270        /*
271         * have we seen a '=' which is 'definitly' the last input line.  seof
272         * will point to the character that holds it. and eof will hold how
273         * many characters to chop off.
274         */
275        if (tmp == '=') {
276            if (seof == -1)
277                seof = n;
278            eof++;
279        }
280
281        if (v == B64_CR) {
282            ln = 0;
283            if (exp_nl)
284                continue;
285        }
286
287        /* eoln */
288        if (v == B64_EOLN) {
289            ln = 0;
290            if (exp_nl) {
291                exp_nl = 0;
292                continue;
293            }
294        }
295        exp_nl = 0;
296
297        /*
298         * If we are at the end of input and it looks like a line, process
299         * it.
300         */
301        if (((i + 1) == inl) && (((n & 3) == 0) || eof)) {
302            v = B64_EOF;
303            /*
304             * In case things were given us in really small records (so two
305             * '=' were given in separate updates), eof may contain the
306             * incorrect number of ending bytes to skip, so let's redo the
307             * count
308             */
309            eof = 0;
310            if (d[n - 1] == '=')
311                eof++;
312            if (d[n - 2] == '=')
313                eof++;
314            /* There will never be more than two '=' */
315        }
316
317        if ((v == B64_EOF && (n & 3) == 0) || (n >= 64)) {
318            /*
319             * This is needed to work correctly on 64 byte input lines.  We
320             * process the line and then need to accept the '\n'
321             */
322            if ((v != B64_EOF) && (n >= 64))
323                exp_nl = 1;
324            if (n > 0) {
325                v = EVP_DecodeBlock(out, d, n);
326                n = 0;
327                if (v < 0) {
328                    rv = 0;
329                    goto end;
330                }
331                if (eof > v) {
332                    rv = -1;
333                    goto end;
334                }
335                ret += (v - eof);
336            } else {
337                eof = 1;
338                v = 0;
339            }
340
341            /*
342             * This is the case where we have had a short but valid input
343             * line
344             */
345            if ((v < ctx->length) && eof) {
346                rv = 0;
347                goto end;
348            } else
349                ctx->length = v;
350
351            if (seof >= 0) {
352                rv = 0;
353                goto end;
354            }
355            out += v;
356        }
357    }
358    rv = 1;
359 end:
360    *outl = ret;
361    ctx->num = n;
362    ctx->line_num = ln;
363    ctx->expect_nl = exp_nl;
364    return (rv);
365}
366
367int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
368{
369    int i, ret = 0, a, b, c, d;
370    unsigned long l;
371
372    /* trim white space from the start of the line. */
373    while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
374        f++;
375        n--;
376    }
377
378    /*
379     * strip off stuff at the end of the line ascii2bin values B64_WS,
380     * B64_EOLN, B64_EOLN and B64_EOF
381     */
382    while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
383        n--;
384
385    if (n % 4 != 0)
386        return (-1);
387
388    for (i = 0; i < n; i += 4) {
389        a = conv_ascii2bin(*(f++));
390        b = conv_ascii2bin(*(f++));
391        c = conv_ascii2bin(*(f++));
392        d = conv_ascii2bin(*(f++));
393        if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80))
394            return (-1);
395        l = ((((unsigned long)a) << 18L) |
396             (((unsigned long)b) << 12L) |
397             (((unsigned long)c) << 6L) | (((unsigned long)d)));
398        *(t++) = (unsigned char)(l >> 16L) & 0xff;
399        *(t++) = (unsigned char)(l >> 8L) & 0xff;
400        *(t++) = (unsigned char)(l) & 0xff;
401        ret += 3;
402    }
403    return (ret);
404}
405
406int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
407{
408    int i;
409
410    *outl = 0;
411    if (ctx->num != 0) {
412        i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
413        if (i < 0)
414            return (-1);
415        ctx->num = 0;
416        *outl = i;
417        return (1);
418    } else
419        return (1);
420}
421
422#ifdef undef
423int EVP_DecodeValid(unsigned char *buf, int len)
424{
425    int i, num = 0, bad = 0;
426
427    if (len == 0)
428        return (-1);
429    while (conv_ascii2bin(*buf) == B64_WS) {
430        buf++;
431        len--;
432        if (len == 0)
433            return (-1);
434    }
435
436    for (i = len; i >= 4; i -= 4) {
437        if ((conv_ascii2bin(buf[0]) >= 0x40) ||
438            (conv_ascii2bin(buf[1]) >= 0x40) ||
439            (conv_ascii2bin(buf[2]) >= 0x40) ||
440            (conv_ascii2bin(buf[3]) >= 0x40))
441            return (-1);
442        buf += 4;
443        num += 1 + (buf[2] != '=') + (buf[3] != '=');
444    }
445    if ((i == 1) && (conv_ascii2bin(buf[0]) == B64_EOLN))
446        return (num);
447    if ((i == 2) && (conv_ascii2bin(buf[0]) == B64_EOLN) &&
448        (conv_ascii2bin(buf[0]) == B64_EOLN))
449        return (num);
450    return (1);
451}
452#endif
453