1 /* $OpenBSD: encode.c,v 1.29 2021/12/12 21:30:13 tb Exp $ */
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 <limits.h>
60 #include <stdio.h>
61 #include <string.h>
62
63 #include <openssl/evp.h>
64
65 #include "evp_locl.h"
66
67 static unsigned char conv_ascii2bin(unsigned char a);
68 #define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f])
69
70 /* 64 char lines
71 * pad input with 0
72 * left over chars are set to =
73 * 1 byte => xx==
74 * 2 bytes => xxx=
75 * 3 bytes => xxxx
76 */
77 #define BIN_PER_LINE (64/4*3)
78 #define CHUNKS_PER_LINE (64/4)
79 #define CHAR_PER_LINE (64+1)
80
81 static const unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
82 abcdefghijklmnopqrstuvwxyz0123456789+/";
83
84 /* 0xF0 is a EOLN
85 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
86 * 0xF2 is EOF
87 * 0xE0 is ignore at start of line.
88 * 0xFF is error
89 */
90
91 #define B64_EOLN 0xF0
92 #define B64_CR 0xF1
93 #define B64_EOF 0xF2
94 #define B64_WS 0xE0
95 #define B64_ERROR 0xFF
96 #define B64_NOT_BASE64(a) (((a)|0x13) == 0xF3)
97 #define B64_BASE64(a) !B64_NOT_BASE64(a)
98
99 static const unsigned char data_ascii2bin[128] = {
100 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
101 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
102 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
103 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
104 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
105 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
106 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
107 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
108 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
109 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
110 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
111 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
112 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
113 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
114 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
115 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
116 };
117
118 static unsigned char
conv_ascii2bin(unsigned char a)119 conv_ascii2bin(unsigned char a)
120 {
121 if (a & 0x80)
122 return B64_ERROR;
123 return data_ascii2bin[a];
124 }
125
126 EVP_ENCODE_CTX *
EVP_ENCODE_CTX_new(void)127 EVP_ENCODE_CTX_new(void)
128 {
129 return calloc(1, sizeof(EVP_ENCODE_CTX));
130 }
131
132 void
EVP_ENCODE_CTX_free(EVP_ENCODE_CTX * ctx)133 EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
134 {
135 free(ctx);
136 }
137
138 void
EVP_EncodeInit(EVP_ENCODE_CTX * ctx)139 EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
140 {
141 ctx->length = 48;
142 ctx->num = 0;
143 ctx->line_num = 0;
144 }
145
146 int
EVP_EncodeUpdate(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl,const unsigned char * in,int inl)147 EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
148 const unsigned char *in, int inl)
149 {
150 int i, j;
151 size_t total = 0;
152
153 *outl = 0;
154 if (inl <= 0)
155 return 0;
156 OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
157 if (ctx->length - ctx->num > inl) {
158 memcpy(&(ctx->enc_data[ctx->num]), in, inl);
159 ctx->num += inl;
160 return 1;
161 }
162 if (ctx->num != 0) {
163 i = ctx->length - ctx->num;
164 memcpy(&(ctx->enc_data[ctx->num]), in, i);
165 in += i;
166 inl -= i;
167 j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
168 ctx->num = 0;
169 out += j;
170 *(out++) = '\n';
171 *out = '\0';
172 total = j + 1;
173 }
174 while (inl >= ctx->length && total <= INT_MAX) {
175 j = EVP_EncodeBlock(out, in, ctx->length);
176 in += ctx->length;
177 inl -= ctx->length;
178 out += j;
179 *(out++) = '\n';
180 *out = '\0';
181 total += j + 1;
182 }
183 if (total > INT_MAX) {
184 /* Too much output data! */
185 *outl = 0;
186 return 0;
187 }
188 if (inl != 0)
189 memcpy(&(ctx->enc_data[0]), in, inl);
190 ctx->num = inl;
191 *outl = total;
192
193 return 1;
194 }
195
196 void
EVP_EncodeFinal(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl)197 EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
198 {
199 unsigned int ret = 0;
200
201 if (ctx->num != 0) {
202 ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
203 out[ret++] = '\n';
204 out[ret] = '\0';
205 ctx->num = 0;
206 }
207 *outl = ret;
208 }
209
210 int
EVP_EncodeBlock(unsigned char * t,const unsigned char * f,int dlen)211 EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
212 {
213 int i, ret = 0;
214 unsigned long l;
215
216 for (i = dlen; i > 0; i -= 3) {
217 if (i >= 3) {
218 l = (((unsigned long)f[0]) << 16L) |
219 (((unsigned long)f[1]) << 8L) | f[2];
220 *(t++) = conv_bin2ascii(l >> 18L);
221 *(t++) = conv_bin2ascii(l >> 12L);
222 *(t++) = conv_bin2ascii(l >> 6L);
223 *(t++) = conv_bin2ascii(l );
224 } else {
225 l = ((unsigned long)f[0]) << 16L;
226 if (i == 2)
227 l |= ((unsigned long)f[1] << 8L);
228
229 *(t++) = conv_bin2ascii(l >> 18L);
230 *(t++) = conv_bin2ascii(l >> 12L);
231 *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
232 *(t++) = '=';
233 }
234 ret += 4;
235 f += 3;
236 }
237
238 *t = '\0';
239 return (ret);
240 }
241
242 void
EVP_DecodeInit(EVP_ENCODE_CTX * ctx)243 EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
244 {
245 ctx->num = 0;
246 ctx->length = 0;
247 ctx->line_num = 0;
248 ctx->expect_nl = 0;
249 }
250
251 int
EVP_DecodeUpdate(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl,const unsigned char * in,int inl)252 EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
253 const unsigned char *in, int inl)
254 {
255 int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len;
256 unsigned char *d;
257
258 n = ctx->num;
259 d = ctx->enc_data;
260
261 if (n > 0 && d[n - 1] == '=') {
262 eof++;
263 if (n > 1 && d[n - 2] == '=')
264 eof++;
265 }
266
267 /* Legacy behaviour: an empty input chunk signals end of input. */
268 if (inl == 0) {
269 rv = 0;
270 goto end;
271 }
272
273 for (i = 0; i < inl; i++) {
274 tmp = *(in++);
275 v = conv_ascii2bin(tmp);
276 if (v == B64_ERROR) {
277 rv = -1;
278 goto end;
279 }
280
281 if (tmp == '=') {
282 eof++;
283 } else if (eof > 0 && B64_BASE64(v)) {
284 /* More data after padding. */
285 rv = -1;
286 goto end;
287 }
288
289 if (eof > 2) {
290 rv = -1;
291 goto end;
292 }
293
294 if (v == B64_EOF) {
295 seof = 1;
296 goto tail;
297 }
298
299 /* Only save valid base64 characters. */
300 if (B64_BASE64(v)) {
301 if (n >= 64) {
302 /*
303 * We increment n once per loop, and empty the
304 * buffer as soon as we reach 64 characters, so
305 * this can only happen if someone's manually
306 * messed with the ctx. Refuse to write any
307 * more data.
308 */
309 rv = -1;
310 goto end;
311 }
312 OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
313 d[n++] = tmp;
314 }
315
316 if (n == 64) {
317 decoded_len = EVP_DecodeBlock(out, d, n);
318 n = 0;
319 if (decoded_len < 0 || eof > decoded_len) {
320 rv = -1;
321 goto end;
322 }
323 ret += decoded_len - eof;
324 out += decoded_len - eof;
325 }
326 }
327
328 /*
329 * Legacy behaviour: if the current line is a full base64-block (i.e.,
330 * has 0 mod 4 base64 characters), it is processed immediately. We keep
331 * this behaviour as applications may not be calling EVP_DecodeFinal
332 * properly.
333 */
334 tail:
335 if (n > 0) {
336 if ((n & 3) == 0) {
337 decoded_len = EVP_DecodeBlock(out, d, n);
338 n = 0;
339 if (decoded_len < 0 || eof > decoded_len) {
340 rv = -1;
341 goto end;
342 }
343 ret += (decoded_len - eof);
344 } else if (seof) {
345 /* EOF in the middle of a base64 block. */
346 rv = -1;
347 goto end;
348 }
349 }
350
351 rv = seof || (n == 0 && eof) ? 0 : 1;
352 end:
353 /* Legacy behaviour. This should probably rather be zeroed on error. */
354 *outl = ret;
355 ctx->num = n;
356 return (rv);
357 }
358
359 int
EVP_DecodeBlock(unsigned char * t,const unsigned char * f,int n)360 EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
361 {
362 int i, ret = 0, a, b, c, d;
363 unsigned long l;
364
365 /* trim white space from the start of the line. */
366 while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
367 f++;
368 n--;
369 }
370
371 /* strip off stuff at the end of the line
372 * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */
373 while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
374 n--;
375
376 if (n % 4 != 0)
377 return (-1);
378
379 for (i = 0; i < n; i += 4) {
380 a = conv_ascii2bin(*(f++));
381 b = conv_ascii2bin(*(f++));
382 c = conv_ascii2bin(*(f++));
383 d = conv_ascii2bin(*(f++));
384 if ((a & 0x80) || (b & 0x80) ||
385 (c & 0x80) || (d & 0x80))
386 return (-1);
387 l = ((((unsigned long)a) << 18L) |
388 (((unsigned long)b) << 12L) |
389 (((unsigned long)c) << 6L) |
390 (((unsigned long)d)));
391 *(t++) = (unsigned char)(l >> 16L) & 0xff;
392 *(t++) = (unsigned char)(l >> 8L) & 0xff;
393 *(t++) = (unsigned char)(l) & 0xff;
394 ret += 3;
395 }
396 return (ret);
397 }
398
399 int
EVP_DecodeFinal(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl)400 EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
401 {
402 int i;
403
404 *outl = 0;
405 if (ctx->num != 0) {
406 i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
407 if (i < 0)
408 return (-1);
409 ctx->num = 0;
410 *outl = i;
411 return (1);
412 } else
413 return (1);
414 }
415