1 /* $OpenBSD: encode.c,v 1.28 2020/03/04 11:53:21 inoguchi 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 static unsigned char conv_ascii2bin(unsigned char a);
66 #define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f])
67
68 /* 64 char lines
69 * pad input with 0
70 * left over chars are set to =
71 * 1 byte => xx==
72 * 2 bytes => xxx=
73 * 3 bytes => xxxx
74 */
75 #define BIN_PER_LINE (64/4*3)
76 #define CHUNKS_PER_LINE (64/4)
77 #define CHAR_PER_LINE (64+1)
78
79 static const unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
80 abcdefghijklmnopqrstuvwxyz0123456789+/";
81
82 /* 0xF0 is a EOLN
83 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
84 * 0xF2 is EOF
85 * 0xE0 is ignore at start of line.
86 * 0xFF is error
87 */
88
89 #define B64_EOLN 0xF0
90 #define B64_CR 0xF1
91 #define B64_EOF 0xF2
92 #define B64_WS 0xE0
93 #define B64_ERROR 0xFF
94 #define B64_NOT_BASE64(a) (((a)|0x13) == 0xF3)
95 #define B64_BASE64(a) !B64_NOT_BASE64(a)
96
97 static const unsigned char data_ascii2bin[128] = {
98 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
99 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
100 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
101 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
102 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
103 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
104 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
105 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
106 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
107 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
108 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
109 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
110 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
111 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
112 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
113 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
114 };
115
116 static unsigned char
conv_ascii2bin(unsigned char a)117 conv_ascii2bin(unsigned char a)
118 {
119 if (a & 0x80)
120 return B64_ERROR;
121 return data_ascii2bin[a];
122 }
123
124 EVP_ENCODE_CTX *
EVP_ENCODE_CTX_new(void)125 EVP_ENCODE_CTX_new(void)
126 {
127 return calloc(1, sizeof(EVP_ENCODE_CTX));
128 }
129
130 void
EVP_ENCODE_CTX_free(EVP_ENCODE_CTX * ctx)131 EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
132 {
133 free(ctx);
134 }
135
136 void
EVP_EncodeInit(EVP_ENCODE_CTX * ctx)137 EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
138 {
139 ctx->length = 48;
140 ctx->num = 0;
141 ctx->line_num = 0;
142 }
143
144 int
EVP_EncodeUpdate(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl,const unsigned char * in,int inl)145 EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
146 const unsigned char *in, int inl)
147 {
148 int i, j;
149 size_t total = 0;
150
151 *outl = 0;
152 if (inl <= 0)
153 return 0;
154 OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
155 if (ctx->length - ctx->num > inl) {
156 memcpy(&(ctx->enc_data[ctx->num]), in, inl);
157 ctx->num += inl;
158 return 1;
159 }
160 if (ctx->num != 0) {
161 i = ctx->length - ctx->num;
162 memcpy(&(ctx->enc_data[ctx->num]), in, i);
163 in += i;
164 inl -= i;
165 j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
166 ctx->num = 0;
167 out += j;
168 *(out++) = '\n';
169 *out = '\0';
170 total = j + 1;
171 }
172 while (inl >= ctx->length && total <= INT_MAX) {
173 j = EVP_EncodeBlock(out, in, ctx->length);
174 in += ctx->length;
175 inl -= ctx->length;
176 out += j;
177 *(out++) = '\n';
178 *out = '\0';
179 total += j + 1;
180 }
181 if (total > INT_MAX) {
182 /* Too much output data! */
183 *outl = 0;
184 return 0;
185 }
186 if (inl != 0)
187 memcpy(&(ctx->enc_data[0]), in, inl);
188 ctx->num = inl;
189 *outl = total;
190
191 return 1;
192 }
193
194 void
EVP_EncodeFinal(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl)195 EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
196 {
197 unsigned int ret = 0;
198
199 if (ctx->num != 0) {
200 ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
201 out[ret++] = '\n';
202 out[ret] = '\0';
203 ctx->num = 0;
204 }
205 *outl = ret;
206 }
207
208 int
EVP_EncodeBlock(unsigned char * t,const unsigned char * f,int dlen)209 EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
210 {
211 int i, ret = 0;
212 unsigned long l;
213
214 for (i = dlen; i > 0; i -= 3) {
215 if (i >= 3) {
216 l = (((unsigned long)f[0]) << 16L) |
217 (((unsigned long)f[1]) << 8L) | f[2];
218 *(t++) = conv_bin2ascii(l >> 18L);
219 *(t++) = conv_bin2ascii(l >> 12L);
220 *(t++) = conv_bin2ascii(l >> 6L);
221 *(t++) = conv_bin2ascii(l );
222 } else {
223 l = ((unsigned long)f[0]) << 16L;
224 if (i == 2)
225 l |= ((unsigned long)f[1] << 8L);
226
227 *(t++) = conv_bin2ascii(l >> 18L);
228 *(t++) = conv_bin2ascii(l >> 12L);
229 *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
230 *(t++) = '=';
231 }
232 ret += 4;
233 f += 3;
234 }
235
236 *t = '\0';
237 return (ret);
238 }
239
240 void
EVP_DecodeInit(EVP_ENCODE_CTX * ctx)241 EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
242 {
243 ctx->num = 0;
244 ctx->length = 0;
245 ctx->line_num = 0;
246 ctx->expect_nl = 0;
247 }
248
249 int
EVP_DecodeUpdate(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl,const unsigned char * in,int inl)250 EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
251 const unsigned char *in, int inl)
252 {
253 int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len;
254 unsigned char *d;
255
256 n = ctx->num;
257 d = ctx->enc_data;
258
259 if (n > 0 && d[n - 1] == '=') {
260 eof++;
261 if (n > 1 && d[n - 2] == '=')
262 eof++;
263 }
264
265 /* Legacy behaviour: an empty input chunk signals end of input. */
266 if (inl == 0) {
267 rv = 0;
268 goto end;
269 }
270
271 for (i = 0; i < inl; i++) {
272 tmp = *(in++);
273 v = conv_ascii2bin(tmp);
274 if (v == B64_ERROR) {
275 rv = -1;
276 goto end;
277 }
278
279 if (tmp == '=') {
280 eof++;
281 } else if (eof > 0 && B64_BASE64(v)) {
282 /* More data after padding. */
283 rv = -1;
284 goto end;
285 }
286
287 if (eof > 2) {
288 rv = -1;
289 goto end;
290 }
291
292 if (v == B64_EOF) {
293 seof = 1;
294 goto tail;
295 }
296
297 /* Only save valid base64 characters. */
298 if (B64_BASE64(v)) {
299 if (n >= 64) {
300 /*
301 * We increment n once per loop, and empty the
302 * buffer as soon as we reach 64 characters, so
303 * this can only happen if someone's manually
304 * messed with the ctx. Refuse to write any
305 * more data.
306 */
307 rv = -1;
308 goto end;
309 }
310 OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
311 d[n++] = tmp;
312 }
313
314 if (n == 64) {
315 decoded_len = EVP_DecodeBlock(out, d, n);
316 n = 0;
317 if (decoded_len < 0 || eof > decoded_len) {
318 rv = -1;
319 goto end;
320 }
321 ret += decoded_len - eof;
322 out += decoded_len - eof;
323 }
324 }
325
326 /*
327 * Legacy behaviour: if the current line is a full base64-block (i.e.,
328 * has 0 mod 4 base64 characters), it is processed immediately. We keep
329 * this behaviour as applications may not be calling EVP_DecodeFinal
330 * properly.
331 */
332 tail:
333 if (n > 0) {
334 if ((n & 3) == 0) {
335 decoded_len = EVP_DecodeBlock(out, d, n);
336 n = 0;
337 if (decoded_len < 0 || eof > decoded_len) {
338 rv = -1;
339 goto end;
340 }
341 ret += (decoded_len - eof);
342 } else if (seof) {
343 /* EOF in the middle of a base64 block. */
344 rv = -1;
345 goto end;
346 }
347 }
348
349 rv = seof || (n == 0 && eof) ? 0 : 1;
350 end:
351 /* Legacy behaviour. This should probably rather be zeroed on error. */
352 *outl = ret;
353 ctx->num = n;
354 return (rv);
355 }
356
357 int
EVP_DecodeBlock(unsigned char * t,const unsigned char * f,int n)358 EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
359 {
360 int i, ret = 0, a, b, c, d;
361 unsigned long l;
362
363 /* trim white space from the start of the line. */
364 while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
365 f++;
366 n--;
367 }
368
369 /* strip off stuff at the end of the line
370 * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */
371 while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
372 n--;
373
374 if (n % 4 != 0)
375 return (-1);
376
377 for (i = 0; i < n; i += 4) {
378 a = conv_ascii2bin(*(f++));
379 b = conv_ascii2bin(*(f++));
380 c = conv_ascii2bin(*(f++));
381 d = conv_ascii2bin(*(f++));
382 if ((a & 0x80) || (b & 0x80) ||
383 (c & 0x80) || (d & 0x80))
384 return (-1);
385 l = ((((unsigned long)a) << 18L) |
386 (((unsigned long)b) << 12L) |
387 (((unsigned long)c) << 6L) |
388 (((unsigned long)d)));
389 *(t++) = (unsigned char)(l >> 16L) & 0xff;
390 *(t++) = (unsigned char)(l >> 8L) & 0xff;
391 *(t++) = (unsigned char)(l) & 0xff;
392 ret += 3;
393 }
394 return (ret);
395 }
396
397 int
EVP_DecodeFinal(EVP_ENCODE_CTX * ctx,unsigned char * out,int * outl)398 EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
399 {
400 int i;
401
402 *outl = 0;
403 if (ctx->num != 0) {
404 i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
405 if (i < 0)
406 return (-1);
407 ctx->num = 0;
408 *outl = i;
409 return (1);
410 } else
411 return (1);
412 }
413