xref: /dragonfly/crypto/libressl/crypto/evp/encode.c (revision 72c33676)
1 /* $OpenBSD: encode.c,v 1.26 2019/01/19 01:24:18 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 #define conv_bin2ascii(a)	(data_bin2ascii[(a)&0x3f])
66 #define conv_ascii2bin(a)	(data_ascii2bin[(a)&0x7f])
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 
96 static const unsigned char data_ascii2bin[128] = {
97 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
98 	0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
99 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
100 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
101 	0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
102 	0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
103 	0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
104 	0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
105 	0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
106 	0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
107 	0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
108 	0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
109 	0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
110 	0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
111 	0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
112 	0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
113 };
114 
115 EVP_ENCODE_CTX *
116 EVP_ENCODE_CTX_new(void)
117 {
118 	return calloc(1, sizeof(EVP_ENCODE_CTX));
119 }
120 
121 void
122 EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
123 {
124 	free(ctx);
125 }
126 
127 void
128 EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
129 {
130 	ctx->length = 48;
131 	ctx->num = 0;
132 	ctx->line_num = 0;
133 }
134 
135 int
136 EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
137     const unsigned char *in, int inl)
138 {
139 	int i, j;
140 	size_t total = 0;
141 
142 	*outl = 0;
143 	if (inl <= 0)
144 		return 0;
145 	OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
146 	if (ctx->length - ctx->num > inl) {
147 		memcpy(&(ctx->enc_data[ctx->num]), in, inl);
148 		ctx->num += inl;
149 		return 1;
150 	}
151 	if (ctx->num != 0) {
152 		i = ctx->length - ctx->num;
153 		memcpy(&(ctx->enc_data[ctx->num]), in, i);
154 		in += i;
155 		inl -= i;
156 		j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
157 		ctx->num = 0;
158 		out += j;
159 		*(out++) = '\n';
160 		*out = '\0';
161 		total = j + 1;
162 	}
163 	while (inl >= ctx->length && total <= INT_MAX) {
164 		j = EVP_EncodeBlock(out, in, ctx->length);
165 		in += ctx->length;
166 		inl -= ctx->length;
167 		out += j;
168 		*(out++) = '\n';
169 		*out = '\0';
170 		total += j + 1;
171 	}
172 	if (total > INT_MAX) {
173 		/* Too much output data! */
174 		*outl = 0;
175 		return 0;
176 	}
177 	if (inl != 0)
178 		memcpy(&(ctx->enc_data[0]), in, inl);
179 	ctx->num = inl;
180 	*outl = total;
181 
182 	return 1;
183 }
184 
185 void
186 EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
187 {
188 	unsigned int ret = 0;
189 
190 	if (ctx->num != 0) {
191 		ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
192 		out[ret++] = '\n';
193 		out[ret] = '\0';
194 		ctx->num = 0;
195 	}
196 	*outl = ret;
197 }
198 
199 int
200 EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
201 {
202 	int i, ret = 0;
203 	unsigned long l;
204 
205 	for (i = dlen; i > 0; i -= 3) {
206 		if (i >= 3) {
207 			l = (((unsigned long)f[0]) << 16L) |
208 			    (((unsigned long)f[1]) << 8L) | f[2];
209 			*(t++) = conv_bin2ascii(l >> 18L);
210 			*(t++) = conv_bin2ascii(l >> 12L);
211 			*(t++) = conv_bin2ascii(l >> 6L);
212 			*(t++) = conv_bin2ascii(l     );
213 		} else {
214 			l = ((unsigned long)f[0]) << 16L;
215 			if (i == 2)
216 				l |= ((unsigned long)f[1] << 8L);
217 
218 			*(t++) = conv_bin2ascii(l >> 18L);
219 			*(t++) = conv_bin2ascii(l >> 12L);
220 			*(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
221 			*(t++) = '=';
222 		}
223 		ret += 4;
224 		f += 3;
225 	}
226 
227 	*t = '\0';
228 	return (ret);
229 }
230 
231 void
232 EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
233 {
234 	ctx->length = 30;
235 	ctx->num = 0;
236 	ctx->line_num = 0;
237 	ctx->expect_nl = 0;
238 }
239 
240 /* -1 for error
241  *  0 for last line
242  *  1 for full line
243  */
244 int
245 EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
246     const unsigned char *in, int inl)
247 {
248 	int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
249 	unsigned char *d;
250 
251 	n = ctx->num;
252 	d = ctx->enc_data;
253 	ln = ctx->line_num;
254 	exp_nl = ctx->expect_nl;
255 
256 	/* last line of input. */
257 	if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
258 		rv = 0;
259 		goto end;
260 	}
261 
262 	/* We parse the input data */
263 	for (i = 0; i < inl; i++) {
264 		/* If the current line is > 80 characters, scream alot */
265 		if (ln >= 80) {
266 			rv = -1;
267 			goto end;
268 		}
269 
270 		/* Get char and put it into the buffer */
271 		tmp= *(in++);
272 		v = conv_ascii2bin(tmp);
273 		/* only save the good data :-) */
274 		if (!B64_NOT_BASE64(v)) {
275 			OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
276 			d[n++] = tmp;
277 			ln++;
278 		} else if (v == B64_ERROR) {
279 			rv = -1;
280 			goto end;
281 		}
282 
283 		/* There should not be base64 data after padding. */
284 		if (eof && tmp != '=' && tmp != '\r' && tmp != '\n' &&
285 		    v != B64_EOF) {
286 			rv = -1;
287 			goto end;
288 		}
289 
290 		/* have we seen a '=' which is 'definitely' the last
291 		 * input line.  seof will point to the character that
292 		 * holds it. and eof will hold how many characters to
293 		 * chop off. */
294 		if (tmp == '=') {
295 			if (seof == -1)
296 				seof = n;
297 			eof++;
298 		}
299 
300 		/* There should be no more than two padding markers. */
301 		if (eof > 2) {
302 			rv = -1;
303 			goto end;
304 		}
305 
306 		if (v == B64_CR) {
307 			ln = 0;
308 			if (exp_nl)
309 				continue;
310 		}
311 
312 		/* eoln */
313 		if (v == B64_EOLN) {
314 			ln = 0;
315 			if (exp_nl) {
316 				exp_nl = 0;
317 				continue;
318 			}
319 		}
320 		exp_nl = 0;
321 
322 		/* If we are at the end of input and it looks like a
323 		 * line, process it. */
324 		if (((i + 1) == inl) && (((n&3) == 0) || eof)) {
325 			v = B64_EOF;
326 			/* In case things were given us in really small
327 			   records (so two '=' were given in separate
328 			   updates), eof may contain the incorrect number
329 			   of ending bytes to skip, so let's redo the count */
330 			eof = 0;
331 			if (d[n-1] == '=')
332 				eof++;
333 			if (d[n-2] == '=')
334 				eof++;
335 			/* There will never be more than two '=' */
336 		}
337 
338 		if ((v == B64_EOF && (n&3) == 0) || (n >= 64)) {
339 			/* This is needed to work correctly on 64 byte input
340 			 * lines.  We process the line and then need to
341 			 * accept the '\n' */
342 			if ((v != B64_EOF) && (n >= 64))
343 				exp_nl = 1;
344 			if (n > 0) {
345 				v = EVP_DecodeBlock(out, d, n);
346 				n = 0;
347 				if (v < 0) {
348 					rv = 0;
349 					goto end;
350 				}
351 				ret += (v - eof);
352 			} else {
353 				eof = 1;
354 				v = 0;
355 			}
356 
357 			/* This is the case where we have had a short
358 			 * but valid input line */
359 			if ((v < ctx->length) && eof) {
360 				rv = 0;
361 				goto end;
362 			} else
363 				ctx->length = v;
364 
365 			if (seof >= 0) {
366 				rv = 0;
367 				goto end;
368 			}
369 			out += v;
370 		}
371 	}
372 	rv = 1;
373 
374 end:
375 	*outl = ret;
376 	ctx->num = n;
377 	ctx->line_num = ln;
378 	ctx->expect_nl = exp_nl;
379 	return (rv);
380 }
381 
382 int
383 EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
384 {
385 	int i, ret = 0, a, b, c, d;
386 	unsigned long l;
387 
388 	/* trim white space from the start of the line. */
389 	while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
390 		f++;
391 		n--;
392 	}
393 
394 	/* strip off stuff at the end of the line
395 	 * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */
396 	while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
397 		n--;
398 
399 	if (n % 4 != 0)
400 		return (-1);
401 
402 	for (i = 0; i < n; i += 4) {
403 		a = conv_ascii2bin(*(f++));
404 		b = conv_ascii2bin(*(f++));
405 		c = conv_ascii2bin(*(f++));
406 		d = conv_ascii2bin(*(f++));
407 		if ((a & 0x80) || (b & 0x80) ||
408 		    (c & 0x80) || (d & 0x80))
409 			return (-1);
410 		l = ((((unsigned long)a) << 18L) |
411 		    (((unsigned long)b) << 12L) |
412 		    (((unsigned long)c) << 6L) |
413 		    (((unsigned long)d)));
414 		*(t++) = (unsigned char)(l >> 16L) & 0xff;
415 		*(t++) = (unsigned char)(l >> 8L) & 0xff;
416 		*(t++) = (unsigned char)(l) & 0xff;
417 		ret += 3;
418 	}
419 	return (ret);
420 }
421 
422 int
423 EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
424 {
425 	int i;
426 
427 	*outl = 0;
428 	if (ctx->num != 0) {
429 		i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
430 		if (i < 0)
431 			return (-1);
432 		ctx->num = 0;
433 		*outl = i;
434 		return (1);
435 	} else
436 		return (1);
437 }
438