1 | /* |
2 | * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include <limits.h> |
12 | #include "internal/cryptlib.h" |
13 | #include <openssl/evp.h> |
14 | #include "crypto/evp.h" |
15 | #include "evp_local.h" |
16 | |
17 | static unsigned char conv_ascii2bin(unsigned char a, |
18 | const unsigned char *table); |
19 | static int evp_encodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t, |
20 | const unsigned char *f, int dlen); |
21 | static int evp_decodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t, |
22 | const unsigned char *f, int n); |
23 | |
24 | #ifndef CHARSET_EBCDIC |
25 | # define conv_bin2ascii(a, table) ((table)[(a)&0x3f]) |
26 | #else |
27 | /* |
28 | * We assume that PEM encoded files are EBCDIC files (i.e., printable text |
29 | * files). Convert them here while decoding. When encoding, output is EBCDIC |
30 | * (text) format again. (No need for conversion in the conv_bin2ascii macro, |
31 | * as the underlying textstring data_bin2ascii[] is already EBCDIC) |
32 | */ |
33 | # define conv_bin2ascii(a, table) ((table)[(a)&0x3f]) |
34 | #endif |
35 | |
36 | /*- |
37 | * 64 char lines |
38 | * pad input with 0 |
39 | * left over chars are set to = |
40 | * 1 byte => xx== |
41 | * 2 bytes => xxx= |
42 | * 3 bytes => xxxx |
43 | */ |
44 | #define BIN_PER_LINE (64/4*3) |
45 | #define CHUNKS_PER_LINE (64/4) |
46 | #define CHAR_PER_LINE (64+1) |
47 | |
48 | static const unsigned char data_bin2ascii[65] = |
49 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" ; |
50 | |
51 | /* SRP uses a different base64 alphabet */ |
52 | static const unsigned char srpdata_bin2ascii[65] = |
53 | "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./" ; |
54 | |
55 | |
56 | /*- |
57 | * 0xF0 is a EOLN |
58 | * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing). |
59 | * 0xF2 is EOF |
60 | * 0xE0 is ignore at start of line. |
61 | * 0xFF is error |
62 | */ |
63 | |
64 | #define B64_EOLN 0xF0 |
65 | #define B64_CR 0xF1 |
66 | #define B64_EOF 0xF2 |
67 | #define B64_WS 0xE0 |
68 | #define B64_ERROR 0xFF |
69 | #define B64_NOT_BASE64(a) (((a)|0x13) == 0xF3) |
70 | #define B64_BASE64(a) (!B64_NOT_BASE64(a)) |
71 | |
72 | static const unsigned char data_ascii2bin[128] = { |
73 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
74 | 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF, |
75 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
76 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
77 | 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
78 | 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F, |
79 | 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, |
80 | 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, |
81 | 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, |
82 | 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, |
83 | 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, |
84 | 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
85 | 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, |
86 | 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, |
87 | 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, |
88 | 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
89 | }; |
90 | |
91 | static const unsigned char srpdata_ascii2bin[128] = { |
92 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
93 | 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF, |
94 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
95 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
96 | 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
97 | 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF2, 0x3E, 0x3F, |
98 | 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, |
99 | 0x08, 0x09, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, |
100 | 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, |
101 | 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, |
102 | 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, |
103 | 0x21, 0x22, 0x23, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
104 | 0xFF, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, |
105 | 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, |
106 | 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, |
107 | 0x3B, 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, |
108 | }; |
109 | |
110 | #ifndef CHARSET_EBCDIC |
111 | static unsigned char conv_ascii2bin(unsigned char a, const unsigned char *table) |
112 | { |
113 | if (a & 0x80) |
114 | return B64_ERROR; |
115 | return table[a]; |
116 | } |
117 | #else |
118 | static unsigned char conv_ascii2bin(unsigned char a, const unsigned char *table) |
119 | { |
120 | a = os_toascii[a]; |
121 | if (a & 0x80) |
122 | return B64_ERROR; |
123 | return table[a]; |
124 | } |
125 | #endif |
126 | |
127 | EVP_ENCODE_CTX *EVP_ENCODE_CTX_new(void) |
128 | { |
129 | return OPENSSL_zalloc(sizeof(EVP_ENCODE_CTX)); |
130 | } |
131 | |
132 | void EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx) |
133 | { |
134 | OPENSSL_free(ctx); |
135 | } |
136 | |
137 | int EVP_ENCODE_CTX_copy(EVP_ENCODE_CTX *dctx, const EVP_ENCODE_CTX *sctx) |
138 | { |
139 | memcpy(dctx, sctx, sizeof(EVP_ENCODE_CTX)); |
140 | |
141 | return 1; |
142 | } |
143 | |
144 | int EVP_ENCODE_CTX_num(EVP_ENCODE_CTX *ctx) |
145 | { |
146 | return ctx->num; |
147 | } |
148 | |
149 | void evp_encode_ctx_set_flags(EVP_ENCODE_CTX *ctx, unsigned int flags) |
150 | { |
151 | ctx->flags = flags; |
152 | } |
153 | |
154 | void EVP_EncodeInit(EVP_ENCODE_CTX *ctx) |
155 | { |
156 | ctx->length = 48; |
157 | ctx->num = 0; |
158 | ctx->line_num = 0; |
159 | ctx->flags = 0; |
160 | } |
161 | |
162 | int EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, |
163 | const unsigned char *in, int inl) |
164 | { |
165 | int i, j; |
166 | size_t total = 0; |
167 | |
168 | *outl = 0; |
169 | if (inl <= 0) |
170 | return 0; |
171 | OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data)); |
172 | if (ctx->length - ctx->num > inl) { |
173 | memcpy(&(ctx->enc_data[ctx->num]), in, inl); |
174 | ctx->num += inl; |
175 | return 1; |
176 | } |
177 | if (ctx->num != 0) { |
178 | i = ctx->length - ctx->num; |
179 | memcpy(&(ctx->enc_data[ctx->num]), in, i); |
180 | in += i; |
181 | inl -= i; |
182 | j = evp_encodeblock_int(ctx, out, ctx->enc_data, ctx->length); |
183 | ctx->num = 0; |
184 | out += j; |
185 | total = j; |
186 | if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0) { |
187 | *(out++) = '\n'; |
188 | total++; |
189 | } |
190 | *out = '\0'; |
191 | } |
192 | while (inl >= ctx->length && total <= INT_MAX) { |
193 | j = evp_encodeblock_int(ctx, out, in, ctx->length); |
194 | in += ctx->length; |
195 | inl -= ctx->length; |
196 | out += j; |
197 | total += j; |
198 | if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0) { |
199 | *(out++) = '\n'; |
200 | total++; |
201 | } |
202 | *out = '\0'; |
203 | } |
204 | if (total > INT_MAX) { |
205 | /* Too much output data! */ |
206 | *outl = 0; |
207 | return 0; |
208 | } |
209 | if (inl != 0) |
210 | memcpy(&(ctx->enc_data[0]), in, inl); |
211 | ctx->num = inl; |
212 | *outl = total; |
213 | |
214 | return 1; |
215 | } |
216 | |
217 | void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) |
218 | { |
219 | unsigned int ret = 0; |
220 | |
221 | if (ctx->num != 0) { |
222 | ret = evp_encodeblock_int(ctx, out, ctx->enc_data, ctx->num); |
223 | if ((ctx->flags & EVP_ENCODE_CTX_NO_NEWLINES) == 0) |
224 | out[ret++] = '\n'; |
225 | out[ret] = '\0'; |
226 | ctx->num = 0; |
227 | } |
228 | *outl = ret; |
229 | } |
230 | |
231 | static int evp_encodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t, |
232 | const unsigned char *f, int dlen) |
233 | { |
234 | int i, ret = 0; |
235 | unsigned long l; |
236 | const unsigned char *table; |
237 | |
238 | if (ctx != NULL && (ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0) |
239 | table = srpdata_bin2ascii; |
240 | else |
241 | table = data_bin2ascii; |
242 | |
243 | for (i = dlen; i > 0; i -= 3) { |
244 | if (i >= 3) { |
245 | l = (((unsigned long)f[0]) << 16L) | |
246 | (((unsigned long)f[1]) << 8L) | f[2]; |
247 | *(t++) = conv_bin2ascii(l >> 18L, table); |
248 | *(t++) = conv_bin2ascii(l >> 12L, table); |
249 | *(t++) = conv_bin2ascii(l >> 6L, table); |
250 | *(t++) = conv_bin2ascii(l, table); |
251 | } else { |
252 | l = ((unsigned long)f[0]) << 16L; |
253 | if (i == 2) |
254 | l |= ((unsigned long)f[1] << 8L); |
255 | |
256 | *(t++) = conv_bin2ascii(l >> 18L, table); |
257 | *(t++) = conv_bin2ascii(l >> 12L, table); |
258 | *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L, table); |
259 | *(t++) = '='; |
260 | } |
261 | ret += 4; |
262 | f += 3; |
263 | } |
264 | |
265 | *t = '\0'; |
266 | return ret; |
267 | } |
268 | |
269 | int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen) |
270 | { |
271 | return evp_encodeblock_int(NULL, t, f, dlen); |
272 | } |
273 | |
274 | void EVP_DecodeInit(EVP_ENCODE_CTX *ctx) |
275 | { |
276 | /* Only ctx->num and ctx->flags are used during decoding. */ |
277 | ctx->num = 0; |
278 | ctx->length = 0; |
279 | ctx->line_num = 0; |
280 | ctx->flags = 0; |
281 | } |
282 | |
283 | /*- |
284 | * -1 for error |
285 | * 0 for last line |
286 | * 1 for full line |
287 | * |
288 | * Note: even though EVP_DecodeUpdate attempts to detect and report end of |
289 | * content, the context doesn't currently remember it and will accept more data |
290 | * in the next call. Therefore, the caller is responsible for checking and |
291 | * rejecting a 0 return value in the middle of content. |
292 | * |
293 | * Note: even though EVP_DecodeUpdate has historically tried to detect end of |
294 | * content based on line length, this has never worked properly. Therefore, |
295 | * we now return 0 when one of the following is true: |
296 | * - Padding or B64_EOF was detected and the last block is complete. |
297 | * - Input has zero-length. |
298 | * -1 is returned if: |
299 | * - Invalid characters are detected. |
300 | * - There is extra trailing padding, or data after padding. |
301 | * - B64_EOF is detected after an incomplete base64 block. |
302 | */ |
303 | int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, |
304 | const unsigned char *in, int inl) |
305 | { |
306 | int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len; |
307 | unsigned char *d; |
308 | const unsigned char *table; |
309 | |
310 | n = ctx->num; |
311 | d = ctx->enc_data; |
312 | |
313 | if (n > 0 && d[n - 1] == '=') { |
314 | eof++; |
315 | if (n > 1 && d[n - 2] == '=') |
316 | eof++; |
317 | } |
318 | |
319 | /* Legacy behaviour: an empty input chunk signals end of input. */ |
320 | if (inl == 0) { |
321 | rv = 0; |
322 | goto end; |
323 | } |
324 | |
325 | if ((ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0) |
326 | table = srpdata_ascii2bin; |
327 | else |
328 | table = data_ascii2bin; |
329 | |
330 | for (i = 0; i < inl; i++) { |
331 | tmp = *(in++); |
332 | v = conv_ascii2bin(tmp, table); |
333 | if (v == B64_ERROR) { |
334 | rv = -1; |
335 | goto end; |
336 | } |
337 | |
338 | if (tmp == '=') { |
339 | eof++; |
340 | } else if (eof > 0 && B64_BASE64(v)) { |
341 | /* More data after padding. */ |
342 | rv = -1; |
343 | goto end; |
344 | } |
345 | |
346 | if (eof > 2) { |
347 | rv = -1; |
348 | goto end; |
349 | } |
350 | |
351 | if (v == B64_EOF) { |
352 | seof = 1; |
353 | goto tail; |
354 | } |
355 | |
356 | /* Only save valid base64 characters. */ |
357 | if (B64_BASE64(v)) { |
358 | if (n >= 64) { |
359 | /* |
360 | * We increment n once per loop, and empty the buffer as soon as |
361 | * we reach 64 characters, so this can only happen if someone's |
362 | * manually messed with the ctx. Refuse to write any more data. |
363 | */ |
364 | rv = -1; |
365 | goto end; |
366 | } |
367 | OPENSSL_assert(n < (int)sizeof(ctx->enc_data)); |
368 | d[n++] = tmp; |
369 | } |
370 | |
371 | if (n == 64) { |
372 | decoded_len = evp_decodeblock_int(ctx, out, d, n); |
373 | n = 0; |
374 | if (decoded_len < 0 || eof > decoded_len) { |
375 | rv = -1; |
376 | goto end; |
377 | } |
378 | ret += decoded_len - eof; |
379 | out += decoded_len - eof; |
380 | } |
381 | } |
382 | |
383 | /* |
384 | * Legacy behaviour: if the current line is a full base64-block (i.e., has |
385 | * 0 mod 4 base64 characters), it is processed immediately. We keep this |
386 | * behaviour as applications may not be calling EVP_DecodeFinal properly. |
387 | */ |
388 | tail: |
389 | if (n > 0) { |
390 | if ((n & 3) == 0) { |
391 | decoded_len = evp_decodeblock_int(ctx, out, d, n); |
392 | n = 0; |
393 | if (decoded_len < 0 || eof > decoded_len) { |
394 | rv = -1; |
395 | goto end; |
396 | } |
397 | ret += (decoded_len - eof); |
398 | } else if (seof) { |
399 | /* EOF in the middle of a base64 block. */ |
400 | rv = -1; |
401 | goto end; |
402 | } |
403 | } |
404 | |
405 | rv = seof || (n == 0 && eof) ? 0 : 1; |
406 | end: |
407 | /* Legacy behaviour. This should probably rather be zeroed on error. */ |
408 | *outl = ret; |
409 | ctx->num = n; |
410 | return rv; |
411 | } |
412 | |
413 | static int evp_decodeblock_int(EVP_ENCODE_CTX *ctx, unsigned char *t, |
414 | const unsigned char *f, int n) |
415 | { |
416 | int i, ret = 0, a, b, c, d; |
417 | unsigned long l; |
418 | const unsigned char *table; |
419 | |
420 | if (ctx != NULL && (ctx->flags & EVP_ENCODE_CTX_USE_SRP_ALPHABET) != 0) |
421 | table = srpdata_ascii2bin; |
422 | else |
423 | table = data_ascii2bin; |
424 | |
425 | /* trim white space from the start of the line. */ |
426 | while ((conv_ascii2bin(*f, table) == B64_WS) && (n > 0)) { |
427 | f++; |
428 | n--; |
429 | } |
430 | |
431 | /* |
432 | * strip off stuff at the end of the line ascii2bin values B64_WS, |
433 | * B64_EOLN, B64_EOLN and B64_EOF |
434 | */ |
435 | while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1], table)))) |
436 | n--; |
437 | |
438 | if (n % 4 != 0) |
439 | return -1; |
440 | |
441 | for (i = 0; i < n; i += 4) { |
442 | a = conv_ascii2bin(*(f++), table); |
443 | b = conv_ascii2bin(*(f++), table); |
444 | c = conv_ascii2bin(*(f++), table); |
445 | d = conv_ascii2bin(*(f++), table); |
446 | if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80)) |
447 | return -1; |
448 | l = ((((unsigned long)a) << 18L) | |
449 | (((unsigned long)b) << 12L) | |
450 | (((unsigned long)c) << 6L) | (((unsigned long)d))); |
451 | *(t++) = (unsigned char)(l >> 16L) & 0xff; |
452 | *(t++) = (unsigned char)(l >> 8L) & 0xff; |
453 | *(t++) = (unsigned char)(l) & 0xff; |
454 | ret += 3; |
455 | } |
456 | return ret; |
457 | } |
458 | |
459 | int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n) |
460 | { |
461 | return evp_decodeblock_int(NULL, t, f, n); |
462 | } |
463 | |
464 | int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) |
465 | { |
466 | int i; |
467 | |
468 | *outl = 0; |
469 | if (ctx->num != 0) { |
470 | i = evp_decodeblock_int(ctx, out, ctx->enc_data, ctx->num); |
471 | if (i < 0) |
472 | return -1; |
473 | ctx->num = 0; |
474 | *outl = i; |
475 | return 1; |
476 | } else |
477 | return 1; |
478 | } |
479 | |