encode.c revision 298999
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 <limits.h> 61#include "cryptlib.h" 62#include <openssl/evp.h> 63 64static unsigned char conv_ascii2bin(unsigned char a); 65#ifndef CHARSET_EBCDIC 66# define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f]) 67#else 68/* 69 * We assume that PEM encoded files are EBCDIC files (i.e., printable text 70 * files). Convert them here while decoding. When encoding, output is EBCDIC 71 * (text) format again. (No need for conversion in the conv_bin2ascii macro, 72 * as the underlying textstring data_bin2ascii[] is already EBCDIC) 73 */ 74# define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f]) 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 const 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#define B64_BASE64(a) !B64_NOT_BASE64(a) 107 108static const unsigned char data_ascii2bin[128] = { 109 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 110 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF, 111 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 112 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 113 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 114 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F, 115 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 116 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 117 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 118 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 119 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 120 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 121 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 122 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 123 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 124 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 125}; 126 127#ifndef CHARSET_EBCDIC 128static unsigned char conv_ascii2bin(unsigned char a) 129{ 130 if (a & 0x80) 131 return B64_ERROR; 132 return data_ascii2bin[a]; 133} 134#else 135static unsigned char conv_ascii2bin(unsigned char a) 136{ 137 a = os_toascii[a]; 138 if (a & 0x80) 139 return B64_ERROR; 140 return data_ascii2bin[a]; 141} 142#endif 143 144void EVP_EncodeInit(EVP_ENCODE_CTX *ctx) 145{ 146 ctx->length = 48; 147 ctx->num = 0; 148 ctx->line_num = 0; 149} 150 151void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, 152 const unsigned char *in, int inl) 153{ 154 int i, j; 155 size_t total = 0; 156 157 *outl = 0; 158 if (inl <= 0) 159 return; 160 OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data)); 161 if (ctx->length - ctx->num > inl) { 162 memcpy(&(ctx->enc_data[ctx->num]), in, inl); 163 ctx->num += inl; 164 return; 165 } 166 if (ctx->num != 0) { 167 i = ctx->length - ctx->num; 168 memcpy(&(ctx->enc_data[ctx->num]), in, i); 169 in += i; 170 inl -= i; 171 j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length); 172 ctx->num = 0; 173 out += j; 174 *(out++) = '\n'; 175 *out = '\0'; 176 total = j + 1; 177 } 178 while (inl >= ctx->length && total <= INT_MAX) { 179 j = EVP_EncodeBlock(out, in, ctx->length); 180 in += ctx->length; 181 inl -= ctx->length; 182 out += j; 183 *(out++) = '\n'; 184 *out = '\0'; 185 total += j + 1; 186 } 187 if (total > INT_MAX) { 188 /* Too much output data! */ 189 *outl = 0; 190 return; 191 } 192 if (inl != 0) 193 memcpy(&(ctx->enc_data[0]), in, inl); 194 ctx->num = inl; 195 *outl = total; 196} 197 198void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) 199{ 200 unsigned int ret = 0; 201 202 if (ctx->num != 0) { 203 ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num); 204 out[ret++] = '\n'; 205 out[ret] = '\0'; 206 ctx->num = 0; 207 } 208 *outl = ret; 209} 210 211int 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 242void EVP_DecodeInit(EVP_ENCODE_CTX *ctx) 243{ 244 /* Only ctx->num is used during decoding. */ 245 ctx->num = 0; 246 ctx->length = 0; 247 ctx->line_num = 0; 248 ctx->expect_nl = 0; 249} 250 251/*- 252 * -1 for error 253 * 0 for last line 254 * 1 for full line 255 * 256 * Note: even though EVP_DecodeUpdate attempts to detect and report end of 257 * content, the context doesn't currently remember it and will accept more data 258 * in the next call. Therefore, the caller is responsible for checking and 259 * rejecting a 0 return value in the middle of content. 260 * 261 * Note: even though EVP_DecodeUpdate has historically tried to detect end of 262 * content based on line length, this has never worked properly. Therefore, 263 * we now return 0 when one of the following is true: 264 * - Padding or B64_EOF was detected and the last block is complete. 265 * - Input has zero-length. 266 * -1 is returned if: 267 * - Invalid characters are detected. 268 * - There is extra trailing padding, or data after padding. 269 * - B64_EOF is detected after an incomplete base64 block. 270 */ 271int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, 272 const unsigned char *in, int inl) 273{ 274 int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len; 275 unsigned char *d; 276 277 n = ctx->num; 278 d = ctx->enc_data; 279 280 if (n > 0 && d[n - 1] == '=') { 281 eof++; 282 if (n > 1 && d[n - 2] == '=') 283 eof++; 284 } 285 286 /* Legacy behaviour: an empty input chunk signals end of input. */ 287 if (inl == 0) { 288 rv = 0; 289 goto end; 290 } 291 292 for (i = 0; i < inl; i++) { 293 tmp = *(in++); 294 v = conv_ascii2bin(tmp); 295 if (v == B64_ERROR) { 296 rv = -1; 297 goto end; 298 } 299 300 if (tmp == '=') { 301 eof++; 302 } else if (eof > 0 && B64_BASE64(v)) { 303 /* More data after padding. */ 304 rv = -1; 305 goto end; 306 } 307 308 if (eof > 2) { 309 rv = -1; 310 goto end; 311 } 312 313 if (v == B64_EOF) { 314 seof = 1; 315 goto tail; 316 } 317 318 /* Only save valid base64 characters. */ 319 if (B64_BASE64(v)) { 320 if (n >= 64) { 321 /* 322 * We increment n once per loop, and empty the buffer as soon as 323 * we reach 64 characters, so this can only happen if someone's 324 * manually messed with the ctx. Refuse to write any more data. 325 */ 326 rv = -1; 327 goto end; 328 } 329 OPENSSL_assert(n < (int)sizeof(ctx->enc_data)); 330 d[n++] = tmp; 331 } 332 333 if (n == 64) { 334 decoded_len = EVP_DecodeBlock(out, d, n); 335 n = 0; 336 if (decoded_len < 0 || eof > decoded_len) { 337 rv = -1; 338 goto end; 339 } 340 ret += decoded_len - eof; 341 out += decoded_len - eof; 342 } 343 } 344 345 /* 346 * Legacy behaviour: if the current line is a full base64-block (i.e., has 347 * 0 mod 4 base64 characters), it is processed immediately. We keep this 348 * behaviour as applications may not be calling EVP_DecodeFinal properly. 349 */ 350tail: 351 if (n > 0) { 352 if ((n & 3) == 0) { 353 decoded_len = EVP_DecodeBlock(out, d, n); 354 n = 0; 355 if (decoded_len < 0 || eof > decoded_len) { 356 rv = -1; 357 goto end; 358 } 359 ret += (decoded_len - eof); 360 } else if (seof) { 361 /* EOF in the middle of a base64 block. */ 362 rv = -1; 363 goto end; 364 } 365 } 366 367 rv = seof || (n == 0 && eof) ? 0 : 1; 368end: 369 /* Legacy behaviour. This should probably rather be zeroed on error. */ 370 *outl = ret; 371 ctx->num = n; 372 return (rv); 373} 374 375int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n) 376{ 377 int i, ret = 0, a, b, c, d; 378 unsigned long l; 379 380 /* trim white space from the start of the line. */ 381 while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) { 382 f++; 383 n--; 384 } 385 386 /* 387 * strip off stuff at the end of the line ascii2bin values B64_WS, 388 * B64_EOLN, B64_EOLN and B64_EOF 389 */ 390 while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1])))) 391 n--; 392 393 if (n % 4 != 0) 394 return (-1); 395 396 for (i = 0; i < n; i += 4) { 397 a = conv_ascii2bin(*(f++)); 398 b = conv_ascii2bin(*(f++)); 399 c = conv_ascii2bin(*(f++)); 400 d = conv_ascii2bin(*(f++)); 401 if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80)) 402 return (-1); 403 l = ((((unsigned long)a) << 18L) | 404 (((unsigned long)b) << 12L) | 405 (((unsigned long)c) << 6L) | (((unsigned long)d))); 406 *(t++) = (unsigned char)(l >> 16L) & 0xff; 407 *(t++) = (unsigned char)(l >> 8L) & 0xff; 408 *(t++) = (unsigned char)(l) & 0xff; 409 ret += 3; 410 } 411 return (ret); 412} 413 414int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) 415{ 416 int i; 417 418 *outl = 0; 419 if (ctx->num != 0) { 420 i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num); 421 if (i < 0) 422 return (-1); 423 ctx->num = 0; 424 *outl = i; 425 return (1); 426 } else 427 return (1); 428} 429 430#ifdef undef 431int EVP_DecodeValid(unsigned char *buf, int len) 432{ 433 int i, num = 0, bad = 0; 434 435 if (len == 0) 436 return (-1); 437 while (conv_ascii2bin(*buf) == B64_WS) { 438 buf++; 439 len--; 440 if (len == 0) 441 return (-1); 442 } 443 444 for (i = len; i >= 4; i -= 4) { 445 if ((conv_ascii2bin(buf[0]) >= 0x40) || 446 (conv_ascii2bin(buf[1]) >= 0x40) || 447 (conv_ascii2bin(buf[2]) >= 0x40) || 448 (conv_ascii2bin(buf[3]) >= 0x40)) 449 return (-1); 450 buf += 4; 451 num += 1 + (buf[2] != '=') + (buf[3] != '='); 452 } 453 if ((i == 1) && (conv_ascii2bin(buf[0]) == B64_EOLN)) 454 return (num); 455 if ((i == 2) && (conv_ascii2bin(buf[0]) == B64_EOLN) && 456 (conv_ascii2bin(buf[0]) == B64_EOLN)) 457 return (num); 458 return (1); 459} 460#endif 461