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 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 * 125 EVP_ENCODE_CTX_new(void) 126 { 127 return calloc(1, sizeof(EVP_ENCODE_CTX)); 128 } 129 130 void 131 EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx) 132 { 133 free(ctx); 134 } 135 136 void 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 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 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 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 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 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 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 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