1 /* $OpenBSD: evp_encode.c,v 1.3 2024/04/09 13:52:41 beck 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 #include "evp_local.h" 66 67 static unsigned char conv_ascii2bin(unsigned char a); 68 #define conv_bin2ascii(a) (data_bin2ascii[(a)&0x3f]) 69 70 /* 64 char lines 71 * pad input with 0 72 * left over chars are set to = 73 * 1 byte => xx== 74 * 2 bytes => xxx= 75 * 3 bytes => xxxx 76 */ 77 #define BIN_PER_LINE (64/4*3) 78 #define CHUNKS_PER_LINE (64/4) 79 #define CHAR_PER_LINE (64+1) 80 81 static const unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\ 82 abcdefghijklmnopqrstuvwxyz0123456789+/"; 83 84 /* 0xF0 is a EOLN 85 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing). 86 * 0xF2 is EOF 87 * 0xE0 is ignore at start of line. 88 * 0xFF is error 89 */ 90 91 #define B64_EOLN 0xF0 92 #define B64_CR 0xF1 93 #define B64_EOF 0xF2 94 #define B64_WS 0xE0 95 #define B64_ERROR 0xFF 96 #define B64_NOT_BASE64(a) (((a)|0x13) == 0xF3) 97 #define B64_BASE64(a) !B64_NOT_BASE64(a) 98 99 static const unsigned char data_ascii2bin[128] = { 100 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 101 0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF, 102 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 103 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 104 0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 105 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F, 106 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 107 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 108 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 109 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 110 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 111 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 112 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 113 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 114 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 115 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 116 }; 117 118 static unsigned char 119 conv_ascii2bin(unsigned char a) 120 { 121 if (a & 0x80) 122 return B64_ERROR; 123 return data_ascii2bin[a]; 124 } 125 126 EVP_ENCODE_CTX * 127 EVP_ENCODE_CTX_new(void) 128 { 129 return calloc(1, sizeof(EVP_ENCODE_CTX)); 130 } 131 LCRYPTO_ALIAS(EVP_ENCODE_CTX_new); 132 133 void 134 EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx) 135 { 136 free(ctx); 137 } 138 LCRYPTO_ALIAS(EVP_ENCODE_CTX_free); 139 140 void 141 EVP_EncodeInit(EVP_ENCODE_CTX *ctx) 142 { 143 ctx->length = 48; 144 ctx->num = 0; 145 ctx->line_num = 0; 146 } 147 LCRYPTO_ALIAS(EVP_EncodeInit); 148 149 int 150 EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, 151 const unsigned char *in, int inl) 152 { 153 int i, j; 154 size_t total = 0; 155 156 *outl = 0; 157 if (inl <= 0) 158 return 0; 159 OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data)); 160 if (ctx->length - ctx->num > inl) { 161 memcpy(&(ctx->enc_data[ctx->num]), in, inl); 162 ctx->num += inl; 163 return 1; 164 } 165 if (ctx->num != 0) { 166 i = ctx->length - ctx->num; 167 memcpy(&(ctx->enc_data[ctx->num]), in, i); 168 in += i; 169 inl -= i; 170 j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length); 171 ctx->num = 0; 172 out += j; 173 *(out++) = '\n'; 174 *out = '\0'; 175 total = j + 1; 176 } 177 while (inl >= ctx->length && total <= INT_MAX) { 178 j = EVP_EncodeBlock(out, in, ctx->length); 179 in += ctx->length; 180 inl -= ctx->length; 181 out += j; 182 *(out++) = '\n'; 183 *out = '\0'; 184 total += j + 1; 185 } 186 if (total > INT_MAX) { 187 /* Too much output data! */ 188 *outl = 0; 189 return 0; 190 } 191 if (inl != 0) 192 memcpy(&(ctx->enc_data[0]), in, inl); 193 ctx->num = inl; 194 *outl = total; 195 196 return 1; 197 } 198 LCRYPTO_ALIAS(EVP_EncodeUpdate); 199 200 void 201 EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) 202 { 203 unsigned int ret = 0; 204 205 if (ctx->num != 0) { 206 ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num); 207 out[ret++] = '\n'; 208 out[ret] = '\0'; 209 ctx->num = 0; 210 } 211 *outl = ret; 212 } 213 LCRYPTO_ALIAS(EVP_EncodeFinal); 214 215 int 216 EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen) 217 { 218 int i, ret = 0; 219 unsigned long l; 220 221 for (i = dlen; i > 0; i -= 3) { 222 if (i >= 3) { 223 l = (((unsigned long)f[0]) << 16L) | 224 (((unsigned long)f[1]) << 8L) | f[2]; 225 *(t++) = conv_bin2ascii(l >> 18L); 226 *(t++) = conv_bin2ascii(l >> 12L); 227 *(t++) = conv_bin2ascii(l >> 6L); 228 *(t++) = conv_bin2ascii(l ); 229 } else { 230 l = ((unsigned long)f[0]) << 16L; 231 if (i == 2) 232 l |= ((unsigned long)f[1] << 8L); 233 234 *(t++) = conv_bin2ascii(l >> 18L); 235 *(t++) = conv_bin2ascii(l >> 12L); 236 *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L); 237 *(t++) = '='; 238 } 239 ret += 4; 240 f += 3; 241 } 242 243 *t = '\0'; 244 return (ret); 245 } 246 LCRYPTO_ALIAS(EVP_EncodeBlock); 247 248 void 249 EVP_DecodeInit(EVP_ENCODE_CTX *ctx) 250 { 251 ctx->num = 0; 252 ctx->length = 0; 253 ctx->line_num = 0; 254 ctx->expect_nl = 0; 255 } 256 LCRYPTO_ALIAS(EVP_DecodeInit); 257 258 int 259 EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, 260 const unsigned char *in, int inl) 261 { 262 int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len; 263 unsigned char *d; 264 265 n = ctx->num; 266 d = ctx->enc_data; 267 268 if (n > 0 && d[n - 1] == '=') { 269 eof++; 270 if (n > 1 && d[n - 2] == '=') 271 eof++; 272 } 273 274 /* Legacy behaviour: an empty input chunk signals end of input. */ 275 if (inl == 0) { 276 rv = 0; 277 goto end; 278 } 279 280 for (i = 0; i < inl; i++) { 281 tmp = *(in++); 282 v = conv_ascii2bin(tmp); 283 if (v == B64_ERROR) { 284 rv = -1; 285 goto end; 286 } 287 288 if (tmp == '=') { 289 eof++; 290 } else if (eof > 0 && B64_BASE64(v)) { 291 /* More data after padding. */ 292 rv = -1; 293 goto end; 294 } 295 296 if (eof > 2) { 297 rv = -1; 298 goto end; 299 } 300 301 if (v == B64_EOF) { 302 seof = 1; 303 goto tail; 304 } 305 306 /* Only save valid base64 characters. */ 307 if (B64_BASE64(v)) { 308 if (n >= 64) { 309 /* 310 * We increment n once per loop, and empty the 311 * buffer as soon as we reach 64 characters, so 312 * this can only happen if someone's manually 313 * messed with the ctx. Refuse to write any 314 * more data. 315 */ 316 rv = -1; 317 goto end; 318 } 319 OPENSSL_assert(n < (int)sizeof(ctx->enc_data)); 320 d[n++] = tmp; 321 } 322 323 if (n == 64) { 324 decoded_len = EVP_DecodeBlock(out, d, n); 325 n = 0; 326 if (decoded_len < 0 || eof > decoded_len) { 327 rv = -1; 328 goto end; 329 } 330 ret += decoded_len - eof; 331 out += decoded_len - eof; 332 } 333 } 334 335 /* 336 * Legacy behaviour: if the current line is a full base64-block (i.e., 337 * has 0 mod 4 base64 characters), it is processed immediately. We keep 338 * this behaviour as applications may not be calling EVP_DecodeFinal 339 * properly. 340 */ 341 tail: 342 if (n > 0) { 343 if ((n & 3) == 0) { 344 decoded_len = EVP_DecodeBlock(out, d, n); 345 n = 0; 346 if (decoded_len < 0 || eof > decoded_len) { 347 rv = -1; 348 goto end; 349 } 350 ret += (decoded_len - eof); 351 } else if (seof) { 352 /* EOF in the middle of a base64 block. */ 353 rv = -1; 354 goto end; 355 } 356 } 357 358 rv = seof || (n == 0 && eof) ? 0 : 1; 359 end: 360 /* Legacy behaviour. This should probably rather be zeroed on error. */ 361 *outl = ret; 362 ctx->num = n; 363 return (rv); 364 } 365 LCRYPTO_ALIAS(EVP_DecodeUpdate); 366 367 int 368 EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n) 369 { 370 int i, ret = 0, a, b, c, d; 371 unsigned long l; 372 373 /* trim white space from the start of the line. */ 374 while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) { 375 f++; 376 n--; 377 } 378 379 /* strip off stuff at the end of the line 380 * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */ 381 while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1])))) 382 n--; 383 384 if (n % 4 != 0) 385 return (-1); 386 387 for (i = 0; i < n; i += 4) { 388 a = conv_ascii2bin(*(f++)); 389 b = conv_ascii2bin(*(f++)); 390 c = conv_ascii2bin(*(f++)); 391 d = conv_ascii2bin(*(f++)); 392 if ((a & 0x80) || (b & 0x80) || 393 (c & 0x80) || (d & 0x80)) 394 return (-1); 395 l = ((((unsigned long)a) << 18L) | 396 (((unsigned long)b) << 12L) | 397 (((unsigned long)c) << 6L) | 398 (((unsigned long)d))); 399 *(t++) = (unsigned char)(l >> 16L) & 0xff; 400 *(t++) = (unsigned char)(l >> 8L) & 0xff; 401 *(t++) = (unsigned char)(l) & 0xff; 402 ret += 3; 403 } 404 return (ret); 405 } 406 LCRYPTO_ALIAS(EVP_DecodeBlock); 407 408 int 409 EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl) 410 { 411 int i; 412 413 *outl = 0; 414 if (ctx->num != 0) { 415 i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num); 416 if (i < 0) 417 return (-1); 418 ctx->num = 0; 419 *outl = i; 420 return (1); 421 } else 422 return (1); 423 } 424 LCRYPTO_ALIAS(EVP_DecodeFinal); 425