lib/libcrypto/evp/encode.c

   1 /* $OpenBSD: encode.c,v 1.24 2016/05/04 15:05:13 tedu 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 void
 116 EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
 117 {
 118         ctx->length = 48;
 119         ctx->num = 0;
 120         ctx->line_num = 0;
 121 }
 122
 123 void
 124 EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
 125     const unsigned char *in, int inl)
 126 {
 127         int i, j;
 128         size_t total = 0;
 129
 130         *outl = 0;
 131         if (inl == 0)
 132                 return;
 133         OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
 134         if (ctx->length - ctx->num > inl) {
 135                 memcpy(&(ctx->enc_data[ctx->num]), in, inl);
 136                 ctx->num += inl;
 137                 return;
 138         }
 139         if (ctx->num != 0) {
 140                 i = ctx->length - ctx->num;
 141                 memcpy(&(ctx->enc_data[ctx->num]), in, i);
 142                 in += i;
 143                 inl -= i;
 144                 j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
 145                 ctx->num = 0;
 146                 out += j;
 147                 *(out++) = '\n';
 148                 *out = '\0';
 149                 total = j + 1;
 150         }
 151         while (inl >= ctx->length && total <= INT_MAX) {
 152                 j = EVP_EncodeBlock(out, in, ctx->length);
 153                 in += ctx->length;
 154                 inl -= ctx->length;
 155                 out += j;
 156                 *(out++) = '\n';
 157                 *out = '\0';
 158                 total += j + 1;
 159         }
 160         if (total > INT_MAX) {
 161                 /* Too much output data! */
 162                 *outl = 0;
 163                 return;
 164         }
 165         if (inl != 0)
 166                 memcpy(&(ctx->enc_data[0]), in, inl);
 167         ctx->num = inl;
 168         *outl = total;
 169 }
 170
 171 void
 172 EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
 173 {
 174         unsigned int ret = 0;
 175
 176         if (ctx->num != 0) {
 177                 ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
 178                 out[ret++] = '\n';
 179                 out[ret] = '\0';
 180                 ctx->num = 0;
 181         }
 182         *outl = ret;
 183 }
 184
 185 int
 186 EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
 187 {
 188         int i, ret = 0;
 189         unsigned long l;
 190
 191         for (i = dlen; i > 0; i -= 3) {
 192                 if (i >= 3) {
 193                         l = (((unsigned long)f[0]) << 16L) |
 194                             (((unsigned long)f[1]) << 8L) | f[2];
 195                         *(t++) = conv_bin2ascii(l >> 18L);
 196                         *(t++) = conv_bin2ascii(l >> 12L);
 197                         *(t++) = conv_bin2ascii(l >> 6L);
 198                         *(t++) = conv_bin2ascii(l     );
 199                 } else {
 200                         l = ((unsigned long)f[0]) << 16L;
 201                         if (i == 2)
 202                                 l |= ((unsigned long)f[1] << 8L);
 203
 204                         *(t++) = conv_bin2ascii(l >> 18L);
 205                         *(t++) = conv_bin2ascii(l >> 12L);
 206                         *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
 207                         *(t++) = '=';
 208                 }
 209                 ret += 4;
 210                 f += 3;
 211         }
 212
 213         *t = '\0';
 214         return (ret);
 215 }
 216
 217 void
 218 EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
 219 {
 220         ctx->length = 30;
 221         ctx->num = 0;
 222         ctx->line_num = 0;
 223         ctx->expect_nl = 0;
 224 }
 225
 226 /* -1 for error
 227  *  0 for last line
 228  *  1 for full line
 229  */
 230 int
 231 EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
 232     const unsigned char *in, int inl)
 233 {
 234         int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
 235         unsigned char *d;
 236
 237         n = ctx->num;
 238         d = ctx->enc_data;
 239         ln = ctx->line_num;
 240         exp_nl = ctx->expect_nl;
 241
 242         /* last line of input. */
 243         if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
 244                 rv = 0;
 245                 goto end;
 246         }
 247
 248         /* We parse the input data */
 249         for (i = 0; i < inl; i++) {
 250                 /* If the current line is > 80 characters, scream alot */
 251                 if (ln >= 80) {
 252                         rv = -1;
 253                         goto end;
 254                 }
 255
 256                 /* Get char and put it into the buffer */
 257                 tmp= *(in++);
 258                 v = conv_ascii2bin(tmp);
 259                 /* only save the good data :-) */
 260                 if (!B64_NOT_BASE64(v)) {
 261                         OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
 262                         d[n++] = tmp;
 263                         ln++;
 264                 } else if (v == B64_ERROR) {
 265                         rv = -1;
 266                         goto end;
 267                 }
 268
 269                 /* There should not be base64 data after padding. */
 270                 if (eof && tmp != '=' && tmp != '\r' && tmp != '\n' &&
 271                     v != B64_EOF) {
 272                         rv = -1;
 273                         goto end;
 274                 }
 275
 276                 /* have we seen a '=' which is 'definitely' the last
 277                  * input line.  seof will point to the character that
 278                  * holds it. and eof will hold how many characters to
 279                  * chop off. */
 280                 if (tmp == '=') {
 281                         if (seof == -1)
 282                                 seof = n;
 283                         eof++;
 284                 }
 285
 286                 /* There should be no more than two padding markers. */
 287                 if (eof > 2) {
 288                         rv = -1;
 289                         goto end;
 290                 }
 291
 292                 if (v == B64_CR) {
 293                         ln = 0;
 294                         if (exp_nl)
 295                                 continue;
 296                 }
 297
 298                 /* eoln */
 299                 if (v == B64_EOLN) {
 300                         ln = 0;
 301                         if (exp_nl) {
 302                                 exp_nl = 0;
 303                                 continue;
 304                         }
 305                 }
 306                 exp_nl = 0;
 307
 308                 /* If we are at the end of input and it looks like a
 309                  * line, process it. */
 310                 if (((i + 1) == inl) && (((n&3) == 0) || eof)) {
 311                         v = B64_EOF;
 312                         /* In case things were given us in really small
 313                            records (so two '=' were given in separate
 314                            updates), eof may contain the incorrect number
 315                            of ending bytes to skip, so let's redo the count */
 316                         eof = 0;
 317                         if (d[n-1] == '=')
 318                                 eof++;
 319                         if (d[n-2] == '=')
 320                                 eof++;
 321                         /* There will never be more than two '=' */
 322                 }
 323
 324                 if ((v == B64_EOF && (n&3) == 0) || (n >= 64)) {
 325                         /* This is needed to work correctly on 64 byte input
 326                          * lines.  We process the line and then need to
 327                          * accept the '\n' */
 328                         if ((v != B64_EOF) && (n >= 64))
 329                                 exp_nl = 1;
 330                         if (n > 0) {
 331                                 v = EVP_DecodeBlock(out, d, n);
 332                                 n = 0;
 333                                 if (v < 0) {
 334                                         rv = 0;
 335                                         goto end;
 336                                 }
 337                                 ret += (v - eof);
 338                         } else {
 339                                 eof = 1;
 340                                 v = 0;
 341                         }
 342
 343                         /* This is the case where we have had a short
 344                          * but valid input line */
 345                         if ((v < ctx->length) && eof) {
 346                                 rv = 0;
 347                                 goto end;
 348                         } else
 349                                 ctx->length = v;
 350
 351                         if (seof >= 0) {
 352                                 rv = 0;
 353                                 goto end;
 354                         }
 355                         out += v;
 356                 }
 357         }
 358         rv = 1;
 359
 360 end:
 361         *outl = ret;
 362         ctx->num = n;
 363         ctx->line_num = ln;
 364         ctx->expect_nl = exp_nl;
 365         return (rv);
 366 }
 367
 368 int
 369 EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
 370 {
 371         int i, ret = 0, a, b, c, d;
 372         unsigned long l;
 373
 374         /* trim white space from the start of the line. */
 375         while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
 376                 f++;
 377                 n--;
 378         }
 379
 380         /* strip off stuff at the end of the line
 381          * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF */
 382         while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
 383                 n--;
 384
 385         if (n % 4 != 0)
 386                 return (-1);
 387
 388         for (i = 0; i < n; i += 4) {
 389                 a = conv_ascii2bin(*(f++));
 390                 b = conv_ascii2bin(*(f++));
 391                 c = conv_ascii2bin(*(f++));
 392                 d = conv_ascii2bin(*(f++));
 393                 if ((a & 0x80) || (b & 0x80) ||
 394                     (c & 0x80) || (d & 0x80))
 395                         return (-1);
 396                 l = ((((unsigned long)a) << 18L) |
 397                     (((unsigned long)b) << 12L) |
 398                     (((unsigned long)c) << 6L) |
 399                     (((unsigned long)d)));
 400                 *(t++) = (unsigned char)(l >> 16L) & 0xff;
 401                 *(t++) = (unsigned char)(l >> 8L) & 0xff;
 402                 *(t++) = (unsigned char)(l) & 0xff;
 403                 ret += 3;
 404         }
 405         return (ret);
 406 }
 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 }