crypto/evp/encode.c

   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 "cryptlib.h"
  61 #include <openssl/evp.h>
  62
  63 #ifndef CHARSET_EBCDIC
  64 # define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
  65 # define conv_ascii2bin(a)       (data_ascii2bin[(a)&0x7f])
  66 #else
  67 /*
  68  * We assume that PEM encoded files are EBCDIC files (i.e., printable text
  69  * files). Convert them here while decoding. When encoding, output is EBCDIC
  70  * (text) format again. (No need for conversion in the conv_bin2ascii macro,
  71  * as the underlying textstring data_bin2ascii[] is already EBCDIC)
  72  */
  73 # define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
  74 # define conv_ascii2bin(a)       (data_ascii2bin[os_toascii[a]&0x7f])
  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
  89 static unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
  90 abcdefghijklmnopqrstuvwxyz0123456789+/";
  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
 107 static unsigned char data_ascii2bin[128] = {
 108     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 109     0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
 110     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 111     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 112     0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 113     0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
 114     0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
 115     0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
 116     0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
 117     0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
 118     0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
 119     0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 120     0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
 121     0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
 122     0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
 123     0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
 124 };
 125
 126 void EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
 127 {
 128     ctx->length = 48;
 129     ctx->num = 0;
 130     ctx->line_num = 0;
 131 }
 132
 133 void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
 134                       const unsigned char *in, int inl)
 135 {
 136     int i, j;
 137     unsigned int total = 0;
 138
 139     *outl = 0;
 140     if (inl == 0)
 141         return;
 142     OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
 143     if ((ctx->num + inl) < ctx->length) {
 144         memcpy(&(ctx->enc_data[ctx->num]), in, inl);
 145         ctx->num += inl;
 146         return;
 147     }
 148     if (ctx->num != 0) {
 149         i = ctx->length - ctx->num;
 150         memcpy(&(ctx->enc_data[ctx->num]), in, i);
 151         in += i;
 152         inl -= i;
 153         j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
 154         ctx->num = 0;
 155         out += j;
 156         *(out++) = '\n';
 157         *out = '\0';
 158         total = j + 1;
 159     }
 160     while (inl >= ctx->length) {
 161         j = EVP_EncodeBlock(out, in, ctx->length);
 162         in += ctx->length;
 163         inl -= ctx->length;
 164         out += j;
 165         *(out++) = '\n';
 166         *out = '\0';
 167         total += j + 1;
 168     }
 169     if (inl != 0)
 170         memcpy(&(ctx->enc_data[0]), in, inl);
 171     ctx->num = inl;
 172     *outl = total;
 173 }
 174
 175 void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
 176 {
 177     unsigned int ret = 0;
 178
 179     if (ctx->num != 0) {
 180         ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
 181         out[ret++] = '\n';
 182         out[ret] = '\0';
 183         ctx->num = 0;
 184     }
 185     *outl = ret;
 186 }
 187
 188 int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
 189 {
 190     int i, ret = 0;
 191     unsigned long l;
 192
 193     for (i = dlen; i > 0; i -= 3) {
 194         if (i >= 3) {
 195             l = (((unsigned long)f[0]) << 16L) |
 196                 (((unsigned long)f[1]) << 8L) | f[2];
 197             *(t++) = conv_bin2ascii(l >> 18L);
 198             *(t++) = conv_bin2ascii(l >> 12L);
 199             *(t++) = conv_bin2ascii(l >> 6L);
 200             *(t++) = conv_bin2ascii(l);
 201         } else {
 202             l = ((unsigned long)f[0]) << 16L;
 203             if (i == 2)
 204                 l |= ((unsigned long)f[1] << 8L);
 205
 206             *(t++) = conv_bin2ascii(l >> 18L);
 207             *(t++) = conv_bin2ascii(l >> 12L);
 208             *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
 209             *(t++) = '=';
 210         }
 211         ret += 4;
 212         f += 3;
 213     }
 214
 215     *t = '\0';
 216     return (ret);
 217 }
 218
 219 void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
 220 {
 221     ctx->length = 30;
 222     ctx->num = 0;
 223     ctx->line_num = 0;
 224     ctx->expect_nl = 0;
 225 }
 226
 227 /*-
 228  * -1 for error
 229  *  0 for last line
 230  *  1 for full line
 231  */
 232 int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
 233                      const unsigned char *in, int inl)
 234 {
 235     int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
 236     unsigned char *d;
 237
 238     n = ctx->num;
 239     d = ctx->enc_data;
 240     ln = ctx->line_num;
 241     exp_nl = ctx->expect_nl;
 242
 243     /* last line of input. */
 244     if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
 245         rv = 0;
 246         goto end;
 247     }
 248
 249     /* We parse the input data */
 250     for (i = 0; i < inl; i++) {
 251         /* If the current line is > 80 characters, scream alot */
 252         if (ln >= 80) {
 253             rv = -1;
 254             goto end;
 255         }
 256
 257         /* Get char and put it into the buffer */
 258         tmp = *(in++);
 259         v = conv_ascii2bin(tmp);
 260         /* only save the good data :-) */
 261         if (!B64_NOT_BASE64(v)) {
 262             OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
 263             d[n++] = tmp;
 264             ln++;
 265         } else if (v == B64_ERROR) {
 266             rv = -1;
 267             goto end;
 268         }
 269
 270         /*
 271          * have we seen a '=' which is 'definitly' the last input line.  seof
 272          * will point to the character that holds it. and eof will hold how
 273          * many characters to chop off.
 274          */
 275         if (tmp == '=') {
 276             if (seof == -1)
 277                 seof = n;
 278             eof++;
 279         }
 280
 281         if (v == B64_CR) {
 282             ln = 0;
 283             if (exp_nl)
 284                 continue;
 285         }
 286
 287         /* eoln */
 288         if (v == B64_EOLN) {
 289             ln = 0;
 290             if (exp_nl) {
 291                 exp_nl = 0;
 292                 continue;
 293             }
 294         }
 295         exp_nl = 0;
 296
 297         /*
 298          * If we are at the end of input and it looks like a line, process
 299          * it.
 300          */
 301         if (((i + 1) == inl) && (((n & 3) == 0) || eof)) {
 302             v = B64_EOF;
 303             /*
 304              * In case things were given us in really small records (so two
 305              * '=' were given in separate updates), eof may contain the
 306              * incorrect number of ending bytes to skip, so let's redo the
 307              * count
 308              */
 309             eof = 0;
 310             if (d[n - 1] == '=')
 311                 eof++;
 312             if (d[n - 2] == '=')
 313                 eof++;
 314             /* There will never be more than two '=' */
 315         }
 316
 317         if ((v == B64_EOF && (n & 3) == 0) || (n >= 64)) {
 318             /*
 319              * This is needed to work correctly on 64 byte input lines.  We
 320              * process the line and then need to accept the '\n'
 321              */
 322             if ((v != B64_EOF) && (n >= 64))
 323                 exp_nl = 1;
 324             if (n > 0) {
 325                 v = EVP_DecodeBlock(out, d, n);
 326                 n = 0;
 327                 if (v < 0) {
 328                     rv = 0;
 329                     goto end;
 330                 }
 331                 if (eof > v) {
 332                     rv = -1;
 333                     goto end;
 334                 }
 335                 ret += (v - eof);
 336             } else {
 337                 eof = 1;
 338                 v = 0;
 339             }
 340
 341             /*
 342              * This is the case where we have had a short but valid input
 343              * line
 344              */
 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  end:
 360     *outl = ret;
 361     ctx->num = n;
 362     ctx->line_num = ln;
 363     ctx->expect_nl = exp_nl;
 364     return (rv);
 365 }
 366
 367 int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
 368 {
 369     int i, ret = 0, a, b, c, d;
 370     unsigned long l;
 371
 372     /* trim white space from the start of the line. */
 373     while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
 374         f++;
 375         n--;
 376     }
 377
 378     /*
 379      * strip off stuff at the end of the line ascii2bin values B64_WS,
 380      * B64_EOLN, B64_EOLN and B64_EOF
 381      */
 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) || (c & 0x80) || (d & 0x80))
 394             return (-1);
 395         l = ((((unsigned long)a) << 18L) |
 396              (((unsigned long)b) << 12L) |
 397              (((unsigned long)c) << 6L) | (((unsigned long)d)));
 398         *(t++) = (unsigned char)(l >> 16L) & 0xff;
 399         *(t++) = (unsigned char)(l >> 8L) & 0xff;
 400         *(t++) = (unsigned char)(l) & 0xff;
 401         ret += 3;
 402     }
 403     return (ret);
 404 }
 405
 406 int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
 407 {
 408     int i;
 409
 410     *outl = 0;
 411     if (ctx->num != 0) {
 412         i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
 413         if (i < 0)
 414             return (-1);
 415         ctx->num = 0;
 416         *outl = i;
 417         return (1);
 418     } else
 419         return (1);
 420 }
 421
 422 #ifdef undef
 423 int EVP_DecodeValid(unsigned char *buf, int len)
 424 {
 425     int i, num = 0, bad = 0;
 426
 427     if (len == 0)
 428         return (-1);
 429     while (conv_ascii2bin(*buf) == B64_WS) {
 430         buf++;
 431         len--;
 432         if (len == 0)
 433             return (-1);
 434     }
 435
 436     for (i = len; i >= 4; i -= 4) {
 437         if ((conv_ascii2bin(buf[0]) >= 0x40) ||
 438             (conv_ascii2bin(buf[1]) >= 0x40) ||
 439             (conv_ascii2bin(buf[2]) >= 0x40) ||
 440             (conv_ascii2bin(buf[3]) >= 0x40))
 441             return (-1);
 442         buf += 4;
 443         num += 1 + (buf[2] != '=') + (buf[3] != '=');
 444     }
 445     if ((i == 1) && (conv_ascii2bin(buf[0]) == B64_EOLN))
 446         return (num);
 447     if ((i == 2) && (conv_ascii2bin(buf[0]) == B64_EOLN) &&
 448         (conv_ascii2bin(buf[0]) == B64_EOLN))
 449         return (num);
 450     return (1);
 451 }
 452 #endif