git.zerfleddert.de Git - proxmark3-svn/blob - common/mbedtls/base64.c

   1 /*
   2  *  RFC 1521 base64 encoding/decoding
   3  *
   4  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
   5  *  SPDX-License-Identifier: GPL-2.0
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License along
  18  *  with this program; if not, write to the Free Software Foundation, Inc.,
  19  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  *  This file is part of mbed TLS (https://tls.mbed.org)
  22  */
  23
  24 #if !defined(MBEDTLS_CONFIG_FILE)
  25 #include "mbedtls/config.h"
  26 #else
  27 #include MBEDTLS_CONFIG_FILE
  28 #endif
  29
  30 #if defined(MBEDTLS_BASE64_C)
  31
  32 #include "mbedtls/base64.h"
  33
  34 #include <stdint.h>
  35
  36 #if defined(MBEDTLS_SELF_TEST)
  37 #include <string.h>
  38 #if defined(MBEDTLS_PLATFORM_C)
  39 #include "mbedtls/platform.h"
  40 #else
  41 #include <stdio.h>
  42 #define mbedtls_printf printf
  43 #endif /* MBEDTLS_PLATFORM_C */
  44 #endif /* MBEDTLS_SELF_TEST */
  45
  46 static const unsigned char base64_enc_map[64] =
  47 {
  48     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
  49     'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
  50     'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
  51     'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
  52     'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
  53     'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
  54     '8', '9', '+', '/'
  55 };
  56
  57 static const unsigned char base64_dec_map[128] =
  58 {
  59     127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  60     127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  61     127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  62     127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
  63     127, 127, 127,  62, 127, 127, 127,  63,  52,  53,
  64      54,  55,  56,  57,  58,  59,  60,  61, 127, 127,
  65     127,  64, 127, 127, 127,   0,   1,   2,   3,   4,
  66       5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
  67      15,  16,  17,  18,  19,  20,  21,  22,  23,  24,
  68      25, 127, 127, 127, 127, 127, 127,  26,  27,  28,
  69      29,  30,  31,  32,  33,  34,  35,  36,  37,  38,
  70      39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
  71      49,  50,  51, 127, 127, 127, 127, 127
  72 };
  73
  74 #define BASE64_SIZE_T_MAX   ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
  75
  76 /*
  77  * Encode a buffer into base64 format
  78  */
  79 int mbedtls_base64_encode( unsigned char *dst, size_t dlen, size_t *olen,
  80                    const unsigned char *src, size_t slen )
  81 {
  82     size_t i, n;
  83     int C1, C2, C3;
  84     unsigned char *p;
  85
  86     if( slen == 0 )
  87     {
  88         *olen = 0;
  89         return( 0 );
  90     }
  91
  92     n = slen / 3 + ( slen % 3 != 0 );
  93
  94     if( n > ( BASE64_SIZE_T_MAX - 1 ) / 4 )
  95     {
  96         *olen = BASE64_SIZE_T_MAX;
  97         return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
  98     }
  99
 100     n *= 4;
 101
 102     if( ( dlen < n + 1 ) || ( NULL == dst ) )
 103     {
 104         *olen = n + 1;
 105         return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
 106     }
 107
 108     n = ( slen / 3 ) * 3;
 109
 110     for( i = 0, p = dst; i < n; i += 3 )
 111     {
 112         C1 = *src++;
 113         C2 = *src++;
 114         C3 = *src++;
 115
 116         *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
 117         *p++ = base64_enc_map[(((C1 &  3) << 4) + (C2 >> 4)) & 0x3F];
 118         *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
 119         *p++ = base64_enc_map[C3 & 0x3F];
 120     }
 121
 122     if( i < slen )
 123     {
 124         C1 = *src++;
 125         C2 = ( ( i + 1 ) < slen ) ? *src++ : 0;
 126
 127         *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
 128         *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
 129
 130         if( ( i + 1 ) < slen )
 131              *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
 132         else *p++ = '=';
 133
 134         *p++ = '=';
 135     }
 136
 137     *olen = p - dst;
 138     *p = 0;
 139
 140     return( 0 );
 141 }
 142
 143 /*
 144  * Decode a base64-formatted buffer
 145  */
 146 int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
 147                    const unsigned char *src, size_t slen )
 148 {
 149     size_t i, n;
 150     uint32_t j, x;
 151     unsigned char *p;
 152
 153     /* First pass: check for validity and get output length */
 154     for( i = n = j = 0; i < slen; i++ )
 155     {
 156         /* Skip spaces before checking for EOL */
 157         x = 0;
 158         while( i < slen && src[i] == ' ' )
 159         {
 160             ++i;
 161             ++x;
 162         }
 163
 164         /* Spaces at end of buffer are OK */
 165         if( i == slen )
 166             break;
 167
 168         if( ( slen - i ) >= 2 &&
 169             src[i] == '\r' && src[i + 1] == '\n' )
 170             continue;
 171
 172         if( src[i] == '\n' )
 173             continue;
 174
 175         /* Space inside a line is an error */
 176         if( x != 0 )
 177             return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
 178
 179         if( src[i] == '=' && ++j > 2 )
 180             return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
 181
 182         if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
 183             return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
 184
 185         if( base64_dec_map[src[i]] < 64 && j != 0 )
 186             return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
 187
 188         n++;
 189     }
 190
 191     if( n == 0 )
 192     {
 193         *olen = 0;
 194         return( 0 );
 195     }
 196
 197     /* The following expression is to calculate the following formula without
 198      * risk of integer overflow in n:
 199      *     n = ( ( n * 6 ) + 7 ) >> 3;
 200      */
 201     n = ( 6 * ( n >> 3 ) ) + ( ( 6 * ( n & 0x7 ) + 7 ) >> 3 );
 202     n -= j;
 203
 204     if( dst == NULL || dlen < n )
 205     {
 206         *olen = n;
 207         return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
 208     }
 209
 210    for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
 211    {
 212         if( *src == '\r' || *src == '\n' || *src == ' ' )
 213             continue;
 214
 215         j -= ( base64_dec_map[*src] == 64 );
 216         x  = ( x << 6 ) | ( base64_dec_map[*src] & 0x3F );
 217
 218         if( ++n == 4 )
 219         {
 220             n = 0;
 221             if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
 222             if( j > 1 ) *p++ = (unsigned char)( x >>  8 );
 223             if( j > 2 ) *p++ = (unsigned char)( x       );
 224         }
 225     }
 226
 227     *olen = p - dst;
 228
 229     return( 0 );
 230 }
 231
 232 #if defined(MBEDTLS_SELF_TEST)
 233
 234 static const unsigned char base64_test_dec[64] =
 235 {
 236     0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,
 237     0xBF, 0x17, 0xD9, 0xA2, 0xC4, 0x17, 0x1A, 0x01,
 238     0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, 0xD7, 0x09,
 239     0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13,
 240     0xCA, 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31,
 241     0x6C, 0x08, 0x34, 0xFF, 0x8D, 0xC2, 0x6C, 0x38,
 242     0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, 0x4B,
 243     0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97
 244 };
 245
 246 static const unsigned char base64_test_enc[] =
 247     "JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK"
 248     "swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw==";
 249
 250 /*
 251  * Checkup routine
 252  */
 253 int mbedtls_base64_self_test( int verbose )
 254 {
 255     size_t len;
 256     const unsigned char *src;
 257     unsigned char buffer[128];
 258
 259     if( verbose != 0 )
 260         mbedtls_printf( "  Base64 encoding test: " );
 261
 262     src = base64_test_dec;
 263
 264     if( mbedtls_base64_encode( buffer, sizeof( buffer ), &len, src, 64 ) != 0 ||
 265          memcmp( base64_test_enc, buffer, 88 ) != 0 )
 266     {
 267         if( verbose != 0 )
 268             mbedtls_printf( "failed\n" );
 269
 270         return( 1 );
 271     }
 272
 273     if( verbose != 0 )
 274         mbedtls_printf( "passed\n  Base64 decoding test: " );
 275
 276     src = base64_test_enc;
 277
 278     if( mbedtls_base64_decode( buffer, sizeof( buffer ), &len, src, 88 ) != 0 ||
 279          memcmp( base64_test_dec, buffer, 64 ) != 0 )
 280     {
 281         if( verbose != 0 )
 282             mbedtls_printf( "failed\n" );
 283
 284         return( 1 );
 285     }
 286
 287     if( verbose != 0 )
 288         mbedtls_printf( "passed\n\n" );
 289
 290     return( 0 );
 291 }
 292
 293 #endif /* MBEDTLS_SELF_TEST */
 294
 295 #endif /* MBEDTLS_BASE64_C */