encoding/apr_base64.c

   1 /* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
   2  * applicable.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /* base64 encoder/decoder. Originally part of main/util.c
  18  * but moved here so that support/ab and apr_sha1.c could
  19  * use it. This meant removing the apr_palloc()s and adding
  20  * ugly 'len' functions, which is quite a nasty cost.
  21  */
  22
  23 #include "apr_base64.h"
  24 #if APR_CHARSET_EBCDIC
  25 #include "apr_xlate.h"
  26 #endif                          /* APR_CHARSET_EBCDIC */
  27
  28 /* aaaack but it's fast and const should make it shared text page. */
  29 static const unsigned char pr2six[256] =
  30 {
  31 #if !APR_CHARSET_EBCDIC
  32     /* ASCII table */
  33     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  34     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  35     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
  36     52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
  37     64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
  38     15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
  39     64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
  40     41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
  41     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  42     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  43     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  44     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  45     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  46     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  47     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  48     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
  49 #else /*APR_CHARSET_EBCDIC*/
  50     /* EBCDIC table */
  51     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  52     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  53     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  54     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  55     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64,
  56     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  57     64, 63, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  58     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  59     64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 64, 64, 64, 64, 64, 64,
  60     64, 35, 36, 37, 38, 39, 40, 41, 42, 43, 64, 64, 64, 64, 64, 64,
  61     64, 64, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64, 64,
  62     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  63     64,  0,  1,  2,  3,  4,  5,  6,  7,  8, 64, 64, 64, 64, 64, 64,
  64     64,  9, 10, 11, 12, 13, 14, 15, 16, 17, 64, 64, 64, 64, 64, 64,
  65     64, 64, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64, 64,
  66     52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64
  67 #endif /*APR_CHARSET_EBCDIC*/
  68 };
  69
  70 #if APR_CHARSET_EBCDIC
  71 static apr_xlate_t *xlate_to_ebcdic;
  72 static unsigned char os_toascii[256];
  73
  74 APU_DECLARE(apr_status_t) apr_base64init_ebcdic(apr_xlate_t *to_ascii,
  75                                              apr_xlate_t *to_ebcdic)
  76 {
  77     int i;
  78     apr_size_t inbytes_left, outbytes_left;
  79     apr_status_t rv;
  80     int onoff;
  81
  82     /* Only single-byte conversion is supported.
  83      */
  84     rv = apr_xlate_sb_get(to_ascii, &onoff);
  85     if (rv) {
  86         return rv;
  87     }
  88     if (!onoff) { /* If conversion is not single-byte-only */
  89         return APR_EINVAL;
  90     }
  91     rv = apr_xlate_sb_get(to_ebcdic, &onoff);
  92     if (rv) {
  93         return rv;
  94     }
  95     if (!onoff) { /* If conversion is not single-byte-only */
  96         return APR_EINVAL;
  97     }
  98     xlate_to_ebcdic = to_ebcdic;
  99     for (i = 0; i < sizeof(os_toascii); i++) {
 100         os_toascii[i] = i;
 101     }
 102     inbytes_left = outbytes_left = sizeof(os_toascii);
 103     apr_xlate_conv_buffer(to_ascii, os_toascii, &inbytes_left,
 104                           os_toascii, &outbytes_left);
 105
 106     return APR_SUCCESS;
 107 }
 108 #endif /*APR_CHARSET_EBCDIC*/
 109
 110 APU_DECLARE(int) apr_base64_decode_len(const char *bufcoded)
 111 {
 112     int nbytesdecoded;
 113     register const unsigned char *bufin;
 114     register int nprbytes;
 115
 116     bufin = (const unsigned char *) bufcoded;
 117     while (pr2six[*(bufin++)] <= 63);
 118
 119     nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
 120     nbytesdecoded = ((nprbytes + 3) / 4) * 3;
 121
 122     return nbytesdecoded + 1;
 123 }
 124
 125 APU_DECLARE(int) apr_base64_decode(char *bufplain, const char *bufcoded)
 126 {
 127 #if APR_CHARSET_EBCDIC
 128     apr_size_t inbytes_left, outbytes_left;
 129 #endif                          /* APR_CHARSET_EBCDIC */
 130     int len;
 131
 132     len = apr_base64_decode_binary((unsigned char *) bufplain, bufcoded);
 133 #if APR_CHARSET_EBCDIC
 134     inbytes_left = outbytes_left = len;
 135     apr_xlate_conv_buffer(xlate_to_ebcdic, bufplain, &inbytes_left,
 136                           bufplain, &outbytes_left);
 137 #endif                          /* APR_CHARSET_EBCDIC */
 138     bufplain[len] = '\0';
 139     return len;
 140 }
 141
 142 /* This is the same as apr_base64_decode() except on EBCDIC machines, where
 143  * the conversion of the output to ebcdic is left out.
 144  */
 145 APU_DECLARE(int) apr_base64_decode_binary(unsigned char *bufplain,
 146                                    const char *bufcoded)
 147 {
 148     int nbytesdecoded;
 149     register const unsigned char *bufin;
 150     register unsigned char *bufout;
 151     register int nprbytes;
 152
 153     bufin = (const unsigned char *) bufcoded;
 154     while (pr2six[*(bufin++)] <= 63);
 155     nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
 156     nbytesdecoded = ((nprbytes + 3) / 4) * 3;
 157
 158     bufout = (unsigned char *) bufplain;
 159     bufin = (const unsigned char *) bufcoded;
 160
 161     while (nprbytes > 4) {
 162         *(bufout++) =
 163             (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
 164         *(bufout++) =
 165             (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
 166         *(bufout++) =
 167             (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
 168         bufin += 4;
 169         nprbytes -= 4;
 170     }
 171
 172     /* Note: (nprbytes == 1) would be an error, so just ingore that case */
 173     if (nprbytes > 1) {
 174         *(bufout++) =
 175             (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
 176     }
 177     if (nprbytes > 2) {
 178         *(bufout++) =
 179             (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
 180     }
 181     if (nprbytes > 3) {
 182         *(bufout++) =
 183             (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
 184     }
 185
 186     nbytesdecoded -= (4 - nprbytes) & 3;
 187     return nbytesdecoded;
 188 }
 189
 190 static const char basis_64[] =
 191     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 192
 193 APU_DECLARE(int) apr_base64_encode_len(int len)
 194 {
 195     return ((len + 2) / 3 * 4) + 1;
 196 }
 197
 198 APU_DECLARE(int) apr_base64_encode(char *encoded, const char *string, int len)
 199 {
 200 #if !APR_CHARSET_EBCDIC
 201     return apr_base64_encode_binary(encoded, (const unsigned char *) string, len);
 202 #else /* APR_CHARSET_EBCDIC */
 203     int i;
 204     char *p;
 205
 206     p = encoded;
 207     for (i = 0; i < len - 2; i += 3) {
 208         *p++ = basis_64[(os_toascii[string[i]] >> 2) & 0x3F];
 209         *p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4) |
 210                         ((int) (os_toascii[string[i + 1]] & 0xF0) >> 4)];
 211         *p++ = basis_64[((os_toascii[string[i + 1]] & 0xF) << 2) |
 212                         ((int) (os_toascii[string[i + 2]] & 0xC0) >> 6)];
 213         *p++ = basis_64[os_toascii[string[i + 2]] & 0x3F];
 214     }
 215     if (i < len) {
 216         *p++ = basis_64[(os_toascii[string[i]] >> 2) & 0x3F];
 217         if (i == (len - 1)) {
 218             *p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4)];
 219             *p++ = '=';
 220         }
 221         else {
 222             *p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4) |
 223                             ((int) (os_toascii[string[i + 1]] & 0xF0) >> 4)];
 224             *p++ = basis_64[((os_toascii[string[i + 1]] & 0xF) << 2)];
 225         }
 226         *p++ = '=';
 227     }
 228
 229     *p++ = '\0';
 230     return p - encoded;
 231 #endif                          /* APR_CHARSET_EBCDIC */
 232 }
 233
 234 /* This is the same as apr_base64_encode() except on EBCDIC machines, where
 235  * the conversion of the input to ascii is left out.
 236  */
 237 APU_DECLARE(int) apr_base64_encode_binary(char *encoded,
 238                                       const unsigned char *string, int len)
 239 {
 240     int i;
 241     char *p;
 242
 243     p = encoded;
 244     for (i = 0; i < len - 2; i += 3) {
 245         *p++ = basis_64[(string[i] >> 2) & 0x3F];
 246         *p++ = basis_64[((string[i] & 0x3) << 4) |
 247                         ((int) (string[i + 1] & 0xF0) >> 4)];
 248         *p++ = basis_64[((string[i + 1] & 0xF) << 2) |
 249                         ((int) (string[i + 2] & 0xC0) >> 6)];
 250         *p++ = basis_64[string[i + 2] & 0x3F];
 251     }
 252     if (i < len) {
 253         *p++ = basis_64[(string[i] >> 2) & 0x3F];
 254         if (i == (len - 1)) {
 255             *p++ = basis_64[((string[i] & 0x3) << 4)];
 256             *p++ = '=';
 257         }
 258         else {
 259             *p++ = basis_64[((string[i] & 0x3) << 4) |
 260                             ((int) (string[i + 1] & 0xF0) >> 4)];
 261             *p++ = basis_64[((string[i + 1] & 0xF) << 2)];
 262         }
 263         *p++ = '=';
 264     }
 265
 266     *p++ = '\0';
 267     return p - encoded;
 268 }