text: /* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
   * applicable.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /* base64 encoder/decoder. Originally part of main/util.c
   * but moved here so that support/ab and apr_sha1.c could
   * use it. This meant removing the apr_palloc()s and adding
   * ugly 'len' functions, which is quite a nasty cost.
   */
  
  #include "apr_base64.h"
  #if APR_CHARSET_EBCDIC
  #include "apr_xlate.h"
  #endif				/* APR_CHARSET_EBCDIC */
  
  /* aaaack but it's fast and const should make it shared text page. */
  static const unsigned char pr2six[256] =
  {
  #if !APR_CHARSET_EBCDIC
      /* ASCII table */
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
      52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
      64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
      15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
      64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
      41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
  #else /*APR_CHARSET_EBCDIC*/
      /* EBCDIC table */
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 63, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 64, 64, 64, 64, 64, 64,
      64, 35, 36, 37, 38, 39, 40, 41, 42, 43, 64, 64, 64, 64, 64, 64,
      64, 64, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64, 64,
      64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
      64,  0,  1,  2,  3,  4,  5,  6,  7,  8, 64, 64, 64, 64, 64, 64,
      64,  9, 10, 11, 12, 13, 14, 15, 16, 17, 64, 64, 64, 64, 64, 64,
      64, 64, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64, 64,
      52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64
  #endif /*APR_CHARSET_EBCDIC*/
  };
  
  #if APR_CHARSET_EBCDIC
  static apr_xlate_t *xlate_to_ebcdic;
  static unsigned char os_toascii[256];
  
  APU_DECLARE(apr_status_t) apr_base64init_ebcdic(apr_xlate_t *to_ascii,
                                               apr_xlate_t *to_ebcdic)
  {
      int i;
      apr_size_t inbytes_left, outbytes_left;
      apr_status_t rv;
      int onoff;
      
      /* Only single-byte conversion is supported.
       */
      rv = apr_xlate_sb_get(to_ascii, &onoff);
      if (rv) {
          return rv;
      }
      if (!onoff) { /* If conversion is not single-byte-only */
          return APR_EINVAL;
      }
      rv = apr_xlate_sb_get(to_ebcdic, &onoff);
      if (rv) {
          return rv;
      }
      if (!onoff) { /* If conversion is not single-byte-only */
          return APR_EINVAL;
      }
      xlate_to_ebcdic = to_ebcdic;
      for (i = 0; i < sizeof(os_toascii); i++) {
          os_toascii[i] = i;
      }
      inbytes_left = outbytes_left = sizeof(os_toascii);
      apr_xlate_conv_buffer(to_ascii, os_toascii, &inbytes_left,
                            os_toascii, &outbytes_left);
  
      return APR_SUCCESS;
  }
  #endif /*APR_CHARSET_EBCDIC*/
  
  APU_DECLARE(int) apr_base64_decode_len(const char *bufcoded)
  {
      int nbytesdecoded;
      register const unsigned char *bufin;
      register int nprbytes;
  
      bufin = (const unsigned char *) bufcoded;
      while (pr2six[*(bufin++)] <= 63);
  
      nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
      nbytesdecoded = ((nprbytes + 3) / 4) * 3;
  
      return nbytesdecoded + 1;
  }
  
  APU_DECLARE(int) apr_base64_decode(char *bufplain, const char *bufcoded)
  {
  #if APR_CHARSET_EBCDIC
      apr_size_t inbytes_left, outbytes_left;
  #endif				/* APR_CHARSET_EBCDIC */
      int len;
      
      len = apr_base64_decode_binary((unsigned char *) bufplain, bufcoded);
  #if APR_CHARSET_EBCDIC
      inbytes_left = outbytes_left = len;
      apr_xlate_conv_buffer(xlate_to_ebcdic, bufplain, &inbytes_left,
                            bufplain, &outbytes_left);
  #endif				/* APR_CHARSET_EBCDIC */
      bufplain[len] = '\0';
      return len;
  }
  
  /* This is the same as apr_base64_decode() except on EBCDIC machines, where
   * the conversion of the output to ebcdic is left out.
   */
  APU_DECLARE(int) apr_base64_decode_binary(unsigned char *bufplain,
  				   const char *bufcoded)
  {
      int nbytesdecoded;
      register const unsigned char *bufin;
      register unsigned char *bufout;
      register int nprbytes;
  
      bufin = (const unsigned char *) bufcoded;
      while (pr2six[*(bufin++)] <= 63);
      nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
      nbytesdecoded = ((nprbytes + 3) / 4) * 3;
  
      bufout = (unsigned char *) bufplain;
      bufin = (const unsigned char *) bufcoded;
  
      while (nprbytes > 4) {
  	*(bufout++) =
  	    (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
  	*(bufout++) =
  	    (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
  	*(bufout++) =
  	    (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
  	bufin += 4;
  	nprbytes -= 4;
      }
  
      /* Note: (nprbytes == 1) would be an error, so just ingore that case */
      if (nprbytes > 1) {
  	*(bufout++) =
  	    (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
      }
      if (nprbytes > 2) {
  	*(bufout++) =
  	    (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
      }
      if (nprbytes > 3) {
  	*(bufout++) =
  	    (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
      }
  
      nbytesdecoded -= (4 - nprbytes) & 3;
      return nbytesdecoded;
  }
  
  static const char basis_64[] =
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  
  APU_DECLARE(int) apr_base64_encode_len(int len)
  {
      return ((len + 2) / 3 * 4) + 1;
  }
  
  APU_DECLARE(int) apr_base64_encode(char *encoded, const char *string, int len)
  {
  #if !APR_CHARSET_EBCDIC
      return apr_base64_encode_binary(encoded, (const unsigned char *) string, len);
  #else /* APR_CHARSET_EBCDIC */
      int i;
      char *p;
  
      p = encoded;
      for (i = 0; i < len - 2; i += 3) {
  	*p++ = basis_64[(os_toascii[string[i]] >> 2) & 0x3F];
  	*p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4) |
  	                ((int) (os_toascii[string[i + 1]] & 0xF0) >> 4)];
  	*p++ = basis_64[((os_toascii[string[i + 1]] & 0xF) << 2) |
  	                ((int) (os_toascii[string[i + 2]] & 0xC0) >> 6)];
  	*p++ = basis_64[os_toascii[string[i + 2]] & 0x3F];
      }
      if (i < len) {
  	*p++ = basis_64[(os_toascii[string[i]] >> 2) & 0x3F];
  	if (i == (len - 1)) {
  	    *p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4)];
  	    *p++ = '=';
  	}
  	else {
  	    *p++ = basis_64[((os_toascii[string[i]] & 0x3) << 4) |
  	                    ((int) (os_toascii[string[i + 1]] & 0xF0) >> 4)];
  	    *p++ = basis_64[((os_toascii[string[i + 1]] & 0xF) << 2)];
  	}
  	*p++ = '=';
      }
  
      *p++ = '\0';
      return p - encoded;
  #endif				/* APR_CHARSET_EBCDIC */
  }
  
  /* This is the same as apr_base64_encode() except on EBCDIC machines, where
   * the conversion of the input to ascii is left out.
   */
  APU_DECLARE(int) apr_base64_encode_binary(char *encoded,
                                        const unsigned char *string, int len)
  {
      int i;
      char *p;
  
      p = encoded;
      for (i = 0; i < len - 2; i += 3) {
  	*p++ = basis_64[(string[i] >> 2) & 0x3F];
  	*p++ = basis_64[((string[i] & 0x3) << 4) |
  	                ((int) (string[i + 1] & 0xF0) >> 4)];
  	*p++ = basis_64[((string[i + 1] & 0xF) << 2) |
  	                ((int) (string[i + 2] & 0xC0) >> 6)];
  	*p++ = basis_64[string[i + 2] & 0x3F];
      }
      if (i < len) {
  	*p++ = basis_64[(string[i] >> 2) & 0x3F];
  	if (i == (len - 1)) {
  	    *p++ = basis_64[((string[i] & 0x3) << 4)];
  	    *p++ = '=';
  	}
  	else {
  	    *p++ = basis_64[((string[i] & 0x3) << 4) |
  	                    ((int) (string[i + 1] & 0xF0) >> 4)];
  	    *p++ = basis_64[((string[i + 1] & 0xF) << 2)];
  	}
  	*p++ = '=';
      }
  
      *p++ = '\0';
      return p - encoded;
  }
  