text: /* coding.c
   *
   * Copyright (C) 2006-2014 wolfSSL Inc.
   *
   * This file is part of CyaSSL.
   *
   * CyaSSL is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * CyaSSL is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
   */
  
  #ifdef HAVE_CONFIG_H
      #include <config.h>
  #endif
  
  #include <cyassl/ctaocrypt/settings.h>
  
  #ifndef NO_CODING
  
  #include <cyassl/ctaocrypt/coding.h>
  #include <cyassl/ctaocrypt/error-crypt.h>
  #include <cyassl/ctaocrypt/logging.h>
  
  
  enum {
      BAD         = 0xFF,  /* invalid encoding */
      PAD         = '=',
      PEM_LINE_SZ = 64
  };
  
  
  static
  const byte base64Decode[] = { 62, BAD, BAD, BAD, 63,   /* + starts at 0x2B */
                                52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
                                BAD, BAD, BAD, BAD, BAD, BAD, BAD,
                                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,
                                BAD, BAD, BAD, BAD, BAD, BAD,
                                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
                              };
  
  
  int Base64_Decode(const byte* in, word32 inLen, byte* out, word32* outLen)
  {
      word32 i = 0;
      word32 j = 0;
      word32 plainSz = inLen - ((inLen + (PEM_LINE_SZ - 1)) / PEM_LINE_SZ );
      const byte maxIdx = (byte)sizeof(base64Decode) + 0x2B - 1;
  
      plainSz = (plainSz * 3 + 3) / 4;
      if (plainSz > *outLen) return BAD_FUNC_ARG;
  
      while (inLen > 3) {
          byte b1, b2, b3;
          byte e1 = in[j++];
          byte e2 = in[j++];
          byte e3 = in[j++];
          byte e4 = in[j++];
  
          int pad3 = 0;
          int pad4 = 0;
  
          if (e1 == 0)            /* end file 0's */
              break;
          if (e3 == PAD)
              pad3 = 1;
          if (e4 == PAD)
              pad4 = 1;
  
          if (e1 < 0x2B || e2 < 0x2B || e3 < 0x2B || e4 < 0x2B) {
              CYASSL_MSG("Bad Base64 Decode data, too small");
              return ASN_INPUT_E;
          }
  
          if (e1 > maxIdx || e2 > maxIdx || e3 > maxIdx || e4 > maxIdx) {
              CYASSL_MSG("Bad Base64 Decode data, too big");
              return ASN_INPUT_E;
          }
  
          e1 = base64Decode[e1 - 0x2B];
          e2 = base64Decode[e2 - 0x2B];
          e3 = (e3 == PAD) ? 0 : base64Decode[e3 - 0x2B];
          e4 = (e4 == PAD) ? 0 : base64Decode[e4 - 0x2B];
  
          b1 = (byte)((e1 << 2) | (e2 >> 4));
          b2 = (byte)(((e2 & 0xF) << 4) | (e3 >> 2));
          b3 = (byte)(((e3 & 0x3) << 6) | e4);
  
          out[i++] = b1;
          if (!pad3)
              out[i++] = b2;
          if (!pad4)
              out[i++] = b3;
          else
              break;
          
          inLen -= 4;
          if (inLen && (in[j] == ' ' || in[j] == '\r' || in[j] == '\n')) {
              byte endLine = in[j++];
              inLen--;
              while (inLen && endLine == ' ') {   /* allow trailing whitespace */
                  endLine = in[j++];
                  inLen--;
              }
              if (endLine == '\r') {
                  if (inLen) {
                      endLine = in[j++];
                      inLen--;
                  }
              }
              if (endLine != '\n') {
                  CYASSL_MSG("Bad end of line in Base64 Decode");
                  return ASN_INPUT_E;
              }
          }
      }
      *outLen = i;
  
      return 0;
  }
  
  
  #if defined(OPENSSL_EXTRA) || defined (SESSION_CERTS) || defined(CYASSL_KEY_GEN) || defined(CYASSL_CERT_GEN) || defined(HAVE_WEBSERVER)
  
  static
  const byte base64Encode[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
                                'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
                                'U', 'V', 'W', 'X', 'Y', 'Z',
                                'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
                                'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
                                'u', 'v', 'w', 'x', 'y', 'z',
                                '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                                '+', '/'
                              };
  
  
  /* make sure *i (idx) won't exceed max, store and possibly escape to out,
   * raw means use e w/o decode,  0 on success */
  static int CEscape(int escaped, byte e, byte* out, word32* i, word32 max,
                    int raw)
  {
      int    doEscape = 0;
      word32 needed = 1;
      word32 idx = *i;
  
      byte basic;
      byte plus    = 0;
      byte equals  = 0;
      byte newline = 0;
  
      if (raw)
          basic = e;
      else
          basic = base64Encode[e];
  
      /* check whether to escape */
      if (escaped) {
          switch ((char)basic) {
              case '+' :
                  plus     = 1;
                  doEscape = 1;
                  needed  += 2;
                  break;
              case '=' :
                  equals   = 1;
                  doEscape = 1;
                  needed  += 2;
                  break;
              case '\n' :
                  newline  = 1;
                  doEscape = 1;
                  needed  += 2;
                  break;
              default:
                  /* do nothing */
                  break;
          }
      }
  
      /* check size */
      if ( (idx+needed) > max) {
          CYASSL_MSG("Escape buffer max too small");
          return BUFFER_E;
      }
  
      /* store it */
      if (doEscape == 0) {
          out[idx++] = basic;
      }
      else {
          out[idx++] = '%';  /* start escape */
  
          if (plus) {
              out[idx++] = '2';
              out[idx++] = 'B';
          }
          else if (equals) {
              out[idx++] = '3';
              out[idx++] = 'D';
          }
          else if (newline) {
              out[idx++] = '0';
              out[idx++] = 'A';
          }
  
      }
      *i = idx;
  
      return 0;
  }
  
  
  /* internal worker, handles both escaped and normal line endings */
  static int DoBase64_Encode(const byte* in, word32 inLen, byte* out,
                             word32* outLen, int escaped)
  {
      int    ret = 0;
      word32 i = 0,
             j = 0,
             n = 0;   /* new line counter */
  
      word32 outSz = (inLen + 3 - 1) / 3 * 4;
      word32 addSz = (outSz + PEM_LINE_SZ - 1) / PEM_LINE_SZ;  /* new lines */
  
      if (escaped)
          addSz *= 3;   /* instead of just \n, we're doing %0A triplet */
  
      outSz += addSz;
  
      /* if escaped we can't predetermine size for one pass encoding, but
       * make sure we have enough if no escapes are in input */
      if (outSz > *outLen) return BAD_FUNC_ARG;
      
      while (inLen > 2) {
          byte b1 = in[j++];
          byte b2 = in[j++];
          byte b3 = in[j++];
  
          /* encoded idx */
          byte e1 = b1 >> 2;
          byte e2 = (byte)(((b1 & 0x3) << 4) | (b2 >> 4));
          byte e3 = (byte)(((b2 & 0xF) << 2) | (b3 >> 6));
          byte e4 = b3 & 0x3F;
  
          /* store */
          ret = CEscape(escaped, e1, out, &i, *outLen, 0);
          if (ret != 0) break;
          ret = CEscape(escaped, e2, out, &i, *outLen, 0);
          if (ret != 0) break;
          ret = CEscape(escaped, e3, out, &i, *outLen, 0);
          if (ret != 0) break;
          ret = CEscape(escaped, e4, out, &i, *outLen, 0);
          if (ret != 0) break;
  
          inLen -= 3;
  
          if ((++n % (PEM_LINE_SZ / 4)) == 0 && inLen) {
              ret = CEscape(escaped, '\n', out, &i, *outLen, 1);
              if (ret != 0) break;
          }
      }
  
      /* last integral */
      if (inLen && ret == 0) {
          int twoBytes = (inLen == 2);
  
          byte b1 = in[j++];
          byte b2 = (twoBytes) ? in[j++] : 0;
  
          byte e1 = b1 >> 2;
          byte e2 = (byte)(((b1 & 0x3) << 4) | (b2 >> 4));
          byte e3 = (byte)((b2 & 0xF) << 2);
  
          ret = CEscape(escaped, e1, out, &i, *outLen, 0);
          if (ret == 0) 
              ret = CEscape(escaped, e2, out, &i, *outLen, 0);
          if (ret == 0) {
              /* third */
              if (twoBytes)
                  ret = CEscape(escaped, e3, out, &i, *outLen, 0);
              else 
                  ret = CEscape(escaped, '=', out, &i, *outLen, 1);
          }
          /* fourth always pad */
          if (ret == 0)
              ret = CEscape(escaped, '=', out, &i, *outLen, 1);
      } 
  
      if (ret == 0) 
          ret = CEscape(escaped, '\n', out, &i, *outLen, 1);
  
      if (i != outSz && escaped == 0 && ret == 0)
          return ASN_INPUT_E; 
  
      *outLen = i;
      return ret; 
  }
  
  
  /* Base64 Encode, PEM style, with \n line endings */
  int Base64_Encode(const byte* in, word32 inLen, byte* out, word32* outLen)
  {
      return DoBase64_Encode(in, inLen, out, outLen, 0);
  }
  
  
  /* Base64 Encode, with %0A esacped line endings instead of \n */
  int Base64_EncodeEsc(const byte* in, word32 inLen, byte* out, word32* outLen)
  {
      return DoBase64_Encode(in, inLen, out, outLen, 1);
  }
  
  
  #endif  /* defined(OPENSSL_EXTRA) || defined (SESSION_CERTS) || defined(CYASSL_KEY_GEN) || defined(CYASSL_CERT_GEN) || defined(HAVE_WEBSERVER) */
  
  
  #if defined(OPENSSL_EXTRA) || defined(HAVE_WEBSERVER) || defined(HAVE_FIPS)
  
  static
  const byte hexDecode[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
                             BAD, BAD, BAD, BAD, BAD, BAD, BAD,
                             10, 11, 12, 13, 14, 15,  /* upper case A-F */
                             BAD, BAD, BAD, BAD, BAD, BAD, BAD, BAD,
                             BAD, BAD, BAD, BAD, BAD, BAD, BAD, BAD,
                             BAD, BAD, BAD, BAD, BAD, BAD, BAD, BAD,
                             BAD, BAD,  /* G - ` */
                             10, 11, 12, 13, 14, 15   /* lower case a-f */
                           };  /* A starts at 0x41 not 0x3A */
  
  int Base16_Decode(const byte* in, word32 inLen, byte* out, word32* outLen)
  {
      word32 inIdx  = 0;
      word32 outIdx = 0;
  
      if (inLen == 1 && *outLen && in) {
          byte b = in[inIdx++] - 0x30;  /* 0 starts at 0x30 */
  
          /* sanity check */
          if (b >=  sizeof(hexDecode)/sizeof(hexDecode[0]))
              return ASN_INPUT_E;
  
          b  = hexDecode[b];
  
          if (b == BAD)
              return ASN_INPUT_E;
          
          out[outIdx++] = b;
  
          *outLen = outIdx;
          return 0;
      }
  
      if (inLen % 2)
          return BAD_FUNC_ARG;
  
      if (*outLen < (inLen / 2))
          return BAD_FUNC_ARG;
  
      while (inLen) {
          byte b  = in[inIdx++] - 0x30;  /* 0 starts at 0x30 */
          byte b2 = in[inIdx++] - 0x30;
  
          /* sanity checks */
          if (b >=  sizeof(hexDecode)/sizeof(hexDecode[0]))
              return ASN_INPUT_E;
          if (b2 >= sizeof(hexDecode)/sizeof(hexDecode[0]))
              return ASN_INPUT_E;
  
          b  = hexDecode[b];
          b2 = hexDecode[b2];
  
          if (b == BAD || b2 == BAD)
              return ASN_INPUT_E;
          
          out[outIdx++] = (byte)((b << 4) | b2);
          inLen -= 2;
      }
  
      *outLen = outIdx;
      return 0;
  }
  
  
  #endif /* (OPENSSL_EXTRA) || (HAVE_WEBSERVER) || (HAVE_FIPS) */
  
  #endif /* NO_CODING */
  