text: /*
   * ModSecurity, http://www.modsecurity.org/
   * Copyright (c) 2015 - 2020 Trustwave Holdings, Inc. (http://www.trustwave.com/)
   *
   * 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
   *
   * If any of the files related to licensing are missing or if you have any
   * other questions related to licensing please contact Trustwave Holdings, Inc.
   * directly using the email address security@modsecurity.org.
   *
   */
  
  #include "src/utils/base64.h"
  
  #include <string.h>
  
  #include <string>
  #include <fstream>
  #include <iostream>
  
  #include "mbedtls/base64.h"
  
  namespace modsecurity {
  namespace Utils {
  
  
  std::string Base64::encode(const std::string& data) {
      size_t encoded_len = 0;
      unsigned char *d;
      std::string ret;
  
      mbedtls_base64_encode(NULL, 0, &encoded_len,
          reinterpret_cast<const unsigned char*>(data.c_str()), data.size());
  
      d = reinterpret_cast<unsigned char*>(malloc(sizeof(char) * encoded_len));
      if (d == NULL) {
          return data;
      }
  
      memset(d, '\0', encoded_len);
  
      mbedtls_base64_encode(d, encoded_len, &encoded_len,
          (unsigned char*) data.c_str(), data.size());
  
      ret.assign(reinterpret_cast<const char*>(d), encoded_len);
      free(d);
  
  
      return ret;
  }
  
  
  std::string Base64::decode(const std::string& data, bool forgiven) {
      if (forgiven) {
          return decode_forgiven(data);
      }
  
      return decode(data);
  }
  
  
  std::string Base64::decode(const std::string& data) {
      size_t decoded_len = 0;
      unsigned char *d;
      std::string ret;
      size_t len = strlen(data.c_str());
  
      mbedtls_base64_decode(NULL, 0, &decoded_len,
          reinterpret_cast<const unsigned char*>(data.c_str()), len);
  
      d = reinterpret_cast<unsigned char*>(malloc(sizeof(char) * decoded_len));
      if (d == NULL) {
          return data;
      }
  
      memset(d, '\0', decoded_len);
  
      mbedtls_base64_decode(d, decoded_len, &decoded_len,
         reinterpret_cast<const unsigned char*>(data.c_str()), len);
  
      ret.assign(reinterpret_cast<const char*>(d), decoded_len);
      free(d);
  
      return ret;
  }
  
  
  std::string Base64::decode_forgiven(const std::string& data) {
      size_t decoded_len = 0;
      unsigned char *d;
      std::string ret;
  
      decode_forgiven_engine(NULL, 0, &decoded_len,
          reinterpret_cast<const unsigned char*>(data.c_str()), data.size());
  
      d = reinterpret_cast<unsigned char*>(malloc(sizeof(char) * decoded_len));
      if (d == NULL) {
          return data;
      }
  
      memset(d, '\0', decoded_len);
  
      decode_forgiven_engine(d, decoded_len, &decoded_len,
         reinterpret_cast<const unsigned char*>(data.c_str()), data.size());
  
      ret.assign(reinterpret_cast<const char*>(d), decoded_len);
      free(d);
  
      return ret;
  }
  
  
  void Base64::decode_forgiven_engine(unsigned char *plain_text,
          size_t plain_text_size, size_t *aiming_size,
          const unsigned char *encoded, size_t input_len) {
      int i = 0, j = 0, k = 0;
      int ch = 0;
      static const char b64_pad = '=';
      static int b64_reverse_t[256] = {
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -2, -1, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,
          52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,
          -2, 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, -2, -2, -2, -2, -2,
          -2, 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, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
          -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2
      };
  
  
      while (/*ch = *encoded++ != '\0' && */input_len-- > 0) {
          ch = *encoded++;
          if (ch == b64_pad) {
              if (*encoded != '=' && (i % 4) == 1) {
                  *aiming_size = 0;
                  return;
              }
              continue;
          }
  
          ch = b64_reverse_t[ch];
          if (ch < 0) {
              continue;
          /*} else if (ch == -2) {
              *aiming_size = 0;
              return;*/
          }
          switch (i % 4) {
              case 0:
                  if (plain_text_size != 0) {
                      plain_text[j] = ch << 2;
                  }
                  break;
              case 1:
                  if (plain_text_size == 0) {
                      j++;
                  } else {
                      plain_text[j++] |= ch >> 4;
                      plain_text[j] = (ch & 0x0f) << 4;
                  }
                  break;
              case 2:
                  if (plain_text_size == 0) {
                      j++;
                  } else {
                      plain_text[j++] |= ch >>2;
                      plain_text[j] = (ch & 0x03) << 6;
                  }
                  break;
              case 3:
                  if (plain_text_size == 0) {
                      j++;
                  } else {
                      plain_text[j++] |= ch;
                  }
                  break;
          }
          i++;
      }
      k = j;
  
      if (ch == b64_pad) {
          switch (i % 4) {
              case 1:
                  *aiming_size = 0;
                  return;
              case 2:
                  k++;
              case 3:
                  if (plain_text_size != 0) {
                      plain_text[k] = 0;
                  }
          }
      }
  
      if (plain_text_size != 0) {
          plain_text[j] = '\0';
      }
  
      if (plain_text_size == 0) {
          *aiming_size = k + 1;
      } else {
          *aiming_size = j;
      }
  }
  
  
  }  // namespace Utils
  }  // namespace modsecurity
  