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ACE_Base64 Class Reference

Encode/Decode a stream of bytes according to Base64 encoding. More...

#include <Codecs.h>

List of all members.

Static Public Member Functions

ACE_Byte * encode (const ACE_Byte *input, const size_t input_len, size_t *output_len)
ACE_Byte * decode (const ACE_Byte *input, size_t *output_len)
size_t length (const ACE_Byte *input)

Protected Member Functions

 ACE_Base64 (void)

Private Member Functions

 ACE_Base64 (ACE_Base64 const &)
ACE_Base64 & operator= (ACE_Base64 const &)

Static Private Member Functions

void init (void)
 Initialize the tables for encoding/decoding.


Static Private Attributes

ACE_Byte decoder_ []
 Alphabet used for decoding i.e decoder_[alphabet_[i = 0..63]] = i.

ACE_Byte member_ []
bool init_ = false
 Boolean to denote whether initialization is complete.

Detailed Description

Encode/Decode a stream of bytes according to Base64 encoding.

This class provides methods to encode or decode a stream of bytes to/from Base64 encoding. It doesn't convert the input stream to a canonical form before encoding.

Definition at line 46 of file Codecs.h.

Constructor & Destructor Documentation

ACE_Base64::ACE_Base64 (  void   )  [inline, protected]
 

Definition at line 90 of file Codecs.h. 

00090 {}

ACE_Base64::ACE_Base64 (  ACE_Base64 const &   )  [private]
 

Member Function Documentation

ACE_Byte * ACE_Base64::decode (  const ACE_Byte *  input,
size_t *  output_len
)  [static]
 

Decodes a stream of Base64 to bytes data

Parameters:
input Encoded Base64 data in byte stream.
output_len Length of the binary byte stream.
Returns:
Binary data in byte stream or NULL if input data cannot be encoded.

Definition at line 125 of file Codecs.cpp.

References ACE_Byte, ACE_ERROR, ACE_OS::ace_isspace(), ACE_NEW_RETURN, ACE_TEXT, decoder_, init(), init_, length(), LM_ERROR, member_, and pad. 

00126 {
00127   if (!ACE_Base64::init_)
00128     ACE_Base64::init();
00129 
00130   if (!input)
00131     return 0;
00132 
00133   size_t result_len = ACE_Base64::length (input);
00134   ACE_Byte* result = 0;
00135   ACE_NEW_RETURN (result, ACE_Byte[result_len], 0);
00136 
00137   ACE_Byte* ptr = const_cast<ACE_Byte*> (input);
00138   while (*ptr != 0 &&
00139          (member_[*(ptr)] == 1 || *ptr == pad
00140           || ACE_OS::ace_isspace (*ptr)))
00141     ++ptr;
00142   size_t input_len = ptr - input;
00143 
00144   int char_count = 0;
00145   int bits = 0;
00146   size_t pos = 0;
00147 
00148   size_t i = 0;
00149   for (; i < input_len; ++i)
00150     {
00151       if (input[i] == pad)
00152         break;
00153       if (!ACE_Base64::member_[input[i]])
00154         continue;
00155       bits += decoder_[input[i]];
00156       ++char_count;
00157 
00158       if (char_count == 4)
00159         {
00160           result[pos++] = static_cast<ACE_Byte> (bits >> 16);
00161           result[pos++] = static_cast<ACE_Byte> ((bits >> 8) & 0xff);
00162           result[pos++] = static_cast<ACE_Byte> (bits & 0xff);
00163           bits = 0;
00164           char_count = 0;
00165         }
00166       else
00167         {
00168           bits <<= 6;
00169         }
00170     }
00171 
00172   int errors = 0;
00173   if ( i == input_len)
00174     {
00175       if (char_count)
00176         {
00177           ACE_ERROR ((LM_ERROR,
00178                       ACE_TEXT ("Decoding incomplete: atleast %d bits truncated\n"),
00179                       (4 - char_count) * 6));
00180           ++errors;
00181         }
00182     }
00183   else
00184     {
00185       switch (char_count)
00186         {
00187         case 1:
00188           ACE_ERROR ((LM_ERROR,
00189                       ACE_TEXT ("Decoding incomplete: atleast 2 bits missing\n")));
00190           ++errors;
00191           break;
00192         case 2:
00193           result[pos++] = static_cast<ACE_Byte> (bits >> 10);
00194           break;
00195         case 3:
00196           result[pos++] = static_cast<ACE_Byte> (bits >> 16);
00197           result[pos++] = static_cast<ACE_Byte> ((bits >> 8) & 0xff);
00198           break;
00199         }
00200     }
00201 
00202   if (errors)
00203     {
00204       delete[] result;
00205       return 0;
00206     }
00207   result[pos] = 0;
00208   *output_len = pos;
00209   return result;
00210 }

ACE_Byte * ACE_Base64::encode (  const ACE_Byte *  input,
const size_t  input_len,
size_t *  output_len
)  [static]
 

Encodes a stream of bytes to Base64 data

Parameters:
input Binary data in byte stream.
input_len Length of the byte stream.
output_len Length of the encoded Base64 byte stream.
Returns:
Encoded Base64 data in byte stream or NULL if input data cannot be encoded.

Definition at line 38 of file Codecs.cpp.

References ACE_Byte, ACE_NEW_RETURN, alphabet, init(), init_, max_columns, and pad. 

00041 {
00042   if (!ACE_Base64::init_)
00043     ACE_Base64::init();
00044 
00045   if (!input)
00046     return 0;
00047 
00048   ACE_Byte* result = 0;
00049 
00050   size_t length = ((input_len + 2) / 3) * 4;
00051   size_t num_lines = length / max_columns + 1;
00052   length += num_lines + 1;
00053   ACE_NEW_RETURN (result, ACE_Byte[length], 0);
00054 
00055   int char_count = 0;
00056   int bits = 0;
00057   size_t pos = 0;
00058   int cols = 0;
00059 
00060   for (size_t i = 0; i < input_len; ++i)
00061     {
00062       bits += input[i];
00063       ++char_count;
00064 
00065       if (char_count == 3)
00066         {
00067           result[pos++] = alphabet[bits >> 18];
00068           result[pos++] = alphabet[(bits >> 12) & 0x3f];
00069           result[pos++] = alphabet[(bits >> 6) & 0x3f];
00070           result[pos++] = alphabet[bits & 0x3f];
00071           cols += 4;
00072           if (cols == max_columns) {
00073             result[pos++] = '\n';
00074             cols = 0;
00075           }
00076           bits = 0;
00077           char_count = 0;
00078         }
00079       else
00080         {
00081           bits <<= 8;
00082         }
00083     }
00084 
00085   if (char_count != 0)
00086     {
00087       bits <<= (16 - (8 * char_count));
00088       result[pos++] = alphabet[bits >> 18];
00089       result[pos++] = alphabet[(bits >> 12) & 0x3f];
00090       if (char_count == 1)
00091         {
00092           result[pos++] = pad;
00093           result[pos++] = pad;
00094         }
00095       else
00096         {
00097           result[pos++] = alphabet[(bits >> 6) & 0x3f];
00098           result[pos++] = pad;
00099         }
00100       if (cols > 0)
00101         result[pos++] = '\n';
00102     }
00103   result[pos] = 0;
00104   *output_len = pos;
00105   return result;
00106 }

void ACE_Base64::init (  void   )  [static, private]
 

Initialize the tables for encoding/decoding.

Definition at line 213 of file Codecs.cpp.

References ACE_Byte, alphabet, decoder_, init_, and member_.

Referenced by decode(), encode(), and length(). 

00214 {
00215   if (!ACE_Base64::init_)
00216     {
00217       for (ACE_Byte i = 0; i < sizeof (alphabet); ++i)
00218         {
00219           ACE_Base64::decoder_[alphabet[i]] = i;
00220           ACE_Base64::member_ [alphabet[i]] = 1;
00221         }
00222       ACE_Base64::init_ = true;
00223     }
00224   return;
00225 }

size_t ACE_Base64::length (  const ACE_Byte *  input  )  [static]
 

Return the length of the encoded input data

Parameters:
input Encoded Base64 data in byte stream.
Returns:
Length of the encoded Base64 data.

Definition at line 109 of file Codecs.cpp.

References ACE_Byte, ACE_OS::ace_isspace(), init(), init_, member_, and pad.

Referenced by decode(). 

00110 {
00111   if (!ACE_Base64::init_)
00112     ACE_Base64::init();
00113 
00114   ACE_Byte* ptr = const_cast<ACE_Byte*> (input);
00115   while (*ptr != 0 &&
00116          (member_[*(ptr)] == 1 || *ptr == pad
00117           || ACE_OS::ace_isspace (*ptr)))
00118     ++ptr;
00119   size_t len = ptr - input;
00120   len = ((len + 3) / 4) * 3 + 1 ;
00121   return len;
00122 }

ACE_Base64& ACE_Base64::operator= (  ACE_Base64 const &   )  [private]
 

Member Data Documentation

ACE_Byte ACE_Base64::decoder_ [static, private]
 

Alphabet used for decoding i.e decoder_[alphabet_[i = 0..63]] = i.

Definition at line 33 of file Codecs.cpp.

Referenced by decode(), and init().

ACE_BEGIN_VERSIONED_NAMESPACE_DECL bool ACE_Base64::init_ = false [static, private]
 

Boolean to denote whether initialization is complete.

Definition at line 31 of file Codecs.cpp.

Referenced by decode(), encode(), init(), and length().

ACE_Byte ACE_Base64::member_ [static, private]
 

Alphabet used to check valid range of encoded input i.e member_[alphabet_[0..63]] = 1

Definition at line 35 of file Codecs.cpp.

Referenced by decode(), init(), and length().

The documentation for this class was generated from the following files:
Generated on Sun Jan 27 12:54:06 2008 for ACE by doxygen 1.3.6