Simple standalone base64 encoder

3 files changed, 159 insertions, 0 deletions

diff --git a/src/codec/base64/base64.cpp b/src/codec/base64/base64.cpp
new file mode 100644
index 000000000..96a686e38
--- /dev/null
+++ b/src/codec/base64/base64.cpp
@@ -0,0 +1,103 @@
+/*
+* Base64 Encoding and Decoding
+* (C) 2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/base64.h>
+#include <botan/mem_ops.h>
+#include <botan/internal/rounding.h>
+#include <stdexcept>
+
+#include <stdio.h>
+#include <assert.h>
+
+namespace Botan {
+
+namespace {
+
+static const byte BIN_TO_BASE64[64] = {
+   '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', '+', '/'
+};
+
+void do_base64_encode(char out[4], const byte in[3])
+   {
+   out[0] = BIN_TO_BASE64[((in[0] & 0xFC) >> 2)];
+   out[1] = BIN_TO_BASE64[((in[0] & 0x03) << 4) | (in[1] >> 4)];
+   out[2] = BIN_TO_BASE64[((in[1] & 0x0F) << 2) | (in[2] >> 6)];
+   out[3] = BIN_TO_BASE64[((in[2] & 0x3F)     )];
+   }
+
+}
+
+size_t base64_encode(char out[],
+                     const byte in[],
+                     size_t input_length,
+                     size_t& input_consumed,
+                     bool final_inputs)
+   {
+   input_consumed = 0;
+
+   size_t input_remaining = input_length;
+   size_t output_produced = 0;
+
+   while(input_remaining >= 3)
+      {
+      do_base64_encode(out + output_produced, in + input_consumed);
+
+      input_consumed += 3;
+      output_produced += 4;
+      input_remaining -= 3;
+      }
+
+   if(final_inputs && input_remaining)
+      {
+      byte remainder[3] = { 0 };
+      for(size_t i = 0; i != input_remaining; ++i)
+         remainder[i] = in[input_consumed + i];
+
+      do_base64_encode(out + output_produced, remainder);
+
+      size_t empty_bits = 8 * (3 - input_remaining);
+      size_t index = output_produced + 4 - 1;
+      while(empty_bits >= 8)
+         {
+         out[index--] = '=';
+         empty_bits -= 6;
+         }
+
+      input_consumed += input_remaining;
+      output_produced += 4;
+      }
+
+   return output_produced;
+   }
+
+std::string base64_encode(const byte input[],
+                          size_t input_length)
+   {
+   std::string output((round_up<size_t>(input_length, 3) / 3) * 4, 0);
+
+   size_t consumed = 0;
+   size_t produced = base64_encode(&output[0],
+                                   input, input_length,
+                                   consumed, true);
+
+   assert(consumed == input_length);
+   assert(produced == output.size());
+
+   return output;
+   }
+
+std::string base64_encode(const MemoryRegion<byte>& input)
+   {
+   return base64_encode(&input[0], input.size());
+   }
+
+
+}
diff --git a/src/codec/base64/base64.h b/src/codec/base64/base64.h
new file mode 100644
index 000000000..551f3daf8
--- /dev/null
+++ b/src/codec/base64/base64.h
@@ -0,0 +1,55 @@
+/*
+* Base64 Encoding and Decoding
+* (C) 2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_BASE64_CODEC_H__
+#define BOTAN_BASE64_CODEC_H__
+
+#include <botan/secmem.h>
+#include <string>
+
+namespace Botan {
+
+/**
+* Perform base64 encoding
+* @param output an array of at least input_length*4/3 bytes
+* @param input is some binary data
+* @param input_length length of input in bytes
+* @param input_consumed is an output parameter which says how many
+*        bytes of input were actually consumed. If less than
+*        input_length, then the range input[consumed:length]
+*        should be passed in later along with more input.
+* @param final_inputs true iff this is the last input, in which case
+         padding chars will be applied if needed
+* @return number of bytes written to output
+*/
+size_t BOTAN_DLL base64_encode(char output[],
+                               const byte input[],
+                               size_t input_length,
+                               size_t& input_consumed,
+                               bool final_inputs);
+
+/**
+* Perform base64 encoding
+* @param input some input
+* @param input_length length of input in bytes
+* @param uppercase should output be upper or lower case?
+* @return base64adecimal representation of input
+*/
+std::string BOTAN_DLL base64_encode(const byte input[],
+                                    size_t input_length);
+
+/**
+* Perform base64 encoding
+* @param input some input
+* @param uppercase should output be upper or lower case?
+* @return base64adecimal representation of input
+*/
+std::string BOTAN_DLL base64_encode(const MemoryRegion<byte>& input);
+
+}
+
+#endif
diff --git a/src/codec/base64/info.txt b/src/codec/base64/info.txt
new file mode 100644
index 000000000..aed5db3b6
--- /dev/null
+++ b/src/codec/base64/info.txt
@@ -0,0 +1 @@
+define BASE64_CODEC