Implement Base32

3 files changed, 417 insertions, 0 deletions

diff --git a/src/lib/codec/base32/base32.cpp b/src/lib/codec/base32/base32.cpp
new file mode 100644
index 000000000..71c0e1e3d
--- /dev/null
+++ b/src/lib/codec/base32/base32.cpp
@@ -0,0 +1,273 @@
+/*
+* Base32 Encoding and Decoding
+* (C) 2018 Erwan Chaussy
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/base32.h>
+#include <botan/exceptn.h>
+#include <botan/mem_ops.h>
+#include <botan/internal/rounding.h>
+
+namespace Botan {
+
+namespace {
+
+static const uint8_t BIN_TO_BASE32[32] =
+   {
+   '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',
+   '2', '3', '4', '5', '6', '7'
+   };
+
+void do_base32_encode(char out[8], const uint8_t in[5])
+   {
+   out[0] = BIN_TO_BASE32[(in[0] & 0xF8) >> 3];
+   out[1] = BIN_TO_BASE32[((in[0] & 0x07) << 2) | (in[1] >> 6)];
+   out[2] = BIN_TO_BASE32[((in[1] & 0x3E) >> 1)];
+   out[3] = BIN_TO_BASE32[((in[1] & 0x01) << 4) | (in[2] >> 4)];
+   out[4] = BIN_TO_BASE32[((in[2] & 0x0F) << 1) | (in[3] >> 7)];
+   out[5] = BIN_TO_BASE32[((in[3] & 0x7C) >> 2)];
+   out[6] = BIN_TO_BASE32[((in[3] & 0x03) << 3) | (in[4] >> 5)];
+   out[7] = BIN_TO_BASE32[in[4] & 0x1F];
+   }
+
+}
+
+size_t base32_encode(char out[],
+                     const uint8_t 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 >= 5)
+      {
+      do_base32_encode(out + output_produced, in + input_consumed);
+
+      input_consumed += 5;
+      output_produced += 8;
+      input_remaining -= 5;
+      }
+
+   if(final_inputs && input_remaining)
+      {
+      uint8_t remainder[5] = {0};
+      for(size_t i = 0; i != input_remaining; ++i)
+         { remainder[i] = in[input_consumed + i]; }
+
+      do_base32_encode(out + output_produced, remainder);
+
+      size_t empty_bits = 8 * (5 - input_remaining);
+      size_t index      = output_produced + 8 - 1;
+      while(empty_bits >= 6)
+         {
+         out[index--] = '=';
+         empty_bits -= 5;
+         }
+
+      input_consumed += input_remaining;
+      output_produced += 8;
+      }
+
+   return output_produced;
+   }
+
+std::string base32_encode(const uint8_t input[],
+                          size_t input_length)
+   {
+   const size_t output_length = base32_encode_max_output(input_length);
+   std::string output(output_length, 0);
+
+   size_t consumed = 0;
+   size_t produced = 0;
+
+   if(output_length > 0)
+      {
+      produced = base32_encode(&output.front(),
+                               input, input_length,
+                               consumed, true);
+      }
+
+   BOTAN_ASSERT_EQUAL(consumed, input_length, "Consumed the entire input");
+   BOTAN_ASSERT_EQUAL(produced, output.size(), "Produced expected size");
+
+   return output;
+   }
+
+size_t base32_decode(uint8_t output[],
+                     const char input[],
+                     size_t input_length,
+                     size_t& input_consumed,
+                     bool final_inputs,
+                     bool ignore_ws)
+   {
+   /*
+   * base32 Decoder Lookup Table
+   * Warning: assumes ASCII encodings
+   */
+   static const uint8_t BASE32_TO_BIN[256] =
+      {
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80,
+      0x80, 0xFF, 0xFF, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0x81, 0xFF, 0xFF, 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04,
+      0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+      0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+      0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+      };
+
+   uint8_t* out_ptr = output;
+   uint8_t decode_buf[8];
+   size_t decode_buf_pos = 0;
+   size_t final_truncate = 0;
+
+   clear_mem(output, input_length * 5 / 8);
+
+   for(size_t i = 0; i != input_length; ++i)
+      {
+      const uint8_t bin = BASE32_TO_BIN[static_cast<uint8_t>(input[i])];
+
+      if(bin <= 0x1F)
+         {
+         decode_buf[decode_buf_pos] = bin;
+         decode_buf_pos += 1;
+         }
+      else if(!(bin == 0x81 || (bin == 0x80 && ignore_ws)))
+         {
+         std::string bad_char(1, input[i]);
+         if(bad_char == "\t")
+            { bad_char = "\\t"; }
+         else if(bad_char == "\n")
+            { bad_char = "\\n"; }
+         else if(bad_char == "\r")
+            { bad_char = "\\r"; }
+
+         throw Invalid_Argument(
+            std::string("base32_decode: invalid base32 character '") +
+            bad_char + "'");
+         }
+
+      /*
+      * If we're at the end of the input, pad with 0s and truncate
+      */
+      if(final_inputs && (i == input_length - 1))
+         {
+         if(decode_buf_pos)
+            {
+            for(size_t j = decode_buf_pos; j != 8; ++j)
+               { decode_buf[j] = 0; }
+            final_truncate = 8 - decode_buf_pos;
+            decode_buf_pos = 8;
+            }
+         }
+
+      if(decode_buf_pos == 8)
+         {
+         out_ptr[0] = (decode_buf[0] << 3) | (decode_buf[1] >> 2);
+         out_ptr[1] = (decode_buf[1] << 6) | (decode_buf[2] << 1) | (decode_buf[3] >> 4);
+         out_ptr[2] = (decode_buf[3] << 4) | (decode_buf[4] >> 1);
+         out_ptr[3] = (decode_buf[4] << 7) | (decode_buf[5] << 2) | (decode_buf[6] >> 3);
+         out_ptr[4] = (decode_buf[6] << 5) | decode_buf[7];
+
+         out_ptr += 5;
+         decode_buf_pos = 0;
+         input_consumed = i + 1;
+         }
+      }
+
+   while(input_consumed < input_length &&
+         BASE32_TO_BIN[static_cast<uint8_t>(input[input_consumed])] == 0x80)
+      {
+      ++input_consumed;
+      }
+
+   size_t written = (out_ptr - output);
+
+   if(final_truncate)
+      {
+      written -= (final_truncate / 2) + 1;
+      }
+
+   return written;
+   }
+
+size_t base32_decode(uint8_t output[],
+                     const char input[],
+                     size_t input_length,
+                     bool ignore_ws)
+   {
+   size_t consumed = 0;
+   size_t written = base32_decode(output, input, input_length,
+                                  consumed, true, ignore_ws);
+
+   if(consumed != input_length)
+      { throw Invalid_Argument("base32_decode: input did not have full bytes"); }
+
+   return written;
+   }
+
+size_t base32_decode(uint8_t output[],
+                     const std::string& input,
+                     bool ignore_ws)
+   {
+   return base32_decode(output, input.data(), input.length(), ignore_ws);
+   }
+
+secure_vector<uint8_t> base32_decode(const char input[],
+                                     size_t input_length,
+                                     bool ignore_ws)
+   {
+   const size_t output_length = base32_decode_max_output(input_length);
+   secure_vector<uint8_t> bin(output_length);
+
+   size_t written = base32_decode(bin.data(),
+                                  input,
+                                  input_length,
+                                  ignore_ws);
+
+   bin.resize(written);
+   return bin;
+   }
+
+secure_vector<uint8_t> base32_decode(const std::string& input,
+                                     bool ignore_ws)
+   {
+   return base32_decode(input.data(), input.size(), ignore_ws);
+   }
+
+size_t base32_encode_max_output(size_t input_length)
+   {
+   return (round_up(input_length, 5) / 5) * 8;
+   }
+
+size_t base32_decode_max_output(size_t input_length)
+   {
+   return (round_up(input_length, 8) * 5) / 8;
+   }
+
+}
diff --git a/src/lib/codec/base32/base32.h b/src/lib/codec/base32/base32.h
new file mode 100644
index 000000000..b3f138b00
--- /dev/null
+++ b/src/lib/codec/base32/base32.h
@@ -0,0 +1,141 @@
+/*
+* Base32 Encoding and Decoding
+* (C) 2018 Erwan Chaussy
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_BASE32_CODEC_H_
+#define BOTAN_BASE32_CODEC_H_
+
+#include <botan/secmem.h>
+#include <string>
+
+namespace Botan {
+
+/**
+* Perform base32 encoding
+* @param output an array of at least base32_encode_max_output 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_PUBLIC_API(2, 7) base32_encode(char output[],
+      const uint8_t input[],
+      size_t input_length,
+      size_t& input_consumed,
+      bool final_inputs);
+
+/**
+* Perform base32 encoding
+* @param input some input
+* @param input_length length of input in bytes
+* @return base32adecimal representation of input
+*/
+std::string BOTAN_PUBLIC_API(2, 7) base32_encode(const uint8_t input[],
+      size_t input_length);
+
+/**
+* Perform base32 encoding
+* @param input some input
+* @return base32adecimal representation of input
+*/
+template <typename Alloc>
+std::string base32_encode(const std::vector<uint8_t, Alloc>& input)
+   {
+   return base32_encode(input.data(), input.size());
+   }
+
+/**
+* Perform base32 decoding
+* @param output an array of at least base32_decode_max_output bytes
+* @param input some base32 input
+* @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 is allowed
+* @param ignore_ws ignore whitespace on input; if false, throw an
+                   exception if whitespace is encountered
+* @return number of bytes written to output
+*/
+size_t BOTAN_PUBLIC_API(2, 7) base32_decode(uint8_t output[],
+      const char input[],
+      size_t input_length,
+      size_t& input_consumed,
+      bool final_inputs,
+      bool ignore_ws = true);
+
+/**
+* Perform base32 decoding
+* @param output an array of at least base32_decode_max_output bytes
+* @param input some base32 input
+* @param input_length length of input in bytes
+* @param ignore_ws ignore whitespace on input; if false, throw an
+                   exception if whitespace is encountered
+* @return number of bytes written to output
+*/
+size_t BOTAN_PUBLIC_API(2, 7) base32_decode(uint8_t output[],
+      const char input[],
+      size_t input_length,
+      bool ignore_ws = true);
+
+/**
+* Perform base32 decoding
+* @param output an array of at least base32_decode_max_output bytes
+* @param input some base32 input
+* @param ignore_ws ignore whitespace on input; if false, throw an
+                   exception if whitespace is encountered
+* @return number of bytes written to output
+*/
+size_t BOTAN_PUBLIC_API(2, 7) base32_decode(uint8_t output[],
+      const std::string& input,
+      bool ignore_ws = true);
+
+/**
+* Perform base32 decoding
+* @param input some base32 input
+* @param input_length the length of input in bytes
+* @param ignore_ws ignore whitespace on input; if false, throw an
+                   exception if whitespace is encountered
+* @return decoded base32 output
+*/
+secure_vector<uint8_t> BOTAN_PUBLIC_API(2, 7) base32_decode(const char input[],
+      size_t input_length,
+      bool ignore_ws = true);
+
+/**
+* Perform base32 decoding
+* @param input some base32 input
+* @param ignore_ws ignore whitespace on input; if false, throw an
+                   exception if whitespace is encountered
+* @return decoded base32 output
+*/
+secure_vector<uint8_t> BOTAN_PUBLIC_API(2, 7) base32_decode(const std::string& input,
+      bool ignore_ws = true);
+
+/**
+* Calculate the size of output buffer for base32_encode
+* @param input_length the length of input in bytes
+* @return the size of output buffer in bytes
+*/
+size_t BOTAN_PUBLIC_API(2, 7) base32_encode_max_output(size_t input_length);
+
+/**
+* Calculate the size of output buffer for base32_decode
+* @param input_length the length of input in bytes
+* @return the size of output buffer in bytes
+*/
+size_t BOTAN_PUBLIC_API(2, 7) base32_decode_max_output(size_t input_length);
+
+} // namespace Botan
+
+#endif
diff --git a/src/lib/codec/base32/info.txt b/src/lib/codec/base32/info.txt
new file mode 100644
index 000000000..8e414c5a3
--- /dev/null
+++ b/src/lib/codec/base32/info.txt
@@ -0,0 +1,3 @@
+<defines>
+BASE32_CODEC -> 20180418
+</defines>