Simplify base32/base64 by moving common logic to code_base.h

3 files changed, 73 insertions, 72 deletions

diff --git a/src/lib/codec/base32/base32.cpp b/src/lib/codec/base32/base32.cpp
index e2eaf4095..fc9883c86 100644
--- a/src/lib/codec/base32/base32.cpp
+++ b/src/lib/codec/base32/base32.cpp
@@ -1,13 +1,13 @@
 /*
 * Base32 Encoding and Decoding
 * (C) 2018 Erwan Chaussy
+* (C) 2018 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
 #include <botan/base32.h>
 #include <botan/internal/codec_base.h>
-#include <botan/exceptn.h>
 #include <botan/internal/rounding.h>
 
 namespace Botan {
@@ -17,6 +17,11 @@ namespace {
 class Base32 final
    {
    public:
+      static inline std::string name() noexcept
+         {
+         return "base32";
+         }
+
       static inline size_t encoding_bytes_in() noexcept
          {
          return m_encoding_bytes_in;
@@ -175,23 +180,7 @@ size_t base32_encode(char out[],
 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;
+   return base_encode_to_string(Base32(), input, input_length);
    }
 
 size_t base32_decode(uint8_t out[],
@@ -209,14 +198,7 @@ size_t base32_decode(uint8_t output[],
                      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;
+   return base_decode_full(Base32(), output, input, input_length, ignore_ws);
    }
 
 size_t base32_decode(uint8_t output[],
@@ -230,16 +212,7 @@ 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;
+   return base_decode_to_vec<secure_vector<uint8_t>>(Base32(), input, input_length, ignore_ws);
    }
 
 secure_vector<uint8_t> base32_decode(const std::string& input,
diff --git a/src/lib/codec/base64/base64.cpp b/src/lib/codec/base64/base64.cpp
index 1f7937727..b4f78bca0 100644
--- a/src/lib/codec/base64/base64.cpp
+++ b/src/lib/codec/base64/base64.cpp
@@ -17,6 +17,11 @@ namespace {
 class Base64 final
    {
    public:
+      static inline std::string name() noexcept
+         {
+         return "base64";
+         }
+
       static inline size_t encoding_bytes_in() noexcept
          {
          return m_encoding_bytes_in;
@@ -170,23 +175,7 @@ size_t base64_encode(char out[],
 std::string base64_encode(const uint8_t input[],
                           size_t input_length)
    {
-   const size_t output_length = Base64::encode_max_output(input_length);
-   std::string output(output_length, 0);
-
-   size_t consumed = 0;
-   size_t produced = 0;
-   
-   if(output_length > 0)
-      {
-      produced = base64_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;
+   return base_encode_to_string(Base64(), input, input_length);
    }
 
 size_t base64_decode(uint8_t out[],
@@ -204,14 +193,7 @@ size_t base64_decode(uint8_t output[],
                      size_t input_length,
                      bool ignore_ws)
    {
-   size_t consumed = 0;
-   size_t written = base64_decode(output, input, input_length,
-                                  consumed, true, ignore_ws);
-
-   if(consumed != input_length)
-      { throw Invalid_Argument("base64_decode: input did not have full bytes"); }
-
-   return written;
+   return base_decode_full(Base64(), output, input, input_length, ignore_ws);
    }
 
 size_t base64_decode(uint8_t output[],
@@ -225,16 +207,7 @@ secure_vector<uint8_t> base64_decode(const char input[],
                                      size_t input_length,
                                      bool ignore_ws)
    {
-   const size_t output_length = Base64::decode_max_output(input_length);
-   secure_vector<uint8_t> bin(output_length);
-
-   size_t written = base64_decode(bin.data(),
-                                  input,
-                                  input_length,
-                                  ignore_ws);
-
-   bin.resize(written);
-   return bin;
+   return base_decode_to_vec<secure_vector<uint8_t>>(Base64(), input, input_length, ignore_ws);
    }
 
 secure_vector<uint8_t> base64_decode(const std::string& input,
diff --git a/src/lib/utils/codec_base.h b/src/lib/utils/codec_base.h
index e7dbc33e4..2338fdfd7 100644
--- a/src/lib/utils/codec_base.h
+++ b/src/lib/utils/codec_base.h
@@ -1,6 +1,7 @@
 /*
 * Base Encoding and Decoding
 * (C) 2018 Erwan Chaussy
+* (C) 2018 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -9,6 +10,7 @@
 #define BOTAN_BASE_CODEC_H_
 
 #include <botan/secmem.h>
+#include <botan/exceptn.h>
 #include <vector>
 #include <string>
 
@@ -79,10 +81,33 @@ size_t base_encode(Base&& base,
    return output_produced;
    }
 
+
+template <typename Base>
+std::string base_encode_to_string(Base&& base, const uint8_t input[], size_t input_length)
+   {
+   const size_t output_length = base.encode_max_output(input_length);
+   std::string output(output_length, 0);
+
+   size_t consumed = 0;
+   size_t produced = 0;
+
+   if(output_length > 0)
+      {
+      produced = base_encode(base, &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;
+   }
+
 /**
 * Perform decoding using the base provided
 * @param base object giving access to the encodings specifications
-* @param output an array of at least base.decode_max_output bytes
+* @param output an array of at least Base::decode_max_output bytes
 * @param input some base input
 * @param input_length length of input in bytes
 * @param input_consumed is an output parameter which says how many
@@ -160,6 +185,36 @@ size_t base_decode(Base&& base,
    return written;
    }
 
+template<typename Base>
+size_t base_decode_full(Base&& base, uint8_t output[], const char input[], size_t input_length, bool ignore_ws)
+   {
+   size_t consumed = 0;
+   const size_t written = base_decode(base, output, input, input_length, consumed, true, ignore_ws);
+
+   if(consumed != input_length)
+      {
+      throw Invalid_Argument(base.name() + " decoding failed, input did not have full bytes");
+      }
+
+   return written;
+   }
+
+template<typename Vector, typename Base>
+Vector base_decode_to_vec(Base&& base,
+                          const char input[],
+                          size_t input_length,
+                          bool ignore_ws)
+   {
+   const size_t output_length = base.decode_max_output(input_length);
+   Vector bin(output_length);
+
+   const size_t written =
+      base_decode_full(base, bin.data(), input, input_length, ignore_ws);
+
+   bin.resize(written);
+   return bin;
+   }
+
 }
 
 #endif