@@ -12,6 +12,7 @@

 #include <bitset>

 #include <unordered_map>

 #include <memory>

+#include <iostream>

 #include "base32.h"

@@ -27,7 +28,7 @@ namespace

 class base32_impl : public base32_ifc

 {

 private:

-    uint64_t calculate_padding_bytes (uint64_t extra_bytes)

+    uint64_t calculate_padding_bytes (uint64_t extra_bytes) const

     {

         auto padding_chars = 0;

@@ -52,7 +53,7 @@ private:

         return padding_chars;

     }

-    std::string &pad_string (uint64_t extra_bytes, std::string &input)

+    std::string &pad_string (uint64_t extra_bytes, std::string &input) const

     {

         auto padding_chars = calculate_padding_bytes (extra_bytes);

@@ -68,7 +69,7 @@ private:

     }

 public:

-    std::string encode (const std::vector<uint8_t> data) override

+    std::string encode (const std::vector<uint8_t> data) const override

     {

         std::string result;

@@ -117,7 +118,7 @@ public:

 private:

-    std::unordered_map <char, unsigned char> construct_lookup_table()

+    std::unordered_map <char, unsigned char> construct_lookup_table() const

     {

         std::unordered_map<char, unsigned char> lookup_table;

@@ -129,7 +130,7 @@ private:

     }

     std::pair<uint8_t, uint8_t> split_value (uint8_t item, uint8_t pos,

-            uint8_t width)

+            uint8_t width) const

     {

         auto shift = width-pos;

         uint8_t part2_mask = (1 << (shift)) - 1;

@@ -140,7 +141,7 @@ private:

     void set_vector_at_bit (std::vector<uint8_t> &data, uint8_t item,

                             std::vector<uint8_t>::size_type byte_offset, uint8_t bit_offset_from_start,

-                            uint8_t width)

+                            uint8_t width) const

     {

         bool need_to_split = bit_offset_from_start + width > 8;

         uint8_t bit_offset_from_end = 7 - bit_offset_from_start;

@@ -159,7 +160,7 @@ private:

         }

     }

-    std::string::size_type calculate_decoded_size (std::string input)

+    std::string::size_type calculate_decoded_size (std::string input) const

     {

         std::string::size_type input_size = input.size();

         std::string::size_type first_equals = input.find_first_of ('=');

@@ -173,8 +174,9 @@ private:

 public:

-    std::vector<uint8_t> decode (std::string input) override

+    std::vector<uint8_t> decode (std::string input) const override

     {

+        //TODO: where to pad input to required size?

         auto lookup_table = construct_lookup_table();

         auto input_size = calculate_decoded_size (input);

@@ -193,6 +195,8 @@ public:

             bits_written += 5;

         }

+

+

         return result;

     }

 };

@@ -19,8 +19,8 @@

 class base32_ifc

 {

 public:

-    virtual std::string encode (std::vector<uint8_t> input) = 0;

-    virtual std::vector<uint8_t> decode (std::string input) = 0;

+    virtual std::string encode (std::vector<uint8_t> input) const = 0;

+    virtual std::vector<uint8_t> decode (std::string input) const = 0;

 };

 class base32

@@ -32,16 +32,15 @@ private:

 public:

     base32 ();

-    std::string encode (std::vector<uint8_t> input)

+    std::string encode (std::vector<uint8_t> input) const

     {

         return delegate_->encode (input);

     };

-    std::vector<uint8_t> decode (std::string input)

+    std::vector<uint8_t> decode (std::string input) const

     {

         return delegate_->decode (input);

     };

 };

 #endif

-

@@ -58,6 +58,18 @@ int precomputed_values()

     succeed();

 }

+int decode_validates_input()

+{

+    // given

+    // The token for key 76I6WTYEUTNCJUREMGKVM45PMA and time '2017/01/01 00:00:00' is 258675

+    base32 codec = base32();

+

+    std::vector<uint8_t> result = codec.decode("\x00");

+    check(result.empty(), "invalid input doesn't produce an empty result");

+

+    succeed();

+}

+

 int roundtrip()

 {

     // given

@@ -66,7 +78,6 @@ int roundtrip()

         { 5, 5, 5, 5, 5, 5, }, { 6, 6, 6, 6, 6, 6, 6, }

     };

-    // The token for key 76I6WTYEUTNCJUREMGKVM45PMA and time '2017/01/01 00:00:00' is 258675

     base32 codec = base32();

     for (auto expected: values) {

@@ -82,6 +93,7 @@ int roundtrip()

 int run_tests()

 {

     test (precomputed_values);

+    test (decode_validates_input);

     test (roundtrip);

     succeed();

 }

@@ -90,4 +102,3 @@ int main (int argc, char *argv[])

 {

     return !run_tests();

 }

-