Base64 Decode impl test

1 files changed, 50 insertions, 35 deletions

diff --git a/modules/codec/c++/base64.hpp b/modules/codec/c++/base64.hpp
index 4c9ae18..56ba79e 100644
--- a/modules/codec/c++/base64.hpp
+++ b/modules/codec/c++/base64.hpp
@@ -40,7 +40,7 @@ public:
 };
 
 namespace impl {
-constexpr char base64_char_map[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+constexpr std::string_view base64_char_map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 }
 
 template<>
@@ -48,6 +48,23 @@ class codec<schema::String, encode::Base64> {
 public:
 	using Schema = schema::String;
 private:
+	bool is_base64(char a) const {
+		for(auto iter : impl::base64_char_map){
+			if(iter == a){
+				return true;
+			}
+		}
+		return false;
+	}
+
+	error_or<uint8_t> find_base64_char_pos(char a) const {
+		for(uint8_t i = 0; i < impl::base64_char_map.size(); ++i){
+			if(impl::base64_char_map.at(i) == a){
+				return i;
+			}
+		}
+		return make_error<err::not_found>("Didn't find base64 char");
+	}
 public:
 	template<typename FromEncode>
 	static error_or<void> encode(const data<Schema, FromEncode>& from, data<Schema,encode::Base64>& to){
@@ -68,10 +85,10 @@ public:
 			s[j] = from.at(i);
 			++j;
 			if(j==3){
-				b64_str.at(k) = impl::base64_char_map[(s[0u] & 0xFC) >> 2];
-				b64_str.at(k+1u) = impl::base64_char_map[((s[0u] & 0x03) << 4) | ((s[1] & 0xF0) >> 4)];
-				b64_str.at(k+2u) = impl::base64_char_map[((s[1u] & 0x0F) << 2) | ((s[2] & 0xC0) >> 6)];
-				b64_str.at(k+3u) = impl::base64_char_map[(s[2u] & 0x3F)];
+				b64_str.at(k) = impl::base64_char_map.at((s[0u] & 0xFC) >> 2);
+				b64_str.at(k+1u) = impl::base64_char_map.at(((s[0u] & 0x03) << 4) | ((s[1] & 0xF0) >> 4));
+				b64_str.at(k+2u) = impl::base64_char_map.at(((s[1u] & 0x0F) << 2) | ((s[2] & 0xC0) >> 6));
+				b64_str.at(k+3u) = impl::base64_char_map.at((s[2u] & 0x3F));
 				j = 0u;
 				k+=4u;
 			}
@@ -82,14 +99,14 @@ public:
 				s[1u] = 0u;
 			}
 
-			b64_str.at(k+0u) = impl::base64_char_map[(s[0u] & 0xFF) >> 2];
-			b64_str.at(k+1u) = impl::base64_char_map[((s[0u] & 0x03)<<4) + ((s[1u]&0xF0)>>4)];
+			b64_str.at(k+0u) = impl::base64_char_map.at((s[0u] & 0xFC) >> 2);
+			b64_str.at(k+1u) = impl::base64_char_map.at(((s[0u] & 0x03)<<4) + ((s[1u]&0xF0)>>4));
 			if(j == 2u){
-				b64_str[k+2u] = impl::base64_char_map[ ((s[1u]&0x0F)<<2) ];
+				b64_str.at(k+2u) = impl::base64_char_map.at( ((s[1u]&0x0F)<<2) );
 			}else {
-				b64_str[k+2u] = '=';
+				b64_str.at(k+2u) = '=';
 			}
-			b64_str[k+3u] = '=';
+			b64_str.at(k+3u) = '=';
 		}
 
 		to = {std::move(b64_str)};
@@ -98,41 +115,39 @@ public:
 
 	template<typename ToDecode>
 	static error_or<void> decode(data<Schema,encode::Base64>& from, data<Schema, ToDecode>& to){
-		return make_error<err::not_implemented>();
-		/*
 		uint64_t b64_len = from.size();
 		if((b64_len % 4) != 0){
-			return make_error<err::invalid_state>("B64 is not padded");
+			return make_error<err::invalid_state>("Base64 String is not padded");
 		}
-		uint64_t section_len = b64_len / 4u;
 
+		uint64_t j{0u};
+		std::array<uint8_t,3> s{};
+		std::array<uint8_t,4> t{};
 		std::string to_str;
 
-		for(uint64_t i = 0u; i < section_len; ++i){
-			uint64_t j = 4u*i;
-
-			std::array<char,3> to_bits{0,0,0};
-			std::array<char,4> from_bits{
-				from.at(j).get(),
-				from.at(j+1u).get(),
-				from.at(j+2u).get(),
-				from.at(j+3u).get()
-			};
-
-			for(char iter : from_bits){
-				if(!is_base64(iter)){
-					return make_error<err::invalid_state>("Not a base64 char");
-				}
+		for(uint64_t i = 0u; i < b64_len && from.at(i) != '='; ++i){
+			auto eo_pos = find_base64_char_pos(from.at(i));
+			if(eo_pos.is_error()){
+				return std::move(eo_pos.get_error());
+			}
+			t[j] = eo_pos.get_value();
+
+			++j;
+			if(j == 4u){
+				s[0u] = (t[0u] << 2) + ((t[1] & 0x30) >> 4);
+				s[1u] = ((s[1u] & 0x0F) << 4) + ((s[2u] & 0x3c) >> 2);
+				s[2u] = ((s[2u] & 0x03) << 6) + s[3u];
+
+				to_str += s[0u];
+				to_str += s[1u];
+				to_str += s[2u];
+
+				j = 0u;
 			}
-			
-			to_bits[0] = char_array			
 		}
 
 		to = {std::move(to_str)};
-
-		return saw::make_void();
-		*/
+		return make_void();
 	}
-
 };
 }