Hashing: Redo API

* Don't assume the printable output of hashes is hex
* Add virtual Compare() function, usable for KDFs like BCrypt

Some changes and bugfixes are by @attilamolnar, original PR #767

1 files changed, 24 insertions, 10 deletions

diff --git a/include/modules/hash.h b/include/modules/hash.h
index da04c45ba..7d46ee74a 100644
--- a/include/modules/hash.h
+++ b/include/modules/hash.h
@@ -26,24 +26,33 @@ class HashProvider : public DataProvider
  public:
 	const unsigned int out_size;
 	const unsigned int block_size;
-	HashProvider(Module* mod, const std::string& Name, int osiz, int bsiz)
-		: DataProvider(mod, Name), out_size(osiz), block_size(bsiz) {}
-	virtual std::string sum(const std::string& data) = 0;
-	inline std::string hexsum(const std::string& data)
+	HashProvider(Module* mod, const std::string& Name, unsigned int osiz = 0, unsigned int bsiz = 0)
+		: DataProvider(mod, "hash/" + Name), out_size(osiz), block_size(bsiz)
 	{
-		return BinToHex(sum(data));
 	}
 
-	inline std::string b64sum(const std::string& data)
+	virtual std::string GenerateRaw(const std::string& data) = 0;
+
+	virtual std::string ToPrintable(const std::string& raw)
+	{
+		return BinToHex(raw);
+	}
+
+	virtual bool Compare(const std::string& input, const std::string& hash)
+	{
+		return InspIRCd::TimingSafeCompare(Generate(input), hash);
+	}
+
+	std::string Generate(const std::string& data)
 	{
-		return BinToBase64(sum(data), NULL, 0);
+		return ToPrintable(GenerateRaw(data));
 	}
 
 	/** HMAC algorithm, RFC 2104 */
 	std::string hmac(const std::string& key, const std::string& msg)
 	{
 		std::string hmac1, hmac2;
-		std::string kbuf = key.length() > block_size ? sum(key) : key;
+		std::string kbuf = key.length() > block_size ? GenerateRaw(key) : key;
 		kbuf.resize(block_size);
 
 		for (size_t n = 0; n < block_size; n++)
@@ -52,7 +61,12 @@ class HashProvider : public DataProvider
 			hmac2.push_back(static_cast<char>(kbuf[n] ^ 0x36));
 		}
 		hmac2.append(msg);
-		hmac1.append(sum(hmac2));
-		return sum(hmac1);
+		hmac1.append(GenerateRaw(hmac2));
+		return GenerateRaw(hmac1);
+	}
+
+	bool IsKDF() const
+	{
+		return (!block_size);
 	}
 };