Add self-tests to the encryption providers.

include/modules/encryption.h

@@ -66,7 +66,18 @@ namespace Encryption
 		/** Checks whether a plain text value matches a hash created by this provider. */
 		virtual bool Compare(const Anope::string &hash, const Anope::string &plain)
 		{
-			return hash.equals_cs(plain);
+			return !hash.empty() && hash.equals_cs(ToPrintable(Encrypt(plain)));
+		}
+
+		/** Called on initialising a encryption provider to check it works properly. */
+		void Check(const Anope::map<Anope::string> &checks)
+		{
+			for (const auto &[hash, plain] : checks)
+			{
+				if (!Compare(hash, plain))
+					throw ModuleException("BUG: unable to generate " + this->name + " hashes safely! Please report this!");
+			}
+			Log(LOG_DEBUG) << "The " << this->name << " encryption provider appears to be working correctly.";
 		}
 
 		/** Creates a new encryption context. */
@@ -102,6 +113,12 @@ namespace Encryption
 
 			return Encrypt(hmac1);
 		}
+
+		/** Converts a hash to its printable form. */
+		virtual Anope::string ToPrintable(const Anope::string &hash)
+		{
+			return Anope::Hex(hash);
+		}
 	};
 
 	/** Helper template for creating simple providers of encryption contexts. */

modules/encryption/enc_md5.cpp

@@ -54,6 +54,11 @@ public:
 	{
 		if (ModuleManager::FindFirstOf(ENCRYPTION) == this)
 			throw ModuleException("enc_md5 is deprecated and can not be used as a primary encryption method");
+
+		md5provider.Check({
+			{ "d41d8cd98f00b204e9800998ecf8427e", "" },
+			{ "9e107d9d372bb6826bd81d3542a419d6", "The quick brown fox jumps over the lazy dog" },
+		});
 	}
 
 	EventReturn OnEncrypt(const Anope::string &src, Anope::string &dest) override

modules/encryption/enc_sha1.cpp

@@ -178,6 +178,11 @@ public:
 	{
 		if (ModuleManager::FindFirstOf(ENCRYPTION) == this)
 			throw ModuleException("enc_sha1 is deprecated and can not be used as a primary encryption method");
+
+		sha1provider.Check({
+			{ "da39a3ee5e6b4b0d3255bfef95601890afd80709", "" },
+			{ "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12", "The quick brown fox jumps over the lazy dog" },
+		});
 	}
 
 	EventReturn OnEncrypt(const Anope::string &src, Anope::string &dest) override

modules/encryption/enc_sha2.cpp

@@ -108,6 +108,22 @@ public:
 		, sha384provider(this, "sha384", SHA384_BLOCK_SIZE, SHA384_DIGEST_SIZE)
 		, sha512provider(this, "sha512", SHA512_BLOCK_SIZE, SHA512_DIGEST_SIZE)
 	{
+		sha224provider.Check({
+			{ "d14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f", "" },
+			{ "730e109bd7a8a32b1cb9d9a09aa2325d2430587ddbc0c38bad911525", "The quick brown fox jumps over the lazy dog" },
+		});
+		sha256provider.Check({
+			{ "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", "" },
+			{ "d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592", "The quick brown fox jumps over the lazy dog" },
+		});
+		sha384provider.Check({
+			{ "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b", "" },
+			{ "ca737f1014a48f4c0b6dd43cb177b0afd9e5169367544c494011e3317dbf9a509cb1e5dc1e85a941bbee3d7f2afbc9b1", "The quick brown fox jumps over the lazy dog" },
+		});
+		sha512provider.Check({
+			{ "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e", "" },
+			{ "07e547d9586f6a73f73fbac0435ed76951218fb7d0c8d788a309d785436bbb642e93a252a954f23912547d1e8a3b5ed6e1bfd7097821233fa0538f3db854fee6", "The quick brown fox jumps over the lazy dog" },
+		});
 	}
 
 	void OnReload(Configuration::Conf *conf) override

modules/extra/enc_argon2.cpp

@@ -104,6 +104,13 @@ public:
 	{
 		return std::make_unique<Argon2Context>(this->type);
 	}
+
+	Anope::string ToPrintable(const Anope::string &hash) override
+	{
+		// We have no way to make this printable without the creating context
+		// so we always return the printed form.
+		return hash;
+	}
 };