LibCrypto: Add HashFunction and implement MD5

Libraries/LibCrypto/Hash/MD5.h

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+#include <LibCrypto/Hash/HashFunction.h>
+
+namespace Crypto {
+
+struct MD5Digest {
+    u8 data[16];
+};
+
+namespace MD5Constants {
+
+constexpr u32 init_A = 0x67452301;
+constexpr u32 init_B = 0xefcdab89;
+constexpr u32 init_C = 0x98badcfe;
+constexpr u32 init_D = 0x10325476;
+constexpr u32 S11 = 7;
+constexpr u32 S12 = 12;
+constexpr u32 S13 = 17;
+constexpr u32 S14 = 22;
+constexpr u32 S21 = 5;
+constexpr u32 S22 = 9;
+constexpr u32 S23 = 14;
+constexpr u32 S24 = 20;
+constexpr u32 S31 = 4;
+constexpr u32 S32 = 11;
+constexpr u32 S33 = 16;
+constexpr u32 S34 = 23;
+constexpr u32 S41 = 6;
+constexpr u32 S42 = 10;
+constexpr u32 S43 = 15;
+constexpr u32 S44 = 21;
+constexpr u8 PADDING[] = {
+    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0
+};
+
+}
+
+class MD5 final : public HashFunction<16, MD5Digest> {
+public:
+    MD5()
+    {
+        m_buffer = ByteBuffer::wrap(m_data_buffer, sizeof(m_data_buffer));
+    }
+
+    virtual void update(const u8*, size_t) override;
+    virtual void update(const ByteBuffer& buffer) override { update(buffer.data(), buffer.size()); };
+    virtual void update(const StringView& string) override { update((const u8*)string.characters_without_null_termination(), string.length()); };
+    virtual DigestType digest() override;
+
+    inline static DigestType hash(const u8* data, size_t length)
+    {
+        MD5 md5;
+        md5.update(data, length);
+        return md5.digest();
+    }
+
+    inline static DigestType hash(const ByteBuffer& buffer) { return hash(buffer.data(), buffer.size()); }
+    inline static DigestType hash(const StringView& buffer) { return hash((const u8*)buffer.characters_without_null_termination(), buffer.length()); }
+
+private:
+    inline void transform(const u8*);
+    inline void reset();
+
+    static void encode(const u32* from, u8* to, size_t length);
+    static void decode(const u8* from, u32* to, size_t length);
+
+    u32 m_A { Constants::init_A }, m_B { Constants::init_B }, m_C { Constants::init_C }, m_D { Constants::init_D };
+    u32 m_count[2] { 0, 0 };
+    ByteBuffer m_buffer;
+
+    u8 m_data_buffer[64];
+};
+
+}
+
+}