LibCrypto: Implement RSA in terms of UnsignedBigInteger

This commit also adds enough ASN.1/DER to parse RSA keys

Libraries/LibCrypto/PK/Code/Code.h

@@ -0,0 +1,59 @@
+/*
+ * 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 <LibCrypto/Hash/HashFunction.h>
+
+namespace Crypto {
+namespace PK {
+
+    enum class VerificationConsistency {
+        Consistent,
+        Inconsistent
+    };
+
+    template <typename HashFunction>
+    class Code {
+    public:
+        template <typename... Args>
+        Code(Args... args)
+            : m_hasher(args...)
+        {
+        }
+
+        virtual void encode(const ByteBuffer& in, ByteBuffer& out, size_t em_bits) = 0;
+        virtual VerificationConsistency verify(const ByteBuffer& msg, const ByteBuffer& emsg, size_t em_bits) = 0;
+
+        const HashFunction& hasher() const { return m_hasher; }
+        HashFunction& hasher() { return m_hasher; }
+
+    protected:
+        HashFunction m_hasher;
+    };
+
+}
+}