LibCrypto: Implement RSA in terms of UnsignedBigInteger

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

Libraries/LibCrypto/ASN1/ASN1.h

@@ -0,0 +1,111 @@
+/*
+ * 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/BigInt/UnsignedBigInteger.h>
+
+namespace Crypto {
+
+namespace ASN1 {
+    enum class Kind {
+        Eol,
+        Boolean,
+        Integer,
+        ShortInteger,
+        BitString,
+        OctetString,
+        Null,
+        ObjectIdentifier,
+        IA5String,
+        PrintableString,
+        Utf8String,
+        UTCTime,
+        Choice,
+        Sequence,
+        Set,
+        SetOf
+    };
+
+    static StringView kind_name(Kind kind)
+    {
+        switch (kind) {
+        case Kind::Eol:
+            return "EndOfList";
+        case Kind::Boolean:
+            return "Boolean";
+        case Kind::Integer:
+            return "Integer";
+        case Kind::ShortInteger:
+            return "ShortInteger";
+        case Kind::BitString:
+            return "BitString";
+        case Kind::OctetString:
+            return "OctetString";
+        case Kind::Null:
+            return "Null";
+        case Kind::ObjectIdentifier:
+            return "ObjectIdentifier";
+        case Kind::IA5String:
+            return "IA5String";
+        case Kind::PrintableString:
+            return "PrintableString";
+        case Kind::Utf8String:
+            return "UTF8String";
+        case Kind::UTCTime:
+            return "UTCTime";
+        case Kind::Choice:
+            return "Choice";
+        case Kind::Sequence:
+            return "Sequence";
+        case Kind::Set:
+            return "Set";
+        case Kind::SetOf:
+            return "SetOf";
+        }
+
+        return "InvalidKind";
+    }
+
+    struct List {
+        Kind kind;
+        void* data;
+        size_t size;
+        bool used;
+        List *prev, *next, *child, *parent;
+    };
+
+    static constexpr void set(List& list, Kind type, void* data, size_t size)
+    {
+        list.kind = type;
+        list.data = data;
+        list.size = size;
+        list.used = false;
+    }
+}
+
+}