added new Asn1RelativeOid class

Author: Crypt32

Asn1Parser/Universal/Asn1RelativeOid.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Numerics;
+using System.Text;
+using SysadminsLV.Asn1Parser.Utils;
+
+namespace SysadminsLV.Asn1Parser.Universal;
+/// <summary>
+/// Represents ASN.1 RELATIVE-OID type.
+/// </summary>
+public class Asn1RelativeOid : Asn1Universal {
+    const Asn1Type TYPE = Asn1Type.RELATIVE_OID;
+
+    /// <summary>
+    /// Initializes a new instance of the <strong>Asn1RelativeOid</strong> class from an existing
+    /// <see cref="Asn1Reader"/> class instance.
+    /// </summary>
+    /// <param name="asn"><see cref="Asn1Reader"/> object in the position that represents relative object identifier.</param>
+    /// <exception cref="Asn1InvalidTagException">
+    /// The current state of <strong>ASN1</strong> object is not relative object identifier.
+    /// </exception>
+    public Asn1RelativeOid(Asn1Reader asn) : base(asn, TYPE) {
+        Value = decode(asn);
+    }
+    /// <summary>
+    /// Initializes a new instance of the <strong>Asn1RelativeOid</strong> class from a byte array
+    /// that represents encoded relative object identifier.
+    /// </summary>
+    /// <param name="rawData">Byte array that represents encoded relative object identifier.</param>
+    public Asn1RelativeOid(Byte[] rawData) : this(new Asn1Reader(rawData)) { }
+    /// <summary>
+    /// Initializes a new instance of the <strong>Asn1RelativeOid</strong> class from a string
+    /// that represents relative object identifier value.
+    /// </summary>
+    /// <param name="relativeOid">
+    ///     String that represents relative object identifier value. This parameter accepts relative OIDs with or without
+    ///     leading dot, e.g. '5', '.5', '5.10', '.5.10'.
+    /// </param>
+    /// <exception cref="ArgumentNullException"><strong>relativeOid</strong> parameter is null.</exception>
+    /// <exception cref="OverflowException">The string is too large.</exception>
+    /// <remarks>Maximum relative object identifier string is 8kb.</remarks>
+    public Asn1RelativeOid(String relativeOid) : base(TYPE) {
+        if (relativeOid == null) {
+            throw new ArgumentNullException(nameof(relativeOid));
+        }
+        m_encode(relativeOid);
+        if (relativeOid.StartsWith(".")) {
+            Value = relativeOid;
+        } else {
+            Value = "." + relativeOid;
+        }
+    }
+
+    /// <summary>
+    /// Gets relative OID value string with leading dot (e.g. '.1', '.1.3').
+    /// </summary>
+    public String Value { get; private set; }
+
+    void m_encode(String oidString) {
+        if (String.IsNullOrWhiteSpace(oidString)) {
+            Initialize(new Asn1Reader([Tag, 0]));
+            Value = String.Empty;
+            return;
+        }
+        oidString = oidString.Trim();
+        if (oidString.Length > 8096) {
+            throw new OverflowException("Oid string is longer than 8kb");
+        }
+        IEnumerable<BigInteger> tokens = oidString
+            .Split(['.'], StringSplitOptions.RemoveEmptyEntries)
+            .Select(BigInteger.Parse);
+        Initialize(new Asn1Reader(Asn1Utils.Encode(encode(tokens), TYPE)));
+    }
+    static Byte[] encode(IEnumerable<BigInteger> tokens) {
+        var rawOid = new List<Byte>();
+        foreach (BigInteger token in tokens) {
+            rawOid.AddRange(OidUtils.EncodeOidArc(token));
+        }
+        
+        return rawOid.ToArray();
+    }
+    static String decode(Asn1Reader asn) {
+        var SB = new StringBuilder();
+        for (Int32 i = 0; i < asn.PayloadLength; i++) {
+            Int32 pi = asn.PayloadStartOffset + i;
+
+            BigInteger value = 0;
+            Boolean proceed;
+            do {
+                value <<= 7;
+                value += asn[pi] & 0x7f;
+                proceed = (asn[pi] & 0x80) > 0;
+                if (proceed) {
+                    i++;
+                    pi++;
+                }
+            } while (proceed);
+
+            SB.Append("." + value);
+        }
+        return SB.ToString();
+    }
+
+    /// <inheritdoc />
+    public override String GetDisplayValue() {
+        return Value;
+    }
+}