1 files changed, 147 insertions, 0 deletions
diff --git a/Crypto/src/bcpg/S2k.cs b/Crypto/src/bcpg/S2k.cs
new file mode 100644
index 000000000..de08c016c
--- /dev/null
+++ b/Crypto/src/bcpg/S2k.cs
@@ -0,0 +1,147 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Bcpg
+{
+ /// <remarks>The string to key specifier class.</remarks>
+ public class S2k
+ : BcpgObject
+ {
+ private const int ExpBias = 6;
+
+ public const int Simple = 0;
+ public const int Salted = 1;
+ public const int SaltedAndIterated = 3;
+ public const int GnuDummyS2K = 101;
+
+ internal int type;
+ internal HashAlgorithmTag algorithm;
+ internal byte[] iv;
+ internal int itCount = -1;
+ internal int protectionMode = -1;
+
+ internal S2k(
+ Stream inStr)
+ {
+ type = inStr.ReadByte();
+ algorithm = (HashAlgorithmTag) inStr.ReadByte();
+
+ //
+ // if this happens we have a dummy-S2k packet.
+ //
+ if (type != GnuDummyS2K)
+ {
+ if (type != 0)
+ {
+ iv = new byte[8];
+ if (Streams.ReadFully(inStr, iv, 0, iv.Length) < iv.Length)
+ throw new EndOfStreamException();
+
+ if (type == 3)
+ {
+ itCount = inStr.ReadByte();
+ }
+ }
+ }
+ else
+ {
+ inStr.ReadByte(); // G
+ inStr.ReadByte(); // N
+ inStr.ReadByte(); // U
+ protectionMode = inStr.ReadByte(); // protection mode
+ }
+ }
+
+ public S2k(
+ HashAlgorithmTag algorithm)
+ {
+ this.type = 0;
+ this.algorithm = algorithm;
+ }
+
+ public S2k(
+ HashAlgorithmTag algorithm,
+ byte[] iv)
+ {
+ this.type = 1;
+ this.algorithm = algorithm;
+ this.iv = iv;
+ }
+
+ public S2k(
+ HashAlgorithmTag algorithm,
+ byte[] iv,
+ int itCount)
+ {
+ this.type = 3;
+ this.algorithm = algorithm;
+ this.iv = iv;
+ this.itCount = itCount;
+ }
+
+ public int Type
+ {
+ get { return type; }
+ }
+
+ /// <summary>The hash algorithm.</summary>
+ public HashAlgorithmTag HashAlgorithm
+ {
+ get { return algorithm; }
+ }
+
+ /// <summary>The IV for the key generation algorithm.</summary>
+ public byte[] GetIV()
+ {
+ return Arrays.Clone(iv);
+ }
+
+ [Obsolete("Use 'IterationCount' property instead")]
+ public long GetIterationCount()
+ {
+ return IterationCount;
+ }
+
+ /// <summary>The iteration count</summary>
+ public long IterationCount
+ {
+ get { return (16 + (itCount & 15)) << ((itCount >> 4) + ExpBias); }
+ }
+
+ /// <summary>The protection mode - only if GnuDummyS2K</summary>
+ public int ProtectionMode
+ {
+ get { return protectionMode; }
+ }
+
+ public override void Encode(
+ BcpgOutputStream bcpgOut)
+ {
+ bcpgOut.WriteByte((byte) type);
+ bcpgOut.WriteByte((byte) algorithm);
+
+ if (type != GnuDummyS2K)
+ {
+ if (type != 0)
+ {
+ bcpgOut.Write(iv);
+ }
+
+ if (type == 3)
+ {
+ bcpgOut.WriteByte((byte) itCount);
+ }
+ }
+ else
+ {
+ bcpgOut.WriteByte((byte) 'G');
+ bcpgOut.WriteByte((byte) 'N');
+ bcpgOut.WriteByte((byte) 'U');
+ bcpgOut.WriteByte((byte) protectionMode);
+ }
+ }
+ }
+}
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