1 files changed, 106 insertions, 0 deletions
diff --git a/Crypto/src/security/AgreementUtilities.cs b/Crypto/src/security/AgreementUtilities.cs
new file mode 100644
index 000000000..d74ec7368
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+++ b/Crypto/src/security/AgreementUtilities.cs
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+using System.Collections;
+using System.Globalization;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.Agreement;
+using Org.BouncyCastle.Crypto.Agreement.Kdf;
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Security
+{
+ /// <remarks>
+ /// Utility class for creating IBasicAgreement objects from their names/Oids
+ /// </remarks>
+ public sealed class AgreementUtilities
+ {
+ private AgreementUtilities()
+ {
+ }
+
+ private static readonly IDictionary algorithms = Platform.CreateHashtable();
+ //private static readonly IDictionary oids = Platform.CreateHashtable();
+
+ static AgreementUtilities()
+ {
+ //algorithms[X9ObjectIdentifiers.DHSinglePassCofactorDHSha1KdfScheme.Id] = ?;
+ algorithms[X9ObjectIdentifiers.DHSinglePassStdDHSha1KdfScheme.Id] = "ECDHWITHSHA1KDF";
+ algorithms[X9ObjectIdentifiers.MqvSinglePassSha1KdfScheme.Id] = "ECMQVWITHSHA1KDF";
+ }
+
+ public static IBasicAgreement GetBasicAgreement(
+ DerObjectIdentifier oid)
+ {
+ return GetBasicAgreement(oid.Id);
+ }
+
+ public static IBasicAgreement GetBasicAgreement(
+ string algorithm)
+ {
+ string upper = algorithm.ToUpperInvariant();
+ string mechanism = (string) algorithms[upper];
+
+ if (mechanism == null)
+ {
+ mechanism = upper;
+ }
+
+ if (mechanism == "DH" || mechanism == "DIFFIEHELLMAN")
+ return new DHBasicAgreement();
+
+ if (mechanism == "ECDH")
+ return new ECDHBasicAgreement();
+
+ if (mechanism == "ECDHC")
+ return new ECDHCBasicAgreement();
+
+ if (mechanism == "ECMQV")
+ return new ECMqvBasicAgreement();
+
+ throw new SecurityUtilityException("Basic Agreement " + algorithm + " not recognised.");
+ }
+
+ public static IBasicAgreement GetBasicAgreementWithKdf(
+ DerObjectIdentifier oid,
+ string wrapAlgorithm)
+ {
+ return GetBasicAgreementWithKdf(oid.Id, wrapAlgorithm);
+ }
+
+ public static IBasicAgreement GetBasicAgreementWithKdf(
+ string agreeAlgorithm,
+ string wrapAlgorithm)
+ {
+ string upper = agreeAlgorithm.ToUpperInvariant();
+ string mechanism = (string) algorithms[upper];
+
+ if (mechanism == null)
+ {
+ mechanism = upper;
+ }
+
+ // 'DHWITHSHA1KDF' retained for backward compatibility
+ if (mechanism == "DHWITHSHA1KDF" || mechanism == "ECDHWITHSHA1KDF")
+ return new ECDHWithKdfBasicAgreement(
+ wrapAlgorithm,
+ new ECDHKekGenerator(
+ new Sha1Digest()));
+
+ if (mechanism == "ECMQVWITHSHA1KDF")
+ return new ECMqvWithKdfBasicAgreement(
+ wrapAlgorithm,
+ new ECDHKekGenerator(
+ new Sha1Digest()));
+
+ throw new SecurityUtilityException("Basic Agreement (with KDF) " + agreeAlgorithm + " not recognised.");
+ }
+
+ public static string GetAlgorithmName(
+ DerObjectIdentifier oid)
+ {
+ return (string) algorithms[oid.Id];
+ }
+ }
+}
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