3rdPartyLibraries/iTechSharp/srcbc/security/AgreementUtilities.cs
2023-06-21 12:46:23 -04:00

100 lines
2.4 KiB
C#

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;
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 Hashtable algorithms = new Hashtable();
// private static readonly Hashtable oids = new Hashtable();
static AgreementUtilities()
{
//algorithms[X9ObjectIdentifiers.DHSinglePassCofactorDHSha1KdfScheme.Id] = ?;
algorithms[X9ObjectIdentifiers.DHSinglePassStdDHSha1KdfScheme.Id] = "DHWITHSHA1KDF";
//algorithms[X9ObjectIdentifiers.MqvSinglePassSha1KdfScheme.Id] = ?;
}
public static IBasicAgreement GetBasicAgreement(
DerObjectIdentifier oid)
{
return GetBasicAgreement(oid.Id);
}
public static IBasicAgreement GetBasicAgreement(
string algorithm)
{
string upper = algorithm.ToUpper(CultureInfo.InvariantCulture);
string mechanism = (string) algorithms[upper];
if (mechanism == null)
{
mechanism = upper;
}
switch (mechanism)
{
case "DH":
return new DHBasicAgreement();
case "ECDH":
return new ECDHBasicAgreement();
case "ECDHC":
return new ECDHCBasicAgreement();
}
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.ToUpper(CultureInfo.InvariantCulture);
string mechanism = (string) algorithms[upper];
if (mechanism == null)
{
mechanism = upper;
}
switch (mechanism)
{
case "DHWITHSHA1KDF":
return new ECDHWithKdfBasicAgreement(
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];
}
}
}