1 files changed, 17 insertions, 1 deletions
diff --git a/crypto/src/crypto/parameters/DsaPublicKeyParameters.cs b/crypto/src/crypto/parameters/DsaPublicKeyParameters.cs
index f11f858f3..3a81bfdd0 100644
--- a/crypto/src/crypto/parameters/DsaPublicKeyParameters.cs
+++ b/crypto/src/crypto/parameters/DsaPublicKeyParameters.cs
@@ -7,6 +7,22 @@ namespace Org.BouncyCastle.Crypto.Parameters
public class DsaPublicKeyParameters
: DsaKeyParameters
{
+ private static BigInteger Validate(BigInteger y, DsaParameters parameters)
+ {
+ // we can't validate without params, fortunately we can't use the key either...
+ if (parameters != null)
+ {
+ if (y.CompareTo(BigInteger.Two) < 0
+ || y.CompareTo(parameters.P.Subtract(BigInteger.Two)) > 0
+ || !y.ModPow(parameters.Q, parameters.P).Equals(BigInteger.One))
+ {
+ throw new ArgumentException("y value does not appear to be in correct group");
+ }
+ }
+
+ return y;
+ }
+
private readonly BigInteger y;
public DsaPublicKeyParameters(
@@ -17,7 +33,7 @@ namespace Org.BouncyCastle.Crypto.Parameters
if (y == null)
throw new ArgumentNullException("y");
- this.y = y;
+ this.y = Validate(y, parameters);
}
public BigInteger Y
|
