diff --git a/crypto/src/asn1/x9/X9FieldID.cs b/crypto/src/asn1/x9/X9FieldID.cs
index c51cc4df2..58823a285 100644
--- a/crypto/src/asn1/x9/X9FieldID.cs
+++ b/crypto/src/asn1/x9/X9FieldID.cs
@@ -1,3 +1,5 @@
+using System;
+
using Org.BouncyCastle.Math;
namespace Org.BouncyCastle.Asn1.X9
@@ -12,80 +14,100 @@ namespace Org.BouncyCastle.Asn1.X9
private readonly DerObjectIdentifier id;
private readonly Asn1Object parameters;
- /**
- * Constructor for elliptic curves over prime fields
- * <code>F<sub>2</sub></code>.
- * @param primeP The prime <code>p</code> defining the prime field.
- */
- public X9FieldID(
- BigInteger primeP)
- {
- this.id = X9ObjectIdentifiers.PrimeField;
- this.parameters = new DerInteger(primeP);
- }
+ /**
+ * Constructor for elliptic curves over prime fields
+ * <code>F<sub>2</sub></code>.
+ * @param primeP The prime <code>p</code> defining the prime field.
+ */
+ public X9FieldID(
+ BigInteger primeP)
+ {
+ this.id = X9ObjectIdentifiers.PrimeField;
+ this.parameters = new DerInteger(primeP);
+ }
- /**
- * Constructor for elliptic curves over binary fields
- * <code>F<sub>2<sup>m</sup></sub></code>.
- * @param m The exponent <code>m</code> of
- * <code>F<sub>2<sup>m</sup></sub></code>.
- * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
- * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
- * represents the reduction polynomial <code>f(z)</code>.
- * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
- * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
- * represents the reduction polynomial <code>f(z)</code>.
- * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
- * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
- * represents the reduction polynomial <code>f(z)</code>..
- */
- public X9FieldID(
- int m,
- int k1,
- int k2,
- int k3)
- {
- this.id = X9ObjectIdentifiers.CharacteristicTwoField;
+ /**
+ * Constructor for elliptic curves over binary fields
+ * <code>F<sub>2<sup>m</sup></sub></code>.
+ * @param m The exponent <code>m</code> of
+ * <code>F<sub>2<sup>m</sup></sub></code>.
+ * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
+ * x<sup>k1</sup> + 1</code>
+ * represents the reduction polynomial <code>f(z)</code>.
+ */
+ public X9FieldID(int m, int k1)
+ : this(m, k1, 0, 0)
+ {
+ }
- Asn1EncodableVector fieldIdParams = new Asn1EncodableVector(new DerInteger(m));
+ /**
+ * Constructor for elliptic curves over binary fields
+ * <code>F<sub>2<sup>m</sup></sub></code>.
+ * @param m The exponent <code>m</code> of
+ * <code>F<sub>2<sup>m</sup></sub></code>.
+ * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
+ * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+ * represents the reduction polynomial <code>f(z)</code>.
+ * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
+ * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+ * represents the reduction polynomial <code>f(z)</code>.
+ * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
+ * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+ * represents the reduction polynomial <code>f(z)</code>..
+ */
+ public X9FieldID(
+ int m,
+ int k1,
+ int k2,
+ int k3)
+ {
+ this.id = X9ObjectIdentifiers.CharacteristicTwoField;
+
+ Asn1EncodableVector fieldIdParams = new Asn1EncodableVector(new DerInteger(m));
- if (k2 == 0)
- {
- fieldIdParams.Add(
- X9ObjectIdentifiers.TPBasis,
- new DerInteger(k1));
- }
- else
- {
- fieldIdParams.Add(
- X9ObjectIdentifiers.PPBasis,
- new DerSequence(
- new DerInteger(k1),
- new DerInteger(k2),
- new DerInteger(k3)));
- }
+ if (k2 == 0)
+ {
+ if (k3 != 0)
+ throw new ArgumentException("inconsistent k values");
- this.parameters = new DerSequence(fieldIdParams);
- }
+ fieldIdParams.Add(
+ X9ObjectIdentifiers.TPBasis,
+ new DerInteger(k1));
+ }
+ else
+ {
+ if (k2 <= k1 || k3 <= k2)
+ throw new ArgumentException("inconsistent k values");
- internal X9FieldID(
- Asn1Sequence seq)
- {
- this.id = (DerObjectIdentifier) seq[0];
- this.parameters = (Asn1Object) seq[1];
- }
+ fieldIdParams.Add(
+ X9ObjectIdentifiers.PPBasis,
+ new DerSequence(
+ new DerInteger(k1),
+ new DerInteger(k2),
+ new DerInteger(k3)));
+ }
+
+ this.parameters = new DerSequence(fieldIdParams);
+ }
+
+ internal X9FieldID(
+ Asn1Sequence seq)
+ {
+ this.id = (DerObjectIdentifier) seq[0];
+ this.parameters = (Asn1Object) seq[1];
+ }
- public DerObjectIdentifier Identifier
+ public DerObjectIdentifier Identifier
{
get { return id; }
}
- public Asn1Object Parameters
+ public Asn1Object Parameters
{
get { return parameters; }
}
- /**
+ /**
* Produce a Der encoding of the following structure.
* <pre>
* FieldID ::= Sequence {
@@ -96,7 +118,7 @@ namespace Org.BouncyCastle.Asn1.X9
*/
public override Asn1Object ToAsn1Object()
{
- return new DerSequence(id, parameters);
+ return new DerSequence(id, parameters);
}
}
}
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