1 files changed, 92 insertions, 0 deletions
diff --git a/Crypto/src/asn1/x509/RSAPublicKeyStructure.cs b/Crypto/src/asn1/x509/RSAPublicKeyStructure.cs
new file mode 100644
index 000000000..bdcba783e
--- /dev/null
+++ b/Crypto/src/asn1/x509/RSAPublicKeyStructure.cs
@@ -0,0 +1,92 @@
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Math;
+
+using System;
+using System.Collections;
+
+namespace Org.BouncyCastle.Asn1.X509
+{
+ public class RsaPublicKeyStructure
+ : Asn1Encodable
+ {
+ private BigInteger modulus;
+ private BigInteger publicExponent;
+
+ public static RsaPublicKeyStructure GetInstance(
+ Asn1TaggedObject obj,
+ bool explicitly)
+ {
+ return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
+ }
+
+ public static RsaPublicKeyStructure GetInstance(
+ object obj)
+ {
+ if (obj == null || obj is RsaPublicKeyStructure)
+ {
+ return (RsaPublicKeyStructure) obj;
+ }
+
+ if (obj is Asn1Sequence)
+ {
+ return new RsaPublicKeyStructure((Asn1Sequence) obj);
+ }
+
+ throw new ArgumentException("Invalid RsaPublicKeyStructure: " + obj.GetType().Name);
+ }
+
+ public RsaPublicKeyStructure(
+ BigInteger modulus,
+ BigInteger publicExponent)
+ {
+ if (modulus == null)
+ throw new ArgumentNullException("modulus");
+ if (publicExponent == null)
+ throw new ArgumentNullException("publicExponent");
+ if (modulus.SignValue <= 0)
+ throw new ArgumentException("Not a valid RSA modulus", "modulus");
+ if (publicExponent.SignValue <= 0)
+ throw new ArgumentException("Not a valid RSA public exponent", "publicExponent");
+
+ this.modulus = modulus;
+ this.publicExponent = publicExponent;
+ }
+
+ private RsaPublicKeyStructure(
+ Asn1Sequence seq)
+ {
+ if (seq.Count != 2)
+ throw new ArgumentException("Bad sequence size: " + seq.Count);
+
+ // Note: we are accepting technically incorrect (i.e. negative) values here
+ modulus = DerInteger.GetInstance(seq[0]).PositiveValue;
+ publicExponent = DerInteger.GetInstance(seq[1]).PositiveValue;
+ }
+
+ public BigInteger Modulus
+ {
+ get { return modulus; }
+ }
+
+ public BigInteger PublicExponent
+ {
+ get { return publicExponent; }
+ }
+
+ /**
+ * This outputs the key in Pkcs1v2 format.
+ * <pre>
+ * RSAPublicKey ::= Sequence {
+ * modulus Integer, -- n
+ * publicExponent Integer, -- e
+ * }
+ * </pre>
+ */
+ public override Asn1Object ToAsn1Object()
+ {
+ return new DerSequence(
+ new DerInteger(Modulus),
+ new DerInteger(PublicExponent));
+ }
+ }
+}
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