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Diffstat (limited to 'libraries/spongycastle/core/src/main/java/org/spongycastle/pqc/crypto/mceliece/McEliecePointchevalCipher.java')
-rw-r--r--libraries/spongycastle/core/src/main/java/org/spongycastle/pqc/crypto/mceliece/McEliecePointchevalCipher.java241
1 files changed, 0 insertions, 241 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/pqc/crypto/mceliece/McEliecePointchevalCipher.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/pqc/crypto/mceliece/McEliecePointchevalCipher.java
deleted file mode 100644
index ba58258bd..000000000
--- a/libraries/spongycastle/core/src/main/java/org/spongycastle/pqc/crypto/mceliece/McEliecePointchevalCipher.java
+++ /dev/null
@@ -1,241 +0,0 @@
-package org.spongycastle.pqc.crypto.mceliece;
-
-import java.security.SecureRandom;
-
-import org.spongycastle.crypto.CipherParameters;
-import org.spongycastle.crypto.Digest;
-import org.spongycastle.crypto.digests.SHA1Digest;
-import org.spongycastle.crypto.params.ParametersWithRandom;
-import org.spongycastle.crypto.prng.DigestRandomGenerator;
-import org.spongycastle.pqc.crypto.MessageEncryptor;
-import org.spongycastle.pqc.math.linearalgebra.ByteUtils;
-import org.spongycastle.pqc.math.linearalgebra.GF2Vector;
-
-/**
- * This class implements the Pointcheval conversion of the McEliecePKCS.
- * Pointcheval presents a generic technique to make a CCA2-secure cryptosystem
- * from any partially trapdoor one-way function in the random oracle model. For
- * details, see D. Engelbert, R. Overbeck, A. Schmidt, "A summary of the
- * development of the McEliece Cryptosystem", technical report.
- */
-public class McEliecePointchevalCipher
- implements MessageEncryptor
-{
-
-
- /**
- * The OID of the algorithm.
- */
- public static final String OID = "1.3.6.1.4.1.8301.3.1.3.4.2.2";
-
- private Digest messDigest;
-
- private SecureRandom sr;
-
- /**
- * The McEliece main parameters
- */
- private int n, k, t;
-
- McElieceCCA2KeyParameters key;
-
- public void init(boolean forSigning,
- CipherParameters param)
- {
-
- if (forSigning)
- {
- if (param instanceof ParametersWithRandom)
- {
- ParametersWithRandom rParam = (ParametersWithRandom)param;
-
- this.sr = rParam.getRandom();
- this.key = (McElieceCCA2PublicKeyParameters)rParam.getParameters();
- this.initCipherEncrypt((McElieceCCA2PublicKeyParameters)key);
-
- }
- else
- {
- this.sr = new SecureRandom();
- this.key = (McElieceCCA2PublicKeyParameters)param;
- this.initCipherEncrypt((McElieceCCA2PublicKeyParameters)key);
- }
- }
- else
- {
- this.key = (McElieceCCA2PrivateKeyParameters)param;
- this.initCipherDecrypt((McElieceCCA2PrivateKeyParameters)key);
- }
-
- }
-
- /**
- * Return the key size of the given key object.
- *
- * @param key the McElieceCCA2KeyParameters object
- * @return the key size of the given key object
- * @throws IllegalArgumentException if the key is invalid
- */
- public int getKeySize(McElieceCCA2KeyParameters key)
- throws IllegalArgumentException
- {
-
- if (key instanceof McElieceCCA2PublicKeyParameters)
- {
- return ((McElieceCCA2PublicKeyParameters)key).getN();
-
- }
- if (key instanceof McElieceCCA2PrivateKeyParameters)
- {
- return ((McElieceCCA2PrivateKeyParameters)key).getN();
- }
- throw new IllegalArgumentException("unsupported type");
-
- }
-
-
- protected int decryptOutputSize(int inLen)
- {
- return 0;
- }
-
- protected int encryptOutputSize(int inLen)
- {
- return 0;
- }
-
-
- public void initCipherEncrypt(McElieceCCA2PublicKeyParameters pubKey)
- {
- this.sr = sr != null ? sr : new SecureRandom();
- this.messDigest = pubKey.getParameters().getDigest();
- n = pubKey.getN();
- k = pubKey.getK();
- t = pubKey.getT();
- }
-
- public void initCipherDecrypt(McElieceCCA2PrivateKeyParameters privKey)
- {
- this.messDigest = privKey.getParameters().getDigest();
- n = privKey.getN();
- k = privKey.getK();
- t = privKey.getT();
- }
-
- public byte[] messageEncrypt(byte[] input)
- throws Exception
- {
-
- int kDiv8 = k >> 3;
-
- // generate random r of length k div 8 bytes
- byte[] r = new byte[kDiv8];
- sr.nextBytes(r);
-
- // generate random vector r' of length k bits
- GF2Vector rPrime = new GF2Vector(k, sr);
-
- // convert r' to byte array
- byte[] rPrimeBytes = rPrime.getEncoded();
-
- // compute (input||r)
- byte[] mr = ByteUtils.concatenate(input, r);
-
- // compute H(input||r)
- messDigest.update(mr, 0, mr.length);
- byte[] hmr = new byte[messDigest.getDigestSize()];
- messDigest.doFinal(hmr, 0);
-
-
- // convert H(input||r) to error vector z
- GF2Vector z = Conversions.encode(n, t, hmr);
-
- // compute c1 = E(rPrime, z)
- byte[] c1 = McElieceCCA2Primitives.encryptionPrimitive((McElieceCCA2PublicKeyParameters)key, rPrime,
- z).getEncoded();
-
- // get PRNG object
- DigestRandomGenerator sr0 = new DigestRandomGenerator(new SHA1Digest());
-
- // seed PRNG with r'
- sr0.addSeedMaterial(rPrimeBytes);
-
- // generate random c2
- byte[] c2 = new byte[input.length + kDiv8];
- sr0.nextBytes(c2);
-
- // XOR with input
- for (int i = 0; i < input.length; i++)
- {
- c2[i] ^= input[i];
- }
- // XOR with r
- for (int i = 0; i < kDiv8; i++)
- {
- c2[input.length + i] ^= r[i];
- }
-
- // return (c1||c2)
- return ByteUtils.concatenate(c1, c2);
- }
-
- public byte[] messageDecrypt(byte[] input)
- throws Exception
- {
-
- int c1Len = (n + 7) >> 3;
- int c2Len = input.length - c1Len;
-
- // split cipher text (c1||c2)
- byte[][] c1c2 = ByteUtils.split(input, c1Len);
- byte[] c1 = c1c2[0];
- byte[] c2 = c1c2[1];
-
- // decrypt c1 ...
- GF2Vector c1Vec = GF2Vector.OS2VP(n, c1);
- GF2Vector[] c1Dec = McElieceCCA2Primitives.decryptionPrimitive((McElieceCCA2PrivateKeyParameters)key,
- c1Vec);
- byte[] rPrimeBytes = c1Dec[0].getEncoded();
- // ... and obtain error vector z
- GF2Vector z = c1Dec[1];
-
- // get PRNG object
- DigestRandomGenerator sr0 = new DigestRandomGenerator(new SHA1Digest());
-
- // seed PRNG with r'
- sr0.addSeedMaterial(rPrimeBytes);
-
- // generate random sequence
- byte[] mrBytes = new byte[c2Len];
- sr0.nextBytes(mrBytes);
-
- // XOR with c2 to obtain (m||r)
- for (int i = 0; i < c2Len; i++)
- {
- mrBytes[i] ^= c2[i];
- }
-
- // compute H(m||r)
- messDigest.update(mrBytes, 0, mrBytes.length);
- byte[] hmr = new byte[messDigest.getDigestSize()];
- messDigest.doFinal(hmr, 0);
-
- // compute Conv(H(m||r))
- c1Vec = Conversions.encode(n, t, hmr);
-
- // check that Conv(H(m||r)) = z
- if (!c1Vec.equals(z))
- {
- throw new Exception("Bad Padding: Invalid ciphertext.");
- }
-
- // split (m||r) to obtain m
- int kDiv8 = k >> 3;
- byte[][] mr = ByteUtils.split(mrBytes, c2Len - kDiv8);
-
- // return plain text m
- return mr[0];
- }
-
-
-}