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-rw-r--r--libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/encodings/OAEPEncoding.java357
1 files changed, 0 insertions, 357 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/encodings/OAEPEncoding.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/encodings/OAEPEncoding.java
deleted file mode 100644
index 11796fcec..000000000
--- a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/encodings/OAEPEncoding.java
+++ /dev/null
@@ -1,357 +0,0 @@
-package org.spongycastle.crypto.encodings;
-
-import java.security.SecureRandom;
-
-import org.spongycastle.crypto.AsymmetricBlockCipher;
-import org.spongycastle.crypto.CipherParameters;
-import org.spongycastle.crypto.Digest;
-import org.spongycastle.crypto.InvalidCipherTextException;
-import org.spongycastle.crypto.digests.SHA1Digest;
-import org.spongycastle.crypto.params.ParametersWithRandom;
-
-/**
- * Optimal Asymmetric Encryption Padding (OAEP) - see PKCS 1 V 2.
- */
-public class OAEPEncoding
- implements AsymmetricBlockCipher
-{
- private byte[] defHash;
- private Digest mgf1Hash;
-
- private AsymmetricBlockCipher engine;
- private SecureRandom random;
- private boolean forEncryption;
-
- public OAEPEncoding(
- AsymmetricBlockCipher cipher)
- {
- this(cipher, new SHA1Digest(), null);
- }
-
- public OAEPEncoding(
- AsymmetricBlockCipher cipher,
- Digest hash)
- {
- this(cipher, hash, null);
- }
-
- public OAEPEncoding(
- AsymmetricBlockCipher cipher,
- Digest hash,
- byte[] encodingParams)
- {
- this(cipher, hash, hash, encodingParams);
- }
-
- public OAEPEncoding(
- AsymmetricBlockCipher cipher,
- Digest hash,
- Digest mgf1Hash,
- byte[] encodingParams)
- {
- this.engine = cipher;
- this.mgf1Hash = mgf1Hash;
- this.defHash = new byte[hash.getDigestSize()];
-
- hash.reset();
-
- if (encodingParams != null)
- {
- hash.update(encodingParams, 0, encodingParams.length);
- }
-
- hash.doFinal(defHash, 0);
- }
-
- public AsymmetricBlockCipher getUnderlyingCipher()
- {
- return engine;
- }
-
- public void init(
- boolean forEncryption,
- CipherParameters param)
- {
- if (param instanceof ParametersWithRandom)
- {
- ParametersWithRandom rParam = (ParametersWithRandom)param;
-
- this.random = rParam.getRandom();
- }
- else
- {
- this.random = new SecureRandom();
- }
-
- engine.init(forEncryption, param);
-
- this.forEncryption = forEncryption;
- }
-
- public int getInputBlockSize()
- {
- int baseBlockSize = engine.getInputBlockSize();
-
- if (forEncryption)
- {
- return baseBlockSize - 1 - 2 * defHash.length;
- }
- else
- {
- return baseBlockSize;
- }
- }
-
- public int getOutputBlockSize()
- {
- int baseBlockSize = engine.getOutputBlockSize();
-
- if (forEncryption)
- {
- return baseBlockSize;
- }
- else
- {
- return baseBlockSize - 1 - 2 * defHash.length;
- }
- }
-
- public byte[] processBlock(
- byte[] in,
- int inOff,
- int inLen)
- throws InvalidCipherTextException
- {
- if (forEncryption)
- {
- return encodeBlock(in, inOff, inLen);
- }
- else
- {
- return decodeBlock(in, inOff, inLen);
- }
- }
-
- public byte[] encodeBlock(
- byte[] in,
- int inOff,
- int inLen)
- throws InvalidCipherTextException
- {
- byte[] block = new byte[getInputBlockSize() + 1 + 2 * defHash.length];
-
- //
- // copy in the message
- //
- System.arraycopy(in, inOff, block, block.length - inLen, inLen);
-
- //
- // add sentinel
- //
- block[block.length - inLen - 1] = 0x01;
-
- //
- // as the block is already zeroed - there's no need to add PS (the >= 0 pad of 0)
- //
-
- //
- // add the hash of the encoding params.
- //
- System.arraycopy(defHash, 0, block, defHash.length, defHash.length);
-
- //
- // generate the seed.
- //
- byte[] seed = new byte[defHash.length];
-
- random.nextBytes(seed);
-
- //
- // mask the message block.
- //
- byte[] mask = maskGeneratorFunction1(seed, 0, seed.length, block.length - defHash.length);
-
- for (int i = defHash.length; i != block.length; i++)
- {
- block[i] ^= mask[i - defHash.length];
- }
-
- //
- // add in the seed
- //
- System.arraycopy(seed, 0, block, 0, defHash.length);
-
- //
- // mask the seed.
- //
- mask = maskGeneratorFunction1(
- block, defHash.length, block.length - defHash.length, defHash.length);
-
- for (int i = 0; i != defHash.length; i++)
- {
- block[i] ^= mask[i];
- }
-
- return engine.processBlock(block, 0, block.length);
- }
-
- /**
- * @exception InvalidCipherTextException if the decrypted block turns out to
- * be badly formatted.
- */
- public byte[] decodeBlock(
- byte[] in,
- int inOff,
- int inLen)
- throws InvalidCipherTextException
- {
- byte[] data = engine.processBlock(in, inOff, inLen);
- byte[] block;
-
- //
- // as we may have zeros in our leading bytes for the block we produced
- // on encryption, we need to make sure our decrypted block comes back
- // the same size.
- //
- if (data.length < engine.getOutputBlockSize())
- {
- block = new byte[engine.getOutputBlockSize()];
-
- System.arraycopy(data, 0, block, block.length - data.length, data.length);
- }
- else
- {
- block = data;
- }
-
- if (block.length < (2 * defHash.length) + 1)
- {
- throw new InvalidCipherTextException("data too short");
- }
-
- //
- // unmask the seed.
- //
- byte[] mask = maskGeneratorFunction1(
- block, defHash.length, block.length - defHash.length, defHash.length);
-
- for (int i = 0; i != defHash.length; i++)
- {
- block[i] ^= mask[i];
- }
-
- //
- // unmask the message block.
- //
- mask = maskGeneratorFunction1(block, 0, defHash.length, block.length - defHash.length);
-
- for (int i = defHash.length; i != block.length; i++)
- {
- block[i] ^= mask[i - defHash.length];
- }
-
- //
- // check the hash of the encoding params.
- // long check to try to avoid this been a source of a timing attack.
- //
- boolean defHashWrong = false;
-
- for (int i = 0; i != defHash.length; i++)
- {
- if (defHash[i] != block[defHash.length + i])
- {
- defHashWrong = true;
- }
- }
-
- if (defHashWrong)
- {
- throw new InvalidCipherTextException("data hash wrong");
- }
-
- //
- // find the data block
- //
- int start;
-
- for (start = 2 * defHash.length; start != block.length; start++)
- {
- if (block[start] != 0)
- {
- break;
- }
- }
-
- if (start >= (block.length - 1) || block[start] != 1)
- {
- throw new InvalidCipherTextException("data start wrong " + start);
- }
-
- start++;
-
- //
- // extract the data block
- //
- byte[] output = new byte[block.length - start];
-
- System.arraycopy(block, start, output, 0, output.length);
-
- return output;
- }
-
- /**
- * int to octet string.
- */
- private void ItoOSP(
- int i,
- byte[] sp)
- {
- sp[0] = (byte)(i >>> 24);
- sp[1] = (byte)(i >>> 16);
- sp[2] = (byte)(i >>> 8);
- sp[3] = (byte)(i >>> 0);
- }
-
- /**
- * mask generator function, as described in PKCS1v2.
- */
- private byte[] maskGeneratorFunction1(
- byte[] Z,
- int zOff,
- int zLen,
- int length)
- {
- byte[] mask = new byte[length];
- byte[] hashBuf = new byte[mgf1Hash.getDigestSize()];
- byte[] C = new byte[4];
- int counter = 0;
-
- mgf1Hash.reset();
-
- while (counter < (length / hashBuf.length))
- {
- ItoOSP(counter, C);
-
- mgf1Hash.update(Z, zOff, zLen);
- mgf1Hash.update(C, 0, C.length);
- mgf1Hash.doFinal(hashBuf, 0);
-
- System.arraycopy(hashBuf, 0, mask, counter * hashBuf.length, hashBuf.length);
-
- counter++;
- }
-
- if ((counter * hashBuf.length) < length)
- {
- ItoOSP(counter, C);
-
- mgf1Hash.update(Z, zOff, zLen);
- mgf1Hash.update(C, 0, C.length);
- mgf1Hash.doFinal(hashBuf, 0);
-
- System.arraycopy(hashBuf, 0, mask, counter * hashBuf.length, mask.length - (counter * hashBuf.length));
- }
-
- return mask;
- }
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 21:17:42 +0000