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author | Kenny Root <kenny@the-b.org> | 2014-10-01 23:04:51 +0100 |
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committer | Kenny Root <kenny@the-b.org> | 2014-10-01 12:48:19 +0100 |
commit | 49b779dcaf03e3598d2709b321e20ea029b25163 (patch) | |
tree | 05af547b1f1433d7dd6f7373d0b25a455e053a03 /app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java | |
parent | d64786d9197090c74072b648e487e3d34817bb57 (diff) | |
download | connectbot-49b779dcaf03e3598d2709b321e20ea029b25163.tar.gz connectbot-49b779dcaf03e3598d2709b321e20ea029b25163.tar.bz2 connectbot-49b779dcaf03e3598d2709b321e20ea029b25163.zip |
Convert to gradle build system
Diffstat (limited to 'app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java')
-rw-r--r-- | app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java b/app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java new file mode 100644 index 0000000..0ae51b3 --- /dev/null +++ b/app/src/main/java/com/trilead/ssh2/crypto/cipher/CBCMode.java @@ -0,0 +1,78 @@ +package com.trilead.ssh2.crypto.cipher; + +/** + * CBCMode. + * + * @author Christian Plattner, plattner@trilead.com + * @version $Id: CBCMode.java,v 1.1 2007/10/15 12:49:55 cplattne Exp $ + */ +public class CBCMode implements BlockCipher +{ + BlockCipher tc; + int blockSize; + boolean doEncrypt; + + byte[] cbc_vector; + byte[] tmp_vector; + + public void init(boolean forEncryption, byte[] key) + { + } + + public CBCMode(BlockCipher tc, byte[] iv, boolean doEncrypt) + throws IllegalArgumentException + { + this.tc = tc; + this.blockSize = tc.getBlockSize(); + this.doEncrypt = doEncrypt; + + if (this.blockSize != iv.length) + throw new IllegalArgumentException("IV must be " + blockSize + + " bytes long! (currently " + iv.length + ")"); + + this.cbc_vector = new byte[blockSize]; + this.tmp_vector = new byte[blockSize]; + System.arraycopy(iv, 0, cbc_vector, 0, blockSize); + } + + public int getBlockSize() + { + return blockSize; + } + + private void encryptBlock(byte[] src, int srcoff, byte[] dst, int dstoff) + { + for (int i = 0; i < blockSize; i++) + cbc_vector[i] ^= src[srcoff + i]; + + tc.transformBlock(cbc_vector, 0, dst, dstoff); + + System.arraycopy(dst, dstoff, cbc_vector, 0, blockSize); + } + + private void decryptBlock(byte[] src, int srcoff, byte[] dst, int dstoff) + { + /* Assume the worst, src and dst are overlapping... */ + + System.arraycopy(src, srcoff, tmp_vector, 0, blockSize); + + tc.transformBlock(src, srcoff, dst, dstoff); + + for (int i = 0; i < blockSize; i++) + dst[dstoff + i] ^= cbc_vector[i]; + + /* ...that is why we need a tmp buffer. */ + + byte[] swap = cbc_vector; + cbc_vector = tmp_vector; + tmp_vector = swap; + } + + public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff) + { + if (doEncrypt) + encryptBlock(src, srcoff, dst, dstoff); + else + decryptBlock(src, srcoff, dst, dstoff); + } +} |