License:
BSD style: see doc/license.txt for details
Version:
Initial release: Feb 2006
author:
Regan Heath, Oskar Linde
This module implements the SHA-256 Algorithm described by Secure
Hash Standard, FIPS PUB 180-2
- class
Sha256
: tango.io.digest.MerkleDamgard.MerkleDamgard;
- this();
- Construct an Sha256
- protected void
reset
();
- Initialize the cipher
Remarks:
Returns the cipher state to it's initial value
- protected void
createDigest
(ubyte[] buf);
- Obtain the digest
Remarks:
Returns a digest of the current cipher state, this may be the
final digest, or a digest of the state between calls to update()
- uint
digestSize
();
- The digest size of Sha-256 is 32 bytes
- protected uint
blockSize
();
- Cipher block size
Returns:
the block size
Remarks:
Specifies the size (in bytes) of the block of data to pass to
each call to transform(). For SHA256 the
blockSize
is 64.
- protected uint
addSize
();
- Length padding size
Returns:
the length padding size
Remarks:
Specifies the size (in bytes) of the padding which uses the
length of the data which has been ciphered, this padding is
carried out by the padLength method. For SHA256 the
addSize
is 8.
- protected void
padMessage
(ubyte[] data);
- Pads the cipher data
Params:
| ubyte[] data |
a slice of the cipher buffer to fill with padding |
Remarks:
Fills the passed buffer slice with the appropriate padding for
the final call to transform(). This padding will fill the cipher
buffer up to blockSize()-addSize().
- protected void
padLength
(ubyte[] data, ulong length);
- Performs the length padding
Params:
| ubyte[] data |
the slice of the cipher buffer to fill with padding |
| ulong length |
the length of the data which has been ciphered |
Remarks:
Fills the passed buffer slice with addSize() bytes of padding
based on the length in bytes of the input data which has been
ciphered.
- protected void
transform
(ubyte[] input);
- Performs the cipher on a block of data
Params:
| data |
the block of data to cipher |
Remarks:
The actual cipher algorithm is carried out by this method on
the passed block of data. This method is called for every
blockSize() bytes of input data and once more with the remaining
data padded to blockSize().
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