use strict;
use vars qw($VERSION %MMAP $AUTOLOAD);
-$VERSION = "1.06";
+$VERSION = "1.14";
%MMAP = (
"SHA-1" => ["Digest::SHA1", ["Digest::SHA", 1], ["Digest::SHA2", 1]],
+ "SHA-224" => [["Digest::SHA", 224]],
"SHA-256" => [["Digest::SHA", 256], ["Digest::SHA2", 256]],
"SHA-384" => [["Digest::SHA", 384], ["Digest::SHA2", 384]],
"SHA-512" => [["Digest::SHA", 512], ["Digest::SHA2", 512]],
"HMAC-MD5" => "Digest::HMAC_MD5",
"HMAC-SHA-1" => "Digest::HMAC_SHA1",
+ "CRC-16" => [["Digest::CRC", type => "crc16"]],
+ "CRC-32" => [["Digest::CRC", type => "crc32"]],
+ "CRC-CCITT" => [["Digest::CRC", type => "crcccitt"]],
);
sub new
An important property of the digest algorithms is that the digest is
I<likely> to change if the message change in some way. Another
-property is that digest functions are one-way functions, i.e. it
+property is that digest functions are one-way functions, that is it
should be I<hard> to find a message that correspond to some given
digest. Algorithms differ in how "likely" and how "hard", as well as
how efficient they are to compute.
+Note that the properties of the algorithms change over time, as the
+algorithms are analyzed and machines grow faster. If your application
+for instance depends on it being "impossible" to generate the same
+digest for a different message it is wise to make it easy to plug in
+stronger algorithms as the one used grow weaker. Using the interface
+documented here should make it easy to change algorithms later.
+
All C<Digest::> modules provide the same programming interface. A
functional interface for simple use, as well as an object oriented
interface that can handle messages of arbitrary length and which can
from data. For the last potentially partial byte only the high order
C<< $nbits % 8 >> bits are used. If $nbits is greater than C<<
length($data) * 8 >>, then this method would do the same as C<<
-$ctx->add($data) >>, i.e. $nbits is silently ignored.
+$ctx->add($data) >>, that is $nbits is silently ignored.
The one argument form of add_bits() takes a $bitstring of "1" and "0"
chars as argument. It's a shorthand for C<< $ctx->add_bits(pack("B*",
read-once operation. Once it has been performed, the $ctx object is
automatically C<reset> and can be used to calculate another digest
value. Call $ctx->clone->digest if you want to calculate the digest
-without reseting the digest state.
+without resetting the digest state.
=item $ctx->hexdigest
different algorithms. It is sorted by throughput based on a benchmark
done with of some implementations of this API:
- Algorithm Size Implementation MB/s
-
- MD4 128 Digest::MD4 v1.1 24.9
- MD5 128 Digest::MD5 v2.30 18.7
- Haval-256 256 Digest::Haval256 v1.0.4 17.0
- SHA-1 160 Digest::SHA1 v2.06 15.3
- SHA-1 160 Digest::SHA v4.0.0 10.1
- SHA-256 256 Digest::SHA2 v1.0.0 7.6
- SHA-256 256 Digest::SHA v4.0.0 6.5
- SHA-384 384 Digest::SHA2 v1.0.0 2.7
- SHA-384 384 Digest::SHA v4.0.0 2.7
- SHA-512 512 Digest::SHA2 v1.0.0 2.7
- SHA-512 512 Digest::SHA v4.0.0 2.7
- Whirlpool 512 Digest::Whirlpool v1.0.2 1.4
- MD2 128 Digest::MD2 v2.03 1.1
-
- Adler-32 32 Digest::Adler32 v0.03 0.2
- MD5 128 Digest::Perl::MD5 v1.5 0.1
-
-These numbers was achieved Nov 2003 with ActivePerl-5.8.1 running
-under Linux on a P-II 350 MHz CPU. The last 2 entries differ by being
+ Algorithm Size Implementation MB/s
+
+ MD4 128 Digest::MD4 v1.3 165.0
+ MD5 128 Digest::MD5 v2.33 98.8
+ SHA-256 256 Digest::SHA2 v1.1.0 66.7
+ SHA-1 160 Digest::SHA v4.3.1 58.9
+ SHA-1 160 Digest::SHA1 v2.10 48.8
+ SHA-256 256 Digest::SHA v4.3.1 41.3
+ Haval-256 256 Digest::Haval256 v1.0.4 39.8
+ SHA-384 384 Digest::SHA2 v1.1.0 19.6
+ SHA-512 512 Digest::SHA2 v1.1.0 19.3
+ SHA-384 384 Digest::SHA v4.3.1 19.2
+ SHA-512 512 Digest::SHA v4.3.1 19.2
+ Whirlpool 512 Digest::Whirlpool v1.0.2 13.0
+ MD2 128 Digest::MD2 v2.03 9.5
+
+ Adler-32 32 Digest::Adler32 v0.03 1.3
+ CRC-16 16 Digest::CRC v0.05 1.1
+ CRC-32 32 Digest::CRC v0.05 1.1
+ MD5 128 Digest::Perl::MD5 v1.5 1.0
+ CRC-CCITT 16 Digest::CRC v0.05 0.8
+
+These numbers was achieved Apr 2004 with ActivePerl-5.8.3 running
+under Linux on a P4 2.8 GHz CPU. The last 5 entries differ by being
pure perl implementations of the algorithms, which explains why they
are so slow.
=head1 SEE ALSO
-L<Digest::Adler32>, L<Digest::Haval256>, L<Digest::HMAC>, L<Digest::MD2>, L<Digest::MD4>, L<Digest::MD5>, L<Digest::SHA>, L<Digest::SHA1>, L<Digest::SHA2>, L<Digest::Whirlpool>
+L<Digest::Adler32>, L<Digest::CRC>, L<Digest::Haval256>,
+L<Digest::HMAC>, L<Digest::MD2>, L<Digest::MD4>, L<Digest::MD5>,
+L<Digest::SHA>, L<Digest::SHA1>, L<Digest::SHA2>, L<Digest::Whirlpool>
New digest implementations should consider subclassing from L<Digest::base>.
projects / p5sagit/p5-mst-13.2.git / blobdiff