.\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .if !\nF .nr F 0 .if \nF>0 \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} .\} .\" ======================================================================== .\" .IX Title "Digest::SHA3 3pm" .TH Digest::SHA3 3pm "2016-07-28" "perl v5.24.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Digest::SHA3 \- Perl extension for SHA\-3 .SH "SYNOPSIS" .IX Header "SYNOPSIS" In programs: .PP .Vb 1 \& # Functional interface \& \& use Digest::SHA3 qw(sha3_224 sha3_256_hex sha3_512_base64 ...); \& \& $digest = sha3_224($data); \& $digest = sha3_256_hex($data); \& $digest = sha3_384_base64($data); \& $digest = sha3_512($data); \& \& # Object\-oriented \& \& use Digest::SHA3; \& \& $sha3 = Digest::SHA3\->new($alg); \& \& $sha3\->add($data); # feed data into stream \& \& $sha3\->addfile(*F); \& $sha3\->addfile($filename); \& \& $sha3\->add_bits($bits); \& $sha3\->add_bits($data, $nbits); \& \& $digest = $sha3\->digest; # compute digest \& $digest = $sha3\->hexdigest; \& $digest = $sha3\->b64digest; \& \& # Compute extendable\-length digest \& \& $sha3 = Digest::SHA3\->new(128000)\->add($data); # SHAKE128 \& $digest = $sha3\->squeeze; \& $digest .= $sha3\->squeeze; \& ... \& \& $sha3 = Digest::SHA3\->new(256000)\->add($data); # SHAKE256 \& $digest = $sha3\->squeeze; \& $digest .= $sha3\->squeeze; \& ... .Ve .SH "ABSTRACT" .IX Header "ABSTRACT" Digest::SHA3 is a complete implementation of the \s-1NIST SHA\-3\s0 cryptographic hash function, as specified in \s-1FIPS 202 \s0(\s-1SHA\-3\s0 Standard: Permutation-Based Hash and Extendable-Output Functions). .PP The module gives Perl programmers a convenient way to calculate \&\s-1SHA3\-224, SHA3\-256, SHA3\-384,\s0 and \s-1SHA3\-512\s0 message digests, as well as variable-length hashes using \s-1SHAKE128\s0 and \s-1SHAKE256. \s0 Digest::SHA3 can handle all types of input, including partial-byte data. .SH "DESCRIPTION" .IX Header "DESCRIPTION" Digest::SHA3 is written in C for speed. If your platform lacks a C compiler, perhaps you can find the module in a binary form compatible with your particular processor and operating system. .PP The programming interface is easy to use: it's the same one found in \s-1CPAN\s0's Digest module. So, if your applications currently use Digest::SHA and you'd prefer the newer flavor of the \s-1NIST\s0 standard, it's a simple matter to convert them. .PP The interface provides two ways to calculate digests: all-at-once, or in stages. To illustrate, the following short program computes the \s-1SHA3\-256\s0 digest of \*(L"hello world\*(R" using each approach: .PP .Vb 1 \& use Digest::SHA3 qw(sha3_256_hex); \& \& $data = "hello world"; \& @frags = split(//, $data); \& \& # all\-at\-once (Functional style) \& $digest1 = sha3_256_hex($data); \& \& # in\-stages (OOP style) \& $state = Digest::SHA3\->new(256); \& for (@frags) { $state\->add($_) } \& $digest2 = $state\->hexdigest; \& \& print $digest1 eq $digest2 ? \& "that\*(Aqs the ticket!\en" : "oops!\en"; .Ve .PP To calculate the digest of an n\-bit message where \fIn\fR is not a multiple of 8, use the \fI\fIadd_bits()\fI\fR method. For example, consider the 446\-bit message consisting of the bit-string \*(L"110\*(R" repeated 148 times, followed by \*(L"11\*(R". Here's how to display its \s-1SHA3\-512\s0 digest: .PP .Vb 4 \& use Digest::SHA3; \& $bits = "110" x 148 . "11"; \& $sha3 = Digest::SHA3\->new(512)\->add_bits($bits); \& print $sha3\->hexdigest, "\en"; .Ve .PP Note that for larger bit-strings, it's more efficient to use the two-argument version \fIadd_bits($data, \f(CI$nbits\fI)\fR, where \fI\f(CI$data\fI\fR is in the customary packed binary format used for Perl strings. .SH "UNICODE AND SIDE EFFECTS" .IX Header "UNICODE AND SIDE EFFECTS" Perl supports Unicode strings as of version 5.6. Such strings may contain wide characters: namely, characters whose ordinal values are greater than 255. This can cause problems for digest algorithms such as \s-1SHA\-3\s0 that are specified to operate on sequences of bytes. .PP The rule by which Digest::SHA3 handles a Unicode string is easy to state, but potentially confusing to grasp: the string is interpreted as a sequence of byte values, where each byte value is equal to the ordinal value (viz. code point) of its corresponding Unicode character. That way, the Unicode string 'abc' has exactly the same digest value as the ordinary string 'abc'. .PP Since a wide character does not fit into a byte, the Digest::SHA3 routines croak if they encounter one. Whereas if a Unicode string contains no wide characters, the module accepts it quite happily. The following code illustrates the two cases: .PP .Vb 2 \& $str1 = pack(\*(AqU*\*(Aq, (0..255)); \& print sha3_224_hex($str1); # ok \& \& $str2 = pack(\*(AqU*\*(Aq, (0..256)); \& print sha3_224_hex($str2); # croaks .Ve .PP Be aware that the digest routines silently convert \s-1UTF\-8\s0 input into its equivalent byte sequence in the native encoding (cf. utf8::downgrade). This side effect influences only the way Perl stores the data internally, but otherwise leaves the actual value of the data intact. .SH "PADDING OF BASE64 DIGESTS" .IX Header "PADDING OF BASE64 DIGESTS" By convention, \s-1CPAN\s0 Digest modules do \fBnot\fR pad their Base64 output. Problems can occur when feeding such digests to other software that expects properly padded Base64 encodings. .PP For the time being, any necessary padding must be done by the user. Fortunately, this is a simple operation: if the length of a Base64\-encoded digest isn't a multiple of 4, simply append \*(L"=\*(R" characters to the end of the digest until it is: .PP .Vb 3 \& while (length($b64_digest) % 4) { \& $b64_digest .= \*(Aq=\*(Aq; \& } .Ve .PP To illustrate, \fIsha3_256_base64(\*(L"abc\*(R")\fR is computed to be .PP .Vb 1 \& Ophdp0/iJbIEXBcta9OQvYVfCG4+nVJbRr/iRRFDFTI .Ve .PP which has a length of 43. So, the properly padded version is .PP .Vb 1 \& Ophdp0/iJbIEXBcta9OQvYVfCG4+nVJbRr/iRRFDFTI= .Ve .SH "EXPORT" .IX Header "EXPORT" None by default. .SH "EXPORTABLE FUNCTIONS" .IX Header "EXPORTABLE FUNCTIONS" Provided your C compiler supports a 64\-bit type (e.g. the \fIlong long\fR of C99, or \fI_\|_int64\fR used by Microsoft C/\*(C+), all of these functions will be available for use. Otherwise you won't be able to perform any of them. .PP In the interest of simplicity, maintainability, and small code size, it's unlikely that future versions of this module will support a 32\-bit implementation. Older platforms using 32\-bit\-only compilers should continue to favor 32\-bit hash implementations such as \s-1SHA\-1, SHA\-224,\s0 or \s-1SHA\-256. \s0 The desire to use the \s-1SHA\-3\s0 hash standard, dating from 2015, should reasonably require that one's compiler adhere to programming language standards dating from at least 1999. .PP \&\fIFunctional style\fR .IP "\fBsha3_224($data, ...)\fR" 4 .IX Item "sha3_224($data, ...)" .PD 0 .IP "\fBsha3_256($data, ...)\fR" 4 .IX Item "sha3_256($data, ...)" .IP "\fBsha3_384($data, ...)\fR" 4 .IX Item "sha3_384($data, ...)" .IP "\fBsha3_512($data, ...)\fR" 4 .IX Item "sha3_512($data, ...)" .IP "\fBshake128($data, ...)\fR" 4 .IX Item "shake128($data, ...)" .IP "\fBshake256($data, ...)\fR" 4 .IX Item "shake256($data, ...)" .PD Logically joins the arguments into a single string, and returns its \&\s-1SHA3\-0/224/256/384/512\s0 digest encoded as a binary string. .Sp The digest size for shake128 is 1344 bits (168 bytes); for shake256, it's 1088 bits (136 bytes). To obtain extendable-output from the \&\s-1SHAKE\s0 algorithms, use the object-oriented interface with repeated calls to the \fIsqueeze\fR method. .IP "\fBsha3_224_hex($data, ...)\fR" 4 .IX Item "sha3_224_hex($data, ...)" .PD 0 .IP "\fBsha3_256_hex($data, ...)\fR" 4 .IX Item "sha3_256_hex($data, ...)" .IP "\fBsha3_384_hex($data, ...)\fR" 4 .IX Item "sha3_384_hex($data, ...)" .IP "\fBsha3_512_hex($data, ...)\fR" 4 .IX Item "sha3_512_hex($data, ...)" .IP "\fBshake128_hex($data, ...)\fR" 4 .IX Item "shake128_hex($data, ...)" .IP "\fBshake256_hex($data, ...)\fR" 4 .IX Item "shake256_hex($data, ...)" .PD Logically joins the arguments into a single string, and returns its \s-1SHA3\-0/224/256/384/512\s0 or \s-1SHAKE128/256\s0 digest encoded as a hexadecimal string. .IP "\fBsha3_224_base64($data, ...)\fR" 4 .IX Item "sha3_224_base64($data, ...)" .PD 0 .IP "\fBsha3_256_base64($data, ...)\fR" 4 .IX Item "sha3_256_base64($data, ...)" .IP "\fBsha3_384_base64($data, ...)\fR" 4 .IX Item "sha3_384_base64($data, ...)" .IP "\fBsha3_512_base64($data, ...)\fR" 4 .IX Item "sha3_512_base64($data, ...)" .IP "\fBshake128_base64($data, ...)\fR" 4 .IX Item "shake128_base64($data, ...)" .IP "\fBshake256_base64($data, ...)\fR" 4 .IX Item "shake256_base64($data, ...)" .PD Logically joins the arguments into a single string, and returns its \s-1SHA3\-0/224/256/384/512\s0 or \s-1SHAKE128/256\s0 digest encoded as a Base64 string. .Sp It's important to note that the resulting string does \fBnot\fR contain the padding characters typical of Base64 encodings. This omission is deliberate, and is done to maintain compatibility with the family of \&\s-1CPAN\s0 Digest modules. See \*(L"\s-1PADDING OF BASE64 DIGESTS\*(R"\s0 for details. .PP \&\fI\s-1OOP\s0 style\fR .IP "\fBnew($alg)\fR" 4 .IX Item "new($alg)" Returns a new Digest::SHA3 object. Allowed values for \fI\f(CI$alg\fI\fR are 224, 256, 384, and 512 for the \s-1SHA3\s0 algorithms; or 128000 and 256000 for \s-1SHAKE128\s0 and \s-1SHAKE256,\s0 respectively. If the argument is missing, \s-1SHA3\-224\s0 will be used by default. .Sp Invoking \fInew\fR as an instance method will not create a new object; instead, it will simply reset the object to the initial state associated with \fI\f(CI$alg\fI\fR. If the argument is missing, the object will continue using the same algorithm that was selected at creation. .IP "\fBreset($alg)\fR" 4 .IX Item "reset($alg)" This method has exactly the same effect as \fInew($alg)\fR. In fact, \&\fIreset\fR is just an alias for \fInew\fR. .IP "\fBhashsize\fR" 4 .IX Item "hashsize" Returns the number of digest bits for this object. The values are 224, 256, 384, 512, 1344, and 1088 for \s-1SHA3\-224, SHA3\-256, SHA3\-384, SHA3\-512, SHAKE128,\s0 and \s-1SHAKE256,\s0 respectively. .IP "\fBalgorithm\fR" 4 .IX Item "algorithm" Returns the digest algorithm for this object. The values are 224, 256, 384, 512, 128000, and 256000 for \s-1SHA3\-224, SHA3\-256, SHA3\-384, SHA3\-512, SHAKE128,\s0 and \s-1SHAKE256,\s0 respectively. .IP "\fBclone\fR" 4 .IX Item "clone" Returns a duplicate copy of the object. .IP "\fBadd($data, ...)\fR" 4 .IX Item "add($data, ...)" Logically joins the arguments into a single string, and uses it to update the current digest state. In other words, the following statements have the same effect: .Sp .Vb 4 \& $sha3\->add("a"); $sha3\->add("b"); $sha3\->add("c"); \& $sha3\->add("a")\->add("b")\->add("c"); \& $sha3\->add("a", "b", "c"); \& $sha3\->add("abc"); .Ve .Sp The return value is the updated object itself. .IP "\fBadd_bits($data, \f(CB$nbits\fB)\fR" 4 .IX Item "add_bits($data, $nbits)" .PD 0 .IP "\fBadd_bits($bits)\fR" 4 .IX Item "add_bits($bits)" .PD Updates the current digest state by appending bits to it. The return value is the updated object itself. .Sp The first form causes the most-significant \fI\f(CI$nbits\fI\fR of \fI\f(CI$data\fI\fR to be appended to the stream. The \fI\f(CI$data\fI\fR argument is in the customary binary format used for Perl strings. .Sp The second form takes an \s-1ASCII\s0 string of \*(L"0\*(R" and \*(L"1\*(R" characters as its argument. It's equivalent to .Sp .Vb 1 \& $sha3\->add_bits(pack("B*", $bits), length($bits)); .Ve .Sp So, the following two statements do the same thing: .Sp .Vb 2 \& $sha3\->add_bits("111100001010"); \& $sha3\->add_bits("\exF0\exA0", 12); .Ve .Sp Note that \s-1SHA\-3\s0 uses \fIleast-significant-bit ordering\fR for its internal state. This means that .Sp .Vb 1 \& $sha3\->add_bits("110"); .Ve .Sp is equivalent to .Sp .Vb 1 \& $sha3\->add_bits("0")\->add_bits("1")\->add_bits("1"); .Ve .Sp The fact that \s-1SHA\-2\s0 and \s-1SHA\-3\s0 employ opposite bit-ordering schemes has resulted in noticeable confusion, even in the cryptographic community. When programming with bitwise inputs, expect to make blunders, repeatedly: if the Scylla of notation doesn't devour you, the Charybdis of semantics almost certainly will. .IP "\fBaddfile(*FILE)\fR" 4 .IX Item "addfile(*FILE)" Reads from \fI\s-1FILE\s0\fR until \s-1EOF,\s0 and appends that data to the current state. The return value is the updated object itself. .IP "\fBaddfile($filename [, \f(CB$mode\fB])\fR" 4 .IX Item "addfile($filename [, $mode])" Reads the contents of \fI\f(CI$filename\fI\fR, and appends that data to the current state. The return value is the updated object itself. .Sp By default, \fI\f(CI$filename\fI\fR is simply opened and read; no special modes or I/O disciplines are used. To change this, set the optional \fI\f(CI$mode\fI\fR argument to one of the following values: .Sp .Vb 1 \& "b" read file in binary mode \& \& "U" use universal newlines \& \& "0" use BITS mode \& \& "p" use portable mode (to be deprecated) .Ve .Sp The \*(L"U\*(R" mode is modeled on Python's \*(L"Universal Newlines\*(R" concept, whereby \&\s-1DOS\s0 and Mac \s-1OS\s0 line terminators are converted internally to \s-1UNIX\s0 newlines before processing. This ensures consistent digest values when working simultaneously across multiple file systems. \fBThe \*(L"U\*(R" mode influences only text files\fR, namely those passing Perl's \fI\-T\fR test; binary files are processed with no translation whatsoever. .Sp The \*(L"p\*(R" mode differs from \*(L"U\*(R" only in that it treats \*(L"\er\er\en\*(R" as a single newline, a quirky feature designed to accommodate legacy applications that occasionally added an extra carriage return before \s-1DOS\s0 line terminators. The \*(L"p\*(R" mode will be phased out eventually in favor of the cleaner and more well-established Universal Newlines concept. .Sp The \s-1BITS\s0 mode (\*(L"0\*(R") interprets the contents of \fI\f(CI$filename\fI\fR as a logical stream of bits, where each \s-1ASCII \s0'0' or '1' character represents a 0 or 1 bit, respectively. All other characters are ignored. This provides a convenient way to calculate the digest values of partial-byte data by using files, rather than having to write programs using the \fIadd_bits\fR method. .IP "\fBdigest\fR" 4 .IX Item "digest" Returns the digest encoded as a binary string. .Sp Note that the \fIdigest\fR method is a read-once operation. Once it has been performed, the Digest::SHA3 object is automatically reset in preparation for calculating another digest value. Call \&\fI\f(CI$sha\fI\->clone\->digest\fR if it's necessary to preserve the original digest state. .IP "\fBhexdigest\fR" 4 .IX Item "hexdigest" Returns the digest encoded as a hexadecimal string. .Sp Like \fIdigest\fR, this method is a read-once operation. Call \&\fI\f(CI$sha\fI\->clone\->hexdigest\fR if it's necessary to preserve the original digest state. .IP "\fBb64digest\fR" 4 .IX Item "b64digest" Returns the digest encoded as a Base64 string. .Sp Like \fIdigest\fR, this method is a read-once operation. Call \&\fI\f(CI$sha\fI\->clone\->b64digest\fR if it's necessary to preserve the original digest state. .Sp It's important to note that the resulting string does \fBnot\fR contain the padding characters typical of Base64 encodings. This omission is deliberate, and is done to maintain compatibility with the family of \s-1CPAN\s0 Digest modules. See \*(L"\s-1PADDING OF BASE64 DIGESTS\*(R"\s0 for details. .IP "\fBsqueeze\fR" 4 .IX Item "squeeze" Returns the next 168 (136) bytes of the \s-1SHAKE128 \s0(\s-1SHAKE256\s0) digest encoded as a binary string. The \fIsqueeze\fR method may be called repeatedly to construct digests of any desired length. .Sp This method is \fBapplicable only to \s-1SHAKE128\s0 and \s-1SHAKE256\s0 objects\fR. .SH "SEE ALSO" .IX Header "SEE ALSO" Digest, Digest::SHA, Digest::Keccak .PP The \s-1FIPS 202 SHA\-3\s0 Standard can be found at: .PP .PP The Keccak/SHA\-3 specifications can be found at: .PP .SH "AUTHOR" .IX Header "AUTHOR" .Vb 1 \& Mark Shelor .Ve .SH "ACKNOWLEDGMENTS" .IX Header "ACKNOWLEDGMENTS" The author is particularly grateful to .PP .Vb 5 \& Guido Bertoni \& Joan Daemen \& Michael Peeters \& Chris Skiscim \& Gilles Van Assche .Ve .PP \&\*(L"Nothing is more fatiguing nor, in the long run, more exasperating than the daily effort to believe things which daily become more incredible. To be done with this effort is an indispensible condition of secure and lasting happiness.\*(R" \&\- Bertrand Russell .SH "COPYRIGHT AND LICENSE" .IX Header "COPYRIGHT AND LICENSE" Copyright (C) 2012\-2016 Mark Shelor .PP This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. .PP perlartistic