.\" Automatically generated by Pod::Man 4.10 (Pod::Simple 3.35) .\" .\" 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 .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Crypt::AuthEnc::CCM 3pm" .TH Crypt::AuthEnc::CCM 3pm "2018-12-01" "perl v5.28.1" "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" Crypt::AuthEnc::CCM \- Authenticated encryption in CCM mode .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 2 \& ### OO interface \& use Crypt::AuthEnc::CCM; \& \& # encrypt and authenticate \& my $ae = Crypt::AuthEnc::CCM\->new("AES", $key, $iv, $adata, $tag_len, $pt_len); \& my $ct = $ae\->encrypt_add(\*(Aqdata1\*(Aq); \& $ct .= $ae\->encrypt_add(\*(Aqdata2\*(Aq); \& $ct .= $ae\->encrypt_add(\*(Aqdata3\*(Aq); \& my $tag = $ae\->encrypt_done(); \& \& # decrypt and verify \& my $ae = Crypt::AuthEnc::CCM\->new("AES", $key, $iv, $adata, $tag_len, $pt_len); \& my $pt = $ae\->decrypt_add(\*(Aqciphertext1\*(Aq); \& $pt .= $ae\->decrypt_add(\*(Aqciphertext2\*(Aq); \& $pt .= $ae\->decrypt_add(\*(Aqciphertext3\*(Aq); \& my $tag = $ae\->decrypt_done(); \& die "decrypt failed" unless $tag eq $expected_tag; \& \& #or \& my $result = $ae\->decrypt_done($expected_tag); # 0 or 1 \& \& ### functional interface \& use Crypt::AuthEnc::CCM qw(ccm_encrypt_authenticate ccm_decrypt_verify); \& \& ($ciphertext, $tag) = ccm_encrypt_authenticate(\*(AqAES\*(Aq, $key, $nonce, $adata, $tag_len, $plaintext); \& $plaintext = ccm_decrypt_verify(\*(AqAES\*(Aq, $key, $nonce, $adata, $ciphertext, $tag); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\s-1CCM\s0 is a encrypt+authenticate mode that is centered around using \s-1AES\s0 (or any 16\-byte cipher) as a primitive. Unlike \s-1EAX\s0 and \s-1OCB\s0 mode, it is only meant for packet mode where the length of the input is known in advance. .SH "EXPORT" .IX Header "EXPORT" Nothing is exported by default. .PP You can export selected functions: .PP .Vb 1 \& use Crypt::AuthEnc::CCM qw(ccm_encrypt_authenticate ccm_decrypt_verify); .Ve .SH "FUNCTIONS" .IX Header "FUNCTIONS" .SS "ccm_encrypt_authenticate" .IX Subsection "ccm_encrypt_authenticate" .Vb 1 \& my ($ciphertext, $tag) = ccm_encrypt_authenticate($cipher, $key, $nonce, $adata, $tag_len, $plaintext); \& \& # $cipher .. \*(AqAES\*(Aq or name of any other cipher with 16\-byte block len \& # $key ..... key of proper length (e.g. 128/192/256bits for AES) \& # $nonce ... unique nonce/salt (no need to keep it secret) \& # $adata ... additional authenticated data \& # $tag_len . required length of output tag .Ve .PP \&\s-1CCM\s0 parameters should follow .PP .Vb 3 \& # tag length: 4, 6, 8, 10, 12, 14, 16 (reasonable minimum is 8) \& # nonce length: 7, 8, 9, 10, 11, 12, 13 (if you are not sure, use 11) \& # BEWARE nonce length determines max. enc/dec data size: max_data_size = 2^(8*(15\-nonce_len)) .Ve .SS "ccm_decrypt_verify" .IX Subsection "ccm_decrypt_verify" .Vb 2 \& my $plaintext = ccm_decrypt_verify($cipher, $key, $nonce, $adata, $ciphertext, $tag); \& # on error returns undef .Ve .SH "METHODS" .IX Header "METHODS" .SS "new" .IX Subsection "new" .Vb 1 \& my $ae = Crypt::AuthEnc::CCM\->new($cipher, $key, $nonce, $adata, $tag_len, $pt_len); \& \& # $cipher .. \*(AqAES\*(Aq or name of any other cipher with 16\-byte block len \& # $key ..... key of proper length (e.g. 128/192/256bits for AES) \& # $nonce ... unique nonce/salt (no need to keep it secret) \& # $adata ... additional authenticated data \& # $tag_len . required length of output tag \& # $pt_len .. expected length of plaintext/ciphertext to encrypt/decrypt .Ve .SS "encrypt_add" .IX Subsection "encrypt_add" .Vb 1 \& $ciphertext = $ae\->encrypt_add($data); # can be called multiple times .Ve .SS "encrypt_done" .IX Subsection "encrypt_done" .Vb 1 \& my $tag = $ae\->encrypt_done; # returns $tag value .Ve .SS "decrypt_add" .IX Subsection "decrypt_add" .Vb 1 \& $plaintext = $ae\->decrypt_add($ciphertext); # can be called multiple times .Ve .SS "decrypt_done" .IX Subsection "decrypt_done" .Vb 3 \& my $tag = $ae\->decrypt_done; # returns $tag value \& #or \& my $result = $ae\->decrypt_done($tag); # returns 1 (success) or 0 (failure) .Ve .SS "clone" .IX Subsection "clone" .Vb 1 \& my $ae_new = $ae\->clone; .Ve .SH "SEE ALSO" .IX Header "SEE ALSO" .IP "\(bu" 4 CryptX, Crypt::AuthEnc::EAX, Crypt::AuthEnc::GCM, Crypt::AuthEnc::OCB .IP "\(bu" 4