1Crypt::CBC(3) User Contributed Perl Documentation Crypt::CBC(3)
2
6 Crypt::CBC - Encrypt Data with Cipher Block Chaining Mode
7
9 use Crypt::CBC;
10 $cipher = Crypt::CBC->new( -pass => 'my secret password',
11 -cipher => 'Cipher::AES'
12 );
13 # one shot mode
15 $ciphertext = $cipher->encrypt("This data is hush hush");
16 $plaintext = $cipher->decrypt($ciphertext);
17 # stream mode
19 $cipher->start('encrypting');
20 open(F,"./BIG_FILE");
21 while (read(F,$buffer,1024)) {
22 print $cipher->crypt($buffer);
23 }
24 print $cipher->finish;
25 # do-it-yourself mode -- specify key && initialization vector yourself
27 $key = Crypt::CBC->random_bytes(8); # assuming a 8-byte block cipher
28 $iv = Crypt::CBC->random_bytes(8);
29 $cipher = Crypt::CBC->new(-pbkdf => 'none',
30 -key => $key,
31 -iv => $iv);
32 $ciphertext = $cipher->encrypt("This data is hush hush");
34 $plaintext = $cipher->decrypt($ciphertext);
35 # encrypting via a filehandle (requires Crypt::FileHandle>
37 $fh = Crypt::CBC->filehandle(-pass => 'secret');
38 open $fh,'>','encrypted.txt" or die $!
39 print $fh "This will be encrypted\n";
40 close $fh;
41
43 This module is a Perl-only implementation of the cryptographic cipher
44 block chaining mode (CBC). In combination with a block cipher such as
45 AES or Blowfish, you can encrypt and decrypt messages of arbitrarily
46 long length. The encrypted messages are compatible with the encryption
47 format used by the OpenSSL package.
48 To use this module, you will first create a Crypt::CBC cipher object
50 with new(). At the time of cipher creation, you specify an encryption
51 key to use and, optionally, a block encryption algorithm. You will
52 then call the start() method to initialize the encryption or decryption
53 process, crypt() to encrypt or decrypt one or more blocks of data, and
54 lastly finish(), to pad and encrypt the final block. For your
55 convenience, you can call the encrypt() and decrypt() methods to
56 operate on a whole data value at once.
57 new()
59 $cipher = Crypt::CBC->new( -pass => 'my secret key',
60 -cipher => 'Cipher::AES',
61 );
62 # or (for compatibility with versions prior to 2.0)
64 $cipher = new Crypt::CBC('my secret key' => 'Cipher::AES');
65 The new() method creates a new Crypt::CBC object. It accepts a list of
67 -argument => value pairs selected from the following list:
68 Argument Description
70 -------- -----------
71 -pass,-key The encryption/decryption passphrase. These arguments
73 are interchangeable, but -pass is preferred
74 ("key" is a misnomer, as it is not the literal
75 encryption key).
76 -cipher The cipher algorithm (defaults to Crypt::Cipher:AES), or
78 a previously created cipher object reference. For
79 convenience, you may omit the initial "Crypt::" part
80 of the classname and use the basename, e.g. "Blowfish"
81 instead of "Crypt::Blowfish".
82 -keysize Force the cipher keysize to the indicated number of bytes. This can be used
84 to set the keysize for variable keylength ciphers such as AES.
85 -chain_mode The block chaining mode to use. Current options are:
87 'cbc' -- cipher-block chaining mode [default]
88 'pcbc' -- plaintext cipher-block chaining mode
89 'cfb' -- cipher feedback mode
90 'ofb' -- output feedback mode
91 'ctr' -- counter mode
92 -pbkdf The passphrase-based key derivation function used to derive
94 the encryption key and initialization vector from the
95 provided passphrase. For backward compatibility, Crypt::CBC
96 will default to "opensslv1", but it is recommended to use
97 the standard "pbkdf2"algorithm instead. If you wish to interoperate
98 with OpenSSL, be aware that different versions of the software
99 support a series of derivation functions.
100 'none' -- The value provided in -pass/-key is used directly.
102 This is the same as passing true to -literal_key.
103 You must also manually specify the IV with -iv.
104 The key and the IV must match the keylength
105 and blocklength of the chosen cipher.
106 'randomiv' -- Use insecure key derivation method found
107 in prehistoric versions of OpenSSL (dangerous)
108 'opensslv1' -- [default] Use the salted MD5 method that was default
109 in versions of OpenSSL through v1.0.2.
110 'opensslv2' -- [better] Use the salted SHA-256 method that was
111 the default in versions of OpenSSL through v1.1.0.
112 'pbkdf2' -- [best] Use the PBKDF2 method that was first
113 introduced in OpenSSL v1.1.1.
114 More derivation functions may be added in the future. To see the
116 supported list, use the command
117 perl -MCrypt::CBC::PBKDF -e 'print join "\n",Crypt::CBC::PBKDF->list'
118 -iter If the 'pbkdf2' key derivation algorithm is used, this specifies the number of
120 hashing cycles to be applied to the passphrase+salt (longer is more secure).
121 [default 10,000]
122 -hasher If the 'pbkdf2' key derivation algorithm is chosen, you can use this to provide
124 an initialized Crypt::PBKDF2::Hash object.
125 [default HMACSHA2 for OpenSSL compatability]
126 -header What type of header to prepend to the ciphertext. One of
128 'salt' -- use OpenSSL-compatible salted header (default)
129 'randomiv' -- Randomiv-compatible "RandomIV" header
130 'none' -- prepend no header at all
131 (compatible with prehistoric versions
132 of OpenSSL)
133 -iv The initialization vector (IV). If not provided, it will be generated
135 by the key derivation function.
136 -salt The salt passed to the key derivation function. If not provided, will be
138 generated randomly (recommended).
139 -padding The padding method, one of "standard" (default),
141 "space", "oneandzeroes", "rijndael_compat",
142 "null", or "none" (default "standard").
143 -literal_key [deprected, use -pbkdf=>'none']
145 If true, the key provided by "-key" or "-pass" is used
146 directly for encryption/decryption without salting or
147 hashing. The key must be the right length for the chosen
148 cipher.
149 [default false)
150 -pcbc [deprecated, use -chaining_mode=>'pcbc']
152 Whether to use the PCBC chaining algorithm rather than
153 the standard CBC algorithm (default false).
154 -add_header [deprecated; use -header instead]
156 Whether to add the salt and IV to the header of the output
157 cipher text.
158 -regenerate_key [deprecated; use -literal_key instead]
160 Whether to use a hash of the provided key to generate
161 the actual encryption key (default true)
162 -prepend_iv [deprecated; use -header instead]
164 Whether to prepend the IV to the beginning of the
165 encrypted stream (default true)
166 Crypt::CBC requires three pieces of information to do its job. First it
168 needs the name of the block cipher algorithm that will encrypt or
169 decrypt the data in blocks of fixed length known as the cipher's
170 "blocksize." Second, it needs an encryption/decryption key to pass to
171 the block cipher. Third, it needs an initialization vector (IV) that
172 will be used to propagate information from one encrypted block to the
173 next. Both the key and the IV must be exactly the same length as the
174 chosen cipher's blocksize.
175 Crypt::CBC can derive the key and the IV from a passphrase that you
177 provide, or can let you specify the true key and IV manually. In
178 addition, you have the option of embedding enough information to
179 regenerate the IV in a short header that is emitted at the start of the
180 encrypted stream, or outputting a headerless encryption stream. In the
181 first case, Crypt::CBC will be able to decrypt the stream given just
182 the original key or passphrase. In the second case, you will have to
183 provide the original IV as well as the key/passphrase.
184 The -cipher option specifies which block cipher algorithm to use to
186 encode each section of the message. This argument is optional and will
187 default to the secure Crypt::Cipher::AES algorithm. You may use any
188 compatible block encryption algorithm that you have installed.
189 Currently, this includes Crypt::Cipher::AES, Crypt::DES,
190 Crypt::DES_EDE3, Crypt::IDEA, Crypt::Blowfish, Crypt::CAST5 and
191 Crypt::Rijndael. You may refer to them using their full names
192 ("Crypt::IDEA") or in abbreviated form ("IDEA").
193 Instead of passing the name of a cipher class, you may pass an already-
195 created block cipher object. This allows you to take advantage of
196 cipher algorithms that have parameterized new() methods, such as
197 Crypt::Eksblowfish:
198 my $eksblowfish = Crypt::Eksblowfish->new(8,$salt,$key);
200 my $cbc = Crypt::CBC->new(-cipher=>$eksblowfish);
201 The -pass argument provides a passphrase to use to generate the
203 encryption key or the literal value of the block cipher key. If used in
204 passphrase mode (which is the default), -pass can be any number of
205 characters; the actual key will be derived by passing the passphrase
206 through a series of hashing operations. To take full advantage of a
207 given block cipher, the length of the passphrase should be at least
208 equal to the cipher's blocksize. For backward compatibility, you may
209 also refer to this argument using -key.
210 To skip this hashing operation and specify the key directly, provide
212 the actual key as a string to -key and specify a key derivation
213 function of "none" to the -pbkdf argument. Alternatively, you may pass
214 a true value to the -literal_key argument. When you manually specify
215 the key in this way, should choose a key of length exactly equal to the
216 cipher's key length. You will also have to specify an IV equal in
217 length to the cipher's blocksize. These choices imply a header mode of
218 "none."
219 If you pass an existing Crypt::* object to new(), then the -pass/-key
221 argument is ignored and the module will generate a warning.
222 The -pbkdf argument specifies the algorithm used to derive the true key
224 and IV from the provided passphrase (PBKDF stands for "passphrase-based
225 key derivation function"). Valid values are:
226 "opensslv1" -- [default] A fast algorithm that derives the key by
228 combining a random salt values with the passphrase via
229 a series of MD5 hashes.
230 "opensslv2" -- an improved version that uses SHA-256 rather
232 than MD5, and has been OpenSSL's default since v1.1.0.
233 However, it has been deprecated in favor of pbkdf2
234 since OpenSSL v1.1.1.
235 "pbkdf2" -- a better algorithm implemented in OpenSSL v1.1.1,
237 described in RFC 2898 L<https://tools.ietf.org/html/rfc2898>
238 "none" -- don't use a derivation function, but treat the passphrase
240 as the literal key. This is the same as B<-literal_key> true.
241 "nosalt" -- an insecure key derivation method used by prehistoric versions
243 of OpenSSL, provided for backward compatibility. Don't use.
244 "opensslv1" was OpenSSL's default key derivation algorithm through
246 version 1.0.2, but is susceptible to dictionary attacks and is no
247 longer supported. It remains the default for Crypt::CBC in order to
248 avoid breaking compatibility with previously-encrypted messages. Using
249 this option will issue a deprecation warning when initiating
250 encryption. You can suppress the warning by passing a true value to the
251 -nodeprecate option.
252 It is recommended to specify the "pbkdf2" key derivation algorithm when
254 compatibility with older versions of Crypt::CBC is not needed. This
255 algorithm is deliberately computationally expensive in order to make
256 dictionary-based attacks harder. As a result, it introduces a slight
257 delay before an encryption or decryption operation starts.
258 The -iter argument is used in conjunction with the "pbkdf2" key
260 derivation option. Its value indicates the number of hashing cycles
261 used to derive the key. Larger values are more secure, but impose a
262 longer delay before encryption/decryption starts. The default is 10,000
263 for compatibility with OpenSSL's default.
264 The -hasher argument is used in conjunction with the "pbkdf2" key
266 derivation option to pass the reference to an initialized
267 Crypt::PBKDF2::Hash object. If not provided, it defaults to the
268 OpenSSL-compatible hash function HMACSHA2 initialized with its default
269 options (SHA-256 hash).
270 The -header argument specifies what type of header, if any, to prepend
272 to the beginning of the encrypted data stream. The header allows
273 Crypt::CBC to regenerate the original IV and correctly decrypt the data
274 without your having to provide the same IV used to encrypt the data.
275 Valid values for the -header are:
276 "salt" -- Combine the passphrase with an 8-byte random value to
278 generate both the block cipher key and the IV from the
279 provided passphrase. The salt will be appended to the
280 beginning of the data stream allowing decryption to
281 regenerate both the key and IV given the correct passphrase.
282 This method is compatible with current versions of OpenSSL.
283 "randomiv" -- Generate the block cipher key from the passphrase, and
285 choose a random 8-byte value to use as the IV. The IV will
286 be prepended to the data stream. This method is compatible
287 with ciphertext produced by versions of the library prior to
288 2.17, but is incompatible with block ciphers that have non
289 8-byte block sizes, such as Rijndael. Crypt::CBC will exit
290 with a fatal error if you try to use this header mode with a
291 non 8-byte cipher. This header type is NOT secure and NOT
292 recommended.
293 "none" -- Do not generate a header. To decrypt a stream encrypted
295 in this way, you will have to provide the true key and IV
296 manually.
297 The "salt" header is now the default as of Crypt::CBC version 2.17. In
299 all earlier versions "randomiv" was the default.
300 When using a "salt" header, you may specify your own value of the salt,
302 by passing the desired 8-byte character string to the -salt argument.
303 Otherwise, the module will generate a random salt for you. Crypt::CBC
304 will generate a fatal error if you specify a salt value that isn't
305 exactly 8 bytes long. For backward compatibility reasons, passing a
306 value of "1" will generate a random salt, the same as if no -salt
307 argument was provided.
308 The -padding argument controls how the last few bytes of the encrypted
310 stream are dealt with when they not an exact multiple of the cipher
311 block length. The default is "standard", the method specified in
312 PKCS#5.
313 The -chaining_mode argument will select among several different block
315 chaining modes. Values are:
316 'cbc' -- [default] traditional Cipher-Block Chaining mode. It has
318 the property that if one block in the ciphertext message
319 is damaged, only that block and the next one will be
320 rendered un-decryptable.
321 'pcbc' -- Plaintext Cipher-Block Chaining mode. This has the property
323 that one damaged ciphertext block will render the
324 remainder of the message unreadable
325 'cfb' -- Cipher Feedback Mode. In this mode, both encryption and decryption
327 are performed using the block cipher's "encrypt" algorithm.
328 The error propagation behaviour is similar to CBC's.
329 'ofb' -- Output Feedback Mode. Similar to CFB, the block cipher's encrypt
331 algorithm is used for both encryption and decryption. If one bit
332 of the plaintext or ciphertext message is damaged, the damage is
333 confined to a single block of the corresponding ciphertext or
334 plaintext, and error correction algorithms can be used to reconstruct
335 the damaged part.
336 'ctr' -- Counter Mode. This mode uses a one-time "nonce" instead of
338 an IV. The nonce is incremented by one for each block of
339 plain or ciphertext, encrypted using the chosen
340 algorithm, and then applied to the block of text. If one
341 bit of the input text is damaged, it only affects 1 bit
342 of the output text. To use CTR mode you will need to
343 install the Perl Math::BigInt module. I recommend
344 installing Math::BigInt::GMP as well in order to avoid a
345 large performance hit.
346 Passing a -pcbc argument of true will have the same effect as
348 -chaining_mode=>'pcbc', and is included for backward compatibility.
349 [deprecated].
350 For more information on chaining modes, see
352 <http://www.crypto-it.net/eng/theory/modes-of-block-ciphers.html>.
353 The -keysize argument can be used to force the cipher's keysize. This
355 is useful for several of the newer algorithms, including AES, ARIA,
356 Blowfish, and CAMELLIA. If -keysize is not specified, then Crypt::CBC
357 will use the value returned by the cipher's max_keylength() method.
358 Note that versions of CBC::Crypt prior to 2.36 could also allow you to
359 set the blocksie, but this was never supported by any ciphers and has
360 been removed.
361 For compatibility with earlier versions of this module, you can provide
363 new() with a hashref containing key/value pairs. The key names are the
364 same as the arguments described earlier, but without the initial
365 hyphen. You may also call new() with one or two positional arguments,
366 in which case the first argument is taken to be the key and the second
367 to be the optional block cipher algorithm.
368 start()
370 $cipher->start('encrypting');
371 $cipher->start('decrypting');
372 The start() method prepares the cipher for a series of encryption or
374 decryption steps, resetting the internal state of the cipher if
375 necessary. You must provide a string indicating whether you wish to
376 encrypt or decrypt. "E" or any word that begins with an "e" indicates
377 encryption. "D" or any word that begins with a "d" indicates
378 decryption.
379 crypt()
381 $ciphertext = $cipher->crypt($plaintext);
382 After calling start(), you should call crypt() as many times as
384 necessary to encrypt the desired data.
385 finish()
387 $ciphertext = $cipher->finish();
388 The CBC algorithm must buffer data blocks internally until they are
390 even multiples of the encryption algorithm's blocksize (typically 8
391 bytes). After the last call to crypt() you should call finish(). This
392 flushes the internal buffer and returns any leftover ciphertext.
393 In a typical application you will read the plaintext from a file or
395 input stream and write the result to standard output in a loop that
396 might look like this:
397 $cipher = new Crypt::CBC('hey jude!');
399 $cipher->start('encrypting');
400 print $cipher->crypt($_) while <>;
401 print $cipher->finish();
402 encrypt()
404 $ciphertext = $cipher->encrypt($plaintext)
405 This convenience function runs the entire sequence of start(), crypt()
407 and finish() for you, processing the provided plaintext and returning
408 the corresponding ciphertext.
409 decrypt()
411 $plaintext = $cipher->decrypt($ciphertext)
412 This convenience function runs the entire sequence of start(), crypt()
414 and finish() for you, processing the provided ciphertext and returning
415 the corresponding plaintext.
416 encrypt_hex(), decrypt_hex()
418 $ciphertext = $cipher->encrypt_hex($plaintext)
419 $plaintext = $cipher->decrypt_hex($ciphertext)
420 These are convenience functions that operate on ciphertext in a
422 hexadecimal representation. encrypt_hex($plaintext) is exactly
423 equivalent to unpack('H*',encrypt($plaintext)). These functions can be
424 useful if, for example, you wish to place the encrypted in an email
425 message.
426 filehandle()
428 This method returns a filehandle for transparent encryption or
429 decryption using Christopher Dunkle's excellent Crypt::FileHandle
430 module. This module must be installed in order to use this method.
431 filehandle() can be called as a class method using the same arguments
433 as new():
434 $fh = Crypt::CBC->filehandle(-cipher=> 'Blowfish',
436 -pass => "You'll never guess");
437 or on a previously-created Crypt::CBC object:
439 $cbc = Crypt::CBC->new(-cipher=> 'Blowfish',
441 -pass => "You'll never guess");
442 $fh = $cbc->filehandle;
443 The filehandle can then be opened using the familiar open() syntax.
445 Printing to a filehandle opened for writing will encrypt the data.
446 Filehandles opened for input will be decrypted.
447 Here is an example:
449 # transparent encryption
451 open $fh,'>','encrypted.out' or die $!;
452 print $fh "You won't be able to read me!\n";
453 close $fh;
454 # transparent decryption
456 open $fh,'<','encrypted.out' or die $!;
457 while (<$fh>) { print $_ }
458 close $fh;
459 get_initialization_vector()
461 $iv = $cipher->get_initialization_vector()
462 This function will return the IV used in encryption and or decryption.
464 The IV is not guaranteed to be set when encrypting until start() is
465 called, and when decrypting until crypt() is called the first time.
466 Unless the IV was manually specified in the new() call, the IV will
467 change with every complete encryption operation.
468 set_initialization_vector()
470 $cipher->set_initialization_vector('76543210')
471 This function sets the IV used in encryption and/or decryption. This
473 function may be useful if the IV is not contained within the ciphertext
474 string being decrypted, or if a particular IV is desired for
475 encryption. Note that the IV must match the chosen cipher's blocksize
476 bytes in length.
477 iv()
479 $iv = $cipher->iv();
480 $cipher->iv($new_iv);
481 As above, but using a single method call.
483 key()
485 $key = $cipher->key();
486 $cipher->key($new_key);
487 Get or set the block cipher key used for encryption/decryption. When
489 encrypting, the key is not guaranteed to exist until start() is called,
490 and when decrypting, the key is not guaranteed to exist until after the
491 first call to crypt(). The key must match the length required by the
492 underlying block cipher.
493 When salted headers are used, the block cipher key will change after
495 each complete sequence of encryption operations.
496 salt()
498 $salt = $cipher->salt();
499 $cipher->salt($new_salt);
500 Get or set the salt used for deriving the encryption key and IV when in
502 OpenSSL compatibility mode.
503 passphrase()
505 $passphrase = $cipher->passphrase();
506 $cipher->passphrase($new_passphrase);
507 This gets or sets the value of the passphrase passed to new() when
509 literal_key is false.
510 $data = random_bytes($numbytes)
512 Return $numbytes worth of random data. On systems that support the
513 "/dev/urandom" device file, this data will be read from the device.
514 Otherwise, it will be generated by repeated calls to the Perl rand()
515 function.
516 cipher(), pbkdf(), padding(), keysize(), blocksize(), chain_mode()
518 These read-only methods return the identity of the chosen block cipher
519 algorithm, the key derivation function (e.g. "opensslv1"), padding
520 method, key and block size of the chosen block cipher, and what
521 chaining mode ("cbc", "ofb" ,etc) is being used.
522 Padding methods
524 Use the 'padding' option to change the padding method.
525 When the last block of plaintext is shorter than the block size, it
527 must be padded. Padding methods include: "standard" (i.e., PKCS#5),
528 "oneandzeroes", "space", "rijndael_compat", "null", and "none".
529 standard: (default) Binary safe
531 pads with the number of bytes that should be truncated. So, if
532 blocksize is 8, then "0A0B0C" will be padded with "05", resulting
533 in "0A0B0C0505050505". If the final block is a full block of 8
534 bytes, then a whole block of "0808080808080808" is appended.
535 oneandzeroes: Binary safe
537 pads with "80" followed by as many "00" necessary to fill the
538 block. If the last block is a full block and blocksize is 8, a
539 block of "8000000000000000" will be appended.
540 rijndael_compat: Binary safe, with caveats
542 similar to oneandzeroes, except that no padding is performed if
543 the last block is a full block. This is provided for
544 compatibility with Crypt::Rijndael's buit-in MODE_CBC.
545 Note that Crypt::Rijndael's implementation of CBC only
546 works with messages that are even multiples of 16 bytes.
547 null: text only
549 pads with as many "00" necessary to fill the block. If the last
550 block is a full block and blocksize is 8, a block of
551 "0000000000000000" will be appended.
552 space: text only
554 same as "null", but with "20".
555 none:
557 no padding added. Useful for special-purpose applications where
558 you wish to add custom padding to the message.
559 Both the standard and oneandzeroes paddings are binary safe. The space
561 and null paddings are recommended only for text data. Which type of
562 padding you use depends on whether you wish to communicate with an
563 external (non Crypt::CBC library). If this is the case, use whatever
564 padding method is compatible.
565 You can also pass in a custom padding function. To do this, create a
567 function that takes the arguments:
568 $padded_block = function($block,$blocksize,$direction);
570 where $block is the current block of data, $blocksize is the size to
572 pad it to, $direction is "e" for encrypting and "d" for decrypting, and
573 $padded_block is the result after padding or depadding.
574 When encrypting, the function should always return a string of
576 <blocksize> length, and when decrypting, can expect the string coming
577 in to always be that length. See _standard_padding(), _space_padding(),
578 _null_padding(), or _oneandzeroes_padding() in the source for examples.
579 Standard and oneandzeroes padding are recommended, as both space and
581 null padding can potentially truncate more characters than they should.
582
584 The CryptX modules Crypt::Mode::CBC, Crypt::Mode::OFB,
585 Crypt::Mode::CFB, and Crypt::Mode::CTR provide fast implementations of
586 the respective cipherblock chaining modes (roughly 5x the speed of
587 Crypt::CBC). Crypt::CBC was designed to encrypt and decrypt messages in
588 a manner compatible with OpenSSL's "enc" function. Hence it handles the
589 derivation of the key and IV from a passphrase using the same
590 conventions as OpenSSL, and it writes out an OpenSSL-compatible header
591 in the encrypted message in a manner that allows the key and IV to be
592 regenerated during decryption.
593 In contrast, the CryptX modules do not automatically derive the key and
595 IV from a passphrase or write out an encrypted header. You will need to
596 derive and store the key and IV by other means (e.g. with CryptX's
597 Crypt::KeyDerivation module, or with Crypt::PBKDF2).
598
600 Three examples, aes.pl, des.pl and idea.pl can be found in the eg/
601 subdirectory of the Crypt-CBC distribution. These implement command-
602 line DES and IDEA encryption algorithms using default parameters, and
603 should be compatible with recent versions of OpenSSL. Note that aes.pl
604 uses the "pbkdf2" key derivation function to generate its keys. The
605 other two were distributed with pre-PBKDF2 versions of Crypt::CBC, and
606 use the older "opensslv1" algorithm.
607
609 The encryption and decryption process is about a tenth the speed of the
610 equivalent OpenSSL tool and about a fifth of the Crypt::Mode::CBC
611 module (both which use compiled C).
612
614 Please report them.
615
617 Lincoln Stein, lstein@cshl.org
618 This module is distributed under the ARTISTIC LICENSE v2 using the same
620 terms as Perl itself.
621
623 perl(1), CryptX, Crypt::FileHandle, Crypt::Cipher::AES,
624 Crypt::Blowfish, Crypt::CAST5, Crypt::DES, Crypt::IDEA, Crypt::Rijndael
625perl v5.32.1 2021-02-12 Crypt::CBC(3)