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DES_CRYPT(3) Linux Programmer's Manual DES_CRYPT(3)
des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast DES
encryption
#include <rpc/des_crypt.h>
int ecb_crypt(char *key, char *data, unsigned datalen,
unsigned mode);
int cbc_crypt(char *key, char *data, unsigned datalen,
unsigned mode, char *ivec);
void des_setparity(char *key);
int DES_FAILED(int status);
ecb_crypt() and cbc_crypt() implement the NBS DES (Data Encryption
Standard). These routines are faster and more general purpose than
crypt(3). They also are able to utilize DES hardware if it is
available. ecb_crypt() encrypts in ECB (Electronic Code Book) mode,
which encrypts blocks of data independently. cbc_crypt() encrypts in
CBC (Cipher Block Chaining) mode, which chains together successive
blocks. CBC mode protects against insertions, deletions and
substitutions of blocks. Also, regularities in the clear text will
not appear in the cipher text.
Here is how to use these routines. The first argument, key, is the
8-byte encryption key with parity. To set the key's parity, which
for DES is in the low bit of each byte, use des_setparity(). The
second argument, data, contains the data to be encrypted or
decrypted. The third argument, datalen, is the length in bytes of
data, which must be a multiple of 8. The fourth argument, mode, is
formed by ORing together some things. For the encryption direction
OR in either DES_ENCRYPT or DES_DECRYPT. For software versus
hardware encryption, OR in either DES_HW or DES_SW. If DES_HW is
specified, and there is no hardware, then the encryption is performed
in software and the routine returns DESERR_NOHWDEVICE. For
cbc_crypt(), the argument ivec is the 8-byte initialization vector
for the chaining. It is updated to the next initialization vector
upon return.
DESERR_NONE
No error.
DESERR_NOHWDEVICE
Encryption succeeded, but done in software instead of the
requested hardware.
DESERR_HWERROR
An error occurred in the hardware or driver.
DESERR_BADPARAM
Bad argument to routine.
Given a result status stat, the macro DES_FAILED(stat) is false only
for the first two statuses.
These functions were added to glibc in version 2.1.
Because they employ the DES block cipher, which is no longer
considered secure, ecb_crypt(), ecb_crypt(), crypt_r(), and
des_setparity() were removed in glibc 2.28. Applications should
switch to a modern cryptography library, such as libgcrypt.
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────┼───────────────┼─────────┤
│ecb_crypt(), cbc_crypt(), │ Thread safety │ MT-Safe │
│des_setparity() │ │ │
└──────────────────────────┴───────────────┴─────────┘
4.3BSD. Not in POSIX.1.
des(1), crypt(3), xcrypt(3)
This page is part of release 5.08 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
2020-04-11 DES_CRYPT(3)
Pages that refer to this page: encrypt(3) , encrypt_r(3) , setkey(3) , setkey_r(3)
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