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des_crypt(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON 

des_crypt(3)            Library Functions Manual            des_crypt(3)

NAME         top

       des_crypt, ecb_crypt, cbc_crypt, des_setparity, DES_FAILED - fast
       DES encryption

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <rpc/des_crypt.h>

       [[deprecated]] int ecb_crypt(char *key, char data[.datalen],
                                    unsigned int datalen, unsigned int mode);
       [[deprecated]] int cbc_crypt(char *key, char data[.datalen],
                                    unsigned int datalen, unsigned int mode,
                                    char *ivec);

       [[deprecated]] void des_setparity(char *key);

       [[deprecated]] int DES_FAILED(int status);

DESCRIPTION         top

       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.

RETURN VALUE         top

       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.

ATTRIBUTES         top

       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()                     │               │         │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       None.

HISTORY         top

       4.3BSD.  glibc 2.1.  Removed in glibc 2.28.

       Because they employ the DES block cipher, which is no longer
       considered secure, these functions were removed.  Applications
       should switch to a modern cryptography library, such as
       libgcrypt.

SEE ALSO         top

       des(1), crypt(3), xcrypt(3)

COLOPHON         top

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Linux man-pages 6.9.1          2024-05-02                   des_crypt(3)

Pages that refer to this page: encrypt(3),  xcrypt(3)

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