des_crypt(3)                                          Library Functions Manual                                         des_crypt(3)

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

       Standard C library (libc, -lc)

       #include <rpc/des_crypt.h>

       int ecb_crypt(char *key, char data[.datalen], unsigned int datalen,
                     unsigned int mode);
       int cbc_crypt(char *key, char data[.datalen], unsigned int datalen,
                     unsigned int 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  (Elec‐
       tronic  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

              No error.

              Encryption succeeded, but done in software instead of the requested hardware.

              An error occurred in the hardware or driver.

              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 in glibc 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(), des_setparity()                                                        │ Thread safety │ MT-Safe │

       4.3BSD.  Not in POSIX.1.

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

Linux man-pages 6.03                                         2022-12-15                                                des_crypt(3)