table of contents
|DES_CRYPT(3)||Library Functions Manual||DES_CRYPT(3)|
fast DES encryption
ecb_crypt(char *key, char *data, unsigned datalen, unsigned mode); int
cbc_crypt(char *key, char *data, unsigned datalen, unsigned mode, char *ivec); void
cbc_crypt() functions 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. The
ecb_crypt() function encrypts in ECB (Electronic Code Book) mode, which encrypts blocks of data independently. The
cbc_crypt() function 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 OR'ing together some things. For the encryption direction OR in either
DES_DECRYPT. For software versus hardware encryption, OR in either
DES_HWis specified, and there is no hardware, then the encryption is performed in software and the routine returns
cbc_crypt(), the ivec argument is the 8-byte initialization vector for the chaining. It is updated to the next initialization vector upon return.
- 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.
DES_FAILED(stat) is false only for the first two statuses.
des_setparity() functions are part of libtirpc.
RESTRICTIONS¶These routines are not available in RPCSRC 4.0. This information is provided to describe the DES interface expected by Secure RPC.
|October 6, 1987||Debian|