=pod
=head1 NAME
DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked,
DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key,
DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt,
DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt,
DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt,
DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt,
DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt,
DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys,
DES_fcrypt, DES_crypt - DES encryption
=head1 SYNOPSIS
#include
void DES_random_key(DES_cblock *ret);
int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);
int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule);
int DES_set_key_checked(const_DES_cblock *key, DES_key_schedule *schedule);
void DES_set_key_unchecked(const_DES_cblock *key, DES_key_schedule *schedule);
void DES_set_odd_parity(DES_cblock *key);
int DES_is_weak_key(const_DES_cblock *key);
void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output,
DES_key_schedule *ks, int enc);
void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output,
DES_key_schedule *ks1, DES_key_schedule *ks2, int enc);
void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output,
DES_key_schedule *ks1, DES_key_schedule *ks2,
DES_key_schedule *ks3, int enc);
void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
long length, DES_key_schedule *schedule, DES_cblock *ivec,
int enc);
void DES_cfb_encrypt(const unsigned char *in, unsigned char *out,
int numbits, long length, DES_key_schedule *schedule,
DES_cblock *ivec, int enc);
void DES_ofb_encrypt(const unsigned char *in, unsigned char *out,
int numbits, long length, DES_key_schedule *schedule,
DES_cblock *ivec);
void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
long length, DES_key_schedule *schedule, DES_cblock *ivec,
int enc);
void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *schedule, DES_cblock *ivec,
int *num, int enc);
void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *schedule, DES_cblock *ivec,
int *num);
void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output,
long length, DES_key_schedule *schedule, DES_cblock *ivec,
const_DES_cblock *inw, const_DES_cblock *outw, int enc);
void DES_ede2_cbc_encrypt(const unsigned char *input, unsigned char *output,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_cblock *ivec, int enc);
void DES_ede2_cfb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_cblock *ivec,
int *num, int enc);
void DES_ede2_ofb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_cblock *ivec, int *num);
void DES_ede3_cbc_encrypt(const unsigned char *input, unsigned char *output,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_key_schedule *ks3,
DES_cblock *ivec, int enc);
void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_key_schedule *ks3,
DES_cblock *ivec, int *num, int enc);
void DES_ede3_ofb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_key_schedule *ks3,
DES_cblock *ivec, int *num);
DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output,
long length, DES_key_schedule *schedule,
const_DES_cblock *ivec);
DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
long length, int out_count, DES_cblock *seed);
void DES_string_to_key(const char *str, DES_cblock *key);
void DES_string_to_2keys(const char *str, DES_cblock *key1, DES_cblock *key2);
char *DES_fcrypt(const char *buf, const char *salt, char *ret);
char *DES_crypt(const char *buf, const char *salt);
=head1 DESCRIPTION
This library contains a fast implementation of the DES encryption
algorithm.
There are two phases to the use of DES encryption. The first is the
generation of a I from a key, the second is the
actual encryption. A DES key is of type I. This type
consists of 8 bytes with odd parity. The least significant bit in
each byte is the parity bit. The key schedule is an expanded form of
the key; it is used to speed the encryption process.
DES_random_key() generates a random key. The random generator must be
seeded when calling this function.
If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to
external circumstances (see L), the operation will fail.
If the function fails, 0 is returned.
Before a DES key can be used, it must be converted into the
architecture dependent I via the
DES_set_key_checked() or DES_set_key_unchecked() function.
DES_set_key_checked() will check that the key passed is of odd parity
and is not a weak or semi-weak key. If the parity is wrong, then -1
is returned. If the key is a weak key, then -2 is returned. If an
error is returned, the key schedule is not generated.
DES_set_key() works like
DES_set_key_checked() if the I flag is nonzero,
otherwise like DES_set_key_unchecked(). These functions are available
for compatibility; it is recommended to use a function that does not
depend on a global variable.
DES_set_odd_parity() sets the parity of the passed I to odd.
DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it
is ok.
The following routines mostly operate on an input and output stream of
Is.
DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
decrypts a single 8-byte I in I
(ECB) mode. It always transforms the input data, pointed to by
I, into the output data, pointed to by the I