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    Command:

    des

    
           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_cbcm_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_enc_read, DES_enc_write - DES encryption
    
    
    

    SYNOPSIS

            #include <openssl/des.h>
    
            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,
                   DES_key_schedule *ks2, DES_key_schedule *ks3, DES_cblock *ivec,
                   int enc);
            void DES_ede3_cbcm_encrypt(const unsigned char *in, unsigned char *out,
                   long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
                   DES_key_schedule *ks3, DES_cblock *ivec1, DES_cblock *ivec2,
                   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);
    
            int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
                   DES_cblock *iv);
            int DES_enc_write(int fd, const void *buf, int len,
                   DES_key_schedule *sched, DES_cblock *iv);
    
    
    

    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 DES_key_schedule from a key, the second is the actual
           encryption.  A DES key is of type DES_cblock. This type is 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 PRNG must be seeded prior
           to using this function (see rand(3)).  If the PRNG could not generate a
           secure key, 0 is returned.
    
           Before a DES key can be used, it must be converted into the
           architecture dependent DES_key_schedule 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 week or semi-weak key.  If the parity is wrong, then -1 is
           The following routines mostly operate on an input and output stream of
           DES_cblocks.
    
           DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
           decrypts a single 8-byte DES_cblock in electronic code book (ECB) mode.
           It always transforms the input data, pointed to by input, into the
           output data, pointed to by the output argument.  If the encrypt
           argument is non-zero (DES_ENCRYPT), the input (cleartext) is encrypted
           in to the output (ciphertext) using the key_schedule specified by the
           schedule argument, previously set via DES_set_key. If encrypt is zero
           (DES_DECRYPT), the input (now ciphertext) is decrypted into the output
           (now cleartext).  Input and output may overlap.  DES_ecb_encrypt() does
           not return a value.
    
           DES_ecb3_encrypt() encrypts/decrypts the input block by using three-key
           Triple-DES encryption in ECB mode.  This involves encrypting the input
           with ks1, decrypting with the key schedule ks2, and then encrypting
           with ks3.  This routine greatly reduces the chances of brute force
           breaking of DES and has the advantage of if ks1, ks2 and ks3 are the
           same, it is equivalent to just encryption using ECB mode and ks1 as the
           key.
    
           The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
           encryption by using ks1 for the final encryption.
    
           DES_ncbc_encrypt() encrypts/decrypts using the cipher-block-chaining
           (CBC) mode of DES.  If the encrypt argument is non-zero, the routine
           cipher-block-chain encrypts the cleartext data pointed to by the input
           argument into the ciphertext pointed to by the output argument, using
           the key schedule provided by the schedule argument, and initialization
           vector provided by the ivec argument.  If the length argument is not an
           integral multiple of eight bytes, the last block is copied to a
           temporary area and zero filled.  The output is always an integral
           multiple of eight bytes.
    
           DES_xcbc_encrypt() is RSA's DESX mode of DES.  It uses inw and outw to
           'whiten' the encryption.  inw and outw are secret (unlike the iv) and
           are as such, part of the key.  So the key is sort of 24 bytes.  This is
           much better than CBC DES.
    
           DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
           three keys. This means that each DES operation inside the CBC mode is
           really an "C=E(ks3,D(ks2,E(ks1,M)))".  This mode is used by SSL.
    
           The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
           reusing ks1 for the final encryption.  "C=E(ks1,D(ks2,E(ks1,M)))".
           This form of Triple-DES is used by the RSAREF library.
    
           DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block
           chaining mode used by Kerberos v4. Its parameters are the same as
           DES_ncbc_encrypt().
    
    
           DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as
           DES_cfb64_encrypt() except that Triple-DES is used.
    
           DES_ofb_encrypt() encrypts using output feedback mode.  This method
           takes an array of characters as input and outputs and array of
           characters.  It does not require any padding to 8 character groups.
           Note: the ivec variable is changed and the new changed value needs to
           be passed to the next call to this function.  Since this function runs
           a complete DES ECB encryption per numbits, this function is only
           suggested for use when sending small numbers of characters.
    
           DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
           Feed Back mode.
    
           DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
           DES_ofb64_encrypt(), using Triple-DES.
    
           The following functions are included in the DES library for
           compatibility with the MIT Kerberos library.
    
           DES_cbc_cksum() produces an 8 byte checksum based on the input stream
           (via CBC encryption).  The last 4 bytes of the checksum are returned
           and the complete 8 bytes are placed in output. This function is used by
           Kerberos v4.  Other applications should use EVP_DigestInit(3) etc.
           instead.
    
           DES_quad_cksum() is a Kerberos v4 function.  It returns a 4 byte
           checksum from the input bytes.  The algorithm can be iterated over the
           input, depending on out_count, 1, 2, 3 or 4 times.  If output is non-
           NULL, the 8 bytes generated by each pass are written into output.
    
           The following are DES-based transformations:
    
           DES_fcrypt() is a fast version of the Unix crypt(3) function.  This
           version takes only a small amount of space relative to other fast
           crypt() implementations.  This is different to the normal crypt in that
           the third parameter is the buffer that the return value is written
           into.  It needs to be at least 14 bytes long.  This function is thread
           safe, unlike the normal crypt.
    
           DES_crypt() is a faster replacement for the normal system crypt().
           This function calls DES_fcrypt() with a static array passed as the
           third parameter.  This emulates the normal non-thread safe semantics of
           crypt(3).
    
           DES_enc_write() writes len bytes to file descriptor fd from buffer buf.
           The data is encrypted via pcbc_encrypt (default) using sched for the
           key and iv as a starting vector.  The actual data send down fd consists
           of 4 bytes (in network byte order) containing the length of the
           following encrypted data.  The encrypted data then follows, padded with
           random data out to a multiple of 8 bytes.
           DES_rw_mode is used to specify the encryption mode to use with
           DES_enc_read() and DES_end_write().  If set to DES_PCBC_MODE (the
           default), DES_pcbc_encrypt is used.  If set to DES_CBC_MODE
           DES_cbc_encrypt is used.
    
    
    

    NOTES

           Single-key DES is insecure due to its short key size.  ECB mode is not
           suitable for most applications; see des_modes(7).
    
           The evp(3) library provides higher-level encryption functions.
    
    
    

    BUGS

           DES_3cbc_encrypt() is flawed and must not be used in applications.
    
           DES_cbc_encrypt() does not modify ivec; use DES_ncbc_encrypt() instead.
    
           DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
           What this means is that if you set numbits to 12, and length to 2, the
           first 12 bits will come from the 1st input byte and the low half of the
           second input byte.  The second 12 bits will have the low 8 bits taken
           from the 3rd input byte and the top 4 bits taken from the 4th input
           byte.  The same holds for output.  This function has been implemented
           this way because most people will be using a multiple of 8 and because
           once you get into pulling bytes input bytes apart things get ugly!
    
           DES_string_to_key() is available for backward compatibility with the
           MIT library.  New applications should use a cryptographic hash
           function.  The same applies for DES_string_to_2key().
    
    
    

    CONFORMING TO

           ANSI X3.106
    
           The des library was written to be source code compatible with the MIT
           Kerberos library.
    
    
    

    SEE ALSO

           crypt(3), des_modes(7), evp(3), rand(3)
    
    
    

    HISTORY

           In OpenSSL 0.9.7, all des_ functions were renamed to DES_ to avoid
           clashes with older versions of libdes.  Compatibility des_ functions
           are provided for a short while, as well as crypt().  Declarations for
           these are in <openssl/des_old.h>. There is no DES_ variant for
           des_random_seed().  This will happen to other functions as well if they
           are deemed redundant (des_random_seed() just calls RAND_seed() and is
           present for backward compatibility only), buggy or already scheduled
           for removal.
    
           des_cbc_cksum(), des_cbc_encrypt(), des_ecb_encrypt(),
           des_is_weak_key(), des_key_sched(), des_pcbc_encrypt(),
           des_quad_cksum(), des_random_key() and des_string_to_key() are
           available in the MIT Kerberos library; des_check_key_parity(),
    
    
    

    AUTHOR

           Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project
           (http://www.openssl.org).
    
    
    

    1.0.1e 2013-02-11 des(3)

    
    
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