1=pod 2 3=head1 NAME 4 5DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked, 6DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key, 7DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt, 8DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt, 9DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt, 10DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt, 11DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt, 12DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys, 13DES_fcrypt, DES_crypt - DES encryption 14 15=head1 SYNOPSIS 16 17 #include <openssl/des.h> 18 19The following functions have been deprecated since OpenSSL 3.0, and can be 20hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 21see L<openssl_user_macros(7)>: 22 23 void DES_random_key(DES_cblock *ret); 24 25 int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule); 26 int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule); 27 int DES_set_key_checked(const_DES_cblock *key, DES_key_schedule *schedule); 28 void DES_set_key_unchecked(const_DES_cblock *key, DES_key_schedule *schedule); 29 30 void DES_set_odd_parity(DES_cblock *key); 31 int DES_is_weak_key(const_DES_cblock *key); 32 33 void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output, 34 DES_key_schedule *ks, int enc); 35 void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output, 36 DES_key_schedule *ks1, DES_key_schedule *ks2, int enc); 37 void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output, 38 DES_key_schedule *ks1, DES_key_schedule *ks2, 39 DES_key_schedule *ks3, int enc); 40 41 void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output, 42 long length, DES_key_schedule *schedule, DES_cblock *ivec, 43 int enc); 44 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, 45 int numbits, long length, DES_key_schedule *schedule, 46 DES_cblock *ivec, int enc); 47 void DES_ofb_encrypt(const unsigned char *in, unsigned char *out, 48 int numbits, long length, DES_key_schedule *schedule, 49 DES_cblock *ivec); 50 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output, 51 long length, DES_key_schedule *schedule, DES_cblock *ivec, 52 int enc); 53 void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out, 54 long length, DES_key_schedule *schedule, DES_cblock *ivec, 55 int *num, int enc); 56 void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out, 57 long length, DES_key_schedule *schedule, DES_cblock *ivec, 58 int *num); 59 60 void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output, 61 long length, DES_key_schedule *schedule, DES_cblock *ivec, 62 const_DES_cblock *inw, const_DES_cblock *outw, int enc); 63 64 void DES_ede2_cbc_encrypt(const unsigned char *input, unsigned char *output, 65 long length, DES_key_schedule *ks1, 66 DES_key_schedule *ks2, DES_cblock *ivec, int enc); 67 void DES_ede2_cfb64_encrypt(const unsigned char *in, unsigned char *out, 68 long length, DES_key_schedule *ks1, 69 DES_key_schedule *ks2, DES_cblock *ivec, 70 int *num, int enc); 71 void DES_ede2_ofb64_encrypt(const unsigned char *in, unsigned char *out, 72 long length, DES_key_schedule *ks1, 73 DES_key_schedule *ks2, DES_cblock *ivec, int *num); 74 75 void DES_ede3_cbc_encrypt(const unsigned char *input, unsigned char *output, 76 long length, DES_key_schedule *ks1, 77 DES_key_schedule *ks2, DES_key_schedule *ks3, 78 DES_cblock *ivec, int enc); 79 void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out, 80 long length, DES_key_schedule *ks1, 81 DES_key_schedule *ks2, DES_key_schedule *ks3, 82 DES_cblock *ivec, int *num, int enc); 83 void DES_ede3_ofb64_encrypt(const unsigned char *in, unsigned char *out, 84 long length, DES_key_schedule *ks1, 85 DES_key_schedule *ks2, DES_key_schedule *ks3, 86 DES_cblock *ivec, int *num); 87 88 DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output, 89 long length, DES_key_schedule *schedule, 90 const_DES_cblock *ivec); 91 DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[], 92 long length, int out_count, DES_cblock *seed); 93 void DES_string_to_key(const char *str, DES_cblock *key); 94 void DES_string_to_2keys(const char *str, DES_cblock *key1, DES_cblock *key2); 95 96 char *DES_fcrypt(const char *buf, const char *salt, char *ret); 97 char *DES_crypt(const char *buf, const char *salt); 98 99=head1 DESCRIPTION 100 101All of the functions described on this page are deprecated. Applications should 102instead use L<EVP_EncryptInit_ex(3)>, L<EVP_EncryptUpdate(3)> and 103L<EVP_EncryptFinal_ex(3)> or the equivalently named decrypt functions. 104 105This library contains a fast implementation of the DES encryption 106algorithm. 107 108There are two phases to the use of DES encryption. The first is the 109generation of a I<DES_key_schedule> from a key, the second is the 110actual encryption. A DES key is of type I<DES_cblock>. This type 111consists of 8 bytes with odd parity. The least significant bit in 112each byte is the parity bit. The key schedule is an expanded form of 113the key; it is used to speed the encryption process. 114 115DES_random_key() generates a random key. The random generator must be 116seeded when calling this function. 117If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to 118external circumstances (see L<RAND(7)>), the operation will fail. 119If the function fails, 0 is returned. 120 121Before a DES key can be used, it must be converted into the 122architecture dependent I<DES_key_schedule> via the 123DES_set_key_checked() or DES_set_key_unchecked() function. 124 125DES_set_key_checked() will check that the key passed is of odd parity 126and is not a weak or semi-weak key. If the parity is wrong, then -1 127is returned. If the key is a weak key, then -2 is returned. If an 128error is returned, the key schedule is not generated. 129 130DES_set_key() works like DES_set_key_checked() and remains for 131backward compatibility. 132 133DES_set_odd_parity() sets the parity of the passed I<key> to odd. 134 135DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it 136is ok. 137 138The following routines mostly operate on an input and output stream of 139I<DES_cblock>s. 140 141DES_ecb_encrypt() is the basic DES encryption routine that encrypts or 142decrypts a single 8-byte I<DES_cblock> in I<electronic code book> 143(ECB) mode. It always transforms the input data, pointed to by 144I<input>, into the output data, pointed to by the I<output> argument. 145If the I<encrypt> argument is nonzero (DES_ENCRYPT), the I<input> 146(cleartext) is encrypted in to the I<output> (ciphertext) using the 147key_schedule specified by the I<schedule> argument, previously set via 148I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now 149ciphertext) is decrypted into the I<output> (now cleartext). Input 150and output may overlap. DES_ecb_encrypt() does not return a value. 151 152DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using 153three-key Triple-DES encryption in ECB mode. This involves encrypting 154the input with I<ks1>, decrypting with the key schedule I<ks2>, and 155then encrypting with I<ks3>. This routine greatly reduces the chances 156of brute force breaking of DES and has the advantage of if I<ks1>, 157I<ks2> and I<ks3> are the same, it is equivalent to just encryption 158using ECB mode and I<ks1> as the key. 159 160The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES 161encryption by using I<ks1> for the final encryption. 162 163DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining> 164(CBC) mode of DES. If the I<encrypt> argument is nonzero, the 165routine cipher-block-chain encrypts the cleartext data pointed to by 166the I<input> argument into the ciphertext pointed to by the I<output> 167argument, using the key schedule provided by the I<schedule> argument, 168and initialization vector provided by the I<ivec> argument. If the 169I<length> argument is not an integral multiple of eight bytes, the 170last block is copied to a temporary area and zero filled. The output 171is always an integral multiple of eight bytes. 172 173DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and 174I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret 175(unlike the iv) and are as such, part of the key. So the key is sort 176of 24 bytes. This is much better than CBC DES. 177 178DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with 179three keys. This means that each DES operation inside the CBC mode is 180C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL. 181 182The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by 183reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>. 184This form of Triple-DES is used by the RSAREF library. 185 186DES_pcbc_encrypt() encrypts/decrypts using the propagating cipher block 187chaining mode used by Kerberos v4. Its parameters are the same as 188DES_ncbc_encrypt(). 189 190DES_cfb_encrypt() encrypts/decrypts using cipher feedback mode. This 191method takes an array of characters as input and outputs an array of 192characters. It does not require any padding to 8 character groups. 193Note: the I<ivec> variable is changed and the new changed value needs to 194be passed to the next call to this function. Since this function runs 195a complete DES ECB encryption per I<numbits>, this function is only 196suggested for use when sending a small number of characters. 197 198DES_cfb64_encrypt() 199implements CFB mode of DES with 64-bit feedback. Why is this 200useful you ask? Because this routine will allow you to encrypt an 201arbitrary number of bytes, without 8 byte padding. Each call to this 202routine will encrypt the input bytes to output and then update ivec 203and num. num contains 'how far' we are though ivec. If this does 204not make much sense, read more about CFB mode of DES. 205 206DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as 207DES_cfb64_encrypt() except that Triple-DES is used. 208 209DES_ofb_encrypt() encrypts using output feedback mode. This method 210takes an array of characters as input and outputs an array of 211characters. It does not require any padding to 8 character groups. 212Note: the I<ivec> variable is changed and the new changed value needs to 213be passed to the next call to this function. Since this function runs 214a complete DES ECB encryption per I<numbits>, this function is only 215suggested for use when sending a small number of characters. 216 217DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output 218Feed Back mode. 219 220DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as 221DES_ofb64_encrypt(), using Triple-DES. 222 223The following functions are included in the DES library for 224compatibility with the MIT Kerberos library. 225 226DES_cbc_cksum() produces an 8 byte checksum based on the input stream 227(via CBC encryption). The last 4 bytes of the checksum are returned 228and the complete 8 bytes are placed in I<output>. This function is 229used by Kerberos v4. Other applications should use 230L<EVP_DigestInit(3)> etc. instead. 231 232DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte 233checksum from the input bytes. The algorithm can be iterated over the 234input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is 235non-NULL, the 8 bytes generated by each pass are written into 236I<output>. 237 238The following are DES-based transformations: 239 240DES_fcrypt() is a fast version of the Unix crypt(3) function. This 241version takes only a small amount of space relative to other fast 242crypt() implementations. This is different to the normal crypt() in 243that the third parameter is the buffer that the return value is 244written into. It needs to be at least 14 bytes long. This function 245is thread safe, unlike the normal crypt(). 246 247DES_crypt() is a faster replacement for the normal system crypt(). 248This function calls DES_fcrypt() with a static array passed as the 249third parameter. This mostly emulates the normal non-thread-safe semantics 250of crypt(3). 251The B<salt> must be two ASCII characters. 252 253The values returned by DES_fcrypt() and DES_crypt() are terminated by NUL 254character. 255 256DES_enc_write() writes I<len> bytes to file descriptor I<fd> from 257buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default) 258using I<sched> for the key and I<iv> as a starting vector. The actual 259data send down I<fd> consists of 4 bytes (in network byte order) 260containing the length of the following encrypted data. The encrypted 261data then follows, padded with random data out to a multiple of 8 262bytes. 263 264=head1 BUGS 265 266DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt() 267instead. 268 269DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits. 270What this means is that if you set numbits to 12, and length to 2, the 271first 12 bits will come from the 1st input byte and the low half of 272the second input byte. The second 12 bits will have the low 8 bits 273taken from the 3rd input byte and the top 4 bits taken from the 4th 274input byte. The same holds for output. This function has been 275implemented this way because most people will be using a multiple of 8 276and because once you get into pulling bytes input bytes apart things 277get ugly! 278 279DES_string_to_key() is available for backward compatibility with the 280MIT library. New applications should use a cryptographic hash function. 281The same applies for DES_string_to_2key(). 282 283=head1 NOTES 284 285The B<des> library was written to be source code compatible with 286the MIT Kerberos library. 287 288Applications should use the higher level functions 289L<EVP_EncryptInit(3)> etc. instead of calling these 290functions directly. 291 292Single-key DES is insecure due to its short key size. ECB mode is 293not suitable for most applications; see L<des_modes(7)>. 294 295=head1 RETURN VALUES 296 297DES_set_key(), DES_key_sched(), and DES_set_key_checked() 298return 0 on success or negative values on error. 299 300DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it 301is ok. 302 303DES_cbc_cksum() and DES_quad_cksum() return 4-byte integer representing the 304last 4 bytes of the checksum of the input. 305 306DES_fcrypt() returns a pointer to the caller-provided buffer and DES_crypt() - 307to a static buffer on success; otherwise they return NULL. 308 309=head1 SEE ALSO 310 311L<des_modes(7)>, 312L<EVP_EncryptInit(3)> 313 314=head1 HISTORY 315 316All of these functions were deprecated in OpenSSL 3.0. 317 318The requirement that the B<salt> parameter to DES_crypt() and DES_fcrypt() 319be two ASCII characters was first enforced in 320OpenSSL 1.1.0. Previous versions tried to use the letter uppercase B<A> 321if both character were not present, and could crash when given non-ASCII 322on some platforms. 323 324=head1 COPYRIGHT 325 326Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 327 328Licensed under the Apache License 2.0 (the "License"). You may not use 329this file except in compliance with the License. You can obtain a copy 330in the file LICENSE in the source distribution or at 331L<https://www.openssl.org/source/license.html>. 332 333=cut 334