1des(3) OpenSSL des(3)
2
6 DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked,
7 DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key,
8 DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt,
9 DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt,
10 DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt,
11 DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt,
12 DES_ede3_cbcm_encrypt, DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt,
13 DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys,
14 DES_fcrypt, DES_crypt, DES_enc_read, DES_enc_write - DES encryption
15
17 #include <openssl/des.h>
18 void DES_random_key(DES_cblock *ret);
20 int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);
22 int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule);
23 int DES_set_key_checked(const_DES_cblock *key,
24 DES_key_schedule *schedule);
25 void DES_set_key_unchecked(const_DES_cblock *key,
26 DES_key_schedule *schedule);
27 void DES_set_odd_parity(DES_cblock *key);
29 int DES_is_weak_key(const_DES_cblock *key);
30 void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output,
32 DES_key_schedule *ks, int enc);
33 void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output,
34 DES_key_schedule *ks1, DES_key_schedule *ks2, int enc);
35 void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output,
36 DES_key_schedule *ks1, DES_key_schedule *ks2,
37 DES_key_schedule *ks3, int enc);
38 void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
40 long length, DES_key_schedule *schedule, DES_cblock *ivec,
41 int enc);
42 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out,
43 int numbits, long length, DES_key_schedule *schedule,
44 DES_cblock *ivec, int enc);
45 void DES_ofb_encrypt(const unsigned char *in, unsigned char *out,
46 int numbits, long length, DES_key_schedule *schedule,
47 DES_cblock *ivec);
48 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
49 long length, DES_key_schedule *schedule, DES_cblock *ivec,
50 int enc);
51 void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
52 long length, DES_key_schedule *schedule, DES_cblock *ivec,
53 int *num, int enc);
54 void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
55 long length, DES_key_schedule *schedule, DES_cblock *ivec,
56 int *num);
57 void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output,
59 long length, DES_key_schedule *schedule, DES_cblock *ivec,
60 const_DES_cblock *inw, const_DES_cblock *outw, int enc);
61 void DES_ede2_cbc_encrypt(const unsigned char *input,
63 unsigned char *output, long length, DES_key_schedule *ks1,
64 DES_key_schedule *ks2, DES_cblock *ivec, int enc);
65 void DES_ede2_cfb64_encrypt(const unsigned char *in,
66 unsigned char *out, long length, DES_key_schedule *ks1,
67 DES_key_schedule *ks2, DES_cblock *ivec, int *num, int enc);
68 void DES_ede2_ofb64_encrypt(const unsigned char *in,
69 unsigned char *out, long length, DES_key_schedule *ks1,
70 DES_key_schedule *ks2, DES_cblock *ivec, int *num);
71 void DES_ede3_cbc_encrypt(const unsigned char *input,
73 unsigned char *output, long length, DES_key_schedule *ks1,
74 DES_key_schedule *ks2, DES_key_schedule *ks3, DES_cblock *ivec,
75 int enc);
76 void DES_ede3_cbcm_encrypt(const unsigned char *in, unsigned char *out,
77 long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
78 DES_key_schedule *ks3, DES_cblock *ivec1, DES_cblock *ivec2,
79 int enc);
80 void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
81 long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
82 DES_key_schedule *ks3, 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 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,
95 DES_cblock *key2);
96 char *DES_fcrypt(const char *buf, const char *salt, char *ret);
98 char *DES_crypt(const char *buf, const char *salt);
99 int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
101 DES_cblock *iv);
102 int DES_enc_write(int fd, const void *buf, int len,
103 DES_key_schedule *sched, DES_cblock *iv);
104
106 This library contains a fast implementation of the DES encryption
107 algorithm.
108 There are two phases to the use of DES encryption. The first is the
110 generation of a DES_key_schedule from a key, the second is the actual
111 encryption. A DES key is of type DES_cblock. This type is consists of
112 8 bytes with odd parity. The least significant bit in each byte is the
113 parity bit. The key schedule is an expanded form of the key; it is
114 used to speed the encryption process.
115 DES_random_key() generates a random key. The PRNG must be seeded prior
117 to using this function (see rand(3)). If the PRNG could not generate a
118 secure key, 0 is returned.
119 Before a DES key can be used, it must be converted into the
121 architecture dependent DES_key_schedule via the DES_set_key_checked()
122 or DES_set_key_unchecked() function.
123 DES_set_key_checked() will check that the key passed is of odd parity
125 and is not a week or semi-weak key. If the parity is wrong, then -1 is
126 returned. If the key is a weak key, then -2 is returned. If an error
127 is returned, the key schedule is not generated.
128 DES_set_key() works like DES_set_key_checked() if the DES_check_key
130 flag is non-zero, otherwise like DES_set_key_unchecked(). These
131 functions are available for compatibility; it is recommended to use a
132 function that does not depend on a global variable.
133 DES_set_odd_parity() sets the parity of the passed key to odd.
135 DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it is
137 ok.
138 The following routines mostly operate on an input and output stream of
140 DES_cblocks.
141 DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
143 decrypts a single 8-byte DES_cblock in electronic code book (ECB) mode.
144 It always transforms the input data, pointed to by input, into the
145 output data, pointed to by the output argument. If the encrypt
146 argument is non-zero (DES_ENCRYPT), the input (cleartext) is encrypted
147 in to the output (ciphertext) using the key_schedule specified by the
148 schedule argument, previously set via DES_set_key. If encrypt is zero
149 (DES_DECRYPT), the input (now ciphertext) is decrypted into the output
150 (now cleartext). Input and output may overlap. DES_ecb_encrypt() does
151 not return a value.
152 DES_ecb3_encrypt() encrypts/decrypts the input block by using three-key
154 Triple-DES encryption in ECB mode. This involves encrypting the input
155 with ks1, decrypting with the key schedule ks2, and then encrypting
156 with ks3. This routine greatly reduces the chances of brute force
157 breaking of DES and has the advantage of if ks1, ks2 and ks3 are the
158 same, it is equivalent to just encryption using ECB mode and ks1 as the
159 key.
160 The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
162 encryption by using ks1 for the final encryption.
163 DES_ncbc_encrypt() encrypts/decrypts using the cipher-block-chaining
165 (CBC) mode of DES. If the encrypt argument is non-zero, the routine
166 cipher-block-chain encrypts the cleartext data pointed to by the input
167 argument into the ciphertext pointed to by the output argument, using
168 the key schedule provided by the schedule argument, and initialization
169 vector provided by the ivec argument. If the length argument is not an
170 integral multiple of eight bytes, the last block is copied to a
171 temporary area and zero filled. The output is always an integral
172 multiple of eight bytes.
173 DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses inw and outw to
175 'whiten' the encryption. inw and outw are secret (unlike the iv) and
176 are as such, part of the key. So the key is sort of 24 bytes. This is
177 much better than CBC DES.
178 DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
180 three keys. This means that each DES operation inside the CBC mode is
181 an "C=E(ks3,D(ks2,E(ks1,M)))". This mode is used by SSL.
182 The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
184 reusing ks1 for the final encryption. "C=E(ks1,D(ks2,E(ks1,M)))".
185 This form of Triple-DES is used by the RSAREF library.
186 DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block
188 chaining mode used by Kerberos v4. Its parameters are the same as
189 DES_ncbc_encrypt().
190 DES_cfb_encrypt() encrypt/decrypts using cipher feedback mode. This
192 method takes an array of characters as input and outputs and array of
193 characters. It does not require any padding to 8 character groups.
194 Note: the ivec variable is changed and the new changed value needs to
195 be passed to the next call to this function. Since this function runs
196 a complete DES ECB encryption per numbits, this function is only
197 suggested for use when sending small numbers of characters.
198 DES_cfb64_encrypt() implements CFB mode of DES with 64bit feedback.
200 Why is this useful you ask? Because this routine will allow you to
201 encrypt an arbitrary number of bytes, no 8 byte padding. Each call to
202 this routine will encrypt the input bytes to output and then update
203 ivec and num. num contains 'how far' we are though ivec. If this does
204 not make much sense, read more about cfb mode of DES :-).
205 DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as
207 DES_cfb64_encrypt() except that Triple-DES is used.
208 DES_ofb_encrypt() encrypts using output feedback mode. This method
210 takes an array of characters as input and outputs and array of
211 characters. It does not require any padding to 8 character groups.
212 Note: the ivec variable is changed and the new changed value needs to
213 be passed to the next call to this function. Since this function runs
214 a complete DES ECB encryption per numbits, this function is only
215 suggested for use when sending small numbers of characters.
216 DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
218 Feed Back mode.
219 DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
221 DES_ofb64_encrypt(), using Triple-DES.
222 The following functions are included in the DES library for
224 compatibility with the MIT Kerberos library.
225 DES_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
228 and the complete 8 bytes are placed in output. This function is used by
229 Kerberos v4. Other applications should use EVP_DigestInit(3) etc.
230 instead.
231 DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte
233 checksum from the input bytes. The algorithm can be iterated over the
234 input, depending on out_count, 1, 2, 3 or 4 times. If output is non-
235 NULL, the 8 bytes generated by each pass are written into output.
236 The following are DES-based transformations:
238 DES_fcrypt() is a fast version of the Unix crypt(3) function. This
240 version takes only a small amount of space relative to other fast
241 crypt() implementations. This is different to the normal crypt in that
242 the third parameter is the buffer that the return value is written
243 into. It needs to be at least 14 bytes long. This function is thread
244 safe, unlike the normal crypt.
245 DES_crypt() is a faster replacement for the normal system crypt().
247 This function calls DES_fcrypt() with a static array passed as the
248 third parameter. This emulates the normal non-thread safe semantics of
249 crypt(3).
250 DES_enc_write() writes len bytes to file descriptor fd from buffer buf.
252 The data is encrypted via pcbc_encrypt (default) using sched for the
253 key and iv as a starting vector. The actual data send down fd consists
254 of 4 bytes (in network byte order) containing the length of the
255 following encrypted data. The encrypted data then follows, padded with
256 random data out to a multiple of 8 bytes.
257 DES_enc_read() is used to read len bytes from file descriptor fd into
259 buffer buf. The data being read from fd is assumed to have come from
260 DES_enc_write() and is decrypted using sched for the key schedule and
261 iv for the initial vector.
262 Warning: The data format used by DES_enc_write() and DES_enc_read() has
264 a cryptographic weakness: When asked to write more than MAXWRITE bytes,
265 DES_enc_write() will split the data into several chunks that are all
266 encrypted using the same IV. So don't use these functions unless you
267 are sure you know what you do (in which case you might not want to use
268 them anyway). They cannot handle non-blocking sockets. DES_enc_read()
269 uses an internal state and thus cannot be used on multiple files.
270 DES_rw_mode is used to specify the encryption mode to use with
272 DES_enc_read() and DES_end_write(). If set to DES_PCBC_MODE (the
273 default), DES_pcbc_encrypt is used. If set to DES_CBC_MODE
274 DES_cbc_encrypt is used.
275
277 Single-key DES is insecure due to its short key size. ECB mode is not
278 suitable for most applications; see des_modes(7).
279 The evp(3) library provides higher-level encryption functions.
281
283 DES_3cbc_encrypt() is flawed and must not be used in applications.
284 DES_cbc_encrypt() does not modify ivec; use DES_ncbc_encrypt() instead.
286 DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
288 What this means is that if you set numbits to 12, and length to 2, the
289 first 12 bits will come from the 1st input byte and the low half of the
290 second input byte. The second 12 bits will have the low 8 bits taken
291 from the 3rd input byte and the top 4 bits taken from the 4th input
292 byte. The same holds for output. This function has been implemented
293 this way because most people will be using a multiple of 8 and because
294 once you get into pulling bytes input bytes apart things get ugly!
295 DES_string_to_key() is available for backward compatibility with the
297 MIT library. New applications should use a cryptographic hash
298 function. The same applies for DES_string_to_2key().
299
301 ANSI X3.106
302 The des library was written to be source code compatible with the MIT
304 Kerberos library.
305
307 crypt(3), des_modes(7), evp(3), rand(3)
308
310 In OpenSSL 0.9.7, all des_ functions were renamed to DES_ to avoid
311 clashes with older versions of libdes. Compatibility des_ functions
312 are provided for a short while, as well as crypt(). Declarations for
313 these are in <openssl/des_old.h>. There is no DES_ variant for
314 des_random_seed(). This will happen to other functions as well if they
315 are deemed redundant (des_random_seed() just calls RAND_seed() and is
316 present for backward compatibility only), buggy or already scheduled
317 for removal.
318 des_cbc_cksum(), des_cbc_encrypt(), des_ecb_encrypt(),
320 des_is_weak_key(), des_key_sched(), des_pcbc_encrypt(),
321 des_quad_cksum(), des_random_key() and des_string_to_key() are
322 available in the MIT Kerberos library; des_check_key_parity(),
323 des_fixup_key_parity() and des_is_weak_key() are available in newer
324 versions of that library.
325 des_set_key_checked() and des_set_key_unchecked() were added in OpenSSL
327 0.9.5.
328 des_generate_random_block(), des_init_random_number_generator(),
330 des_new_random_key(), des_set_random_generator_seed() and
331 des_set_sequence_number() and des_rand_data() are used in newer
332 versions of Kerberos but are not implemented here.
333 des_random_key() generated cryptographically weak random data in SSLeay
335 and in OpenSSL prior version 0.9.5, as well as in the original MIT
336 library.
337
339 Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project
340 (http://www.openssl.org).
3411.0.2k 2017-01-26 des(3)