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author | mpi <> | 2014-04-16 09:50:10 +0000 |
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committer | mpi <> | 2014-04-16 09:50:10 +0000 |
commit | 27c3c9e543412112b877fdf1f01c5fe54d220138 (patch) | |
tree | 31806a01d35adccbe3db5ef7b8b8875fdd34c5b8 /src/lib/libcrypto/doc/DES_set_key.pod | |
parent | f07c2e093541aacc69da893d98de5de30830a555 (diff) | |
download | openbsd-27c3c9e543412112b877fdf1f01c5fe54d220138.tar.gz openbsd-27c3c9e543412112b877fdf1f01c5fe54d220138.tar.bz2 openbsd-27c3c9e543412112b877fdf1f01c5fe54d220138.zip |
Sync the list of man pages for libcrypto, explicity rename conflicting
pages instead of doing it in the Makefiles and move a libssl page where
it belongs.
ok miod@
Diffstat (limited to 'src/lib/libcrypto/doc/DES_set_key.pod')
-rw-r--r-- | src/lib/libcrypto/doc/DES_set_key.pod | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/src/lib/libcrypto/doc/DES_set_key.pod b/src/lib/libcrypto/doc/DES_set_key.pod new file mode 100644 index 0000000000..6f0cf1cc5e --- /dev/null +++ b/src/lib/libcrypto/doc/DES_set_key.pod | |||
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1 | =pod | ||
2 | |||
3 | =head1 NAME | ||
4 | |||
5 | DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked, | ||
6 | DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key, | ||
7 | DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt, | ||
8 | DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt, | ||
9 | DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt, | ||
10 | DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt, | ||
11 | DES_ede3_cbcm_encrypt, DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt, | ||
12 | DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys, | ||
13 | DES_fcrypt, DES_crypt, DES_enc_read, DES_enc_write - DES encryption | ||
14 | |||
15 | =head1 SYNOPSIS | ||
16 | |||
17 | #include <openssl/des.h> | ||
18 | |||
19 | void DES_random_key(DES_cblock *ret); | ||
20 | |||
21 | 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 | |||
28 | void DES_set_odd_parity(DES_cblock *key); | ||
29 | int DES_is_weak_key(const_DES_cblock *key); | ||
30 | |||
31 | 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 | |||
39 | 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 | |||
58 | 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 | |||
62 | 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 | |||
72 | 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 | |||
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, | ||
95 | DES_cblock *key2); | ||
96 | |||
97 | char *DES_fcrypt(const char *buf, const char *salt, char *ret); | ||
98 | char *DES_crypt(const char *buf, const char *salt); | ||
99 | |||
100 | 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 | |||
105 | =head1 DESCRIPTION | ||
106 | |||
107 | This library contains a fast implementation of the DES encryption | ||
108 | algorithm. | ||
109 | |||
110 | There are two phases to the use of DES encryption. The first is the | ||
111 | generation of a I<DES_key_schedule> from a key, the second is the | ||
112 | actual encryption. A DES key is of type I<DES_cblock>. This type is | ||
113 | consists of 8 bytes with odd parity. The least significant bit in | ||
114 | each byte is the parity bit. The key schedule is an expanded form of | ||
115 | the key; it is used to speed the encryption process. | ||
116 | |||
117 | DES_random_key() generates a random key. The PRNG must be seeded | ||
118 | prior to using this function (see L<rand(3)|rand(3)>). If the PRNG | ||
119 | could not generate a secure key, 0 is returned. | ||
120 | |||
121 | Before a DES key can be used, it must be converted into the | ||
122 | architecture dependent I<DES_key_schedule> via the | ||
123 | DES_set_key_checked() or DES_set_key_unchecked() function. | ||
124 | |||
125 | DES_set_key_checked() will check that the key passed is of odd parity | ||
126 | and is not a week or semi-weak key. If the parity is wrong, then -1 | ||
127 | is returned. If the key is a weak key, then -2 is returned. If an | ||
128 | error is returned, the key schedule is not generated. | ||
129 | |||
130 | DES_set_key() works like | ||
131 | DES_set_key_checked() if the I<DES_check_key> flag is non-zero, | ||
132 | otherwise like DES_set_key_unchecked(). These functions are available | ||
133 | for compatibility; it is recommended to use a function that does not | ||
134 | depend on a global variable. | ||
135 | |||
136 | DES_set_odd_parity() sets the parity of the passed I<key> to odd. | ||
137 | |||
138 | DES_is_weak_key() returns 1 is the passed key is a weak key, 0 if it | ||
139 | is ok. The probability that a randomly generated key is weak is | ||
140 | 1/2^52, so it is not really worth checking for them. | ||
141 | |||
142 | The following routines mostly operate on an input and output stream of | ||
143 | I<DES_cblock>s. | ||
144 | |||
145 | DES_ecb_encrypt() is the basic DES encryption routine that encrypts or | ||
146 | decrypts a single 8-byte I<DES_cblock> in I<electronic code book> | ||
147 | (ECB) mode. It always transforms the input data, pointed to by | ||
148 | I<input>, into the output data, pointed to by the I<output> argument. | ||
149 | If the I<encrypt> argument is non-zero (DES_ENCRYPT), the I<input> | ||
150 | (cleartext) is encrypted in to the I<output> (ciphertext) using the | ||
151 | key_schedule specified by the I<schedule> argument, previously set via | ||
152 | I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now | ||
153 | ciphertext) is decrypted into the I<output> (now cleartext). Input | ||
154 | and output may overlap. DES_ecb_encrypt() does not return a value. | ||
155 | |||
156 | DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using | ||
157 | three-key Triple-DES encryption in ECB mode. This involves encrypting | ||
158 | the input with I<ks1>, decrypting with the key schedule I<ks2>, and | ||
159 | then encrypting with I<ks3>. This routine greatly reduces the chances | ||
160 | of brute force breaking of DES and has the advantage of if I<ks1>, | ||
161 | I<ks2> and I<ks3> are the same, it is equivalent to just encryption | ||
162 | using ECB mode and I<ks1> as the key. | ||
163 | |||
164 | The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES | ||
165 | encryption by using I<ks1> for the final encryption. | ||
166 | |||
167 | DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining> | ||
168 | (CBC) mode of DES. If the I<encrypt> argument is non-zero, the | ||
169 | routine cipher-block-chain encrypts the cleartext data pointed to by | ||
170 | the I<input> argument into the ciphertext pointed to by the I<output> | ||
171 | argument, using the key schedule provided by the I<schedule> argument, | ||
172 | and initialization vector provided by the I<ivec> argument. If the | ||
173 | I<length> argument is not an integral multiple of eight bytes, the | ||
174 | last block is copied to a temporary area and zero filled. The output | ||
175 | is always an integral multiple of eight bytes. | ||
176 | |||
177 | DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and | ||
178 | I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret | ||
179 | (unlike the iv) and are as such, part of the key. So the key is sort | ||
180 | of 24 bytes. This is much better than CBC DES. | ||
181 | |||
182 | DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with | ||
183 | three keys. This means that each DES operation inside the CBC mode is | ||
184 | really an C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL. | ||
185 | |||
186 | The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by | ||
187 | reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>. | ||
188 | This form of Triple-DES is used by the RSAREF library. | ||
189 | |||
190 | DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block | ||
191 | chaining mode used by Kerberos v4. Its parameters are the same as | ||
192 | DES_ncbc_encrypt(). | ||
193 | |||
194 | DES_cfb_encrypt() encrypt/decrypts using cipher feedback mode. This | ||
195 | method takes an array of characters as input and outputs and array of | ||
196 | characters. It does not require any padding to 8 character groups. | ||
197 | Note: the I<ivec> variable is changed and the new changed value needs to | ||
198 | be passed to the next call to this function. Since this function runs | ||
199 | a complete DES ECB encryption per I<numbits>, this function is only | ||
200 | suggested for use when sending small numbers of characters. | ||
201 | |||
202 | DES_cfb64_encrypt() | ||
203 | implements CFB mode of DES with 64bit feedback. Why is this | ||
204 | useful you ask? Because this routine will allow you to encrypt an | ||
205 | arbitrary number of bytes, no 8 byte padding. Each call to this | ||
206 | routine will encrypt the input bytes to output and then update ivec | ||
207 | and num. num contains 'how far' we are though ivec. If this does | ||
208 | not make much sense, read more about cfb mode of DES :-). | ||
209 | |||
210 | DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as | ||
211 | DES_cfb64_encrypt() except that Triple-DES is used. | ||
212 | |||
213 | DES_ofb_encrypt() encrypts using output feedback mode. This method | ||
214 | takes an array of characters as input and outputs and array of | ||
215 | characters. It does not require any padding to 8 character groups. | ||
216 | Note: the I<ivec> variable is changed and the new changed value needs to | ||
217 | be passed to the next call to this function. Since this function runs | ||
218 | a complete DES ECB encryption per numbits, this function is only | ||
219 | suggested for use when sending small numbers of characters. | ||
220 | |||
221 | DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output | ||
222 | Feed Back mode. | ||
223 | |||
224 | DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as | ||
225 | DES_ofb64_encrypt(), using Triple-DES. | ||
226 | |||
227 | The following functions are included in the DES library for | ||
228 | compatibility with the MIT Kerberos library. | ||
229 | |||
230 | DES_cbc_cksum() produces an 8 byte checksum based on the input stream | ||
231 | (via CBC encryption). The last 4 bytes of the checksum are returned | ||
232 | and the complete 8 bytes are placed in I<output>. This function is | ||
233 | used by Kerberos v4. Other applications should use | ||
234 | L<EVP_DigestInit(3)|EVP_DigestInit(3)> etc. instead. | ||
235 | |||
236 | DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte | ||
237 | checksum from the input bytes. The algorithm can be iterated over the | ||
238 | input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is | ||
239 | non-NULL, the 8 bytes generated by each pass are written into | ||
240 | I<output>. | ||
241 | |||
242 | The following are DES-based transformations: | ||
243 | |||
244 | DES_fcrypt() is a fast version of the Unix crypt(3) function. This | ||
245 | version takes only a small amount of space relative to other fast | ||
246 | crypt() implementations. This is different to the normal crypt in | ||
247 | that the third parameter is the buffer that the return value is | ||
248 | written into. It needs to be at least 14 bytes long. This function | ||
249 | is thread safe, unlike the normal crypt. | ||
250 | |||
251 | DES_crypt() is a faster replacement for the normal system crypt(). | ||
252 | This function calls DES_fcrypt() with a static array passed as the | ||
253 | third parameter. This emulates the normal non-thread safe semantics | ||
254 | of crypt(3). | ||
255 | |||
256 | DES_enc_write() writes I<len> bytes to file descriptor I<fd> from | ||
257 | buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default) | ||
258 | using I<sched> for the key and I<iv> as a starting vector. The actual | ||
259 | data send down I<fd> consists of 4 bytes (in network byte order) | ||
260 | containing the length of the following encrypted data. The encrypted | ||
261 | data then follows, padded with random data out to a multiple of 8 | ||
262 | bytes. | ||
263 | |||
264 | DES_enc_read() is used to read I<len> bytes from file descriptor | ||
265 | I<fd> into buffer I<buf>. The data being read from I<fd> is assumed to | ||
266 | have come from DES_enc_write() and is decrypted using I<sched> for | ||
267 | the key schedule and I<iv> for the initial vector. | ||
268 | |||
269 | B<Warning:> The data format used by DES_enc_write() and DES_enc_read() | ||
270 | has a cryptographic weakness: When asked to write more than MAXWRITE | ||
271 | bytes, DES_enc_write() will split the data into several chunks that | ||
272 | are all encrypted using the same IV. So don't use these functions | ||
273 | unless you are sure you know what you do (in which case you might not | ||
274 | want to use them anyway). They cannot handle non-blocking sockets. | ||
275 | DES_enc_read() uses an internal state and thus cannot be used on | ||
276 | multiple files. | ||
277 | |||
278 | I<DES_rw_mode> is used to specify the encryption mode to use with | ||
279 | DES_enc_read() and DES_end_write(). If set to I<DES_PCBC_MODE> (the | ||
280 | default), DES_pcbc_encrypt is used. If set to I<DES_CBC_MODE> | ||
281 | DES_cbc_encrypt is used. | ||
282 | |||
283 | =head1 NOTES | ||
284 | |||
285 | Single-key DES is insecure due to its short key size. ECB mode is | ||
286 | not suitable for most applications; see L<des_modes(7)|des_modes(7)>. | ||
287 | |||
288 | The L<evp(3)|evp(3)> library provides higher-level encryption functions. | ||
289 | |||
290 | =head1 BUGS | ||
291 | |||
292 | DES_3cbc_encrypt() is flawed and must not be used in applications. | ||
293 | |||
294 | DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt() | ||
295 | instead. | ||
296 | |||
297 | DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits. | ||
298 | What this means is that if you set numbits to 12, and length to 2, the | ||
299 | first 12 bits will come from the 1st input byte and the low half of | ||
300 | the second input byte. The second 12 bits will have the low 8 bits | ||
301 | taken from the 3rd input byte and the top 4 bits taken from the 4th | ||
302 | input byte. The same holds for output. This function has been | ||
303 | implemented this way because most people will be using a multiple of 8 | ||
304 | and because once you get into pulling bytes input bytes apart things | ||
305 | get ugly! | ||
306 | |||
307 | DES_string_to_key() is available for backward compatibility with the | ||
308 | MIT library. New applications should use a cryptographic hash function. | ||
309 | The same applies for DES_string_to_2key(). | ||
310 | |||
311 | =head1 CONFORMING TO | ||
312 | |||
313 | ANSI X3.106 | ||
314 | |||
315 | The B<des> library was written to be source code compatible with | ||
316 | the MIT Kerberos library. | ||
317 | |||
318 | =head1 SEE ALSO | ||
319 | |||
320 | crypt(3), L<des_modes(7)|des_modes(7)>, L<evp(3)|evp(3)>, L<rand(3)|rand(3)> | ||
321 | |||
322 | =head1 HISTORY | ||
323 | |||
324 | In OpenSSL 0.9.7, all des_ functions were renamed to DES_ to avoid | ||
325 | clashes with older versions of libdes. Compatibility des_ functions | ||
326 | are provided for a short while, as well as crypt(). | ||
327 | Declarations for these are in <openssl/des_old.h>. There is no DES_ | ||
328 | variant for des_random_seed(). | ||
329 | This will happen to other functions | ||
330 | as well if they are deemed redundant (des_random_seed() just calls | ||
331 | RAND_seed() and is present for backward compatibility only), buggy or | ||
332 | already scheduled for removal. | ||
333 | |||
334 | des_cbc_cksum(), des_cbc_encrypt(), des_ecb_encrypt(), | ||
335 | des_is_weak_key(), des_key_sched(), des_pcbc_encrypt(), | ||
336 | des_quad_cksum(), des_random_key() and des_string_to_key() | ||
337 | are available in the MIT Kerberos library; | ||
338 | des_check_key_parity(), des_fixup_key_parity() and des_is_weak_key() | ||
339 | are available in newer versions of that library. | ||
340 | |||
341 | des_set_key_checked() and des_set_key_unchecked() were added in | ||
342 | OpenSSL 0.9.5. | ||
343 | |||
344 | des_generate_random_block(), des_init_random_number_generator(), | ||
345 | des_new_random_key(), des_set_random_generator_seed() and | ||
346 | des_set_sequence_number() and des_rand_data() are used in newer | ||
347 | versions of Kerberos but are not implemented here. | ||
348 | |||
349 | des_random_key() generated cryptographically weak random data in | ||
350 | SSLeay and in OpenSSL prior version 0.9.5, as well as in the original | ||
351 | MIT library. | ||
352 | |||
353 | =head1 AUTHOR | ||
354 | |||
355 | Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project | ||
356 | (http://www.openssl.org). | ||
357 | |||
358 | =cut | ||