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_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
17 #include <openssl/des.h>
19 void DES_random_key(DES_cblock *ret);
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);
28 void DES_set_odd_parity(DES_cblock *key);
29 int DES_is_weak_key(const_DES_cblock *key);
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);
39 void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
40 long length, DES_key_schedule *schedule, DES_cblock *ivec,
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,
48 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
49 long length, DES_key_schedule *schedule, DES_cblock *ivec,
51 void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
52 long length, DES_key_schedule *schedule, DES_cblock *ivec,
54 void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
55 long length, DES_key_schedule *schedule, DES_cblock *ivec,
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);
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);
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,
76 void DES_ede3_cfb64_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 *ivec, int *num, int enc);
79 void DES_ede3_ofb64_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);
84 DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output,
85 long length, DES_key_schedule *schedule,
86 const_DES_cblock *ivec);
87 DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
88 long length, int out_count, DES_cblock *seed);
89 void DES_string_to_key(const char *str, DES_cblock *key);
90 void DES_string_to_2keys(const char *str, DES_cblock *key1,
93 char *DES_fcrypt(const char *buf, const char *salt, char *ret);
94 char *DES_crypt(const char *buf, const char *salt);
96 int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
98 int DES_enc_write(int fd, const void *buf, int len,
99 DES_key_schedule *sched, DES_cblock *iv);
103 This library contains a fast implementation of the DES encryption
106 There are two phases to the use of DES encryption. The first is the
107 generation of a I<DES_key_schedule> from a key, the second is the
108 actual encryption. A DES key is of type I<DES_cblock>. This type is
109 consists of 8 bytes with odd parity. The least significant bit in
110 each byte is the parity bit. The key schedule is an expanded form of
111 the key; it is used to speed the encryption process.
113 DES_random_key() generates a random key. The PRNG must be seeded
114 prior to using this function (see L<rand(3)>). If the PRNG
115 could not generate a secure key, 0 is returned.
117 Before a DES key can be used, it must be converted into the
118 architecture dependent I<DES_key_schedule> via the
119 DES_set_key_checked() or DES_set_key_unchecked() function.
121 DES_set_key_checked() will check that the key passed is of odd parity
122 and is not a week or semi-weak key. If the parity is wrong, then -1
123 is returned. If the key is a weak key, then -2 is returned. If an
124 error is returned, the key schedule is not generated.
126 DES_set_key() works like
127 DES_set_key_checked() if the I<DES_check_key> flag is non-zero,
128 otherwise like DES_set_key_unchecked(). These functions are available
129 for compatibility; it is recommended to use a function that does not
130 depend on a global variable.
132 DES_set_odd_parity() sets the parity of the passed I<key> to odd.
134 DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it
137 The following routines mostly operate on an input and output stream of
140 DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
141 decrypts a single 8-byte I<DES_cblock> in I<electronic code book>
142 (ECB) mode. It always transforms the input data, pointed to by
143 I<input>, into the output data, pointed to by the I<output> argument.
144 If the I<encrypt> argument is non-zero (DES_ENCRYPT), the I<input>
145 (cleartext) is encrypted in to the I<output> (ciphertext) using the
146 key_schedule specified by the I<schedule> argument, previously set via
147 I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now
148 ciphertext) is decrypted into the I<output> (now cleartext). Input
149 and output may overlap. DES_ecb_encrypt() does not return a value.
151 DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using
152 three-key Triple-DES encryption in ECB mode. This involves encrypting
153 the input with I<ks1>, decrypting with the key schedule I<ks2>, and
154 then encrypting with I<ks3>. This routine greatly reduces the chances
155 of brute force breaking of DES and has the advantage of if I<ks1>,
156 I<ks2> and I<ks3> are the same, it is equivalent to just encryption
157 using ECB mode and I<ks1> as the key.
159 The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
160 encryption by using I<ks1> for the final encryption.
162 DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining>
163 (CBC) mode of DES. If the I<encrypt> argument is non-zero, the
164 routine cipher-block-chain encrypts the cleartext data pointed to by
165 the I<input> argument into the ciphertext pointed to by the I<output>
166 argument, using the key schedule provided by the I<schedule> argument,
167 and initialization vector provided by the I<ivec> argument. If the
168 I<length> argument is not an integral multiple of eight bytes, the
169 last block is copied to a temporary area and zero filled. The output
170 is always an integral multiple of eight bytes.
172 DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and
173 I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret
174 (unlike the iv) and are as such, part of the key. So the key is sort
175 of 24 bytes. This is much better than CBC DES.
177 DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
178 three keys. This means that each DES operation inside the CBC mode is
179 an C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL.
181 The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
182 reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>.
183 This form of Triple-DES is used by the RSAREF library.
185 DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block
186 chaining mode used by Kerberos v4. Its parameters are the same as
189 DES_cfb_encrypt() encrypt/decrypts using cipher feedback mode. This
190 method takes an array of characters as input and outputs and array of
191 characters. It does not require any padding to 8 character groups.
192 Note: the I<ivec> variable is changed and the new changed value needs to
193 be passed to the next call to this function. Since this function runs
194 a complete DES ECB encryption per I<numbits>, this function is only
195 suggested for use when sending small numbers of characters.
198 implements CFB mode of DES with 64bit feedback. Why is this
199 useful you ask? Because this routine will allow you to encrypt an
200 arbitrary number of bytes, no 8 byte padding. Each call to this
201 routine will encrypt the input bytes to output and then update ivec
202 and num. num contains 'how far' we are though ivec. If this does
203 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
206 DES_cfb64_encrypt() except that Triple-DES is used.
208 DES_ofb_encrypt() encrypts using output feedback mode. This method
209 takes an array of characters as input and outputs and array of
210 characters. It does not require any padding to 8 character groups.
211 Note: the I<ivec> variable is changed and the new changed value needs to
212 be passed to the next call to this function. Since this function runs
213 a complete DES ECB encryption per numbits, this function is only
214 suggested for use when sending small numbers of characters.
216 DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
219 DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
220 DES_ofb64_encrypt(), using Triple-DES.
222 The following functions are included in the DES library for
223 compatibility with the MIT Kerberos library.
225 DES_cbc_cksum() produces an 8 byte checksum based on the input stream
226 (via CBC encryption). The last 4 bytes of the checksum are returned
227 and the complete 8 bytes are placed in I<output>. This function is
228 used by Kerberos v4. Other applications should use
229 L<EVP_DigestInit(3)> etc. instead.
231 DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte
232 checksum from the input bytes. The algorithm can be iterated over the
233 input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is
234 non-NULL, the 8 bytes generated by each pass are written into
237 The following are DES-based transformations:
239 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
242 that the third parameter is the buffer that the return value is
243 written into. It needs to be at least 14 bytes long. This function
244 is thread safe, unlike the normal crypt.
246 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
251 DES_enc_write() writes I<len> bytes to file descriptor I<fd> from
252 buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default)
253 using I<sched> for the key and I<iv> as a starting vector. The actual
254 data send down I<fd> consists of 4 bytes (in network byte order)
255 containing the length of the following encrypted data. The encrypted
256 data then follows, padded with random data out to a multiple of 8
259 DES_enc_read() is used to read I<len> bytes from file descriptor
260 I<fd> into buffer I<buf>. The data being read from I<fd> is assumed to
261 have come from DES_enc_write() and is decrypted using I<sched> for
262 the key schedule and I<iv> for the initial vector.
264 B<Warning:> The data format used by DES_enc_write() and DES_enc_read()
265 has a cryptographic weakness: When asked to write more than MAXWRITE
266 bytes, DES_enc_write() will split the data into several chunks that
267 are all encrypted using the same IV. So don't use these functions
268 unless you are sure you know what you do (in which case you might not
269 want to use them anyway). They cannot handle non-blocking sockets.
270 DES_enc_read() uses an internal state and thus cannot be used on
273 I<DES_rw_mode> is used to specify the encryption mode to use with
274 DES_enc_read() and DES_end_write(). If set to I<DES_PCBC_MODE> (the
275 default), DES_pcbc_encrypt is used. If set to I<DES_CBC_MODE>
276 DES_cbc_encrypt is used.
280 DES_3cbc_encrypt() is flawed and must not be used in applications.
282 DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt()
285 DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
286 What this means is that if you set numbits to 12, and length to 2, the
287 first 12 bits will come from the 1st input byte and the low half of
288 the second input byte. The second 12 bits will have the low 8 bits
289 taken from the 3rd input byte and the top 4 bits taken from the 4th
290 input byte. The same holds for output. This function has been
291 implemented this way because most people will be using a multiple of 8
292 and because once you get into pulling bytes input bytes apart things
295 DES_string_to_key() is available for backward compatibility with the
296 MIT library. New applications should use a cryptographic hash function.
297 The same applies for DES_string_to_2key().
303 The B<des> library was written to be source code compatible with
304 the MIT Kerberos library.
308 Applications should use the higher level functions
309 L<EVP_EncryptInit(3)> etc. instead of calling these
312 Single-key DES is insecure due to its short key size. ECB mode is
313 not suitable for most applications; see L<des_modes(7)>.
318 L<EVP_EncryptInit(3)>