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_read_password, DES_read_2passwords, DES_read_pw_string,
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
18 #include <openssl/des.h>
20 void DES_random_key(DES_cblock *ret);
22 int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);
23 int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule);
24 int DES_set_key_checked(const_DES_cblock *key,
25 DES_key_schedule *schedule);
26 void DES_set_key_unchecked(const_DES_cblock *key,
27 DES_key_schedule *schedule);
29 void DES_set_odd_parity(DES_cblock *key);
30 int DES_is_weak_key(const_DES_cblock *key);
32 void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output,
33 DES_key_schedule *ks, int enc);
34 void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output,
35 DES_key_schedule *ks1, DES_key_schedule *ks2, int enc);
36 void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output,
37 DES_key_schedule *ks1, DES_key_schedule *ks2,
38 DES_key_schedule *ks3, int enc);
40 void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
41 long length, DES_key_schedule *schedule, DES_cblock *ivec,
43 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out,
44 int numbits, long length, DES_key_schedule *schedule,
45 DES_cblock *ivec, int enc);
46 void DES_ofb_encrypt(const unsigned char *in, unsigned char *out,
47 int numbits, long length, DES_key_schedule *schedule,
49 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
50 long length, DES_key_schedule *schedule, DES_cblock *ivec,
52 void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
53 long length, DES_key_schedule *schedule, DES_cblock *ivec,
55 void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
56 long length, DES_key_schedule *schedule, DES_cblock *ivec,
59 void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output,
60 long length, DES_key_schedule *schedule, DES_cblock *ivec,
61 const_DES_cblock *inw, const_DES_cblock *outw, int enc);
63 void DES_ede2_cbc_encrypt(const unsigned char *input,
64 unsigned char *output, long length, DES_key_schedule *ks1,
65 DES_key_schedule *ks2, DES_cblock *ivec, int enc);
66 void DES_ede2_cfb64_encrypt(const unsigned char *in,
67 unsigned char *out, long length, DES_key_schedule *ks1,
68 DES_key_schedule *ks2, DES_cblock *ivec, int *num, int enc);
69 void DES_ede2_ofb64_encrypt(const unsigned char *in,
70 unsigned char *out, long length, DES_key_schedule *ks1,
71 DES_key_schedule *ks2, DES_cblock *ivec, int *num);
73 void DES_ede3_cbc_encrypt(const unsigned char *input,
74 unsigned char *output, long length, DES_key_schedule *ks1,
75 DES_key_schedule *ks2, DES_key_schedule *ks3, DES_cblock *ivec,
77 void DES_ede3_cbcm_encrypt(const unsigned char *in, unsigned char *out,
78 long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
79 DES_key_schedule *ks3, DES_cblock *ivec1, DES_cblock *ivec2,
81 void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
82 long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
83 DES_key_schedule *ks3, DES_cblock *ivec, int *num, int enc);
84 void DES_ede3_ofb64_encrypt(const unsigned char *in, unsigned char *out,
85 long length, DES_key_schedule *ks1,
86 DES_key_schedule *ks2, DES_key_schedule *ks3,
87 DES_cblock *ivec, int *num);
89 int DES_read_password(DES_cblock *key, const char *prompt, int verify);
90 int DES_read_2passwords(DES_cblock *key1, DES_cblock *key2,
91 const char *prompt, int verify);
92 int DES_read_pw_string(char *buf, int length, const char *prompt,
95 DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output,
96 long length, DES_key_schedule *schedule,
97 const_DES_cblock *ivec);
98 DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
99 long length, int out_count, DES_cblock *seed);
100 void DES_string_to_key(const char *str, DES_cblock *key);
101 void DES_string_to_2keys(const char *str, DES_cblock *key1,
104 char *DES_fcrypt(const char *buf, const char *salt, char *ret);
105 char *DES_crypt(const char *buf, const char *salt);
107 int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
109 int DES_enc_write(int fd, const void *buf, int len,
110 DES_key_schedule *sched, DES_cblock *iv);
114 This library contains a fast implementation of the DES encryption
117 There are two phases to the use of DES encryption. The first is the
118 generation of a I<DES_key_schedule> from a key, the second is the
119 actual encryption. A DES key is of type I<DES_cblock>. This type is
120 consists of 8 bytes with odd parity. The least significant bit in
121 each byte is the parity bit. The key schedule is an expanded form of
122 the key; it is used to speed the encryption process.
124 DES_random_key() generates a random key. The PRNG must be seeded
125 prior to using this function (see L<rand(3)|rand(3)>; for backward
126 compatibility the function DES_random_seed() is available as well).
127 If the PRNG could not generate a secure key, 0 is returned. In
128 earlier versions of the library, DES_random_key() did not generate
131 Before a DES key can be used, it must be converted into the
132 architecture dependent I<DES_key_schedule> via the
133 DES_set_key_checked() or DES_set_key_unchecked() function.
135 DES_set_key_checked() will check that the key passed is of odd parity
136 and is not a week or semi-weak key. If the parity is wrong, then -1
137 is returned. If the key is a weak key, then -2 is returned. If an
138 error is returned, the key schedule is not generated.
140 DES_set_key() (called DES_key_sched() in the MIT library) works like
141 DES_set_key_checked() if the I<DES_check_key> flag is non-zero,
142 otherwise like DES_set_key_unchecked(). These functions are available
143 for compatibility; it is recommended to use a function that does not
144 depend on a global variable.
146 DES_set_odd_parity() (called DES_fixup_key_parity() in the MIT
147 library) sets the parity of the passed I<key> to odd.
149 DES_is_weak_key() returns 1 is the passed key is a weak key, 0 if it
150 is ok. The probability that a randomly generated key is weak is
151 1/2^52, so it is not really worth checking for them.
153 The following routines mostly operate on an input and output stream of
156 DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
157 decrypts a single 8-byte I<DES_cblock> in I<electronic code book>
158 (ECB) mode. It always transforms the input data, pointed to by
159 I<input>, into the output data, pointed to by the I<output> argument.
160 If the I<encrypt> argument is non-zero (DES_ENCRYPT), the I<input>
161 (cleartext) is encrypted in to the I<output> (ciphertext) using the
162 key_schedule specified by the I<schedule> argument, previously set via
163 I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now
164 ciphertext) is decrypted into the I<output> (now cleartext). Input
165 and output may overlap. DES_ecb_encrypt() does not return a value.
167 DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using
168 three-key Triple-DES encryption in ECB mode. This involves encrypting
169 the input with I<ks1>, decrypting with the key schedule I<ks2>, and
170 then encrypting with I<ks3>. This routine greatly reduces the chances
171 of brute force breaking of DES and has the advantage of if I<ks1>,
172 I<ks2> and I<ks3> are the same, it is equivalent to just encryption
173 using ECB mode and I<ks1> as the key.
175 The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
176 encryption by using I<ks1> for the final encryption.
178 DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining>
179 (CBC) mode of DES. If the I<encrypt> argument is non-zero, the
180 routine cipher-block-chain encrypts the cleartext data pointed to by
181 the I<input> argument into the ciphertext pointed to by the I<output>
182 argument, using the key schedule provided by the I<schedule> argument,
183 and initialization vector provided by the I<ivec> argument. If the
184 I<length> argument is not an integral multiple of eight bytes, the
185 last block is copied to a temporary area and zero filled. The output
186 is always an integral multiple of eight bytes.
188 DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and
189 I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret
190 (unlike the iv) and are as such, part of the key. So the key is sort
191 of 24 bytes. This is much better than CBC DES.
193 DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
194 three keys. This means that each DES operation inside the CBC mode is
195 really an C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL.
197 The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
198 reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>.
199 This form of Triple-DES is used by the RSAREF library.
201 DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block
202 chaining mode used by Kerberos v4. Its parameters are the same as
205 DES_cfb_encrypt() encrypt/decrypts using cipher feedback mode. This
206 method takes an array of characters as input and outputs and array of
207 characters. It does not require any padding to 8 character groups.
208 Note: the I<ivec> variable is changed and the new changed value needs to
209 be passed to the next call to this function. Since this function runs
210 a complete DES ECB encryption per I<numbits>, this function is only
211 suggested for use when sending small numbers of characters.
214 implements CFB mode of DES with 64bit feedback. Why is this
215 useful you ask? Because this routine will allow you to encrypt an
216 arbitrary number of bytes, no 8 byte padding. Each call to this
217 routine will encrypt the input bytes to output and then update ivec
218 and num. num contains 'how far' we are though ivec. If this does
219 not make much sense, read more about cfb mode of DES :-).
221 DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as
222 DES_cfb64_encrypt() except that Triple-DES is used.
224 DES_ofb_encrypt() encrypts using output feedback mode. This method
225 takes an array of characters as input and outputs and array of
226 characters. It does not require any padding to 8 character groups.
227 Note: the I<ivec> variable is changed and the new changed value needs to
228 be passed to the next call to this function. Since this function runs
229 a complete DES ECB encryption per numbits, this function is only
230 suggested for use when sending small numbers of characters.
232 DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
235 DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
236 DES_ofb64_encrypt(), using Triple-DES.
238 The following functions are included in the DES library for
239 compatibility with the MIT Kerberos library. DES_read_pw_string()
240 is also available under the name EVP_read_pw_string().
242 DES_read_pw_string() writes the string specified by I<prompt> to
243 standard output, turns echo off and reads in input string from the
244 terminal. The string is returned in I<buf>, which must have space for
245 at least I<length> bytes. If I<verify> is set, the user is asked for
246 the password twice and unless the two copies match, an error is
247 returned. A return code of -1 indicates a system error, 1 failure due
248 to use interaction, and 0 is success.
250 DES_read_password() does the same and converts the password to a DES
251 key by calling DES_string_to_key(); DES_read_2password() operates in
252 the same way as DES_read_password() except that it generates two keys
253 by using the DES_string_to_2key() function. DES_string_to_key() is
254 available for backward compatibility with the MIT library. New
255 applications should use a cryptographic hash function. The same
256 applies for DES_string_to_2key().
258 DES_cbc_cksum() produces an 8 byte checksum based on the input stream
259 (via CBC encryption). The last 4 bytes of the checksum are returned
260 and the complete 8 bytes are placed in I<output>. This function is
261 used by Kerberos v4. Other applications should use
262 L<EVP_DigestInit(3)|EVP_DigestInit(3)> etc. instead.
264 DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte
265 checksum from the input bytes. The algorithm can be iterated over the
266 input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is
267 non-NULL, the 8 bytes generated by each pass are written into
270 The following are DES-based transformations:
272 DES_fcrypt() is a fast version of the Unix crypt(3) function. This
273 version takes only a small amount of space relative to other fast
274 crypt() implementations. This is different to the normal crypt in
275 that the third parameter is the buffer that the return value is
276 written into. It needs to be at least 14 bytes long. This function
277 is thread safe, unlike the normal crypt.
279 DES_crypt() is a faster replacement for the normal system crypt().
280 This function calls DES_fcrypt() with a static array passed as the
281 third parameter. This emulates the normal non-thread safe semantics
284 DES_enc_write() writes I<len> bytes to file descriptor I<fd> from
285 buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default)
286 using I<sched> for the key and I<iv> as a starting vector. The actual
287 data send down I<fd> consists of 4 bytes (in network byte order)
288 containing the length of the following encrypted data. The encrypted
289 data then follows, padded with random data out to a multiple of 8
292 DES_enc_read() is used to read I<len> bytes from file descriptor
293 I<fd> into buffer I<buf>. The data being read from I<fd> is assumed to
294 have come from DES_enc_write() and is decrypted using I<sched> for
295 the key schedule and I<iv> for the initial vector.
297 B<Warning:> The data format used by DES_enc_write() and DES_enc_read()
298 has a cryptographic weakness: When asked to write more than MAXWRITE
299 bytes, DES_enc_write() will split the data into several chunks that
300 are all encrypted using the same IV. So don't use these functions
301 unless you are sure you know what you do (in which case you might not
302 want to use them anyway). They cannot handle non-blocking sockets.
303 DES_enc_read() uses an internal state and thus cannot be used on
306 I<DES_rw_mode> is used to specify the encryption mode to use with
307 DES_enc_read() and DES_end_write(). If set to I<DES_PCBC_MODE> (the
308 default), DES_pcbc_encrypt is used. If set to I<DES_CBC_MODE>
309 DES_cbc_encrypt is used.
313 Single-key DES is insecure due to its short key size. ECB mode is
314 not suitable for most applications; see L<DES_modes(7)|DES_modes(7)>.
316 The L<evp(3)|evp(3)> library provides higher-level encryption functions.
320 DES_3cbc_encrypt() is flawed and must not be used in applications.
322 DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt()
325 DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
326 What this means is that if you set numbits to 12, and length to 2, the
327 first 12 bits will come from the 1st input byte and the low half of
328 the second input byte. The second 12 bits will have the low 8 bits
329 taken from the 3rd input byte and the top 4 bits taken from the 4th
330 input byte. The same holds for output. This function has been
331 implemented this way because most people will be using a multiple of 8
332 and because once you get into pulling bytes input bytes apart things
335 DES_read_pw_string() is the most machine/OS dependent function and
336 normally generates the most problems when porting this code.
342 The B<des> library was written to be source code compatible with
343 the MIT Kerberos library.
347 crypt(3), L<des_modes(7)|des_modes(7)>, L<evp(3)|evp(3)>, L<rand(3)|rand(3)>
351 In OpenSSL 0.9.7, All des_ functions were renamed to DES_ to avoid
352 clashes with older versions of libdes. Compatibility des_ functions
353 are provided for a short while, as well as crypt().
355 des_cbc_cksum(), des_cbc_encrypt(), des_ecb_encrypt(),
356 des_is_weak_key(), des_key_sched(), des_pcbc_encrypt(),
357 des_quad_cksum(), des_random_key(), des_read_password() and
358 des_string_to_key() are available in the MIT Kerberos library;
359 des_check_key_parity(), des_fixup_key_parity() and des_is_weak_key()
360 are available in newer versions of that library.
362 des_set_key_checked() and des_set_key_unchecked() were added in
365 des_generate_random_block(), des_init_random_number_generator(),
366 des_new_random_key(), des_set_random_generator_seed() and
367 des_set_sequence_number() and des_rand_data() are used in newer
368 versions of Kerberos but are not implemented here.
370 des_random_key() generated cryptographically weak random data in
371 SSLeay and in OpenSSL prior version 0.9.5, as well as in the original
376 Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project
377 (http://www.openssl.org).