DES_random_key.pod 15 KB

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  1. =pod
  2. =head1 NAME
  3. DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked,
  4. DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key,
  5. DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt,
  6. DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt,
  7. DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt,
  8. DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt,
  9. DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt,
  10. DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys,
  11. DES_fcrypt, DES_crypt - DES encryption
  12. =head1 SYNOPSIS
  13. #include <openssl/des.h>
  14. The following functions have been deprecated since OpenSSL 3.0, and can be
  15. hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
  16. see L<openssl_user_macros(7)>:
  17. void DES_random_key(DES_cblock *ret);
  18. int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);
  19. int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule);
  20. int DES_set_key_checked(const_DES_cblock *key, DES_key_schedule *schedule);
  21. void DES_set_key_unchecked(const_DES_cblock *key, DES_key_schedule *schedule);
  22. void DES_set_odd_parity(DES_cblock *key);
  23. int DES_is_weak_key(const_DES_cblock *key);
  24. void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output,
  25. DES_key_schedule *ks, int enc);
  26. void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output,
  27. DES_key_schedule *ks1, DES_key_schedule *ks2, int enc);
  28. void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output,
  29. DES_key_schedule *ks1, DES_key_schedule *ks2,
  30. DES_key_schedule *ks3, int enc);
  31. void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
  32. long length, DES_key_schedule *schedule, DES_cblock *ivec,
  33. int enc);
  34. void DES_cfb_encrypt(const unsigned char *in, unsigned char *out,
  35. int numbits, long length, DES_key_schedule *schedule,
  36. DES_cblock *ivec, int enc);
  37. void DES_ofb_encrypt(const unsigned char *in, unsigned char *out,
  38. int numbits, long length, DES_key_schedule *schedule,
  39. DES_cblock *ivec);
  40. void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
  41. long length, DES_key_schedule *schedule, DES_cblock *ivec,
  42. int enc);
  43. void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
  44. long length, DES_key_schedule *schedule, DES_cblock *ivec,
  45. int *num, int enc);
  46. void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
  47. long length, DES_key_schedule *schedule, DES_cblock *ivec,
  48. int *num);
  49. void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output,
  50. long length, DES_key_schedule *schedule, DES_cblock *ivec,
  51. const_DES_cblock *inw, const_DES_cblock *outw, int enc);
  52. void DES_ede2_cbc_encrypt(const unsigned char *input, unsigned char *output,
  53. long length, DES_key_schedule *ks1,
  54. DES_key_schedule *ks2, DES_cblock *ivec, int enc);
  55. void DES_ede2_cfb64_encrypt(const unsigned char *in, unsigned char *out,
  56. long length, DES_key_schedule *ks1,
  57. DES_key_schedule *ks2, DES_cblock *ivec,
  58. int *num, int enc);
  59. void DES_ede2_ofb64_encrypt(const unsigned char *in, unsigned char *out,
  60. long length, DES_key_schedule *ks1,
  61. DES_key_schedule *ks2, DES_cblock *ivec, int *num);
  62. void DES_ede3_cbc_encrypt(const unsigned char *input, unsigned char *output,
  63. long length, DES_key_schedule *ks1,
  64. DES_key_schedule *ks2, DES_key_schedule *ks3,
  65. DES_cblock *ivec, int enc);
  66. void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
  67. long length, DES_key_schedule *ks1,
  68. DES_key_schedule *ks2, DES_key_schedule *ks3,
  69. DES_cblock *ivec, int *num, int enc);
  70. void DES_ede3_ofb64_encrypt(const unsigned char *in, unsigned char *out,
  71. long length, DES_key_schedule *ks1,
  72. DES_key_schedule *ks2, DES_key_schedule *ks3,
  73. DES_cblock *ivec, int *num);
  74. DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output,
  75. long length, DES_key_schedule *schedule,
  76. const_DES_cblock *ivec);
  77. DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
  78. long length, int out_count, DES_cblock *seed);
  79. void DES_string_to_key(const char *str, DES_cblock *key);
  80. void DES_string_to_2keys(const char *str, DES_cblock *key1, DES_cblock *key2);
  81. char *DES_fcrypt(const char *buf, const char *salt, char *ret);
  82. char *DES_crypt(const char *buf, const char *salt);
  83. =head1 DESCRIPTION
  84. All of the functions described on this page are deprecated. Applications should
  85. instead use L<EVP_EncryptInit_ex(3)>, L<EVP_EncryptUpdate(3)> and
  86. L<EVP_EncryptFinal_ex(3)> or the equivalently named decrypt functions.
  87. This library contains a fast implementation of the DES encryption
  88. algorithm.
  89. There are two phases to the use of DES encryption. The first is the
  90. generation of a I<DES_key_schedule> from a key, the second is the
  91. actual encryption. A DES key is of type I<DES_cblock>. This type
  92. consists of 8 bytes with odd parity. The least significant bit in
  93. each byte is the parity bit. The key schedule is an expanded form of
  94. the key; it is used to speed the encryption process.
  95. DES_random_key() generates a random key. The random generator must be
  96. seeded when calling this function.
  97. If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to
  98. external circumstances (see L<RAND(7)>), the operation will fail.
  99. If the function fails, 0 is returned.
  100. Before a DES key can be used, it must be converted into the
  101. architecture dependent I<DES_key_schedule> via the
  102. DES_set_key_checked() or DES_set_key_unchecked() function.
  103. DES_set_key_checked() will check that the key passed is of odd parity
  104. and is not a weak or semi-weak key. If the parity is wrong, then -1
  105. is returned. If the key is a weak key, then -2 is returned. If an
  106. error is returned, the key schedule is not generated.
  107. DES_set_key() works like DES_set_key_checked() and remains for
  108. backward compatibility.
  109. DES_set_odd_parity() sets the parity of the passed I<key> to odd.
  110. DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it
  111. is ok.
  112. The following routines mostly operate on an input and output stream of
  113. I<DES_cblock>s.
  114. DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
  115. decrypts a single 8-byte I<DES_cblock> in I<electronic code book>
  116. (ECB) mode. It always transforms the input data, pointed to by
  117. I<input>, into the output data, pointed to by the I<output> argument.
  118. If the I<encrypt> argument is nonzero (DES_ENCRYPT), the I<input>
  119. (cleartext) is encrypted in to the I<output> (ciphertext) using the
  120. key_schedule specified by the I<schedule> argument, previously set via
  121. I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now
  122. ciphertext) is decrypted into the I<output> (now cleartext). Input
  123. and output may overlap. DES_ecb_encrypt() does not return a value.
  124. DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using
  125. three-key Triple-DES encryption in ECB mode. This involves encrypting
  126. the input with I<ks1>, decrypting with the key schedule I<ks2>, and
  127. then encrypting with I<ks3>. This routine greatly reduces the chances
  128. of brute force breaking of DES and has the advantage of if I<ks1>,
  129. I<ks2> and I<ks3> are the same, it is equivalent to just encryption
  130. using ECB mode and I<ks1> as the key.
  131. The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
  132. encryption by using I<ks1> for the final encryption.
  133. DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining>
  134. (CBC) mode of DES. If the I<encrypt> argument is nonzero, the
  135. routine cipher-block-chain encrypts the cleartext data pointed to by
  136. the I<input> argument into the ciphertext pointed to by the I<output>
  137. argument, using the key schedule provided by the I<schedule> argument,
  138. and initialization vector provided by the I<ivec> argument. If the
  139. I<length> argument is not an integral multiple of eight bytes, the
  140. last block is copied to a temporary area and zero filled. The output
  141. is always an integral multiple of eight bytes.
  142. DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and
  143. I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret
  144. (unlike the iv) and are as such, part of the key. So the key is sort
  145. of 24 bytes. This is much better than CBC DES.
  146. DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
  147. three keys. This means that each DES operation inside the CBC mode is
  148. C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL.
  149. The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
  150. reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>.
  151. This form of Triple-DES is used by the RSAREF library.
  152. DES_pcbc_encrypt() encrypts/decrypts using the propagating cipher block
  153. chaining mode used by Kerberos v4. Its parameters are the same as
  154. DES_ncbc_encrypt().
  155. DES_cfb_encrypt() encrypts/decrypts using cipher feedback mode. This
  156. method takes an array of characters as input and outputs an array of
  157. characters. It does not require any padding to 8 character groups.
  158. Note: the I<ivec> variable is changed and the new changed value needs to
  159. be passed to the next call to this function. Since this function runs
  160. a complete DES ECB encryption per I<numbits>, this function is only
  161. suggested for use when sending a small number of characters.
  162. DES_cfb64_encrypt()
  163. implements CFB mode of DES with 64-bit feedback. Why is this
  164. useful you ask? Because this routine will allow you to encrypt an
  165. arbitrary number of bytes, without 8 byte padding. Each call to this
  166. routine will encrypt the input bytes to output and then update ivec
  167. and num. num contains 'how far' we are though ivec. If this does
  168. not make much sense, read more about CFB mode of DES.
  169. DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as
  170. DES_cfb64_encrypt() except that Triple-DES is used.
  171. DES_ofb_encrypt() encrypts using output feedback mode. This method
  172. takes an array of characters as input and outputs an array of
  173. characters. It does not require any padding to 8 character groups.
  174. Note: the I<ivec> variable is changed and the new changed value needs to
  175. be passed to the next call to this function. Since this function runs
  176. a complete DES ECB encryption per I<numbits>, this function is only
  177. suggested for use when sending a small number of characters.
  178. DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
  179. Feed Back mode.
  180. DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
  181. DES_ofb64_encrypt(), using Triple-DES.
  182. The following functions are included in the DES library for
  183. compatibility with the MIT Kerberos library.
  184. DES_cbc_cksum() produces an 8 byte checksum based on the input stream
  185. (via CBC encryption). The last 4 bytes of the checksum are returned
  186. and the complete 8 bytes are placed in I<output>. This function is
  187. used by Kerberos v4. Other applications should use
  188. L<EVP_DigestInit(3)> etc. instead.
  189. DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte
  190. checksum from the input bytes. The algorithm can be iterated over the
  191. input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is
  192. non-NULL, the 8 bytes generated by each pass are written into
  193. I<output>.
  194. The following are DES-based transformations:
  195. DES_fcrypt() is a fast version of the Unix crypt(3) function. This
  196. version takes only a small amount of space relative to other fast
  197. crypt() implementations. This is different to the normal crypt() in
  198. that the third parameter is the buffer that the return value is
  199. written into. It needs to be at least 14 bytes long. This function
  200. is thread safe, unlike the normal crypt().
  201. DES_crypt() is a faster replacement for the normal system crypt().
  202. This function calls DES_fcrypt() with a static array passed as the
  203. third parameter. This mostly emulates the normal non-thread-safe semantics
  204. of crypt(3).
  205. The B<salt> must be two ASCII characters.
  206. The values returned by DES_fcrypt() and DES_crypt() are terminated by NUL
  207. character.
  208. DES_enc_write() writes I<len> bytes to file descriptor I<fd> from
  209. buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default)
  210. using I<sched> for the key and I<iv> as a starting vector. The actual
  211. data send down I<fd> consists of 4 bytes (in network byte order)
  212. containing the length of the following encrypted data. The encrypted
  213. data then follows, padded with random data out to a multiple of 8
  214. bytes.
  215. =head1 BUGS
  216. DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt()
  217. instead.
  218. DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
  219. What this means is that if you set numbits to 12, and length to 2, the
  220. first 12 bits will come from the 1st input byte and the low half of
  221. the second input byte. The second 12 bits will have the low 8 bits
  222. taken from the 3rd input byte and the top 4 bits taken from the 4th
  223. input byte. The same holds for output. This function has been
  224. implemented this way because most people will be using a multiple of 8
  225. and because once you get into pulling bytes input bytes apart things
  226. get ugly!
  227. DES_string_to_key() is available for backward compatibility with the
  228. MIT library. New applications should use a cryptographic hash function.
  229. The same applies for DES_string_to_2key().
  230. =head1 NOTES
  231. The B<des> library was written to be source code compatible with
  232. the MIT Kerberos library.
  233. Applications should use the higher level functions
  234. L<EVP_EncryptInit(3)> etc. instead of calling these
  235. functions directly.
  236. Single-key DES is insecure due to its short key size. ECB mode is
  237. not suitable for most applications; see L<des_modes(7)>.
  238. =head1 RETURN VALUES
  239. DES_set_key(), DES_key_sched(), and DES_set_key_checked()
  240. return 0 on success or negative values on error.
  241. DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it
  242. is ok.
  243. DES_cbc_cksum() and DES_quad_cksum() return 4-byte integer representing the
  244. last 4 bytes of the checksum of the input.
  245. DES_fcrypt() returns a pointer to the caller-provided buffer and DES_crypt() -
  246. to a static buffer on success; otherwise they return NULL.
  247. =head1 SEE ALSO
  248. L<des_modes(7)>,
  249. L<EVP_EncryptInit(3)>
  250. =head1 HISTORY
  251. All of these functions were deprecated in OpenSSL 3.0.
  252. The requirement that the B<salt> parameter to DES_crypt() and DES_fcrypt()
  253. be two ASCII characters was first enforced in
  254. OpenSSL 1.1.0. Previous versions tried to use the letter uppercase B<A>
  255. if both character were not present, and could crash when given non-ASCII
  256. on some platforms.
  257. =head1 COPYRIGHT
  258. Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
  259. Licensed under the Apache License 2.0 (the "License"). You may not use
  260. this file except in compliance with the License. You can obtain a copy
  261. in the file LICENSE in the source distribution or at
  262. L<https://www.openssl.org/source/license.html>.
  263. =cut