1BF_ENCRYPT(3) OpenSSL BF_ENCRYPT(3)
2
6 BF_set_key, BF_encrypt, BF_decrypt, BF_ecb_encrypt, BF_cbc_encrypt,
7 BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options - Blowfish encryption
8
10 #include <openssl/blowfish.h>
11 void BF_set_key(BF_KEY *key, int len, const unsigned char *data);
13 void BF_ecb_encrypt(const unsigned char *in, unsigned char *out,
15 BF_KEY *key, int enc);
16 void BF_cbc_encrypt(const unsigned char *in, unsigned char *out,
17 long length, BF_KEY *schedule,
18 unsigned char *ivec, int enc);
19 void BF_cfb64_encrypt(const unsigned char *in, unsigned char *out,
20 long length, BF_KEY *schedule,
21 unsigned char *ivec, int *num, int enc);
22 void BF_ofb64_encrypt(const unsigned char *in, unsigned char *out,
23 long length, BF_KEY *schedule,
24 unsigned char *ivec, int *num);
25 const char *BF_options(void);
26 void BF_encrypt(BF_LONG *data, const BF_KEY *key);
28 void BF_decrypt(BF_LONG *data, const BF_KEY *key);
29
31 This library implements the Blowfish cipher, which was invented and
32 described by Counterpane (see http://www.counterpane.com/blowfish.html
33 ).
34 Blowfish is a block cipher that operates on 64 bit (8 byte) blocks of
36 data. It uses a variable size key, but typically, 128 bit (16 byte)
37 keys are considered good for strong encryption. Blowfish can be used
38 in the same modes as DES (see des_modes(7)). Blowfish is currently one
39 of the faster block ciphers. It is quite a bit faster than DES, and
40 much faster than IDEA or RC2.
41 Blowfish consists of a key setup phase and the actual encryption or
43 decryption phase.
44 BF_set_key() sets up the BF_KEY key using the len bytes long key at
46 data.
47 BF_ecb_encrypt() is the basic Blowfish encryption and decryption
49 function. It encrypts or decrypts the first 64 bits of in using the
50 key key, putting the result in out. enc decides if encryption
51 (BF_ENCRYPT) or decryption (BF_DECRYPT) shall be performed. The vector
52 pointed at by in and out must be 64 bits in length, no less. If they
53 are larger, everything after the first 64 bits is ignored.
54 The mode functions BF_cbc_encrypt(), BF_cfb64_encrypt() and
56 BF_ofb64_encrypt() all operate on variable length data. They all take
57 an initialization vector ivec which needs to be passed along into the
58 next call of the same function for the same message. ivec may be
59 initialized with anything, but the recipient needs to know what it was
60 initialized with, or it won't be able to decrypt. Some programs and
61 protocols simplify this, like SSH, where ivec is simply initialized to
62 zero. BF_cbc_encrypt() operates on data that is a multiple of 8 bytes
63 long, while BF_cfb64_encrypt() and BF_ofb64_encrypt() are used to
64 encrypt a variable number of bytes (the amount does not have to be an
65 exact multiple of 8). The purpose of the latter two is to simulate
66 stream ciphers, and therefore, they need the parameter num, which is a
67 pointer to an integer where the current offset in ivec is stored
68 between calls. This integer must be initialized to zero when ivec is
69 initialized.
70 BF_cbc_encrypt() is the Cipher Block Chaining function for Blowfish.
72 It encrypts or decrypts the 64 bits chunks of in using the key
73 schedule, putting the result in out. enc decides if encryption
74 (BF_ENCRYPT) or decryption (BF_DECRYPT) shall be performed. ivec must
75 point at an 8 byte long initialization vector.
76 BF_cfb64_encrypt() is the CFB mode for Blowfish with 64 bit feedback.
78 It encrypts or decrypts the bytes in in using the key schedule, putting
79 the result in out. enc decides if encryption (BF_ENCRYPT) or
80 decryption (BF_DECRYPT) shall be performed. ivec must point at an 8
81 byte long initialization vector. num must point at an integer which
82 must be initially zero.
83 BF_ofb64_encrypt() is the OFB mode for Blowfish with 64 bit feedback.
85 It uses the same parameters as BF_cfb64_encrypt(), which must be
86 initialized the same way.
87 BF_encrypt() and BF_decrypt() are the lowest level functions for
89 Blowfish encryption. They encrypt/decrypt the first 64 bits of the
90 vector pointed by data, using the key key. These functions should not
91 be used unless you implement 'modes' of Blowfish. The alternative is
92 to use BF_ecb_encrypt(). If you still want to use these functions, you
93 should be aware that they take each 32-bit chunk in host-byte order,
94 which is little-endian on little-endian platforms and big-endian on
95 big-endian ones.
96
98 None of the functions presented here return any value.
99
101 Applications should use the higher level functions EVP_EncryptInit(3)
102 etc. instead of calling these functions directly.
103
105 EVP_EncryptInit(3), des_modes(7)
106
108 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
109 Licensed under the OpenSSL license (the "License"). You may not use
111 this file except in compliance with the License. You can obtain a copy
112 in the file LICENSE in the source distribution or at
113 <https://www.openssl.org/source/license.html>.
1141.1.1q 2023-02-06 BF_ENCRYPT(3)