BF_set_key, BF_encrypt, BF_decrypt, BF_ecb_encrypt, BF_cbc_encrypt,
BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options - Blowfish encryption
#include <openssl/blowfish.h>
The following functions have been deprecated since OpenSSL 3.0, and can be
hidden entirely by defining
OPENSSL_API_COMPAT with a suitable version
value, see
openssl_user_macros(7):
void BF_set_key(BF_KEY *key, int len, const unsigned char *data);
void BF_ecb_encrypt(const unsigned char *in, unsigned char *out,
BF_KEY *key, int enc);
void BF_cbc_encrypt(const unsigned char *in, unsigned char *out,
long length, BF_KEY *schedule,
unsigned char *ivec, int enc);
void BF_cfb64_encrypt(const unsigned char *in, unsigned char *out,
long length, BF_KEY *schedule,
unsigned char *ivec, int *num, int enc);
void BF_ofb64_encrypt(const unsigned char *in, unsigned char *out,
long length, BF_KEY *schedule,
unsigned char *ivec, int *num);
const char *BF_options(void);
void BF_encrypt(BF_LONG *data, const BF_KEY *key);
void BF_decrypt(BF_LONG *data, const BF_KEY *key);
All of the functions described on this page are deprecated. Applications should
instead use
EVP_EncryptInit_ex(3),
EVP_EncryptUpdate(3) and
EVP_EncryptFinal_ex(3) or the equivalently named decrypt functions.
This library implements the Blowfish cipher, which was invented and described by
Counterpane (see
http://www.counterpane.com/blowfish.html ).
Blowfish is a block cipher that operates on 64 bit (8 byte) blocks of data. It
uses a variable size key, but typically, 128 bit (16 byte) keys are considered
good for strong encryption. Blowfish can be used in the same modes as DES (see
des_modes(7)). Blowfish is currently one of the faster block ciphers.
It is quite a bit faster than DES, and much faster than IDEA or RC2.
Blowfish consists of a key setup phase and the actual encryption or decryption
phase.
BF_set_key() sets up the
BF_KEY key using the
len
bytes long key at
data.
BF_ecb_encrypt() is the basic Blowfish encryption and decryption
function. It encrypts or decrypts the first 64 bits of
in using the key
key, putting the result in
out.
enc decides if encryption
(
BF_ENCRYPT) or decryption (
BF_DECRYPT) shall be performed.
The vector pointed at by
in and
out must be 64 bits in length,
no less. If they are larger, everything after the first 64 bits is ignored.
The mode functions
BF_cbc_encrypt(),
BF_cfb64_encrypt() and
BF_ofb64_encrypt() all operate on variable length data. They all take
an initialization vector
ivec which needs to be passed along into the
next call of the same function for the same message.
ivec may be
initialized with anything, but the recipient needs to know what it was
initialized with, or it won't be able to decrypt. Some programs and protocols
simplify this, like SSH, where
ivec is simply initialized to zero.
BF_cbc_encrypt() operates on data that is a multiple of 8 bytes long,
while
BF_cfb64_encrypt() and
BF_ofb64_encrypt() are used to
encrypt a variable number of bytes (the amount does not have to be an exact
multiple of 8). The purpose of the latter two is to simulate stream ciphers,
and therefore, they need the parameter
num, which is a pointer to an
integer where the current offset in
ivec is stored between calls. This
integer must be initialized to zero when
ivec is initialized.
BF_cbc_encrypt() is the Cipher Block Chaining function for Blowfish. It
encrypts or decrypts the 64 bits chunks of
in using the key
schedule, putting the result in
out.
enc decides if
encryption (BF_ENCRYPT) or decryption (BF_DECRYPT) shall be performed.
ivec must point at an 8 byte long initialization vector.
BF_cfb64_encrypt() is the CFB mode for Blowfish with 64 bit feedback. It
encrypts or decrypts the bytes in
in using the key
schedule,
putting the result in
out.
enc decides if encryption
(
BF_ENCRYPT) or decryption (
BF_DECRYPT) shall be performed.
ivec must point at an 8 byte long initialization vector.
num
must point at an integer which must be initially zero.
BF_ofb64_encrypt() is the OFB mode for Blowfish with 64 bit feedback. It
uses the same parameters as
BF_cfb64_encrypt(), which must be
initialized the same way.
BF_encrypt() and
BF_decrypt() are the lowest level functions for
Blowfish encryption. They encrypt/decrypt the first 64 bits of the vector
pointed by
data, using the key
key. These functions should not
be used unless you implement 'modes' of Blowfish. The alternative is to use
BF_ecb_encrypt(). If you still want to use these functions, you should
be aware that they take each 32-bit chunk in host-byte order, which is
little-endian on little-endian platforms and big-endian on big-endian ones.
None of the functions presented here return any value.
Applications should use the higher level functions
EVP_EncryptInit(3)
etc. instead of calling these functions directly.
EVP_EncryptInit(3),
des_modes(7)
All of these functions were deprecated in OpenSSL 3.0.
Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at
<
https://www.openssl.org/source/license.html>.