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blowfish(3)			    OpenSSL			   blowfish(3)

NAME
       blowfish, BF_set_key, BF_encrypt, BF_decrypt, BF_ecb_encrypt,
       BF_cbc_encrypt, BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options -
       Blowfish	encryption

SYNOPSIS
	#include <openssl/blowfish.h>

	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);

DESCRIPTION
       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 an 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.

RETURN VALUES
       None of the functions presented here return any value.

NOTE
       Applications should use the higher level	functions EVP_EncryptInit(3)
       etc. instead of calling the blowfish functions directly.

SEE ALSO
       des_modes(7)

HISTORY
       The Blowfish functions are available in all versions of SSLeay and
       OpenSSL.

1.0.1e				  2013-02-11			   blowfish(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | NOTE | SEE ALSO | HISTORY

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