diff options
Diffstat (limited to 'doc/crypto/blowfish.pod')
| -rw-r--r-- | doc/crypto/blowfish.pod | 37 |
1 files changed, 17 insertions, 20 deletions
diff --git a/doc/crypto/blowfish.pod b/doc/crypto/blowfish.pod index 65b8be388c..4320af0809 100644 --- a/doc/crypto/blowfish.pod +++ b/doc/crypto/blowfish.pod @@ -11,6 +11,9 @@ BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options - Blowfish encryption void BF_set_key(BF_KEY *key, int len, const unsigned char *data); + void BF_encrypt(BF_LONG *data,const BF_KEY *key); + void BF_decrypt(BF_LONG *data,const BF_KEY *key); + 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, @@ -22,9 +25,6 @@ BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options - Blowfish encryption 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); - =head1 DESCRIPTION This library implements the Blowfish cipher, which is invented and described @@ -43,6 +43,11 @@ phase. BF_set_key() sets up the B<BF_KEY> B<key> using the B<len> bytes long key at B<data>. +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 +B<data>, using the key B<key>. These functions should not be used unless you +implement 'modes' of Blowfish. + BF_ecb_encrypt() is the basic Blowfish encryption and decryption function. It encrypts or decrypts the first 64 bits of B<in> using the key B<key>, putting the result in B<out>. B<enc> decides if encryption (B<BF_ENCRYPT>) @@ -51,45 +56,37 @@ B<in> and B<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 +all operate on variable length data. They all take an initialisation vector B<ivec> which needs to be passed along into the next call of the same function -for the same message. B<ivec> may be initialized with anything, but the -recipient needs to know what it was initialized with, or it won't be able +for the same message. B<ivec> may be initialised with anything, but the +recipient needs to know what it was initialised with, or it won't be able to decrypt. Some programs and protocols simplify this, like SSH, where -B<ivec> is simply initialized to zero. +B<ivec> is simply initialised to zero. BF_cbc_encrypt() operates of 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 B<num>, which is a pointer to an integer where the current -offset in B<ivec> is stored between calls. This integer must be initialized -to zero when B<ivec> is initialized. +offset in B<ivec> is stored between calls. This integer must be initialised +to zero when B<ivec> is initialised. BF_cbc_encrypt() is the Cipher Block Chaining function for Blowfish. It encrypts or decrypts the 64 bits chunks of B<in> using the key B<schedule>, putting the result in B<out>. B<enc> decides if encryption (BF_ENCRYPT) or decryption (BF_DECRYPT) shall be performed. B<ivec> must point at an 8 byte -long initialization vector. +long initialisation vector. BF_cfb64_encrypt() is the CFB mode for Blowfish with 64 bit feedback. It encrypts or decrypts the bytes in B<in> using the key B<schedule>, putting the result in B<out>. B<enc> decides if encryption (B<BF_ENCRYPT>) or decryption (B<BF_DECRYPT>) shall be performed. B<ivec> must point at an -8 byte long initialization vector. B<num> must point at an integer which must +8 byte long initialisation vector. B<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 +It uses the same parameters as BF_cfb64_encrypt(), which must be initialised 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 -B<data>, using the key B<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. - =head1 RETURN VALUES None of the functions presented here return any value. |