syncthing/vendor/golang.org/x/crypto/blowfish/cipher.go
Jakob Borg 65aaa607ab Use Go 1.5 vendoring instead of Godeps
Change made by:

- running "gvt fetch" on each of the packages mentioned in
  Godeps/Godeps.json
- `rm -rf Godeps`
- tweaking the build scripts to not mention Godeps
- tweaking the build scripts to test `./lib/...`, `./cmd/...` explicitly
  (to avoid testing vendor)
- tweaking the build scripts to not juggle GOPATH for Godeps and instead
  set GO15VENDOREXPERIMENT.

This also results in some updated packages at the same time I bet.

Building with Go 1.3 and 1.4 still *works* but won't use our vendored
dependencies - the user needs to have the actual packages in their
GOPATH then, which they'll get with a normal "go get". Building with Go
1.6+ will get our vendored dependencies by default even when not using
our build script, which is nice.

By doing this we gain some freedom in that we can pick and choose
manually what to include in vendor, as it's not based on just dependency
analysis of our own code. This is also a risk as we might pick up
dependencies we are unaware of, as the build may work locally with those
packages present in GOPATH. On the other hand the build server will
detect this as it has no packages in it's GOPATH beyond what is included
in the repo.

Recommended tool to manage dependencies is github.com/FiloSottile/gvt.
2016-03-05 21:21:24 +01:00

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3.0 KiB
Go

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package blowfish implements Bruce Schneier's Blowfish encryption algorithm.
package blowfish // import "golang.org/x/crypto/blowfish"
// The code is a port of Bruce Schneier's C implementation.
// See http://www.schneier.com/blowfish.html.
import "strconv"
// The Blowfish block size in bytes.
const BlockSize = 8
// A Cipher is an instance of Blowfish encryption using a particular key.
type Cipher struct {
p [18]uint32
s0, s1, s2, s3 [256]uint32
}
type KeySizeError int
func (k KeySizeError) Error() string {
return "crypto/blowfish: invalid key size " + strconv.Itoa(int(k))
}
// NewCipher creates and returns a Cipher.
// The key argument should be the Blowfish key, from 1 to 56 bytes.
func NewCipher(key []byte) (*Cipher, error) {
var result Cipher
if k := len(key); k < 1 || k > 56 {
return nil, KeySizeError(k)
}
initCipher(&result)
ExpandKey(key, &result)
return &result, nil
}
// NewSaltedCipher creates a returns a Cipher that folds a salt into its key
// schedule. For most purposes, NewCipher, instead of NewSaltedCipher, is
// sufficient and desirable. For bcrypt compatiblity, the key can be over 56
// bytes.
func NewSaltedCipher(key, salt []byte) (*Cipher, error) {
if len(salt) == 0 {
return NewCipher(key)
}
var result Cipher
if k := len(key); k < 1 {
return nil, KeySizeError(k)
}
initCipher(&result)
expandKeyWithSalt(key, salt, &result)
return &result, nil
}
// BlockSize returns the Blowfish block size, 8 bytes.
// It is necessary to satisfy the Block interface in the
// package "crypto/cipher".
func (c *Cipher) BlockSize() int { return BlockSize }
// Encrypt encrypts the 8-byte buffer src using the key k
// and stores the result in dst.
// Note that for amounts of data larger than a block,
// it is not safe to just call Encrypt on successive blocks;
// instead, use an encryption mode like CBC (see crypto/cipher/cbc.go).
func (c *Cipher) Encrypt(dst, src []byte) {
l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
l, r = encryptBlock(l, r, c)
dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
}
// Decrypt decrypts the 8-byte buffer src using the key k
// and stores the result in dst.
func (c *Cipher) Decrypt(dst, src []byte) {
l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
l, r = decryptBlock(l, r, c)
dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
}
func initCipher(c *Cipher) {
copy(c.p[0:], p[0:])
copy(c.s0[0:], s0[0:])
copy(c.s1[0:], s1[0:])
copy(c.s2[0:], s2[0:])
copy(c.s3[0:], s3[0:])
}