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Diffstat (limited to 'vendor/golang.org/x/crypto/blowfish/cipher.go')
-rw-r--r-- | vendor/golang.org/x/crypto/blowfish/cipher.go | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/blowfish/cipher.go b/vendor/golang.org/x/crypto/blowfish/cipher.go new file mode 100644 index 000000000..213bf204a --- /dev/null +++ b/vendor/golang.org/x/crypto/blowfish/cipher.go @@ -0,0 +1,99 @@ +// 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. +// +// Blowfish is a legacy cipher and its short block size makes it vulnerable to +// birthday bound attacks (see https://sweet32.info). It should only be used +// where compatibility with legacy systems, not security, is the goal. +// +// Deprecated: any new system should use AES (from crypto/aes, if necessary in +// an AEAD mode like crypto/cipher.NewGCM) or XChaCha20-Poly1305 (from +// golang.org/x/crypto/chacha20poly1305). +package blowfish // import "golang.org/x/crypto/blowfish" + +// The code is a port of Bruce Schneier's C implementation. +// See https://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 compatibility, 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:]) +} |