6.3 KiB
module cipher
Contents
- new_cbc
- new_cfb_decrypter
- new_cfb_encrypter
- new_ctr
- new_ofb
- safe_xor_bytes
- xor_bytes
- xor_words
- Block
- BlockMode
- Stream
- Cbc
- Cfb
- Ctr
- Ofb
new_cbc
fn new_cbc(b Block, iv []u8) Cbc
new_cbc returns a DesCbc which encrypts in cipher block chaining mode, using the given Block. The length of iv must be the same as the Block's block size.
new_cfb_decrypter
fn new_cfb_decrypter(b Block, iv []u8) Cfb
new_cfb_decrypter returns a Cfb which decrypts with cipher feedback mode, using the given Block. The iv must be the same length as the Block's block size
new_cfb_encrypter
fn new_cfb_encrypter(b Block, iv []u8) Cfb
new_cfb_encrypter returns a Cfb which encrypts with cipher feedback mode, using the given Block. The iv must be the same length as the Block's block size
new_ctr
fn new_ctr(b Block, iv []u8) Ctr
new_ctr returns a Ctr which encrypts/decrypts using the given Block in counter mode. The length of iv must be the same as the Block's block size.
new_ofb
fn new_ofb(b Block, iv []u8) Ofb
new_ofb returns a Ofb that encrypts or decrypts using the block cipher b in output feedback mode. The initialization vector iv's length must be equal to b's block size.
safe_xor_bytes
fn safe_xor_bytes(mut dst []u8, a []u8, b []u8, n int)
safe_xor_bytes XORs the bytes in a and b into dst it does so n times. Please note: n needs to be smaller or equal than the length of a and b.
xor_bytes
fn xor_bytes(mut dst []u8, a []u8, b []u8) int
Note: Implement other versions (joe-c)xor_bytes xors the bytes in a and b. The destination should have enough space, otherwise xor_bytes will panic. Returns the number of bytes xor'd.
xor_words
fn xor_words(mut dst []u8, a []u8, b []u8)
xor_words XORs multiples of 4 or 8 bytes (depending on architecture.) The slice arguments a and b are assumed to be of equal length.
Block
interface Block {
block_size int // block_size returns the cipher's block size.
encrypt(mut dst []u8, src []u8) // Encrypt encrypts the first block in src into dst.
// Dst and src must overlap entirely or not at all.
decrypt(mut dst []u8, src []u8) // Decrypt decrypts the first block in src into dst.
// Dst and src must overlap entirely or not at all.
}
A Block represents an implementation of block cipher using a given key. It provides the capability to encrypt or decrypt individual blocks. The mode implementations extend that capability to streams of blocks.
BlockMode
interface BlockMode {
block_size int // block_size returns the mode's block size.
crypt_blocks(mut dst []u8, src []u8) // crypt_blocks encrypts or decrypts a number of blocks. The length of
// src must be a multiple of the block size. Dst and src must overlap
// entirely or not at all.
//
// If len(dst) < len(src), crypt_blocks should panic. It is acceptable
// to pass a dst bigger than src, and in that case, crypt_blocks will
// only update dst[:len(src)] and will not touch the rest of dst.
//
// Multiple calls to crypt_blocks behave as if the concatenation of
// the src buffers was passed in a single run. That is, BlockMode
// maintains state and does not reset at each crypt_blocks call.
}
A BlockMode represents a block cipher running in a block-based mode (CBC, ECB etc).
Stream
interface Stream {
mut:
// xor_key_stream XORs each byte in the given slice with a byte from the
// cipher's key stream. Dst and src must overlap entirely or not at all.
//
// If len(dst) < len(src), xor_key_stream should panic. It is acceptable
// to pass a dst bigger than src, and in that case, xor_key_stream will
// only update dst[:len(src)] and will not touch the rest of dst.
//
// Multiple calls to xor_key_stream behave as if the concatenation of
// the src buffers was passed in a single run. That is, Stream
// maintains state and does not reset at each xor_key_stream call.
xor_key_stream(mut dst []u8, src []u8)
}
A Stream represents a stream cipher.
Cbc
free
fn (mut x Cbc) free()
free the resources taken by the Cbc x
encrypt_blocks
fn (mut x Cbc) encrypt_blocks(mut dst_ []u8, src_ []u8)
encrypt_blocks encrypts the blocks in src_ to dst_. Please note: dst_ is mutable for performance reasons.
decrypt_blocks
fn (mut x Cbc) decrypt_blocks(mut dst []u8, src []u8)
decrypt_blocks decrypts the blocks in src to dst. Please note: dst is mutable for performance reasons.
Cfb
free
fn (mut x Cfb) free()
free the resources taken by the Cfb x
xor_key_stream
fn (mut x Cfb) xor_key_stream(mut dst []u8, src []u8)
xor_key_stream xors each byte in the given slice with a byte from the key stream.
Ctr
free
fn (mut x Ctr) free()
free the resources taken by the Ctr c
xor_key_stream
fn (mut x Ctr) xor_key_stream(mut dst []u8, src []u8)
xor_key_stream xors each byte in the given slice with a byte from the key stream.
Ofb
xor_key_stream
fn (mut x Ofb) xor_key_stream(mut dst []u8, src []u8)
xor_key_stream xors each byte in the given slice with a byte from the key stream.