Historical interest only: marketplace-2014 implementation of SSH.
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#lang racket/base
;; Provide AES CTR mode, since OpenSSL's EVP support for AES CTR mode
;; is still ifdef'd out.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
;;;
;;; This file is part of marketplace-ssh.
;;;
;;; marketplace-ssh is free software: you can redistribute it and/or
;;; modify it under the terms of the GNU General Public License as
;;; published by the Free Software Foundation, either version 3 of the
;;; License, or (at your option) any later version.
;;;
;;; marketplace-ssh is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with marketplace-ssh. If not, see
;;; <http://www.gnu.org/licenses/>.
(provide start-aes-ctr
aes-ctr-process!)
(require ffi/unsafe)
(require ffi/unsafe/define)
(require openssl/libcrypto)
(define _AES_KEY-pointer _pointer)
(define AES_BLOCK_SIZE 16)
(define sizeof-AES_KEY 244) ;; TODO: figure out a good way to get this
;; from the header file or the library
;; itself
(define-ffi-definer define-crypto libcrypto
#:default-make-fail make-not-available)
(define-crypto AES_set_encrypt_key (_fun _pointer _int _AES_KEY-pointer -> _int))
;;(define-crypto AES_set_decrypt_key (_fun _pointer _int _AES_KEY-pointer -> _int))
(define-crypto AES_ctr128_encrypt
(_fun _pointer ;; in
_pointer ;; out
_long ;; length
_AES_KEY-pointer ;; key
_pointer ;; ivec, AES_BLOCK_SIZE bytes
_pointer ;; ecount_buf, AES_BLOCK_SIZE bytes
_pointer ;; int pointer, the "num" field of the ongoing state (??)
-> _void))
(struct aes-ctr-state (key ivec ecount num) #:transparent)
(define (start-aes-ctr key initialization-vector)
(let ((key-buffer (malloc sizeof-AES_KEY))
(ivec (make-bytes AES_BLOCK_SIZE))
(ecount (make-bytes AES_BLOCK_SIZE))
(num (make-bytes (ctype-sizeof _int))))
(AES_set_encrypt_key key
(* 8 (bytes-length key)) ;; measured in bits
key-buffer)
(bytes-copy! ivec 0 initialization-vector 0 AES_BLOCK_SIZE)
(bytes-fill! ecount 0)
(bytes-fill! num 0)
(aes-ctr-state key-buffer
ivec
ecount
num)))
(define (aes-ctr-process! state input-block)
(define block-length (bytes-length input-block))
(define output-block (make-bytes block-length))
(AES_ctr128_encrypt input-block
output-block
block-length
(aes-ctr-state-key state)
(aes-ctr-state-ivec state)
(aes-ctr-state-ecount state)
(aes-ctr-state-num state))
output-block)