diff options
Diffstat (limited to 'src/aead/gcm.lisp')
| -rw-r--r-- | src/aead/gcm.lisp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/aead/gcm.lisp b/src/aead/gcm.lisp index 334f259..9a851fd 100644 --- a/src/aead/gcm.lisp +++ b/src/aead/gcm.lisp @@ -1,6 +1,8 @@ ;;;; -*- mode: lisp; indent-tabs-mode: nil -*- ;;;; gcm.lisp -- Galois counter mode +;; See nistspecialpublication800-38d.pdf about GCM and GMAC. + (in-package :crypto) @@ -16,6 +18,14 @@ :initform 0 :type (integer 0 *)))) +(defun inc32 (x) + (assert (= 16 (length x))) + (concatenate + '(simple-array (unsigned-byte 8) (16)) + (subseq x 0 12) + (integer-to-octets (1+ (octets-to-integer x :n-bits 32 :start 12)) + :n-bits 32))) + (defmethod shared-initialize :after ((mode gcm) slot-names &rest initargs &key key cipher-name initialization-vector &allow-other-keys) (declare (ignore slot-names initargs) (type simple-octet-vector key initialization-vector)) @@ -24,7 +34,7 @@ (reinitialize-instance (gcm-mac mode) :key key :initialization-vector initialization-vector))) - (iv (concatenate 'simple-octet-vector initialization-vector #(0 0 0 2))) + (iv (inc32 (gmac-j0 mac))) (cipher (if (or (null (gcm-cipher mode)) cipher-name) (make-cipher cipher-name :key key |