Add AES crypto library

Add support for AES using an implementation from Karl Malbrain.
This offers small code size (around 5KB on ARM) and supports 128-bit
AES only.

Signed-off-by: Yen Lin <yelin@nvidia.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/include/aes.h b/include/aes.h
new file mode 100644
index 0000000..41b0db2
--- /dev/null
+++ b/include/aes.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2010 - 2011 NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program 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 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef _AES_REF_H_
+#define _AES_REF_H_
+
+/*
+ * AES encryption library, with small code size, supporting only 128-bit AES
+ *
+ * AES is a stream cipher which works a block at a time, with each block
+ * in this case being AES_KEY_LENGTH bytes.
+ */
+
+enum {
+	AES_STATECOLS	= 4,	/* columns in the state & expanded key */
+	AES_KEYCOLS	= 4,	/* columns in a key */
+	AES_ROUNDS	= 10,	/* rounds in encryption */
+
+	AES_KEY_LENGTH	= 128 / 8,
+	AES_EXPAND_KEY_LENGTH	= 4 * AES_STATECOLS * (AES_ROUNDS + 1),
+};
+
+/**
+ * Expand a key into a key schedule, which is then used for the other
+ * operations.
+ *
+ * \param key		Key, of length AES_KEY_LENGTH bytes
+ * \param expkey	Buffer to place expanded key, AES_EXPAND_KEY_LENGTH
+ */
+void aes_expand_key(u8 *key, u8 *expkey);
+
+/**
+ * Encrypt a single block of data
+ *
+ * in		Input data
+ * expkey	Expanded key to use for encryption (from aes_expand_key())
+ * out		Output data
+ */
+void aes_encrypt(u8 *in, u8 *expkey, u8 *out);
+
+/**
+ * Decrypt a single block of data
+ *
+ * in		Input data
+ * expkey	Expanded key to use for decryption (from aes_expand_key())
+ * out		Output data
+ */
+void aes_decrypt(u8 *in, u8 *expkey, u8 *out);
+
+#endif /* _AES_REF_H_ */