1 files changed, 119 insertions, 0 deletions
diff --git a/board/cr50/dcrypto/aes.c b/board/cr50/dcrypto/aes.c
new file mode 100644
index 0000000000..86e31fcca4
--- /dev/null
+++ b/board/cr50/dcrypto/aes.c
@@ -0,0 +1,119 @@
+/* Copyright 2015 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "dcrypto.h"
+#include "internal.h"
+
+#include "registers.h"
+
+static void set_control_register(
+	unsigned mode, unsigned key_size, unsigned encrypt)
+{
+	GWRITE_FIELD(KEYMGR, AES_CTRL, RESET, CTRL_NO_SOFT_RESET);
+	GWRITE_FIELD(KEYMGR, AES_CTRL, KEYSIZE, key_size);
+	GWRITE_FIELD(KEYMGR, AES_CTRL, CIPHER_MODE, mode);
+	GWRITE_FIELD(KEYMGR, AES_CTRL, ENC_MODE, encrypt);
+	GWRITE_FIELD(KEYMGR, AES_CTRL, CTR_ENDIAN, CTRL_CTR_BIG_ENDIAN);
+	GWRITE_FIELD(KEYMGR, AES_CTRL, ENABLE, CTRL_ENABLE);
+}
+
+static int wait_read_data(volatile uint32_t *addr)
+{
+	int empty;
+	int count = 20;     /* Wait these many ~cycles. */
+
+	do {
+		empty = REG32(addr);
+		count--;
+	} while (count && empty);
+
+	return empty ? 0 : 1;
+}
+
+int DCRYPTO_aes_init(const uint8_t *key, uint32_t key_len, const uint8_t *iv,
+		enum cipher_mode c_mode, enum encrypt_mode e_mode)
+{
+	int i;
+	const uint32_t *p;
+	uint32_t key_mode;
+
+	switch (key_len) {
+	case 128:
+		key_mode = 0;
+		break;
+	case 192:
+		key_mode = 1;
+		break;
+	case 256:
+		key_mode = 2;
+		break;
+	default:
+		/* Invalid key length specified. */
+		return 0;
+	}
+	set_control_register(c_mode, key_mode, e_mode);
+
+	/* Initialize hardware with AES key */
+	p = (uint32_t *) key;
+	for (i = 0; i < (key_len >> 5); i++)
+		GR_KEYMGR_AES_KEY(i) = p[i];
+	/* Trigger key expansion. */
+	GREG32(KEYMGR, AES_KEY_START) = 1;
+
+	/* Wait for key expansion. */
+	if (!wait_read_data(GREG32_ADDR(KEYMGR, AES_KEY_START))) {
+		/* Should not happen. */
+		return 0;
+	}
+
+	/* Initialize IV for modes that require it. */
+	if (iv) {
+		p = (uint32_t *) iv;
+		for (i = 0; i < 4; i++)
+			GR_KEYMGR_AES_CTR(i) = p[i];
+	}
+	return 1;
+}
+
+int DCRYPTO_aes_block(const uint8_t *in, uint8_t *out)
+{
+	int i;
+	uint32_t *outw;
+	const uint32_t *inw = (const uint32_t *) in;
+
+	/* Write plaintext. */
+	for (i = 0; i < 4; i++)
+		GREG32(KEYMGR, AES_WFIFO_DATA) = inw[i];
+
+	/* Wait for the result. */
+	if (!wait_read_data(GREG32_ADDR(KEYMGR, AES_RFIFO_EMPTY))) {
+		/* Should not happen, ciphertext not ready. */
+		return 0;
+	}
+
+	/* Read ciphertext. */
+	outw = (uint32_t *) out;
+	for (i = 0; i < 4; i++)
+		outw[i] = GREG32(KEYMGR, AES_RFIFO_DATA);
+	return 1;
+}
+
+void DCRYPTO_aes_write_iv(const uint8_t *iv)
+{
+	int i;
+	const uint32_t *p = (const uint32_t *) iv;
+
+	for (i = 0; i < 4; i++)
+		GR_KEYMGR_AES_CTR(i) = p[i];
+}
+
+void DCRYPTO_aes_read_iv(uint8_t *iv)
+{
+	int i;
+	uint32_t *p = (uint32_t *) iv;
+
+	for (i = 0; i < 4; i++)
+		p[i] = GR_KEYMGR_AES_CTR(i);
+}