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-rw-r--r--arch/arm/mach-tegra/tegra20/crypto.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/tegra20/crypto.c b/arch/arm/mach-tegra/tegra20/crypto.c
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index 0000000000..ec95d7ceb1
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+++ b/arch/arm/mach-tegra/tegra20/crypto.c
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+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2010 - 2011 NVIDIA Corporation <www.nvidia.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/errno.h>
+#include "crypto.h"
+#include "aes.h"
+
+static u8 zero_key[16];
+
+#define AES_CMAC_CONST_RB 0x87 /* from RFC 4493, Figure 2.2 */
+
+enum security_op {
+ SECURITY_SIGN = 1 << 0, /* Sign the data */
+ SECURITY_ENCRYPT = 1 << 1, /* Encrypt the data */
+};
+
+/**
+ * Shift a vector left by one bit
+ *
+ * \param in Input vector
+ * \param out Output vector
+ * \param size Length of vector in bytes
+ */
+static void left_shift_vector(u8 *in, u8 *out, int size)
+{
+ int carry = 0;
+ int i;
+
+ for (i = size - 1; i >= 0; i--) {
+ out[i] = (in[i] << 1) | carry;
+ carry = in[i] >> 7; /* get most significant bit */
+ }
+}
+
+/**
+ * Sign a block of data, putting the result into dst.
+ *
+ * \param key Input AES key, length AES_KEY_LENGTH
+ * \param key_schedule Expanded key to use
+ * \param src Source data of length 'num_aes_blocks' blocks
+ * \param dst Destination buffer, length AES_KEY_LENGTH
+ * \param num_aes_blocks Number of AES blocks to encrypt
+ */
+static void sign_object(u8 *key, u8 *key_schedule, u8 *src, u8 *dst,
+ u32 num_aes_blocks)
+{
+ u8 tmp_data[AES_KEY_LENGTH];
+ u8 left[AES_KEY_LENGTH];
+ u8 k1[AES_KEY_LENGTH];
+ u8 *cbc_chain_data;
+ unsigned i;
+
+ cbc_chain_data = zero_key; /* Convenient array of 0's for IV */
+
+ /* compute K1 constant needed by AES-CMAC calculation */
+ for (i = 0; i < AES_KEY_LENGTH; i++)
+ tmp_data[i] = 0;
+
+ aes_cbc_encrypt_blocks(key_schedule, tmp_data, left, 1);
+
+ left_shift_vector(left, k1, sizeof(left));
+
+ if ((left[0] >> 7) != 0) /* get MSB of L */
+ k1[AES_KEY_LENGTH-1] ^= AES_CMAC_CONST_RB;
+
+ /* compute the AES-CMAC value */
+ for (i = 0; i < num_aes_blocks; i++) {
+ /* Apply the chain data */
+ aes_apply_cbc_chain_data(cbc_chain_data, src, tmp_data);
+
+ /* for the final block, XOR K1 into the IV */
+ if (i == num_aes_blocks - 1)
+ aes_apply_cbc_chain_data(tmp_data, k1, tmp_data);
+
+ /* encrypt the AES block */
+ aes_encrypt(tmp_data, key_schedule, dst);
+
+ debug("sign_obj: block %d of %d\n", i, num_aes_blocks);
+
+ /* Update pointers for next loop. */
+ cbc_chain_data = dst;
+ src += AES_KEY_LENGTH;
+ }
+}
+
+/**
+ * Encrypt and sign a block of data (depending on security mode).
+ *
+ * \param key Input AES key, length AES_KEY_LENGTH
+ * \param oper Security operations mask to perform (enum security_op)
+ * \param src Source data
+ * \param length Size of source data
+ * \param sig_dst Destination address for signature, AES_KEY_LENGTH bytes
+ */
+static int encrypt_and_sign(u8 *key, enum security_op oper, u8 *src,
+ u32 length, u8 *sig_dst)
+{
+ u32 num_aes_blocks;
+ u8 key_schedule[AES_EXPAND_KEY_LENGTH];
+
+ debug("encrypt_and_sign: length = %d\n", length);
+
+ /*
+ * The only need for a key is for signing/checksum purposes, so
+ * if not encrypting, expand a key of 0s.
+ */
+ aes_expand_key(oper & SECURITY_ENCRYPT ? key : zero_key, key_schedule);
+
+ num_aes_blocks = (length + AES_KEY_LENGTH - 1) / AES_KEY_LENGTH;
+
+ if (oper & SECURITY_ENCRYPT) {
+ /* Perform this in place, resulting in src being encrypted. */
+ debug("encrypt_and_sign: begin encryption\n");
+ aes_cbc_encrypt_blocks(key_schedule, src, src, num_aes_blocks);
+ debug("encrypt_and_sign: end encryption\n");
+ }
+
+ if (oper & SECURITY_SIGN) {
+ /* encrypt the data, overwriting the result in signature. */
+ debug("encrypt_and_sign: begin signing\n");
+ sign_object(key, key_schedule, src, sig_dst, num_aes_blocks);
+ debug("encrypt_and_sign: end signing\n");
+ }
+
+ return 0;
+}
+
+int sign_data_block(u8 *source, unsigned length, u8 *signature)
+{
+ return encrypt_and_sign(zero_key, SECURITY_SIGN, source,
+ length, signature);
+}