mirror of
https://github.com/espressif/esp-idf.git
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ad7cb5f5c1
This commit add following crypto changes 1. Update current crypto code with upstream supplicant code 2. Add a proper porting layer to use mbedtls APIs for all the crypto operations used by supplicant. Internal crypto will be used when USE_MBEDLTS flag is disabled in supplicant's menuconfig. This commit also removes the clutter in crypto files due to partial porting of some APIs to mbedtls, all the code from those files have been removed and rewritten in a generic way, this is inspired from current upstream code. This also reduces the lib size significantly, supplicant's lib size reduces around ~567kb after this change(NB: lib size doesn't indicate reduction in final bin size).
81 lines
1.8 KiB
C
81 lines
1.8 KiB
C
/*
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* AES key unwrap (RFC3394)
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*
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* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "aes.h"
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#include "aes_wrap.h"
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/**
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* aes_unwrap - Unwrap key with AES Key Wrap Algorithm (RFC3394)
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* @kek: Key encryption key (KEK)
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* @kek_len: Length of KEK in octets
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* @n: Length of the plaintext key in 64-bit units; e.g., 2 = 128-bit = 16
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* bytes
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* @cipher: Wrapped key to be unwrapped, (n + 1) * 64 bits
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* @plain: Plaintext key, n * 64 bits
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* Returns: 0 on success, -1 on failure (e.g., integrity verification failed)
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*/
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int aes_unwrap(const u8 *kek, size_t kek_len, int n, const u8 *cipher,
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u8 *plain)
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{
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u8 a[8], *r, b[AES_BLOCK_SIZE];
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int i, j;
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void *ctx;
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unsigned int t;
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/* 1) Initialize variables. */
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os_memcpy(a, cipher, 8);
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r = plain;
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os_memcpy(r, cipher + 8, 8 * n);
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ctx = aes_decrypt_init(kek, kek_len);
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if (ctx == NULL)
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return -1;
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/* 2) Compute intermediate values.
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* For j = 5 to 0
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* For i = n to 1
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* B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i
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* A = MSB(64, B)
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* R[i] = LSB(64, B)
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*/
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for (j = 5; j >= 0; j--) {
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r = plain + (n - 1) * 8;
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for (i = n; i >= 1; i--) {
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os_memcpy(b, a, 8);
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t = n * j + i;
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b[7] ^= t;
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b[6] ^= t >> 8;
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b[5] ^= t >> 16;
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b[4] ^= t >> 24;
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os_memcpy(b + 8, r, 8);
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aes_decrypt(ctx, b, b);
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os_memcpy(a, b, 8);
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os_memcpy(r, b + 8, 8);
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r -= 8;
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}
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}
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aes_decrypt_deinit(ctx);
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/* 3) Output results.
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*
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* These are already in @plain due to the location of temporary
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* variables. Just verify that the IV matches with the expected value.
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*/
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for (i = 0; i < 8; i++) {
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if (a[i] != 0xa6)
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return -1;
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}
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return 0;
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}
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