2  * Counter with CBC-MAC (CCM) with AES
4  * Copyright (c) 2010-2012, Jouni Malinen <j@w1.fi>
12 #include "common.h"
38 	b[0] |= (((M - 2) / 2) /* M' */ << 3);  in aes_ccm_auth_start()
39 	b[0] |= (L - 1) /* L' */;  in aes_ccm_auth_start()
40 	os_memcpy(&b[1], nonce, 15 - L);  in aes_ccm_auth_start()
41 	WPA_PUT_BE16(&b[AES_BLOCK_SIZE - L], plain_len);  in aes_ccm_auth_start()
51 	os_memset(aad_buf + 2 + aad_len, 0, sizeof(aad_buf) - 2 - aad_len);  in aes_ccm_auth_start()
56 	if (aad_len > AES_BLOCK_SIZE - 2) {  in aes_ccm_auth_start()
76 		/* XOR zero-padded last block */  in aes_ccm_auth()
87 	a[0] = L - 1; /* Flags = L' */  in aes_ccm_encr_start()
88 	os_memcpy(&a[1], nonce, 15 - L);  in aes_ccm_encr_start()
100 		WPA_PUT_BE16(&a[AES_BLOCK_SIZE - 2], i);  in aes_ccm_encr()
108 		WPA_PUT_BE16(&a[AES_BLOCK_SIZE - 2], i);  in aes_ccm_encr()
110 		/* XOR zero-padded last block */  in aes_ccm_encr()
117 static void aes_ccm_encr_auth(void *aes, size_t M, u8 *x, u8 *a, u8 *auth)  in aes_ccm_encr_auth()  argument
124 	WPA_PUT_BE16(&a[AES_BLOCK_SIZE - 2], 0);  in aes_ccm_encr_auth()
127 		auth[i] = x[i] ^ tmp[i];  in aes_ccm_encr_auth()
128 	wpa_hexdump_key(MSG_EXCESSIVE, "CCM U", auth, M);  in aes_ccm_encr_auth()
132 static void aes_ccm_decr_auth(void *aes, size_t M, u8 *a, const u8 *auth, u8 *t)  in aes_ccm_decr_auth()  argument
137 	wpa_hexdump_key(MSG_EXCESSIVE, "CCM U", auth, M);  in aes_ccm_decr_auth()
139 	WPA_PUT_BE16(&a[AES_BLOCK_SIZE - 2], 0);  in aes_ccm_decr_auth()
142 		t[i] = auth[i] ^ tmp[i];  in aes_ccm_decr_auth()
147 /* AES-CCM with fixed L=2 and aad_len <= 30 assumption */
150 	       const u8 *aad, size_t aad_len, u8 *crypt, u8 *auth)  in aes_ccm_ae()  argument
157 		return -1;  in aes_ccm_ae()
161 		return -1;  in aes_ccm_ae()
169 	aes_ccm_encr_auth(aes, M, x, a, auth);  in aes_ccm_ae()
177 /* AES-CCM with fixed L=2 and aad_len <= 30 assumption */
180 	       const u8 *aad, size_t aad_len, const u8 *auth, u8 *plain)  in aes_ccm_ad()  argument
188 		return -1;  in aes_ccm_ad()
192 		return -1;  in aes_ccm_ad()
196 	aes_ccm_decr_auth(aes, M, a, auth, t);  in aes_ccm_ad()
207 		wpa_printf(MSG_EXCESSIVE, "CCM: Auth mismatch");  in aes_ccm_ad()
208 		return -1;  in aes_ccm_ad()