1 /*
2 * AES (Rijndael) cipher - encrypt
3 *
4 * Modifications to public domain implementation:
5 * - cleanup
6 * - use C pre-processor to make it easier to change S table access
7 * - added option (AES_SMALL_TABLES) for reducing code size by about 8 kB at
8 * cost of reduced throughput (quite small difference on Pentium 4,
9 * 10-25% when using -O1 or -O2 optimization)
10 *
11 * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
12 *
13 * This software may be distributed under the terms of the BSD license.
14 * See README for more details.
15 */
16
17 #include "includes.h"
18
19 #include "common.h"
20 #include "crypto.h"
21 #include "aes_i.h"
22
rijndaelEncrypt(const u32 rk[],int Nr,const u8 pt[16],u8 ct[16])23 static void rijndaelEncrypt(const u32 rk[], int Nr, const u8 pt[16], u8 ct[16])
24 {
25 u32 s0, s1, s2, s3, t0, t1, t2, t3;
26 #ifndef FULL_UNROLL
27 int r;
28 #endif /* ?FULL_UNROLL */
29
30 /*
31 * map byte array block to cipher state
32 * and add initial round key:
33 */
34 s0 = GETU32(pt ) ^ rk[0];
35 s1 = GETU32(pt + 4) ^ rk[1];
36 s2 = GETU32(pt + 8) ^ rk[2];
37 s3 = GETU32(pt + 12) ^ rk[3];
38
39 #define ROUND(i,d,s) \
40 d##0 = TE0(s##0) ^ TE1(s##1) ^ TE2(s##2) ^ TE3(s##3) ^ rk[4 * i]; \
41 d##1 = TE0(s##1) ^ TE1(s##2) ^ TE2(s##3) ^ TE3(s##0) ^ rk[4 * i + 1]; \
42 d##2 = TE0(s##2) ^ TE1(s##3) ^ TE2(s##0) ^ TE3(s##1) ^ rk[4 * i + 2]; \
43 d##3 = TE0(s##3) ^ TE1(s##0) ^ TE2(s##1) ^ TE3(s##2) ^ rk[4 * i + 3]
44
45 #ifdef FULL_UNROLL
46
47 ROUND(1,t,s);
48 ROUND(2,s,t);
49 ROUND(3,t,s);
50 ROUND(4,s,t);
51 ROUND(5,t,s);
52 ROUND(6,s,t);
53 ROUND(7,t,s);
54 ROUND(8,s,t);
55 ROUND(9,t,s);
56 if (Nr > 10) {
57 ROUND(10,s,t);
58 ROUND(11,t,s);
59 if (Nr > 12) {
60 ROUND(12,s,t);
61 ROUND(13,t,s);
62 }
63 }
64
65 rk += Nr << 2;
66
67 #else /* !FULL_UNROLL */
68
69 /* Nr - 1 full rounds: */
70 r = Nr >> 1;
71 for (;;) {
72 ROUND(1,t,s);
73 rk += 8;
74 if (--r == 0)
75 break;
76 ROUND(0,s,t);
77 }
78
79 #endif /* ?FULL_UNROLL */
80
81 #undef ROUND
82
83 /*
84 * apply last round and
85 * map cipher state to byte array block:
86 */
87 s0 = TE41(t0) ^ TE42(t1) ^ TE43(t2) ^ TE44(t3) ^ rk[0];
88 PUTU32(ct , s0);
89 s1 = TE41(t1) ^ TE42(t2) ^ TE43(t3) ^ TE44(t0) ^ rk[1];
90 PUTU32(ct + 4, s1);
91 s2 = TE41(t2) ^ TE42(t3) ^ TE43(t0) ^ TE44(t1) ^ rk[2];
92 PUTU32(ct + 8, s2);
93 s3 = TE41(t3) ^ TE42(t0) ^ TE43(t1) ^ TE44(t2) ^ rk[3];
94 PUTU32(ct + 12, s3);
95 }
96
97
aes_encrypt_init(const u8 * key,size_t len)98 void * aes_encrypt_init(const u8 *key, size_t len)
99 {
100 u32 *rk;
101 int res;
102 rk = os_malloc(AES_PRIV_SIZE);
103 if (rk == NULL)
104 return NULL;
105 res = rijndaelKeySetupEnc(rk, key, len * 8);
106 if (res < 0) {
107 os_free(rk);
108 return NULL;
109 }
110 rk[AES_PRIV_NR_POS] = res;
111 return rk;
112 }
113
114
aes_encrypt(void * ctx,const u8 * plain,u8 * crypt)115 int aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
116 {
117 u32 *rk = ctx;
118 rijndaelEncrypt(ctx, rk[AES_PRIV_NR_POS], plain, crypt);
119 return 0;
120 }
121
122
aes_encrypt_deinit(void * ctx)123 void aes_encrypt_deinit(void *ctx)
124 {
125 os_memset(ctx, 0, AES_PRIV_SIZE);
126 os_free(ctx);
127 }
128