summaryrefslogtreecommitdiffstats
path: root/src/vppinfra/crypto/aes_ctr.h
blob: 74a9f96d90de79bdb07075bb6ba3f8fc468d0f22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/* SPDX-License-Identifier: Apache-2.0
 * Copyright(c) 2024 Cisco Systems, Inc.
 */

#ifndef __crypto_aes_ctr_h__
#define __crypto_aes_ctr_h__

#include <vppinfra/clib.h>
#include <vppinfra/vector.h>
#include <vppinfra/cache.h>
#include <vppinfra/string.h>
#include <vppinfra/crypto/aes.h>

typedef struct
{
  const aes_expaned_key_t exp_key[AES_KEY_ROUNDS (AES_KEY_256) + 1];
} aes_ctr_key_data_t;

typedef struct
{
  const aes_expaned_key_t exp_key[AES_KEY_ROUNDS (AES_KEY_256) + 1];
  aes_counter_t ctr;		   /* counter (reflected) */
  u8 keystream_bytes[N_AES_BYTES]; /* keystream leftovers */
  u32 n_keystream_bytes;	   /* number of keystream leftovers */
} aes_ctr_ctx_t;

static_always_inline aes_counter_t
aes_ctr_one_block (aes_ctr_ctx_t *ctx, aes_counter_t ctr, const u8 *src,
		   u8 *dst, u32 n_parallel, u32 n_bytes, int rounds, int last)
{
  u32 __clib_aligned (N_AES_BYTES)
  inc[] = { N_AES_LANES, 0, 0, 0, N_AES_LANES, 0, 0, 0,
	    N_AES_LANES, 0, 0, 0, N_AES_LANES, 0, 0, 0 };
  const aes_expaned_key_t *k = ctx->exp_key;
  const aes_mem_t *sv = (aes_mem_t *) src;
  aes_mem_t *dv = (aes_mem_t *) dst;
  aes_data_t d[4], t[4];
  u32 r;

  n_bytes -= (n_parallel - 1) * N_AES_BYTES;

  /* AES First Round */
  for (int i = 0; i < n_parallel; i++)
    {
#if N_AES_LANES == 4
      t[i] = k[0].x4 ^ (u8x64) aes_reflect ((u8x64) ctr);
#elif N_AES_LANES == 2
      t[i] = k[0].x2 ^ (u8x32) aes_reflect ((u8x32) ctr);
#else
      t[i] = k[0].x1 ^ (u8x16) aes_reflect ((u8x16) ctr);
#endif
      ctr += *(aes_counter_t *) inc;
    }

  /* Load Data */
  for (int i = 0; i < n_parallel - last; i++)
    d[i] = sv[i];

  if (last)
    d[n_parallel - 1] =
      aes_load_partial ((u8 *) (sv + n_parallel - 1), n_bytes);

  /* AES Intermediate Rounds */
  for (r = 1; r < rounds; r++)
    aes_enc_round (t, k + r, n_parallel);

  /* AES Last Round */
  aes_enc_last_round (t, d, k + r, n_parallel);

  /* Store Data */
  for (int i = 0; i < n_parallel - last; i++)
    dv[i] = d[i];

  if (last)
    {
      aes_store_partial (d[n_parallel - 1], dv + n_parallel - 1, n_bytes);
      *(aes_data_t *) ctx->keystream_bytes = t[n_parallel - 1];
      ctx->n_keystream_bytes = N_AES_BYTES - n_bytes;
    }

  return ctr;
}

static_always_inline void
clib_aes_ctr_init (aes_ctr_ctx_t *ctx, const aes_ctr_key_data_t *kd,
		   const u8 *iv, aes_key_size_t ks)
{
  u32x4 ctr = (u32x4) u8x16_reflect (*(u8x16u *) iv);
#if N_AES_LANES == 4
  ctx->ctr = (aes_counter_t) u32x16_splat_u32x4 (ctr) +
	     (u32x16){ 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0 };
#elif N_AES_LANES == 2
  ctx->ctr = (aes_counter_t) u32x8_splat_u32x4 (ctr) +
	     (u32x8){ 0, 0, 0, 0, 1, 0, 0, 0 };
#else
  ctx->ctr = ctr;
#endif
  for (int i = 0; i < AES_KEY_ROUNDS (ks) + 1; i++)
    ((aes_expaned_key_t *) ctx->exp_key)[i] = kd->exp_key[i];
  ctx->n_keystream_bytes = 0;
}

static_always_inline void
clib_aes_ctr_transform (aes_ctr_ctx_t *ctx, const u8 *src, u8 *dst,
			u32 n_bytes, aes_key_size_t ks)
{
  int r = AES_KEY_ROUNDS (ks);
  aes_counter_t ctr = ctx->ctr;

  if (ctx->n_keystream_bytes)
    {
      u8 *ks = ctx->keystream_bytes + N_AES_BYTES - ctx->n_keystream_bytes;

      if (ctx->n_keystream_bytes >= n_bytes)
	{
	  for (int i = 0; i < n_bytes; i++)
	    dst[i] = src[i] ^ ks[i];
	  ctx->n_keystream_bytes -= n_bytes;
	  return;
	}

      for (int i = 0; i < ctx->n_keystream_bytes; i++)
	dst++[0] = src++[0] ^ ks[i];

      n_bytes -= ctx->n_keystream_bytes;
      ctx->n_keystream_bytes = 0;
    }

  /* main loop */
  for (int n = 4 * N_AES_BYTES; n_bytes >= n; n_bytes -= n, dst += n, src += n)
    ctr = aes_ctr_one_block (ctx, ctr, src, dst, 4, n, r, 0);

  if (n_bytes)
    {
      if (n_bytes > 3 * N_AES_BYTES)
	ctr = aes_ctr_one_block (ctx, ctr, src, dst, 4, n_bytes, r, 1);
      else if (n_bytes > 2 * N_AES_BYTES)
	ctr = aes_ctr_one_block (ctx, ctr, src, dst, 3, n_bytes, r, 1);
      else if (n_bytes > N_AES_BYTES)
	ctr = aes_ctr_one_block (ctx, ctr, src, dst, 2, n_bytes, r, 1);
      else
	ctr = aes_ctr_one_block (ctx, ctr, src, dst, 1, n_bytes, r, 1);
    }
  else
    ctx->n_keystream_bytes = 0;

  ctx->ctr = ctr;
}

static_always_inline void
clib_aes_ctr_key_expand (aes_ctr_key_data_t *kd, const u8 *key,
			 aes_key_size_t ks)
{
  u8x16 ek[AES_KEY_ROUNDS (AES_KEY_256) + 1];
  aes_expaned_key_t *k = (aes_expaned_key_t *) kd->exp_key;

  /* expand AES key */
  aes_key_expand (ek, key, ks);
  for (int i = 0; i < AES_KEY_ROUNDS (ks) + 1; i++)
    k[i].lanes[0] = k[i].lanes[1] = k[i].lanes[2] = k[i].lanes[3] = ek[i];
}

static_always_inline void
clib_aes128_ctr (const aes_ctr_key_data_t *kd, const u8 *src, u32 n_bytes,
		 const u8 *iv, u8 *dst)
{
  aes_ctr_ctx_t ctx;
  clib_aes_ctr_init (&ctx, kd, iv, AES_KEY_128);
  clib_aes_ctr_transform (&ctx, src, dst, n_bytes, AES_KEY_128);
}

static_always_inline void
clib_aes192_ctr (const aes_ctr_key_data_t *kd, const u8 *src, u32 n_bytes,
		 const u8 *iv, u8 *dst)
{
  aes_ctr_ctx_t ctx;
  clib_aes_ctr_init (&ctx, kd, iv, AES_KEY_192);
  clib_aes_ctr_transform (&ctx, src, dst, n_bytes, AES_KEY_192);
}

static_always_inline void
clib_aes256_ctr (const aes_ctr_key_data_t *kd, const u8 *src, u32 n_bytes,
		 const u8 *iv, u8 *dst)
{
  aes_ctr_ctx_t ctx;
  clib_aes_ctr_init (&ctx, kd, iv, AES_KEY_256);
  clib_aes_ctr_transform (&ctx, src, dst, n_bytes, AES_KEY_256);
}

#endif /* __crypto_aes_ctr_h__ */