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authorDamjan Marion <damarion@cisco.com>2023-03-23 13:44:01 +0000
committerDave Wallace <dwallacelf@gmail.com>2023-03-27 10:09:50 +0000
commit4172448954d7787f511c91eecfb48897e946ed0b (patch)
tree85bd6e3c19334013eda8c9bf8cfce4df560c7f67 /src/vppinfra/crypto/aes_gcm.h
parent75776f03a82065fb877d7d3a47de8ee2e72d5061 (diff)
vppinfra: small improvement and polishing of AES GCM code
Type: improvement Change-Id: Ie9661792ec68d4ea3c62ee9eb31b455d3b2b0a42 Signed-off-by: Damjan Marion <damarion@cisco.com>
Diffstat (limited to 'src/vppinfra/crypto/aes_gcm.h')
-rw-r--r--src/vppinfra/crypto/aes_gcm.h133
1 files changed, 77 insertions, 56 deletions
diff --git a/src/vppinfra/crypto/aes_gcm.h b/src/vppinfra/crypto/aes_gcm.h
index 8a5f76c3b33..3d1b220f7b8 100644
--- a/src/vppinfra/crypto/aes_gcm.h
+++ b/src/vppinfra/crypto/aes_gcm.h
@@ -103,9 +103,15 @@ typedef struct
aes_gcm_counter_t Y;
/* ghash */
- ghash_data_t gd;
+ ghash_ctx_t gd;
} aes_gcm_ctx_t;
+static_always_inline u8x16
+aes_gcm_final_block (aes_gcm_ctx_t *ctx)
+{
+ return (u8x16) ((u64x2){ ctx->data_bytes, ctx->aad_bytes } << 3);
+}
+
static_always_inline void
aes_gcm_ghash_mul_first (aes_gcm_ctx_t *ctx, aes_data_t data, u32 n_lanes)
{
@@ -137,19 +143,18 @@ aes_gcm_ghash_mul_next (aes_gcm_ctx_t *ctx, aes_data_t data)
}
static_always_inline void
-aes_gcm_ghash_mul_bit_len (aes_gcm_ctx_t *ctx)
+aes_gcm_ghash_mul_final_block (aes_gcm_ctx_t *ctx)
{
- u8x16 r = (u8x16) ((u64x2){ ctx->data_bytes, ctx->aad_bytes } << 3);
#if N_LANES == 4
u8x64 h = u8x64_insert_u8x16 (u8x64_zero (), ctx->Hi[NUM_HI - 1], 0);
- u8x64 r4 = u8x64_insert_u8x16 (u8x64_zero (), r, 0);
+ u8x64 r4 = u8x64_insert_u8x16 (u8x64_zero (), aes_gcm_final_block (ctx), 0);
ghash4_mul_next (&ctx->gd, r4, h);
#elif N_LANES == 2
u8x32 h = u8x32_insert_lo (u8x32_zero (), ctx->Hi[NUM_HI - 1]);
- u8x32 r2 = u8x32_insert_lo (u8x32_zero (), r);
+ u8x32 r2 = u8x32_insert_lo (u8x32_zero (), aes_gcm_final_block (ctx));
ghash2_mul_next (&ctx->gd, r2, h);
#else
- ghash_mul_next (&ctx->gd, r, ctx->Hi[NUM_HI - 1]);
+ ghash_mul_next (&ctx->gd, aes_gcm_final_block (ctx), ctx->Hi[NUM_HI - 1]);
#endif
}
@@ -178,7 +183,7 @@ aes_gcm_ghash (aes_gcm_ctx_t *ctx, u8 *data, u32 n_left)
aes_gcm_ghash_mul_first (ctx, d[0], 8 * N_LANES + 1);
for (i = 1; i < 8; i++)
aes_gcm_ghash_mul_next (ctx, d[i]);
- aes_gcm_ghash_mul_bit_len (ctx);
+ aes_gcm_ghash_mul_final_block (ctx);
aes_gcm_ghash_reduce (ctx);
aes_gcm_ghash_reduce2 (ctx);
aes_gcm_ghash_final (ctx);
@@ -243,16 +248,14 @@ aes_gcm_ghash (aes_gcm_ctx_t *ctx, u8 *data, u32 n_left)
}
if (ctx->operation == AES_GCM_OP_GMAC)
- aes_gcm_ghash_mul_bit_len (ctx);
+ aes_gcm_ghash_mul_final_block (ctx);
aes_gcm_ghash_reduce (ctx);
aes_gcm_ghash_reduce2 (ctx);
aes_gcm_ghash_final (ctx);
}
else if (ctx->operation == AES_GCM_OP_GMAC)
- {
- u8x16 r = (u8x16) ((u64x2){ ctx->data_bytes, ctx->aad_bytes } << 3);
- ctx->T = ghash_mul (r ^ ctx->T, ctx->Hi[NUM_HI - 1]);
- }
+ ctx->T =
+ ghash_mul (aes_gcm_final_block (ctx) ^ ctx->T, ctx->Hi[NUM_HI - 1]);
done:
/* encrypt counter 0 E(Y0, k) */
@@ -267,6 +270,11 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
const aes_gcm_expaned_key_t Ke0 = ctx->Ke[0];
uword i = 0;
+ /* As counter is stored in network byte order for performance reasons we
+ are incrementing least significant byte only except in case where we
+ overlow. As we are processing four 128, 256 or 512-blocks in parallel
+ except the last round, overflow can happen only when n_blocks == 4 */
+
#if N_LANES == 4
const u32x16 ctr_inv_4444 = { 0, 0, 0, 4 << 24, 0, 0, 0, 4 << 24,
0, 0, 0, 4 << 24, 0, 0, 0, 4 << 24 };
@@ -275,15 +283,10 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
4, 0, 0, 0, 4, 0, 0, 0, 4, 0, 0, 0, 4, 0, 0, 0,
};
- /* As counter is stored in network byte order for performance reasons we
- are incrementing least significant byte only except in case where we
- overlow. As we are processing four 512-blocks in parallel except the
- last round, overflow can happen only when n == 4 */
-
if (n_blocks == 4)
for (; i < 2; i++)
{
- r[i] = Ke0.x4 ^ (u8x64) ctx->Y;
+ r[i] = Ke0.x4 ^ (u8x64) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_4444;
}
@@ -293,7 +296,7 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x4 ^ (u8x64) ctx->Y;
+ r[i] = Ke0.x4 ^ (u8x64) ctx->Y; /* Initial AES round */
Yr += ctr_4444;
ctx->Y = (u32x16) aes_gcm_reflect ((u8x64) Yr);
}
@@ -302,7 +305,7 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
{
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x4 ^ (u8x64) ctx->Y;
+ r[i] = Ke0.x4 ^ (u8x64) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_4444;
}
}
@@ -311,15 +314,10 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
const u32x8 ctr_inv_22 = { 0, 0, 0, 2 << 24, 0, 0, 0, 2 << 24 };
const u32x8 ctr_22 = { 2, 0, 0, 0, 2, 0, 0, 0 };
- /* As counter is stored in network byte order for performance reasons we
- are incrementing least significant byte only except in case where we
- overlow. As we are processing four 512-blocks in parallel except the
- last round, overflow can happen only when n == 4 */
-
if (n_blocks == 4)
for (; i < 2; i++)
{
- r[i] = Ke0.x2 ^ (u8x32) ctx->Y;
+ r[i] = Ke0.x2 ^ (u8x32) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_22;
}
@@ -329,7 +327,7 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x2 ^ (u8x32) ctx->Y;
+ r[i] = Ke0.x2 ^ (u8x32) ctx->Y; /* Initial AES round */
Yr += ctr_22;
ctx->Y = (u32x8) aes_gcm_reflect ((u8x32) Yr);
}
@@ -338,7 +336,7 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
{
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x2 ^ (u8x32) ctx->Y;
+ r[i] = Ke0.x2 ^ (u8x32) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_22;
}
}
@@ -350,20 +348,20 @@ aes_gcm_enc_first_round (aes_gcm_ctx_t *ctx, aes_data_t *r, uword n_blocks)
{
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x1 ^ (u8x16) ctx->Y;
+ r[i] = Ke0.x1 ^ (u8x16) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_1;
}
ctx->counter += n_blocks;
}
else
{
- r[i++] = Ke0.x1 ^ (u8x16) ctx->Y;
+ r[i++] = Ke0.x1 ^ (u8x16) ctx->Y; /* Initial AES round */
ctx->Y += ctr_inv_1;
ctx->counter += 1;
for (; i < n_blocks; i++)
{
- r[i] = Ke0.x1 ^ (u8x16) ctx->Y;
+ r[i] = Ke0.x1 ^ (u8x16) ctx->Y; /* Initial AES round */
ctx->counter++;
ctx->Y[3] = clib_host_to_net_u32 (ctx->counter);
}
@@ -510,8 +508,7 @@ aes_gcm_calc (aes_gcm_ctx_t *ctx, aes_data_t *d, const u8 *src, u8 *dst, u32 n,
}
static_always_inline void
-aes_gcm_calc_double (aes_gcm_ctx_t *ctx, aes_data_t *d, const u8 *src, u8 *dst,
- int with_ghash)
+aes_gcm_calc_double (aes_gcm_ctx_t *ctx, aes_data_t *d, const u8 *src, u8 *dst)
{
const aes_gcm_expaned_key_t *k = ctx->Ke;
const aes_mem_t *sv = (aes_mem_t *) src;
@@ -680,7 +677,7 @@ aes_gcm_calc_last (aes_gcm_ctx_t *ctx, aes_data_t *d, int n_blocks,
aes_gcm_enc_ctr0_round (ctx, 8);
aes_gcm_enc_ctr0_round (ctx, 9);
- aes_gcm_ghash_mul_bit_len (ctx);
+ aes_gcm_ghash_mul_final_block (ctx);
aes_gcm_ghash_reduce (ctx);
for (i = 10; i < ctx->rounds; i++)
@@ -731,6 +728,7 @@ aes_gcm_enc (aes_gcm_ctx_t *ctx, const u8 *src, u8 *dst, u32 n_left)
}
return;
}
+
aes_gcm_calc (ctx, d, src, dst, 4, 4 * N, /* with_ghash */ 0);
/* next */
@@ -739,7 +737,7 @@ aes_gcm_enc (aes_gcm_ctx_t *ctx, const u8 *src, u8 *dst, u32 n_left)
src += 4 * N;
for (; n_left >= 8 * N; n_left -= 8 * N, src += 8 * N, dst += 8 * N)
- aes_gcm_calc_double (ctx, d, src, dst, /* with_ghash */ 1);
+ aes_gcm_calc_double (ctx, d, src, dst);
if (n_left >= 4 * N)
{
@@ -785,8 +783,11 @@ static_always_inline void
aes_gcm_dec (aes_gcm_ctx_t *ctx, const u8 *src, u8 *dst, uword n_left)
{
aes_data_t d[4] = {};
+ ghash_ctx_t gd;
+
+ /* main encryption loop */
for (; n_left >= 8 * N; n_left -= 8 * N, dst += 8 * N, src += 8 * N)
- aes_gcm_calc_double (ctx, d, src, dst, /* with_ghash */ 1);
+ aes_gcm_calc_double (ctx, d, src, dst);
if (n_left >= 4 * N)
{
@@ -798,27 +799,48 @@ aes_gcm_dec (aes_gcm_ctx_t *ctx, const u8 *src, u8 *dst, uword n_left)
src += N * 4;
}
- if (n_left == 0)
- goto done;
+ if (n_left)
+ {
+ ctx->last = 1;
- ctx->last = 1;
+ if (n_left > 3 * N)
+ aes_gcm_calc (ctx, d, src, dst, 4, n_left, /* with_ghash */ 1);
+ else if (n_left > 2 * N)
+ aes_gcm_calc (ctx, d, src, dst, 3, n_left, /* with_ghash */ 1);
+ else if (n_left > N)
+ aes_gcm_calc (ctx, d, src, dst, 2, n_left, /* with_ghash */ 1);
+ else
+ aes_gcm_calc (ctx, d, src, dst, 1, n_left, /* with_ghash */ 1);
+ }
- if (n_left > 3 * N)
- aes_gcm_calc (ctx, d, src, dst, 4, n_left, /* with_ghash */ 1);
- else if (n_left > 2 * N)
- aes_gcm_calc (ctx, d, src, dst, 3, n_left, /* with_ghash */ 1);
- else if (n_left > N)
- aes_gcm_calc (ctx, d, src, dst, 2, n_left, /* with_ghash */ 1);
- else
- aes_gcm_calc (ctx, d, src, dst, 1, n_left, /* with_ghash */ 1);
+ /* interleaved counter 0 encryption E(Y0, k) and ghash of final GCM
+ * (bit length) block */
- u8x16 r;
-done:
- r = (u8x16) ((u64x2){ ctx->data_bytes, ctx->aad_bytes } << 3);
- ctx->T = ghash_mul (r ^ ctx->T, ctx->Hi[NUM_HI - 1]);
+ aes_gcm_enc_ctr0_round (ctx, 0);
+ aes_gcm_enc_ctr0_round (ctx, 1);
- /* encrypt counter 0 E(Y0, k) */
- for (int i = 0; i < ctx->rounds + 1; i += 1)
+ ghash_mul_first (&gd, aes_gcm_final_block (ctx) ^ ctx->T,
+ ctx->Hi[NUM_HI - 1]);
+
+ aes_gcm_enc_ctr0_round (ctx, 2);
+ aes_gcm_enc_ctr0_round (ctx, 3);
+
+ ghash_reduce (&gd);
+
+ aes_gcm_enc_ctr0_round (ctx, 4);
+ aes_gcm_enc_ctr0_round (ctx, 5);
+
+ ghash_reduce2 (&gd);
+
+ aes_gcm_enc_ctr0_round (ctx, 6);
+ aes_gcm_enc_ctr0_round (ctx, 7);
+
+ ctx->T = ghash_final (&gd);
+
+ aes_gcm_enc_ctr0_round (ctx, 8);
+ aes_gcm_enc_ctr0_round (ctx, 9);
+
+ for (int i = 10; i < ctx->rounds + 1; i += 1)
aes_gcm_enc_ctr0_round (ctx, i);
}
@@ -835,6 +857,7 @@ aes_gcm (const u8 *src, u8 *dst, const u8 *aad, u8 *ivp, u8 *tag,
.operation = op,
.data_bytes = data_bytes,
.aad_bytes = aad_bytes,
+ .Ke = kd->Ke,
.Hi = kd->Hi },
*ctx = &_ctx;
@@ -843,7 +866,7 @@ aes_gcm (const u8 *src, u8 *dst, const u8 *aad, u8 *ivp, u8 *tag,
Y0[2] = *(u32u *) (ivp + 8);
Y0[3] = 1 << 24;
ctx->EY0 = (u8x16) Y0;
- ctx->Ke = kd->Ke;
+
#if N_LANES == 4
ctx->Y = u32x16_splat_u32x4 (Y0) + (u32x16){
0, 0, 0, 1 << 24, 0, 0, 0, 2 << 24, 0, 0, 0, 3 << 24, 0, 0, 0, 4 << 24,
@@ -858,8 +881,6 @@ aes_gcm (const u8 *src, u8 *dst, const u8 *aad, u8 *ivp, u8 *tag,
/* calculate ghash for AAD */
aes_gcm_ghash (ctx, addt, aad_bytes);
- clib_prefetch_load (tag);
-
/* ghash and encrypt/edcrypt */
if (op == AES_GCM_OP_ENCRYPT)
aes_gcm_enc (ctx, src, dst, data_bytes);