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authorMatthias Schiffer <mschiffer@universe-factory.net>2012-09-15 06:01:11 +0200
committerMatthias Schiffer <mschiffer@universe-factory.net>2012-09-15 06:01:11 +0200
commit37385fcd836bcc086b56b8dc7089d5038c203f13 (patch)
treee4baf6ea1c24ebb8fbc93f02526acb56d186c606 /src
parent430a8557d4421f41fbf834909f7598cfc64e3311 (diff)
downloadfastd-37385fcd836bcc086b56b8dc7089d5038c203f13.tar
fastd-37385fcd836bcc086b56b8dc7089d5038c203f13.zip
Rework some parts of the AES128-GCM method
These changes improve the performance of the AES128-GCM method by ~10% on my Intel CPU when compiled with -O2. Furthermore, the AES and the GHASH parts are separated now, allowing to switch to other implementations of the algorithms more easily.
Diffstat (limited to 'src')
-rw-r--r--src/fastd.c44
-rw-r--r--src/fastd.h4
-rw-r--r--src/method_aes128_gcm.c159
-rw-r--r--src/method_null.c8
-rw-r--r--src/method_xsalsa20_poly1305.c6
-rw-r--r--src/protocol_ec25519_fhmqvc.c2
6 files changed, 137 insertions, 86 deletions
diff --git a/src/fastd.c b/src/fastd.c
index dadcd17..3bbf30f 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -264,7 +264,7 @@ static size_t methods_min_encrypt_head_space(fastd_context *ctx) {
ret = s;
}
- return ret;
+ return ALIGN(ret, 8);
}
static size_t methods_min_decrypt_head_space(fastd_context *ctx) {
@@ -280,6 +280,38 @@ static size_t methods_min_decrypt_head_space(fastd_context *ctx) {
ret = s;
}
+ return ALIGN(ret, 8);
+}
+
+static size_t methods_min_encrypt_tail_space(fastd_context *ctx) {
+ size_t ret = ctx->conf->methods[0]->min_encrypt_tail_space(ctx);
+
+ int i;
+ for (i = 0; i < MAX_METHODS; i++) {
+ if (!ctx->conf->methods[i])
+ break;
+
+ size_t s = ctx->conf->methods[i]->min_encrypt_tail_space(ctx);
+ if (s > ret)
+ ret = s;
+ }
+
+ return ret;
+}
+
+static size_t methods_min_decrypt_tail_space(fastd_context *ctx) {
+ size_t ret = ctx->conf->methods[0]->min_decrypt_tail_space(ctx);
+
+ int i;
+ for (i = 0; i < MAX_METHODS; i++) {
+ if (!ctx->conf->methods[i])
+ break;
+
+ size_t s = ctx->conf->methods[i]->min_decrypt_tail_space(ctx);
+ if (s > ret)
+ ret = s;
+ }
+
return ret;
}
@@ -360,7 +392,7 @@ void fastd_handle_receive(fastd_context *ctx, fastd_peer *peer, fastd_buffer buf
fastd_peer *dest_peer;
for (dest_peer = ctx->peers; dest_peer; dest_peer = dest_peer->next) {
if (dest_peer != peer && fastd_peer_is_established(dest_peer)) {
- fastd_buffer send_buffer = fastd_buffer_alloc(buffer.len, methods_min_encrypt_head_space(ctx), 0);
+ fastd_buffer send_buffer = fastd_buffer_alloc(buffer.len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
memcpy(send_buffer.data, buffer.data, buffer.len);
ctx->conf->protocol->send(ctx, dest_peer, send_buffer);
}
@@ -479,7 +511,7 @@ static void handle_tasks(fastd_context *ctx) {
case TASK_KEEPALIVE:
pr_debug(ctx, "sending keepalive to %P", task->peer);
- ctx->conf->protocol->send(ctx, task->peer, fastd_buffer_alloc(0, methods_min_encrypt_head_space(ctx), 0));
+ ctx->conf->protocol->send(ctx, task->peer, fastd_buffer_alloc(0, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx)));
break;
default:
@@ -492,7 +524,7 @@ static void handle_tasks(fastd_context *ctx) {
static void handle_tun(fastd_context *ctx) {
size_t max_len = fastd_max_packet_size(ctx);
- fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_encrypt_head_space(ctx), 0);
+ fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
ssize_t len = read(ctx->tunfd, buffer.data, max_len);
if (len < 0) {
@@ -529,7 +561,7 @@ static void handle_tun(fastd_context *ctx) {
if (peer == NULL) {
for (peer = ctx->peers; peer; peer = peer->next) {
if (fastd_peer_is_established(peer)) {
- fastd_buffer send_buffer = fastd_buffer_alloc(len, methods_min_encrypt_head_space(ctx), 0);
+ fastd_buffer send_buffer = fastd_buffer_alloc(len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
memcpy(send_buffer.data, buffer.data, len);
ctx->conf->protocol->send(ctx, peer, send_buffer);
}
@@ -541,7 +573,7 @@ static void handle_tun(fastd_context *ctx) {
static void handle_socket(fastd_context *ctx, int sockfd) {
size_t max_len = PACKET_TYPE_LEN + methods_max_packet_size(ctx);
- fastd_buffer buffer = fastd_buffer_alloc(max_len, ALIGN8(methods_min_decrypt_head_space(ctx)), 0);
+ fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_decrypt_head_space(ctx), methods_min_decrypt_tail_space(ctx));
uint8_t *packet_type;
fastd_peer_address recvaddr;
diff --git a/src/fastd.h b/src/fastd.h
index 12702e7..e1c531b 100644
--- a/src/fastd.h
+++ b/src/fastd.h
@@ -91,6 +91,8 @@ struct _fastd_method {
size_t (*max_packet_size)(fastd_context *ctx);
size_t (*min_encrypt_head_space)(fastd_context *ctx);
size_t (*min_decrypt_head_space)(fastd_context *ctx);
+ size_t (*min_encrypt_tail_space)(fastd_context *ctx);
+ size_t (*min_decrypt_tail_space)(fastd_context *ctx);
fastd_method_session_state* (*session_init)(fastd_context *ctx, uint8_t *secret, size_t length, bool initiator);
bool (*session_is_valid)(fastd_context *ctx, fastd_method_session_state *session);
@@ -349,7 +351,7 @@ static inline void fastd_string_stack_free(fastd_string_stack *str) {
}
}
-#define ALIGN8(l) (((l+7)/8)*8)
+#define ALIGN(l, a) (((l+a-1)/a)*a)
static inline bool timespec_after(const struct timespec *tp1, const struct timespec *tp2) {
return (tp1->tv_sec > tp2->tv_sec ||
diff --git a/src/method_aes128_gcm.c b/src/method_aes128_gcm.c
index b0c3232..9f2d6b4 100644
--- a/src/method_aes128_gcm.c
+++ b/src/method_aes128_gcm.c
@@ -87,14 +87,19 @@ static size_t method_max_packet_size(fastd_context *ctx) {
}
-static size_t method_min_encrypt_head_space(fastd_context *ctx) {
+static size_t method_min_head_space(fastd_context *ctx) {
return 0;
}
-static size_t method_min_decrypt_head_space(fastd_context *ctx) {
- return 0;
+static size_t method_min_encrypt_tail_space(fastd_context *ctx) {
+ return (BLOCKBYTES-1);
+}
+
+static size_t method_min_decrypt_tail_space(fastd_context *ctx) {
+ return (2*BLOCKBYTES-1);
}
+
static const block_t r = { .b = {0xe1} };
static inline uint8_t shr(block_t *out, const block_t *in, int n) {
@@ -110,15 +115,13 @@ static inline uint8_t shr(block_t *out, const block_t *in, int n) {
return (c >> (8-n));
}
-static inline void xor(uint8_t *x, const uint8_t *a, const uint8_t *b, unsigned int l) {
- int i;
- for (i = 0; i < l; i++)
- x[i] = a[i] ^ b[i];
+static inline void xor(block_t *x, const block_t *a, const block_t *b) {
+ x->qw[0] = a->qw[0] ^ b->qw[0];
+ x->qw[1] = a->qw[1] ^ b->qw[1];
}
-static inline void xor_block(block_t *x, const block_t *a) {
- x->qw[0] ^= a->qw[0];
- x->qw[1] ^= a->qw[1];
+static inline void xor_a(block_t *x, const block_t *a) {
+ xor(x, x, a);
}
static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8_t *secret, size_t length, bool initiator) {
@@ -137,8 +140,7 @@ static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8
crypto_stream_aes128ctr_beforenm(session->d, secret);
- uint8_t zerononce[crypto_stream_aes128ctr_NONCEBYTES];
- memset(zerononce, 0, crypto_stream_aes128ctr_NONCEBYTES);
+ static const uint8_t zerononce[crypto_stream_aes128ctr_NONCEBYTES] = {};
block_t Hbase[4];
crypto_stream_aes128ctr_afternm(Hbase[0].b, BLOCKBYTES, zerononce, session->d);
@@ -149,7 +151,7 @@ static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8
for (i = 1; i < 4; i++) {
uint8_t carry = shr(&Hbase[i], &Hbase[i-1], 1);
if (carry)
- xor_block(&Hbase[i], &r);
+ xor_a(&Hbase[i], &r);
shr(&Rbase[i], &Rbase[i-1], 1);
}
@@ -162,8 +164,8 @@ static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8
int j;
for (j = 0; j < 4; j++) {
if (i & (8 >> j)) {
- xor_block(&session->H[0][i], &Hbase[j]);
- xor_block(&R[i], &Rbase[j]);
+ xor_a(&session->H[0][i], &Hbase[j]);
+ xor_a(&R[i], &Rbase[j]);
}
}
}
@@ -173,7 +175,7 @@ static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8
for (j = 0; j < 16; j++) {
uint8_t carry = shr(&session->H[i][j], &session->H[i-1][j], 4);
- xor_block(&session->H[i][j], &R[carry]);
+ xor_a(&session->H[i][j], &R[carry]);
}
}
@@ -207,57 +209,73 @@ static void method_session_free(fastd_context *ctx, fastd_method_session_state *
}
}
-static void mulH(uint8_t out[BLOCKBYTES], const uint8_t in[BLOCKBYTES], fastd_method_session_state *session) {
- block_t out2;
- memset(&out2, 0, BLOCKBYTES);
+static void mulH_a(block_t *x, fastd_method_session_state *session) {
+ block_t out = {};
int i;
for (i = 0; i < 16; i++) {
- xor_block(&out2, &session->H[2*i][in[i]>>4]);
- xor_block(&out2, &session->H[2*i+1][in[i]&0xf]);
+ xor_a(&out, &session->H[2*i][x->b[i]>>4]);
+ xor_a(&out, &session->H[2*i+1][x->b[i]&0xf]);
}
- memcpy(out, &out2, BLOCKBYTES);
+ *x = out;
}
-#define BLOCKPTR(buf, i) (((uint8_t*)(buf))+(i)*BLOCKBYTES)
+static inline void xor_blocks(block_t *out, const block_t *in1, const block_t *in2, size_t n_blocks) {
+ int i;
+ for (i = 0; i < n_blocks; i++)
+ xor(&out[i], &in1[i], &in2[i]);
+}
+
+static inline void put_size(block_t *out, size_t len) {
+ memset(out, 0, BLOCKBYTES-5);
+ out->b[BLOCKBYTES-5] = len >> 29;
+ out->b[BLOCKBYTES-4] = len >> 21;
+ out->b[BLOCKBYTES-3] = len >> 13;
+ out->b[BLOCKBYTES-2] = len >> 5;
+ out->b[BLOCKBYTES-1] = len << 3;
+}
+
+static inline void ghash(block_t *out, const block_t *blocks, size_t n_blocks, fastd_method_session_state *session) {
+ memset(out, 0, sizeof(block_t));
+
+ int i;
+ for (i = 0; i < n_blocks; i++) {
+ xor_a(out, &blocks[i]);
+ mulH_a(out, session);
+ }
+}
static bool method_encrypt(fastd_context *ctx, fastd_peer *peer, fastd_method_session_state *session, fastd_buffer *out, fastd_buffer in) {
- *out = fastd_buffer_alloc(in.len, NONCEBYTES+BLOCKBYTES, 0);
- uint8_t *sig = ((uint8_t*)out->data) - BLOCKBYTES;
+ size_t tail_len = ALIGN(in.len, BLOCKBYTES)-in.len;
+ *out = fastd_buffer_alloc(in.len, ALIGN(NONCEBYTES+BLOCKBYTES, 8), BLOCKBYTES+tail_len);
- memset(sig, 0, BLOCKBYTES);
+ if (tail_len)
+ memset(in.data+in.len, 0, tail_len);
uint8_t nonce[crypto_stream_aes128ctr_NONCEBYTES];
memcpy(nonce, session->send_nonce, NONCEBYTES);
memset(nonce+NONCEBYTES, 0, crypto_stream_aes128ctr_NONCEBYTES-NONCEBYTES-1);
nonce[crypto_stream_aes128ctr_NONCEBYTES-1] = 1;
- uint8_t stream[in.len+BLOCKBYTES];
- crypto_stream_aes128ctr_afternm(stream, in.len+BLOCKBYTES, nonce, session->d);
+ int n_blocks = (in.len+BLOCKBYTES-1)/BLOCKBYTES;
- int blocks = (in.len+BLOCKBYTES-1)/BLOCKBYTES;
+ block_t stream[n_blocks+1];
+ crypto_stream_aes128ctr_afternm((uint8_t*)stream, sizeof(stream), nonce, session->d);
- int i;
- for (i = 0; i < blocks; i++) {
- int len = BLOCKBYTES;
- if (i == blocks-1)
- len = in.len - i*BLOCKBYTES;
+ block_t *inblocks = in.data;
+ block_t *outblocks = out->data;
- xor(BLOCKPTR(out->data, i), BLOCKPTR(in.data, i), BLOCKPTR(stream, i+1), len);
+ xor_blocks(outblocks, inblocks, stream+1, n_blocks);
- xor(sig, sig, BLOCKPTR(out->data, i), len);
- mulH(sig, sig, session);
- }
+ if (tail_len)
+ memset(out->data+out->len, 0, tail_len);
- sig[BLOCKBYTES-5] ^= (in.len >> 29) & 0xff;
- sig[BLOCKBYTES-4] ^= (in.len >> 21) & 0xff;
- sig[BLOCKBYTES-3] ^= (in.len >> 13) & 0xff;
- sig[BLOCKBYTES-2] ^= (in.len >> 5) & 0xff;
- sig[BLOCKBYTES-1] ^= (in.len << 3) & 0xff;
- mulH(sig, sig, session);
+ put_size(&outblocks[n_blocks], in.len);
- xor(sig, sig, stream, BLOCKBYTES);
+ block_t *sig = outblocks-1;
+ ghash(sig, outblocks, n_blocks+1, session);
+ xor_a(sig, &stream[0]);
fastd_buffer_free(in);
@@ -294,48 +312,37 @@ static bool method_decrypt(fastd_context *ctx, fastd_peer *peer, fastd_method_se
fastd_buffer_push_head(&in, NONCEBYTES+BLOCKBYTES);
- *out = fastd_buffer_alloc(in.len, 0, 0);
+ size_t tail_len = ALIGN(in.len, BLOCKBYTES)-in.len;
+ *out = fastd_buffer_alloc(in.len, 0, tail_len);
- uint8_t sig[BLOCKBYTES];
- memset(sig, 0, BLOCKBYTES);
+ int n_blocks = (in.len+BLOCKBYTES-1)/BLOCKBYTES;
- uint8_t stream[in.len+BLOCKBYTES];
- crypto_stream_aes128ctr_afternm(stream, in.len+BLOCKBYTES, nonce, session->d);
+ block_t stream[n_blocks+1];
+ crypto_stream_aes128ctr_afternm((uint8_t*)stream, sizeof(stream), nonce, session->d);
- int blocks = (in.len+BLOCKBYTES-1)/BLOCKBYTES;
+ block_t *inblocks = in.data;
+ block_t *outblocks = out->data;
- int i;
- for (i = 0; i < blocks; i++) {
- int len = BLOCKBYTES;
- if (i == blocks-1)
- len = in.len - i*BLOCKBYTES;
+ if (tail_len)
+ memset(in.data+in.len, 0, tail_len);
- xor(BLOCKPTR(out->data, i), BLOCKPTR(in.data, i), BLOCKPTR(stream, i+1), len);
+ put_size(&inblocks[n_blocks], in.len);
- xor(sig, sig, BLOCKPTR(in.data, i), len);
- mulH(sig, sig, session);
- }
-
- sig[BLOCKBYTES-5] ^= (in.len >> 29) & 0xff;
- sig[BLOCKBYTES-4] ^= (in.len >> 21) & 0xff;
- sig[BLOCKBYTES-3] ^= (in.len >> 13) & 0xff;
- sig[BLOCKBYTES-2] ^= (in.len >> 5) & 0xff;
- sig[BLOCKBYTES-1] ^= (in.len << 3) & 0xff;
- mulH(sig, sig, session);
-
- xor(sig, sig, stream, BLOCKBYTES);
+ block_t sig;
+ ghash(&sig, inblocks, n_blocks+1, session);
+ xor_a(&sig, &stream[0]);
- fastd_buffer_pull_head(&in, BLOCKBYTES);
-
- if (memcmp(sig, in.data, BLOCKBYTES) != 0) {
+ if (memcmp(&sig, inblocks-1, BLOCKBYTES) != 0) {
fastd_buffer_free(*out);
/* restore input buffer */
- fastd_buffer_pull_head(&in, NONCEBYTES);
+ fastd_buffer_pull_head(&in, NONCEBYTES+BLOCKBYTES);
return false;
}
+ xor_blocks(outblocks, inblocks, stream+1, n_blocks);
+
fastd_buffer_free(in);
if (age < 0) {
@@ -361,8 +368,10 @@ const fastd_method fastd_method_aes128_gcm = {
.name = "aes128-gcm",
.max_packet_size = method_max_packet_size,
- .min_encrypt_head_space = method_min_encrypt_head_space,
- .min_decrypt_head_space = method_min_decrypt_head_space,
+ .min_encrypt_head_space = method_min_head_space,
+ .min_decrypt_head_space = method_min_head_space,
+ .min_encrypt_tail_space = method_min_encrypt_tail_space,
+ .min_decrypt_tail_space = method_min_decrypt_tail_space,
.session_init = method_session_init,
.session_is_valid = method_session_is_valid,
diff --git a/src/method_null.c b/src/method_null.c
index e8b3fca..7cdbe00 100644
--- a/src/method_null.c
+++ b/src/method_null.c
@@ -31,7 +31,7 @@ static size_t method_max_packet_size(fastd_context *ctx) {
return fastd_max_packet_size(ctx);
}
-static size_t method_min_head_space(fastd_context *ctx) {
+static size_t method_min_head_tail_space(fastd_context *ctx) {
return 0;
}
@@ -66,8 +66,10 @@ const fastd_method fastd_method_null = {
.name = "null",
.max_packet_size = method_max_packet_size,
- .min_encrypt_head_space = method_min_head_space,
- .min_decrypt_head_space = method_min_head_space,
+ .min_encrypt_head_space = method_min_head_tail_space,
+ .min_decrypt_head_space = method_min_head_tail_space,
+ .min_encrypt_tail_space = method_min_head_tail_space,
+ .min_decrypt_tail_space = method_min_head_tail_space,
.session_init = method_session_init,
.session_is_valid = method_session_is_valid,
diff --git a/src/method_xsalsa20_poly1305.c b/src/method_xsalsa20_poly1305.c
index c7fb040..23f4c5d 100644
--- a/src/method_xsalsa20_poly1305.c
+++ b/src/method_xsalsa20_poly1305.c
@@ -86,6 +86,10 @@ static size_t method_min_decrypt_head_space(fastd_context *ctx) {
return (crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES - NONCEBYTES);
}
+static size_t method_min_tail_space(fastd_context *ctx) {
+ return 0;
+}
+
static fastd_method_session_state* method_session_init(fastd_context *ctx, uint8_t *secret, size_t length, bool initiator) {
int i;
@@ -220,6 +224,8 @@ const fastd_method fastd_method_xsalsa20_poly1305 = {
.max_packet_size = method_max_packet_size,
.min_encrypt_head_space = method_min_encrypt_head_space,
.min_decrypt_head_space = method_min_decrypt_head_space,
+ .min_encrypt_tail_space = method_min_tail_space,
+ .min_decrypt_tail_space = method_min_tail_space,
.session_init = method_session_init,
.session_is_valid = method_session_is_valid,
diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c
index b27f4d6..964c21d 100644
--- a/src/protocol_ec25519_fhmqvc.c
+++ b/src/protocol_ec25519_fhmqvc.c
@@ -726,7 +726,7 @@ static void protocol_send(fastd_context *ctx, fastd_peer *peer, fastd_buffer buf
}
static void send_empty(fastd_context *ctx, fastd_peer *peer, protocol_session *session) {
- session_send(ctx, peer, fastd_buffer_alloc(0, session->method->min_encrypt_head_space(ctx), 0), session);
+ session_send(ctx, peer, fastd_buffer_alloc(0, ALIGN(session->method->min_encrypt_head_space(ctx), 8), session->method->min_encrypt_tail_space(ctx)), session);
}
static void protocol_init_peer_state(fastd_context *ctx, fastd_peer *peer) {