[git commit] tls: code shrink

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=219c9d4b5d12b3b965da838eb467b955ef928170
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
xwrite_encrypted                                     599     585     -14

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 include/platform.h |  5 +++++
 networking/tls.c   | 31 ++++++++++++++++---------------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/include/platform.h b/include/platform.h
index c365d5c8c..50365a31c 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -236,6 +236,7 @@ typedef uint64_t bb__aliased_uint64_t FIX_ALIASING;
 # define move_from_unaligned32(v, u32p) ((v) = *(bb__aliased_uint32_t*)(u32p))
 # define move_to_unaligned16(u16p, v)   (*(bb__aliased_uint16_t*)(u16p) = (v))
 # define move_to_unaligned32(u32p, v)   (*(bb__aliased_uint32_t*)(u32p) = (v))
+# define move_to_unaligned64(u64p, v)   (*(bb__aliased_uint64_t*)(u64p) = (v))
 /* #elif ... - add your favorite arch today! */
 #else
 # define BB_UNALIGNED_MEMACCESS_OK 0
@@ -252,6 +253,10 @@ typedef uint64_t bb__aliased_uint64_t FIX_ALIASING;
 	uint32_t __t = (v); \
 	memcpy((u32p), &__t, 4); \
 } while (0)
+# define move_to_unaligned64(u64p, v) do { \
+	uint64_t __t = (v); \
+	memcpy((u64p), &__t, 8); \
+} while (0)
 #endif
 
 /* Unaligned, fixed-endian accessors */
diff --git a/networking/tls.c b/networking/tls.c
index 3b4f1b7e2..2a0098674 100644
--- a/networking/tls.c
+++ b/networking/tls.c
@@ -788,14 +788,15 @@ static void xwrite_encrypted_aesgcm(tls_state_t *tls, unsigned size, unsigned ty
 {
 #define COUNTER(v) (*(uint32_t*)(v + 12))
 
-	uint8_t aad[13 + 3];   /* +3 creates [16] buffer, simplifying GHASH() */
-	uint8_t nonce[12 + 4]; /* +4 creates space for AES block counter */
-	uint8_t scratch[AES_BLOCK_SIZE]; //[16]
-	uint8_t authtag[AES_BLOCK_SIZE]; //[16]
+	uint8_t aad[13 + 3] ALIGNED(4);   /* +3 creates [16] buffer, simplifying GHASH() */
+	uint8_t nonce[12 + 4] ALIGNED(4); /* +4 creates space for AES block counter */
+	uint8_t scratch[AES_BLOCK_SIZE] ALIGNED(4); //[16]
+	uint8_t authtag[AES_BLOCK_SIZE] ALIGNED(4); //[16]
 	uint8_t *buf;
 	struct record_hdr *xhdr;
 	unsigned remaining;
 	unsigned cnt;
+	uint64_t t64;
 
 	buf = tls->outbuf + OUTBUF_PFX; /* see above for the byte it points to */
 	dump_hex("xwrite_encrypted_aesgcm plaintext:%s\n", buf, size);
@@ -810,13 +811,13 @@ static void xwrite_encrypted_aesgcm(tls_state_t *tls, unsigned size, unsigned ty
 	/* set aad[12], and clear aad[13..15] */
 	COUNTER(aad) = SWAP_LE32(size & 0xff);
 
-	memcpy(nonce,     tls->client_write_IV, 4);
-	memcpy(nonce + 4, &tls->write_seq64_be, 8);
-	memcpy(aad,       &tls->write_seq64_be, 8);
-	memcpy(buf - 8,   &tls->write_seq64_be, 8);
-//optimize
+	memcpy(nonce, tls->client_write_IV, 4);
+	t64 = tls->write_seq64_be;
+	move_to_unaligned64(nonce + 4, t64);
+	move_to_unaligned64(aad,       t64);
+	move_to_unaligned64(buf - 8,   t64);
 	/* seq64 is not used later in this func, can increment here */
-	tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
+	tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(t64));
 
 	cnt = 1;
 	remaining = size;
@@ -923,13 +924,14 @@ static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size)
 {
 #define COUNTER(v) (*(uint32_t*)(v + 12))
 
-	//uint8_t aad[13 + 3]; /* +3 creates [16] buffer, simplifying GHASH() */
-	uint8_t nonce[12 + 4]; /* +4 creates space for AES block counter */
-	uint8_t scratch[AES_BLOCK_SIZE]; //[16]
-	//uint8_t authtag[AES_BLOCK_SIZE]; //[16]
+	//uint8_t aad[13 + 3] ALIGNED(4); /* +3 creates [16] buffer, simplifying GHASH() */
+	uint8_t nonce[12 + 4] ALIGNED(4); /* +4 creates space for AES block counter */
+	uint8_t scratch[AES_BLOCK_SIZE] ALIGNED(4); //[16]
+	//uint8_t authtag[AES_BLOCK_SIZE] ALIGNED(4); //[16]
 	unsigned remaining;
 	unsigned cnt;
 
+	//memcpy(aad, buf, 8);
 	//aad[8] = type;
 	//aad[9] = TLS_MAJ;
 	//aad[10] = TLS_MIN;
@@ -937,7 +939,6 @@ static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size)
 	///* set aad[12], and clear aad[13..15] */
 	//COUNTER(aad) = SWAP_LE32(size & 0xff);
 
-	//memcpy(aad,       &tls->write_seq64_be, 8);
 	memcpy(nonce,     tls->server_write_IV, 4);
 	memcpy(nonce + 4, buf, 8);
 	buf += 8;