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tls: in AES-CBC code, do not set key for every record - do it once

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function                                             old     new   delta
aes_setkey                                            16     212    +196
tls_handshake                                       1941    1977     +36
aes_encrypt_1                                        382     396     +14
xwrite_encrypted                                     605     604      -1
tls_xread_record                                     659     656      -3
aes_encrypt_one_block                                 65      59      -6
aes_cbc_encrypt                                      172     121     -51
aesgcm_setkey                                         58       -     -58
aes_cbc_decrypt                                      958     881     -77
KeyExpansion                                         188       -    -188
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 3/5 up/down: 246/-384)         Total: -138 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2018-11-23 18:02:44 +01:00
parent 83e5c627e1
commit 5e4236d226
5 changed files with 28 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
networking/tls_aes.c
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@@ -326,8 +326,11 @@ static void InvMixColumns(unsigned astate[16])
}
}
static void aes_encrypt_1(unsigned astate[16], unsigned rounds, const uint32_t *RoundKey)
static void aes_encrypt_1(struct tls_aes *aes, unsigned astate[16])
{
unsigned rounds = aes->rounds;
const uint32_t *RoundKey = aes->key;
for (;;) {
AddRoundKey(astate, RoundKey);
RoundKey += 4;
@@ -355,22 +358,19 @@ void FAST_FUNC aes_encrypt_one_block(struct tls_aes *aes, const void *data, void
for (i = 0; i < 16; i++)
astate[i] = pt[i];
aes_encrypt_1(astate, aes->rounds, aes->key);
aes_encrypt_1(aes, astate);
for (i = 0; i < 16; i++)
ct[i] = astate[i];
}
void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst)
void FAST_FUNC aes_cbc_encrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst)
{
uint32_t RoundKey[60];
uint8_t iv2[16];
unsigned rounds;
const uint8_t *pt = data;
uint8_t *ct = dst;
memcpy(iv2, iv, 16);
rounds = KeyExpansion(RoundKey, key, klen);
while (len > 0) {
{
/* almost aes_encrypt_one_block(rounds, RoundKey, pt, ct);
@@ -381,7 +381,7 @@ void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void *
unsigned astate[16];
for (i = 0; i < 16; i++)
astate[i] = pt[i] ^ iv2[i];
aes_encrypt_1(astate, rounds, RoundKey);
aes_encrypt_1(aes, astate);
for (i = 0; i < 16; i++)
iv2[i] = ct[i] = astate[i];
}
@@ -391,8 +391,11 @@ void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void *
}
}
static void aes_decrypt_1(unsigned astate[16], unsigned rounds, const uint32_t *RoundKey)
static void aes_decrypt_1(struct tls_aes *aes, unsigned astate[16])
{
unsigned rounds = aes->rounds;
const uint32_t *RoundKey = aes->key;
RoundKey += rounds * 4;
AddRoundKey(astate, RoundKey);
for (;;) {
@@ -407,8 +410,10 @@ static void aes_decrypt_1(unsigned astate[16], unsigned rounds, const uint32_t *
}
#if 0 //UNUSED
static void aes_decrypt_one_block(unsigned rounds, const uint32_t *RoundKey, const void *data, void *dst)
static void aes_decrypt_one_block(struct tls_aes *aes, const void *data, void *dst)
{
unsigned rounds = aes->rounds;
const uint32_t *RoundKey = aes->key;
unsigned astate[16];
unsigned i;
@@ -417,25 +422,22 @@ static void aes_decrypt_one_block(unsigned rounds, const uint32_t *RoundKey, con
for (i = 0; i < 16; i++)
astate[i] = ct[i];
aes_decrypt_1(astate, rounds, RoundKey);
aes_decrypt_1(aes, astate);
for (i = 0; i < 16; i++)
pt[i] = astate[i];
}
#endif
void FAST_FUNC aes_cbc_decrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst)
void FAST_FUNC aes_cbc_decrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst)
{
uint32_t RoundKey[60];
uint8_t iv2[16];
uint8_t iv3[16];
unsigned rounds;
uint8_t *ivbuf;
uint8_t *ivnext;
const uint8_t *ct = data;
uint8_t *pt = dst;
rounds = KeyExpansion(RoundKey, key, klen);
ivbuf = memcpy(iv2, iv, 16);
while (len) {
ivnext = (ivbuf==iv2) ? iv3 : iv2;
@@ -447,7 +449,7 @@ void FAST_FUNC aes_cbc_decrypt(const void *key, int klen, void *iv, const void *
unsigned astate[16];
for (i = 0; i < 16; i++)
ivnext[i] = astate[i] = ct[i];
aes_decrypt_1(astate, rounds, RoundKey);
aes_decrypt_1(aes, astate);
for (i = 0; i < 16; i++)
pt[i] = astate[i] ^ ivbuf[i];
}