[or-cvs] r11536: Re-optimize counter-mode: save about 15% on my core2 by (1) (in tor/trunk: . src/common)
nickm at seul.org
nickm at seul.org
Thu Sep 20 17:07:45 UTC 2007
Author: nickm
Date: 2007-09-20 13:07:45 -0400 (Thu, 20 Sep 2007)
New Revision: 11536
Modified:
tor/trunk/
tor/trunk/ChangeLog
tor/trunk/configure.in
tor/trunk/src/common/aes.c
Log:
r15210 at catbus: nickm | 2007-09-20 13:04:05 -0400
Re-optimize counter-mode: save about 15% on my core2 by (1) not regenerating the entire counter buffer every time we encrypt a block of keystream (2) using the platform-optimized htonl to convert to big-endian (It's a single instruction on 486 and later ) and (3) not even keeping a separate "counter" and "buffer" when the platform is big-endian. The third still needs testing.
Property changes on: tor/trunk
___________________________________________________________________
svk:merge ticket from /tor/trunk [r15210] on 8246c3cf-6607-4228-993b-4d95d33730f1
Modified: tor/trunk/ChangeLog
===================================================================
--- tor/trunk/ChangeLog 2007-09-20 16:01:02 UTC (rev 11535)
+++ tor/trunk/ChangeLog 2007-09-20 17:07:45 UTC (rev 11536)
@@ -15,6 +15,12 @@
temporarily runs an old version of Tor and then switches back to a new
one, she doesn't automatically lose her guards.
+ o Minor features (speed):
+ - When implementing AES counter mode, update only the portions of the
+ counter buffer that need to change, and don't keep separate
+ network-order and host-order counters when they are the same (i.e., on
+ big-endian hosts.)
+
o Minor features (controller):
- Accept LF instead of CRLF on controller, since some software has a
hard time generating real Internet newlines.
Modified: tor/trunk/configure.in
===================================================================
--- tor/trunk/configure.in 2007-09-20 16:01:02 UTC (rev 11535)
+++ tor/trunk/configure.in 2007-09-20 17:07:45 UTC (rev 11536)
@@ -143,6 +143,8 @@
CFLAGS="$CFLAGS -c99"
fi
+AC_C_BIGENDIAN
+
AC_SEARCH_LIBS(socket, [socket])
AC_SEARCH_LIBS(gethostbyname, [nsl])
AC_SEARCH_LIBS(dlopen, [dl])
Modified: tor/trunk/src/common/aes.c
===================================================================
--- tor/trunk/src/common/aes.c 2007-09-20 16:01:02 UTC (rev 11535)
+++ tor/trunk/src/common/aes.c 2007-09-20 17:07:45 UTC (rev 11536)
@@ -130,6 +130,7 @@
/* Interface to AES code, and counter implementation */
struct aes_cnt_cipher {
+ /** This next element (howevever it's defined) is the AES key. */
#if defined(USE_OPENSSL_EVP)
EVP_CIPHER_CTX key;
#elif defined(USE_OPENSSL_AES)
@@ -138,14 +139,38 @@
u32 rk[4*(MAXNR+1)];
int nr;
#endif
+
+#if !defined(WORDS_BIGENDIAN) || defined(USE_RIJNDAEL_COUNTER_OPTIMIZATION)
+ /** These four values, together, implement a 128-bit counter, with
+ * counter0 as the low-order word and counter3 as the high-order word. */
u32 counter3;
u32 counter2;
u32 counter1;
u32 counter0;
+#endif
+
+#ifndef USE_RIJNDAEL_COUNTER_OPTIMIZATION
+ union {
+ /** The counter, in big-endian order, as bytes. */
+ u8 buf[16];
+ /** The counter, in big-endian order, as big-endian words. Note that
+ * on big-endian platforms, this is redundant with counter3...0,
+ * so we just use these values instead. */
+ u32 buf32[4];
+ } ctr_buf;
+#endif
+ /** The encrypted value of ctr_buf. */
u8 buf[16];
+ /** Our current stream position within buf. */
u8 pos;
};
+#if defined(WORDS_BIGENDIAN) && !defined(USE_RIJNDAEL_COUNTER_OPTIMIZIZATION)
+#define COUNTER(c, n) ((c)->ctr_buf.buf32[3-(n)])
+#else
+#define COUNTER(c, n) ((c)->counter ## n)
+#endif
+
/**
* Helper function: set <b>cipher</b>'s internal buffer to the encrypted
* value of the current counter.
@@ -164,37 +189,17 @@
cipher->counter3, cipher->counter2,
cipher->counter1, cipher->counter0, cipher->buf);
#else
- u32 counter0 = cipher->counter0;
- u32 counter1 = cipher->counter1;
- u32 counter2 = cipher->counter2;
- u32 counter3 = cipher->counter3;
- u8 buf[16];
- buf[15] = (counter0 >> 0) & 0xff;
- buf[14] = (counter0 >> 8) & 0xff;
- buf[13] = (counter0 >> 16) & 0xff;
- buf[12] = (counter0 >> 24) & 0xff;
- buf[11] = (counter1 >> 0) & 0xff;
- buf[10] = (counter1 >> 8) & 0xff;
- buf[ 9] = (counter1 >> 16) & 0xff;
- buf[ 8] = (counter1 >> 24) & 0xff;
- buf[ 7] = (counter2 >> 0) & 0xff;
- buf[ 6] = (counter2 >> 8) & 0xff;
- buf[ 5] = (counter2 >> 16) & 0xff;
- buf[ 4] = (counter2 >> 24) & 0xff;
- buf[ 3] = (counter3 >> 0) & 0xff;
- buf[ 2] = (counter3 >> 8) & 0xff;
- buf[ 1] = (counter3 >> 16) & 0xff;
- buf[ 0] = (counter3 >> 24) & 0xff;
#if defined(USE_OPENSSL_EVP)
{
int outl=16, inl=16;
- EVP_EncryptUpdate(&cipher->key, cipher->buf, &outl, buf, inl);
+ EVP_EncryptUpdate(&cipher->key, cipher->buf, &outl,
+ cipher->ctr_buf.buf, inl);
}
#elif defined(USE_OPENSSL_AES)
- AES_encrypt(buf, cipher->buf, &cipher->key);
+ AES_encrypt(cipher->ctr_buf.buf, cipher->buf, &cipher->key);
#else
- rijndaelEncrypt(cipher->rk, cipher->nr, buf, cipher->buf);
+ rijndaelEncrypt(cipher->rk, cipher->nr, cipher->ctr_buf.buf, cipher->buf);
#endif
#endif
}
@@ -232,10 +237,14 @@
cipher->nr = rijndaelKeySetupEnc(cipher->rk, (const unsigned char*)key,
key_bits);
#endif
- cipher->counter0 = 0;
- cipher->counter1 = 0;
- cipher->counter2 = 0;
- cipher->counter3 = 0;
+ COUNTER(cipher, 0) = 0;
+ COUNTER(cipher, 1) = 0;
+ COUNTER(cipher, 2) = 0;
+ COUNTER(cipher, 3) = 0;
+#ifndef USE_RIJNDAEL_COUNTER_OPTIMIZATION
+ memset(cipher->ctr_buf.buf, 0, sizeof(cipher->ctr_buf.buf));
+#endif
+
cipher->pos = 0;
_aes_fill_buf(cipher);
}
@@ -253,6 +262,14 @@
tor_free(cipher);
}
+#if defined(USE_RIJNDAEL_COUNTER_OPTIMIZATION) || defined(WORDS_BIGENDIAN)
+#define UPDATE_CTR_BUF(c, n)
+#else
+#define UPDATE_CTR_BUF(c, n) STMT_BEGIN \
+ (c)->ctr_buf.buf32[3-(n)] = htonl((c)->counter ## n); \
+ STMT_END
+#endif
+
/** Encrypt <b>len</b> bytes from <b>input</b>, storing the result in
* <b>output</b>. Uses the key in <b>cipher</b>, and advances the counter
* by <b>len</b> bytes as it encrypts.
@@ -261,6 +278,7 @@
aes_crypt(aes_cnt_cipher_t *cipher, const char *input, size_t len,
char *output)
{
+
/* XXXX This function is up to 5% of our runtime in some profiles;
* we should look into unrolling some of the loops; taking advantage
* of alignmement, using a bigger buffer, and so on. Not till after 0.1.2.x,
@@ -274,13 +292,17 @@
*(output++) = *(input++) ^ cipher->buf[c];
} while (++c != 16);
cipher->pos = c = 0;
- if (PREDICT_UNLIKELY(! ++cipher->counter0)) {
- if (PREDICT_UNLIKELY(! ++cipher->counter1)) {
- if (PREDICT_UNLIKELY(! ++cipher->counter2)) {
- ++cipher->counter3;
+ if (PREDICT_UNLIKELY(! ++COUNTER(cipher, 0))) {
+ if (PREDICT_UNLIKELY(! ++COUNTER(cipher, 1))) {
+ if (PREDICT_UNLIKELY(! ++COUNTER(cipher, 2))) {
+ ++COUNTER(cipher, 3);
+ UPDATE_CTR_BUF(cipher, 3);
}
+ UPDATE_CTR_BUF(cipher, 2);
}
+ UPDATE_CTR_BUF(cipher, 1);
}
+ UPDATE_CTR_BUF(cipher, 0);
_aes_fill_buf(cipher);
}
}
@@ -317,6 +339,9 @@
cipher->counter1 = ntohl(get_uint32(iv+8));
cipher->counter0 = ntohl(get_uint32(iv+12));
cipher->pos = 0;
+#ifndef USE_RIJNDAEL_COUNTER_OPTIMIZATION
+ memcpy(cipher->ctr_buf.buf, iv, 16);
+#endif
_aes_fill_buf(cipher);
}
@@ -1026,3 +1051,4 @@
return 0;
}
#endif
+
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