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Import 08-SEP-2012 version of ocb.c

... plus the local changes from:

  3b2604b Handle early gcc compilers that are missing __builtin_bswap64 or __builtin_ctz
  e8236c5 Use AlignedBuffer stedda posix_memalign(). Should work on PPC OS X 10.5.
  9827d12 Switch to OpenSSL AES
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commit 029e8bbde5e53b2e3454241143050cef27705cbe 1 parent e50822e
@kmcallister kmcallister authored committed
Showing with 220 additions and 38 deletions.
  1. +220 −38 src/crypto/ocb.cc
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258 src/crypto/ocb.cc
@@ -1,7 +1,7 @@
/*------------------------------------------------------------------------
-/ OCB Version 3 Reference Code (Optimized C) Last modified 13-JUL-2011
+/ OCB Version 3 Reference Code (Optimized C) Last modified 08-SEP-2012
/-------------------------------------------------------------------------
-/ Copyright (c) 2011 Ted Krovetz.
+/ Copyright (c) 2012 Ted Krovetz.
/
/ Permission to use, copy, modify, and/or distribute this software for any
/ purpose with or without fee is hereby granted, provided that the above
@@ -18,6 +18,8 @@
/ Phillip Rogaway holds patents relevant to OCB. See the following for
/ his patent grant: http://www.cs.ucdavis.edu/~rogaway/ocb/grant.htm
/
+/ Special thanks to Keegan McAllister for suggesting several good improvements
+/
/ Comments are welcome: Ted Krovetz <ted@krovetz.net> - Dedicated to Laurel K
/------------------------------------------------------------------------- */
@@ -31,7 +33,7 @@
/ So, when on machines with these facilities, all pointers passed to
/ any function should be 16-byte aligned.
/ - Plaintext and ciphertext pointers may be equal (ie, plaintext gets
-/ encrypted in-place), but no other pair of pointers may be equal.
+/ encrypted in-place), but no other pair of pointers may be equal.
/ - This code assumes all x86 processors have SSE2 and SSSE3 instructions
/ when compiling under MSVC. If untrue, alter the #define.
/ - This code is tested for C99 and recent versions of GCC and MSVC. */
@@ -56,7 +58,7 @@
/ The L values can be precomputed during initialization (requiring extra
/ space in ae_ctx), generated as needed (slightly slowing encryption and
/ decryption), or some combination of the two. L_TABLE_SZ specifies how many
-/ L values to precomute. L_TABLE_SZ must be at least 3. L_TABLE_SZ*16 bytes
+/ L values to precompute. L_TABLE_SZ must be at least 3. L_TABLE_SZ*16 bytes
/ are used for L values in ae_ctx. Plaintext and ciphertexts shorter than
/ 2^L_TABLE_SZ blocks need no L values calculated dynamically. */
#define L_TABLE_SZ 16
@@ -122,7 +124,7 @@
#else
#if (L_TABLE_SZ <= 9) && (L_TABLE_SZ_IS_ENOUGH) /* < 2^13 byte texts */
static inline unsigned ntz(unsigned x) {
- static const unsigned char tz_table[] = {0,
+ static const unsigned char tz_table[] = {0,
2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,7,
2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,8,
2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,6,2,3,2,4,2,3,2,5,2,3,2,4,2,3,2,7,
@@ -131,8 +133,8 @@
}
#else /* From http://supertech.csail.mit.edu/papers/debruijn.pdf */
static inline unsigned ntz(unsigned x) {
- static const unsigned char tz_table[32] =
- { 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
+ static const unsigned char tz_table[32] =
+ { 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9};
return tz_table[((uint32_t)((x & -x) * 0x077CB531u)) >> 27];
}
@@ -282,7 +284,7 @@
} else
return b;
}
-
+
/* KtopStr is reg correct by 64 bits, return mem correct */
block gen_offset(uint64_t KtopStr[3], unsigned bot) {
block rval;
@@ -302,7 +304,7 @@
"adcs %H1,%H1,%H1\n\t"
"adcs %0,%0,%0\n\t"
"adcs %H0,%H0,%H0\n\t"
- "it cs\n\t"
+ "it cs\n\t"
"eorcs %1,%1,#135"
: "+r"(b.l), "+r"(b.r) : : "cc");
return b;
@@ -315,7 +317,7 @@
return b;
}
#endif
-
+
#endif
/* ----------------------------------------------------------------------- */
@@ -420,7 +422,7 @@ static void AES_ecb_encrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
x3 = _mm_xor_si128(x3,_mm_shuffle_epi32(x0, 255)); \
kp[idx+2] = x0; tmp = x3
-void AES_128_Key_Expansion(const unsigned char *userkey, void *key)
+static void AES_128_Key_Expansion(const unsigned char *userkey, void *key)
{
__m128i x0,x1,x2;
__m128i *kp = (__m128i *)key;
@@ -438,7 +440,7 @@ void AES_128_Key_Expansion(const unsigned char *userkey, void *key)
EXPAND_ASSIST(x0,x1,x2,x0,255,54); kp[10] = x0;
}
-void AES_192_Key_Expansion(const unsigned char *userkey, void *key)
+static void AES_192_Key_Expansion(const unsigned char *userkey, void *key)
{
__m128i x0,x1,x2,x3,tmp,*kp = (__m128i *)key;
kp[0] = x0 = _mm_loadu_si128((__m128i*)userkey);
@@ -450,7 +452,7 @@ void AES_192_Key_Expansion(const unsigned char *userkey, void *key)
EXPAND192_STEP(10,64);
}
-void AES_256_Key_Expansion(const unsigned char *userkey, void *key)
+static void AES_256_Key_Expansion(const unsigned char *userkey, void *key)
{
__m128i x0,x1,x2,x3,*kp = (__m128i *)key;
kp[0] = x0 = _mm_loadu_si128((__m128i*)userkey );
@@ -471,7 +473,7 @@ void AES_256_Key_Expansion(const unsigned char *userkey, void *key)
EXPAND_ASSIST(x0,x1,x2,x3,255,64); kp[14] = x0;
}
-int AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key)
+static int AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key)
{
if (bits == 128) {
AES_128_Key_Expansion (userKey,key);
@@ -486,7 +488,7 @@ int AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *k
return 0;
}
- void AES_set_decrypt_key_fast(AES_KEY *dkey, const AES_KEY *ekey)
+static void AES_set_decrypt_key_fast(AES_KEY *dkey, const AES_KEY *ekey)
{
int j = 0;
int i = ROUNDS(ekey);
@@ -499,7 +501,7 @@ int AES_set_encrypt_key(const unsigned char *userKey, const int bits, AES_KEY *k
dkey->rd_key[i] = ekey->rd_key[j];
}
-int AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key)
+static int AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key)
{
AES_KEY temp_key;
AES_set_encrypt_key(userKey,bits,&temp_key);
@@ -568,12 +570,12 @@ static inline void AES_ecb_decrypt_blks(block *blks, unsigned nblks, AES_KEY *ke
/ Each item in the OCB context is stored either "memory correct" or
/ "register correct". On big-endian machines, this is identical. On
/ little-endian machines, one must choose whether the byte-string
-/ is in the corrct order when it resides in memory or in registers.
+/ is in the correct order when it resides in memory or in registers.
/ It must be register correct whenever it is to be manipulated
/ arithmetically, but must be memory correct whenever it interacts
/ with the plaintext or ciphertext.
/------------------------------------------------------------------------- */
-
+
struct _ae_ctx {
block offset; /* Memory correct */
block checksum; /* Memory correct */
@@ -641,10 +643,10 @@ int ae_init(ae_ctx *ctx, const void *key, int key_len, int nonce_len, int tag_le
{
unsigned i;
block tmp_blk;
-
+
if (nonce_len != 12)
return AE_NOT_SUPPORTED;
-
+
/* Initialize encryption & decryption keys */
#if (OCB_KEY_LEN > 0)
key_len = OCB_KEY_LEN;
@@ -655,11 +657,11 @@ int ae_init(ae_ctx *ctx, const void *key, int key_len, int nonce_len, int tag_le
#else
AES_set_decrypt_key((unsigned char *)key, (int)(key_len*8), &ctx->decrypt_key);
#endif
-
+
/* Zero things that need zeroing */
ctx->cached_Top = ctx->ad_checksum = zero_block();
ctx->ad_blocks_processed = 0;
-
+
/* Compute key-dependent values */
AES_encrypt((unsigned char *)&ctx->cached_Top,
(unsigned char *)&ctx->Lstar, &ctx->encrypt_key);
@@ -676,7 +678,7 @@ int ae_init(ae_ctx *ctx, const void *key, int key_len, int nonce_len, int tag_le
#if (OCB_TAG_LEN == 0)
ctx->tag_len = tag_len;
#else
- (void) tag_len; /* Supress var not used error */
+ (void) tag_len; /* Suppress var not used error */
#endif
return AE_SUCCESS;
@@ -710,13 +712,13 @@ static block gen_offset_from_nonce(ae_ctx *ctx, const void *nonce)
return gen_offset(ctx->KtopStr, idx);
}
- void process_ad(ae_ctx *ctx, const void *ad, int ad_len, int final)
+static void process_ad(ae_ctx *ctx, const void *ad, int ad_len, int final)
{
union { uint32_t u32[4]; uint8_t u8[16]; block bl; } tmp;
block ad_offset, ad_checksum;
const block * adp = (block *)ad;
unsigned i,k,tz,remaining;
-
+
ad_offset = ctx->ad_offset;
ad_checksum = ctx->ad_checksum;
i = ad_len/(BPI*16);
@@ -767,7 +769,7 @@ static block gen_offset_from_nonce(ae_ctx *ctx, const void *nonce)
if (final) {
block ta[BPI];
-
+
/* Process remaining associated data, compute its tag contribution */
remaining = ((unsigned)ad_len) % (BPI*16);
if (remaining) {
@@ -916,10 +918,10 @@ int ae_encrypt(ae_ctx * ctx,
ctx->blocks_processed = block_num;
ctx->checksum = checksum;
}
-
+
if (final) {
block ta[BPI+1], oa[BPI];
-
+
/* Process remaining plaintext and compute its tag contribution */
unsigned remaining = ((unsigned)pt_len) % (BPI*16);
k = 0; /* How many blocks in ta[] need ECBing */
@@ -988,7 +990,7 @@ int ae_encrypt(ae_ctx * ctx,
case 2: ctp[1] = xor_block(ta[1], oa[1]);
case 1: ctp[0] = xor_block(ta[0], oa[0]);
}
-
+
/* Tag is placed at the correct location
*/
if (tag) {
@@ -1014,6 +1016,28 @@ int ae_encrypt(ae_ctx * ctx,
/* ----------------------------------------------------------------------- */
+/* Compare two regions of memory, taking a constant amount of time for a
+ given buffer size -- under certain assumptions about the compiler
+ and machine, of course.
+
+ Use this to avoid timing side-channel attacks.
+
+ Returns 0 for memory regions with equal contents; non-zero otherwise. */
+static int constant_time_memcmp(const void *av, const void *bv, size_t n) {
+ const uint8_t *a = (const uint8_t *) av;
+ const uint8_t *b = (const uint8_t *) bv;
+ uint8_t result = 0;
+ size_t i;
+
+ for (i=0; i<n; i++) {
+ result |= *a ^ *b;
+ a++;
+ b++;
+ }
+
+ return (int) result;
+}
+
int ae_decrypt(ae_ctx *ctx,
const void *nonce,
const void *ct,
@@ -1029,7 +1053,7 @@ int ae_decrypt(ae_ctx *ctx,
unsigned i, k;
block *ctp = (block *)ct;
block *ptp = (block *)pt;
-
+
/* Reduce ct_len tag bundled in ct */
if ((final) && (!tag))
#if (OCB_TAG_LEN > 0)
@@ -1109,10 +1133,10 @@ int ae_decrypt(ae_ctx *ctx,
ctx->blocks_processed = block_num;
ctx->checksum = checksum;
}
-
+
if (final) {
block ta[BPI+1], oa[BPI];
-
+
/* Process remaining plaintext and compute its tag contribution */
unsigned remaining = ((unsigned)ct_len) % (BPI*16);
k = 0; /* How many blocks in ta[] need ECBing */
@@ -1176,7 +1200,7 @@ int ae_decrypt(ae_ctx *ctx,
case 1: ptp[0] = xor_block(ta[0], oa[0]);
checksum = xor_block(checksum, ptp[0]);
}
-
+
/* Calculate expected tag */
offset = xor_block(offset, ctx->Ldollar);
tmp.bl = xor_block(offset, checksum);
@@ -1194,10 +1218,10 @@ int ae_decrypt(ae_ctx *ctx,
int len = ctx->tag_len;
#endif
if (tag) {
- if (memcmp(tag,tmp.u8,len) != 0)
+ if (constant_time_memcmp(tag,tmp.u8,len) != 0)
ct_len = AE_INVALID;
} else {
- if (memcmp((char *)ct + ct_len,tmp.u8,len) != 0)
+ if (constant_time_memcmp((char *)ct + ct_len,tmp.u8,len) != 0)
ct_len = AE_INVALID;
}
}
@@ -1205,10 +1229,168 @@ int ae_decrypt(ae_ctx *ctx,
return ct_len;
}
+/* ----------------------------------------------------------------------- */
+/* Simple test program */
+/* ----------------------------------------------------------------------- */
+
+#if 0
+
+#include <stdio.h>
+#include <time.h>
+
+#if __GNUC__
+ #define ALIGN(n) __attribute__ ((aligned(n)))
+#elif _MSC_VER
+ #define ALIGN(n) __declspec(align(n))
+#else /* Not GNU/Microsoft: delete alignment uses. */
+ #define ALIGN(n)
+#endif
+
+static void pbuf(void *p, unsigned len, const void *s)
+{
+ unsigned i;
+ if (s)
+ printf("%s", (char *)s);
+ for (i = 0; i < len; i++)
+ printf("%02X", (unsigned)(((unsigned char *)p)[i]));
+ printf("\n");
+}
+
+static void vectors(ae_ctx *ctx, int len)
+{
+ ALIGN(16) char pt[128];
+ ALIGN(16) char ct[144];
+ ALIGN(16) char nonce[] = {0,1,2,3,4,5,6,7,8,9,10,11};
+ int i;
+ for (i=0; i < 128; i++) pt[i] = i;
+ i = ae_encrypt(ctx,nonce,pt,len,pt,len,ct,NULL,AE_FINALIZE);
+ printf("P=%d,A=%d: ",len,len); pbuf(ct, i, NULL);
+ i = ae_encrypt(ctx,nonce,pt,0,pt,len,ct,NULL,AE_FINALIZE);
+ printf("P=%d,A=%d: ",0,len); pbuf(ct, i, NULL);
+ i = ae_encrypt(ctx,nonce,pt,len,pt,0,ct,NULL,AE_FINALIZE);
+ printf("P=%d,A=%d: ",len,0); pbuf(ct, i, NULL);
+}
+
+void validate()
+{
+ ALIGN(16) char pt[1024];
+ ALIGN(16) char ct[1024];
+ ALIGN(16) char tag[16];
+ ALIGN(16) char nonce[12] = {0,};
+ ALIGN(16) char key[32] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
+ ALIGN(16) char valid[] = {0xB2,0xB4,0x1C,0xBF,0x9B,0x05,0x03,0x7D,
+ 0xA7,0xF1,0x6C,0x24,0xA3,0x5C,0x1C,0x94};
+ ae_ctx ctx;
+ char *val_buf, *next;
+ int i, len;
+
+ val_buf = (char *)malloc(22400 + 16);
+ next = val_buf = (char *)(((size_t)val_buf + 16) & ~((size_t)15));
+
+ if (0) {
+ ae_init(&ctx, key, 16, 12, 16);
+ /* pbuf(&ctx, sizeof(ctx), "CTX: "); */
+ vectors(&ctx,0);
+ vectors(&ctx,8);
+ vectors(&ctx,16);
+ vectors(&ctx,24);
+ vectors(&ctx,32);
+ vectors(&ctx,40);
+ }
+
+ memset(key,0,32);
+ memset(pt,0,128);
+ ae_init(&ctx, key, 16, 12, 16);
+
+ /* RFC Vector test */
+ for (i = 0; i < 128; i++) {
+ int first = ((i/3)/(BPI*16))*(BPI*16);
+ int second = first;
+ int third = i - (first + second);
+
+ nonce[11] = i;
+
+ if (0) {
+ ae_encrypt(&ctx,nonce,pt,i,pt,i,ct,NULL,AE_FINALIZE);
+ memcpy(next,ct,(size_t)i+16);
+ next = next+i+16;
+
+ ae_encrypt(&ctx,nonce,pt,i,pt,0,ct,NULL,AE_FINALIZE);
+ memcpy(next,ct,(size_t)i+16);
+ next = next+i+16;
+
+ ae_encrypt(&ctx,nonce,pt,0,pt,i,ct,NULL,AE_FINALIZE);
+ memcpy(next,ct,16);
+ next = next+16;
+ } else {
+ ae_encrypt(&ctx,nonce,pt,first,pt,first,ct,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt+first,second,pt+first,second,ct+first,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt+first+second,third,pt+first+second,third,ct+first+second,NULL,AE_FINALIZE);
+ memcpy(next,ct,(size_t)i+16);
+ next = next+i+16;
+
+ ae_encrypt(&ctx,nonce,pt,first,pt,0,ct,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt+first,second,pt,0,ct+first,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt+first+second,third,pt,0,ct+first+second,NULL,AE_FINALIZE);
+ memcpy(next,ct,(size_t)i+16);
+ next = next+i+16;
+
+ ae_encrypt(&ctx,nonce,pt,0,pt,first,ct,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt,0,pt+first,second,ct,NULL,AE_PENDING);
+ ae_encrypt(&ctx,NULL,pt,0,pt+first+second,third,ct,NULL,AE_FINALIZE);
+ memcpy(next,ct,16);
+ next = next+16;
+ }
+
+ }
+ nonce[11] = 0;
+ ae_encrypt(&ctx,nonce,NULL,0,val_buf,next-val_buf,ct,tag,AE_FINALIZE);
+ pbuf(tag,16,0);
+ if (memcmp(valid,tag,16) == 0)
+ printf("Vectors: PASS\n");
+ else
+ printf("Vectors: FAIL\n");
+
+
+ /* Encrypt/Decrypt test */
+ for (i = 0; i < 128; i++) {
+ int first = ((i/3)/(BPI*16))*(BPI*16);
+ int second = first;
+ int third = i - (first + second);
+
+ nonce[11] = i%128;
+
+ if (1) {
+ len = ae_encrypt(&ctx,nonce,val_buf,i,val_buf,i,ct,tag,AE_FINALIZE);
+ len = ae_encrypt(&ctx,nonce,val_buf,i,val_buf,-1,ct,tag,AE_FINALIZE);
+ len = ae_decrypt(&ctx,nonce,ct,len,val_buf,-1,pt,tag,AE_FINALIZE);
+ if (len == -1) { printf("Authentication error: %d\n", i); return; }
+ if (len != i) { printf("Length error: %d\n", i); return; }
+ if (memcmp(val_buf,pt,i)) { printf("Decrypt error: %d\n", i); return; }
+ } else {
+ len = ae_encrypt(&ctx,nonce,val_buf,i,val_buf,i,ct,NULL,AE_FINALIZE);
+ ae_decrypt(&ctx,nonce,ct,first,val_buf,first,pt,NULL,AE_PENDING);
+ ae_decrypt(&ctx,NULL,ct+first,second,val_buf+first,second,pt+first,NULL,AE_PENDING);
+ len = ae_decrypt(&ctx,NULL,ct+first+second,len-(first+second),val_buf+first+second,third,pt+first+second,NULL,AE_FINALIZE);
+ if (len == -1) { printf("Authentication error: %d\n", i); return; }
+ if (memcmp(val_buf,pt,i)) { printf("Decrypt error: %d\n", i); return; }
+ }
+
+ }
+ printf("Decrypt: PASS\n");
+}
+
+int main()
+{
+ validate();
+ return 0;
+}
+#endif
+
#if USE_AES_NI
-char infoString[] = "OCB (AES-NI)";
+char infoString[] = "OCB3 (AES-NI)";
#elif USE_REFERENCE_AES
-char infoString[] = "OCB (Reference AES)";
+char infoString[] = "OCB3 (Reference)";
#elif USE_OPENSSL_AES
-char infoString[] = "OCB (OpenSSL AES)";
+char infoString[] = "OCB3 (OpenSSL)";
#endif
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