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ocb.cc
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ocb.cc
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/*------------------------------------------------------------------------
/ OCB Version 3 Reference Code (Optimized C) Last modified 13-JUL-2011
/-------------------------------------------------------------------------
/ Copyright (c) 2011 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
/ copyright notice and this permission notice appear in all copies.
/
/ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
/ WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
/ MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
/ ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
/ WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
/ ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
/ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
/
/ Phillip Rogaway holds patents relevant to OCB. See the following for
/ his patent grant: http://www.cs.ucdavis.edu/~rogaway/ocb/grant.htm
/
/ Comments are welcome: Ted Krovetz <ted@krovetz.net> - Dedicated to Laurel K
/------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------- */
/* Usage notes */
/* ----------------------------------------------------------------------- */
/* - When AE_PENDING is passed as the 'final' parameter of any function,
/ the length parameters must be a multiple of (BPI*16).
/ - When available, SSE or AltiVec registers are used to manipulate data.
/ 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.
/ - 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. */
/* ----------------------------------------------------------------------- */
/* User configuration options */
/* ----------------------------------------------------------------------- */
/* Set the AES key length to use and length of authentication tag to produce.
/ Setting either to 0 requires the value be set at runtime via ae_init().
/ Some optimizations occur for each when set to a fixed value. */
#define OCB_KEY_LEN 16 /* 0, 16, 24 or 32. 0 means set in ae_init */
#define OCB_TAG_LEN 16 /* 0 to 16. 0 means set in ae_init */
/* This implementation has built-in support for multiple AES APIs. Set any
/ one of the following to non-zero to specify which to use. */
#define USE_OPENSSL_AES 0 /* http://openssl.org */
#define USE_REFERENCE_AES 1 /* Internet search: rijndael-alg-fst.c */
#define USE_AES_NI 0 /* Uses compiler's intrinsics */
/* During encryption and decryption, various "L values" are required.
/ 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
/ 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
/* Set L_TABLE_SZ_IS_ENOUGH non-zero iff you know that all plaintexts
/ will be shorter than 2^(L_TABLE_SZ+4) bytes in length. This results
/ in better performance. */
#define L_TABLE_SZ_IS_ENOUGH 1
/* ----------------------------------------------------------------------- */
/* Includes and compiler specific definitions */
/* ----------------------------------------------------------------------- */
#include "ae.h"
#include <stdlib.h>
#include <string.h>
/* Define standard sized integers */
#if defined(_MSC_VER) && (_MSC_VER < 1600)
typedef unsigned __int8 uint8_t;
typedef unsigned __int32 uint32_t;
typedef unsigned __int64 uint64_t;
typedef __int64 int64_t;
#else
#include <stdint.h>
#endif
/* Compiler-specific intrinsics and fixes: bswap64, ntz */
#if _MSC_VER
#define inline __inline /* MSVC doesn't recognize "inline" in C */
#define restrict __restrict /* MSVC doesn't recognize "restrict" in C */
#define __SSE2__ (_M_IX86 || _M_AMD64 || _M_X64) /* Assume SSE2 */
#define __SSSE3__ (_M_IX86 || _M_AMD64 || _M_X64) /* Assume SSSE3 */
#include <intrin.h>
#pragma intrinsic(_byteswap_uint64, _BitScanForward, memcpy)
#elif __GNUC__
#define inline __inline__ /* No "inline" in GCC ansi C mode */
#define restrict __restrict__ /* No "restrict" in GCC ansi C mode */
#endif
#if _MSC_VER
#define bswap64(x) _byteswap_uint64(x)
#elif HAVE_DECL___BUILTIN_BSWAP64
#define bswap64(x) __builtin_bswap64(x) /* GCC 4.3+ */
#else
#define bswap32(x) \
((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \
(((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24))
static inline uint64_t bswap64(uint64_t x) {
union { uint64_t u64; uint32_t u32[2]; } in, out;
in.u64 = x;
out.u32[0] = bswap32(in.u32[1]);
out.u32[1] = bswap32(in.u32[0]);
return out.u64;
}
#endif
#if _MSC_VER
static inline unsigned ntz(unsigned x) {_BitScanForward(&x,x);return x;}
#elif HAVE_DECL___BUILTIN_CTZ
#define ntz(x) __builtin_ctz((unsigned)(x)) /* GCC 3.4+ */
#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,
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,
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};
return tz_table[x/4];
}
#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,
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];
}
#endif
#endif
/* ----------------------------------------------------------------------- */
/* Define blocks and operations -- Patch if incorrect on your compiler. */
/* ----------------------------------------------------------------------- */
#if __SSE2__
#include <xmmintrin.h> /* SSE instructions and _mm_malloc */
#include <emmintrin.h> /* SSE2 instructions */
typedef __m128i block;
#define xor_block(x,y) _mm_xor_si128(x,y)
#define zero_block() _mm_setzero_si128()
#define unequal_blocks(x,y) \
(_mm_movemask_epi8(_mm_cmpeq_epi8(x,y)) != 0xffff)
#if __SSSE3__ || USE_AES_NI
#include <tmmintrin.h> /* SSSE3 instructions */
#define swap_if_le(b) \
_mm_shuffle_epi8(b,_mm_set_epi8(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15))
#else
static inline block swap_if_le(block b) {
block a = _mm_shuffle_epi32 (b, _MM_SHUFFLE(0,1,2,3));
a = _mm_shufflehi_epi16(a, _MM_SHUFFLE(2,3,0,1));
a = _mm_shufflelo_epi16(a, _MM_SHUFFLE(2,3,0,1));
return _mm_xor_si128(_mm_srli_epi16(a,8), _mm_slli_epi16(a,8));
}
#endif
static inline block gen_offset(uint64_t KtopStr[3], unsigned bot) {
block hi = _mm_load_si128((__m128i *)(KtopStr+0)); /* hi = B A */
block lo = _mm_loadu_si128((__m128i *)(KtopStr+1)); /* lo = C B */
__m128i lshift = _mm_cvtsi32_si128(bot);
__m128i rshift = _mm_cvtsi32_si128(64-bot);
lo = _mm_xor_si128(_mm_sll_epi64(hi,lshift),_mm_srl_epi64(lo,rshift));
#if __SSSE3__ || USE_AES_NI
return _mm_shuffle_epi8(lo,_mm_set_epi8(8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7));
#else
return swap_if_le(_mm_shuffle_epi32(lo, _MM_SHUFFLE(1,0,3,2)));
#endif
}
static inline block double_block(block bl) {
const __m128i mask = _mm_set_epi32(135,1,1,1);
__m128i tmp = _mm_srai_epi32(bl, 31);
tmp = _mm_and_si128(tmp, mask);
tmp = _mm_shuffle_epi32(tmp, _MM_SHUFFLE(2,1,0,3));
bl = _mm_slli_epi32(bl, 1);
return _mm_xor_si128(bl,tmp);
}
#elif __ALTIVEC__
#include <altivec.h>
typedef vector unsigned block;
#define xor_block(x,y) vec_xor(x,y)
#define zero_block() vec_splat_u32(0)
#define unequal_blocks(x,y) vec_any_ne(x,y)
#define swap_if_le(b) (b)
#if __PPC64__
block gen_offset(uint64_t KtopStr[3], unsigned bot) {
union {uint64_t u64[2]; block bl;} rval;
rval.u64[0] = (KtopStr[0] << bot) | (KtopStr[1] >> (64-bot));
rval.u64[1] = (KtopStr[1] << bot) | (KtopStr[2] >> (64-bot));
return rval.bl;
}
#else
/* Special handling: Shifts are mod 32, and no 64-bit types */
block gen_offset(uint64_t KtopStr[3], unsigned bot) {
const vector unsigned k32 = {32,32,32,32};
vector unsigned hi = *(vector unsigned *)(KtopStr+0);
vector unsigned lo = *(vector unsigned *)(KtopStr+2);
vector unsigned bot_vec;
if (bot < 32) {
lo = vec_sld(hi,lo,4);
} else {
vector unsigned t = vec_sld(hi,lo,4);
lo = vec_sld(hi,lo,8);
hi = t;
bot = bot - 32;
}
if (bot == 0) return hi;
*(unsigned *)&bot_vec = bot;
vector unsigned lshift = vec_splat(bot_vec,0);
vector unsigned rshift = vec_sub(k32,lshift);
hi = vec_sl(hi,lshift);
lo = vec_sr(lo,rshift);
return vec_xor(hi,lo);
}
#endif
static inline block double_block(block b) {
const vector unsigned char mask = {135,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};
const vector unsigned char perm = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0};
const vector unsigned char shift7 = vec_splat_u8(7);
const vector unsigned char shift1 = vec_splat_u8(1);
vector unsigned char c = (vector unsigned char)b;
vector unsigned char t = vec_sra(c,shift7);
t = vec_and(t,mask);
t = vec_perm(t,t,perm);
c = vec_sl(c,shift1);
return (block)vec_xor(c,t);
}
#elif __ARM_NEON__
#include <arm_neon.h>
typedef int8x16_t block; /* Yay! Endian-neutral reads! */
#define xor_block(x,y) veorq_s8(x,y)
#define zero_block() vdupq_n_s8(0)
static inline int unequal_blocks(block a, block b) {
int64x2_t t=veorq_s64((int64x2_t)a,(int64x2_t)b);
return (vgetq_lane_s64(t,0)|vgetq_lane_s64(t,1))!=0;
}
#define swap_if_le(b) (b) /* Using endian-neutral int8x16_t */
/* KtopStr is reg correct by 64 bits, return mem correct */
block gen_offset(uint64_t KtopStr[3], unsigned bot) {
const union { unsigned x; unsigned char endian; } little = { 1 };
const int64x2_t k64 = {-64,-64};
uint64x2_t hi = *(uint64x2_t *)(KtopStr+0); /* hi = A B */
uint64x2_t lo = *(uint64x2_t *)(KtopStr+1); /* hi = B C */
int64x2_t ls = vdupq_n_s64(bot);
int64x2_t rs = vqaddq_s64(k64,ls);
block rval = (block)veorq_u64(vshlq_u64(hi,ls),vshlq_u64(lo,rs));
if (little.endian)
rval = vrev64q_s8(rval);
return rval;
}
static inline block double_block(block b)
{
const block mask = {135,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1};
block tmp = vshrq_n_s8(b,7);
tmp = vandq_s8(tmp, mask);
tmp = vextq_s8(tmp, tmp, 1); /* Rotate high byte to end */
b = vshlq_n_s8(b,1);
return veorq_s8(tmp,b);
}
#else
typedef struct { uint64_t l,r; } block;
static inline block xor_block(block x, block y) {
x.l^=y.l; x.r^=y.r; return x;
}
static inline block zero_block(void) { const block t = {0,0}; return t; }
#define unequal_blocks(x, y) ((((x).l^(y).l)|((x).r^(y).r)) != 0)
static inline block swap_if_le(block b) {
const union { unsigned x; unsigned char endian; } little = { 1 };
if (little.endian) {
block r;
r.l = bswap64(b.l);
r.r = bswap64(b.r);
return r;
} else
return b;
}
/* KtopStr is reg correct by 64 bits, return mem correct */
block gen_offset(uint64_t KtopStr[3], unsigned bot) {
block rval;
if (bot != 0) {
rval.l = (KtopStr[0] << bot) | (KtopStr[1] >> (64-bot));
rval.r = (KtopStr[1] << bot) | (KtopStr[2] >> (64-bot));
} else {
rval.l = KtopStr[0];
rval.r = KtopStr[1];
}
return swap_if_le(rval);
}
#if __GNUC__ && __arm__
static inline block double_block(block b) {
__asm__ ("adds %1,%1,%1\n\t"
"adcs %H1,%H1,%H1\n\t"
"adcs %0,%0,%0\n\t"
"adcs %H0,%H0,%H0\n\t"
"it cs\n\t"
"eorcs %1,%1,#135"
: "+r"(b.l), "+r"(b.r) : : "cc");
return b;
}
#else
static inline block double_block(block b) {
uint64_t t = (uint64_t)((int64_t)b.l >> 63);
b.l = (b.l + b.l) ^ (b.r >> 63);
b.r = (b.r + b.r) ^ (t & 135);
return b;
}
#endif
#endif
/* ----------------------------------------------------------------------- */
/* AES - Code uses OpenSSL API. Other implementations get mapped to it. */
/* ----------------------------------------------------------------------- */
/*---------------*/
#if USE_OPENSSL_AES
/*---------------*/
#include <openssl/aes.h> /* http://openssl.org/ */
/* How to ECB encrypt an array of blocks, in place */
static inline void AES_ecb_encrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
while (nblks) {
--nblks;
AES_encrypt((unsigned char *)(blks+nblks), (unsigned char *)(blks+nblks), key);
}
}
static inline void AES_ecb_decrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
while (nblks) {
--nblks;
AES_decrypt((unsigned char *)(blks+nblks), (unsigned char *)(blks+nblks), key);
}
}
#define BPI 4 /* Number of blocks in buffer per ECB call */
/*-------------------*/
#elif USE_REFERENCE_AES
/*-------------------*/
#include "rijndael-alg-fst.h" /* Barreto's Public-Domain Code */
#if (OCB_KEY_LEN == 0)
typedef struct { uint32_t rd_key[60]; int rounds; } AES_KEY;
#define ROUNDS(ctx) ((ctx)->rounds)
#define AES_set_encrypt_key(x, y, z) \
do {rijndaelKeySetupEnc((z)->rd_key, x, y); (z)->rounds = y/32+6;} while (0)
#define AES_set_decrypt_key(x, y, z) \
do {rijndaelKeySetupDec((z)->rd_key, x, y); (z)->rounds = y/32+6;} while (0)
#else
typedef struct { uint32_t rd_key[OCB_KEY_LEN+28]; } AES_KEY;
#define ROUNDS(ctx) (6+OCB_KEY_LEN/4)
#define AES_set_encrypt_key(x, y, z) rijndaelKeySetupEnc((z)->rd_key, x, y)
#define AES_set_decrypt_key(x, y, z) rijndaelKeySetupDec((z)->rd_key, x, y)
#endif
#define AES_encrypt(x,y,z) rijndaelEncrypt((z)->rd_key, ROUNDS(z), x, y)
#define AES_decrypt(x,y,z) rijndaelDecrypt((z)->rd_key, ROUNDS(z), x, y)
static void AES_ecb_encrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
while (nblks) {
--nblks;
AES_encrypt((unsigned char *)(blks+nblks), (unsigned char *)(blks+nblks), key);
}
}
void AES_ecb_decrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
while (nblks) {
--nblks;
AES_decrypt((unsigned char *)(blks+nblks), (unsigned char *)(blks+nblks), key);
}
}
#define BPI 4 /* Number of blocks in buffer per ECB call */
/*----------*/
#elif USE_AES_NI
/*----------*/
#include <wmmintrin.h>
#if (OCB_KEY_LEN == 0)
typedef struct { __m128i rd_key[15]; int rounds; } AES_KEY;
#define ROUNDS(ctx) ((ctx)->rounds)
#else
typedef struct { __m128i rd_key[7+OCB_KEY_LEN/4]; } AES_KEY;
#define ROUNDS(ctx) (6+OCB_KEY_LEN/4)
#endif
#define EXPAND_ASSIST(v1,v2,v3,v4,shuff_const,aes_const) \
v2 = _mm_aeskeygenassist_si128(v4,aes_const); \
v3 = _mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps(v3), \
_mm_castsi128_ps(v1), 16)); \
v1 = _mm_xor_si128(v1,v3); \
v3 = _mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps(v3), \
_mm_castsi128_ps(v1), 140)); \
v1 = _mm_xor_si128(v1,v3); \
v2 = _mm_shuffle_epi32(v2,shuff_const); \
v1 = _mm_xor_si128(v1,v2)
#define EXPAND192_STEP(idx,aes_const) \
EXPAND_ASSIST(x0,x1,x2,x3,85,aes_const); \
x3 = _mm_xor_si128(x3,_mm_slli_si128 (x3, 4)); \
x3 = _mm_xor_si128(x3,_mm_shuffle_epi32(x0, 255)); \
kp[idx] = _mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps(tmp), \
_mm_castsi128_ps(x0), 68)); \
kp[idx+1] = _mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps(x0), \
_mm_castsi128_ps(x3), 78)); \
EXPAND_ASSIST(x0,x1,x2,x3,85,(aes_const*2)); \
x3 = _mm_xor_si128(x3,_mm_slli_si128 (x3, 4)); \
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)
{
__m128i x0,x1,x2;
__m128i *kp = (__m128i *)key;
kp[0] = x0 = _mm_loadu_si128((__m128i*)userkey);
x2 = _mm_setzero_si128();
EXPAND_ASSIST(x0,x1,x2,x0,255,1); kp[1] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,2); kp[2] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,4); kp[3] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,8); kp[4] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,16); kp[5] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,32); kp[6] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,64); kp[7] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,128); kp[8] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,27); kp[9] = x0;
EXPAND_ASSIST(x0,x1,x2,x0,255,54); kp[10] = x0;
}
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);
tmp = x3 = _mm_loadu_si128((__m128i*)(userkey+16));
x2 = _mm_setzero_si128();
EXPAND192_STEP(1,1);
EXPAND192_STEP(4,4);
EXPAND192_STEP(7,16);
EXPAND192_STEP(10,64);
}
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 );
kp[1] = x3 = _mm_loadu_si128((__m128i*)(userkey+16));
x2 = _mm_setzero_si128();
EXPAND_ASSIST(x0,x1,x2,x3,255,1); kp[2] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,1); kp[3] = x3;
EXPAND_ASSIST(x0,x1,x2,x3,255,2); kp[4] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,2); kp[5] = x3;
EXPAND_ASSIST(x0,x1,x2,x3,255,4); kp[6] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,4); kp[7] = x3;
EXPAND_ASSIST(x0,x1,x2,x3,255,8); kp[8] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,8); kp[9] = x3;
EXPAND_ASSIST(x0,x1,x2,x3,255,16); kp[10] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,16); kp[11] = x3;
EXPAND_ASSIST(x0,x1,x2,x3,255,32); kp[12] = x0;
EXPAND_ASSIST(x3,x1,x2,x0,170,32); kp[13] = x3;
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)
{
if (bits == 128) {
AES_128_Key_Expansion (userKey,key);
} else if (bits == 192) {
AES_192_Key_Expansion (userKey,key);
} else if (bits == 256) {
AES_256_Key_Expansion (userKey,key);
}
#if (OCB_KEY_LEN == 0)
key->rounds = 6+bits/32;
#endif
return 0;
}
void AES_set_decrypt_key_fast(AES_KEY *dkey, const AES_KEY *ekey)
{
int j = 0;
int i = ROUNDS(ekey);
#if (OCB_KEY_LEN == 0)
dkey->rounds = i;
#endif
dkey->rd_key[i--] = ekey->rd_key[j++];
while (i)
dkey->rd_key[i--] = _mm_aesimc_si128(ekey->rd_key[j++]);
dkey->rd_key[i] = ekey->rd_key[j];
}
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);
AES_set_decrypt_key_fast(key, &temp_key);
return 0;
}
static inline void AES_encrypt(const unsigned char *in,
unsigned char *out, const AES_KEY *key)
{
int j,rnds=ROUNDS(key);
const __m128i *sched = ((__m128i *)(key->rd_key));
__m128i tmp = _mm_load_si128 ((__m128i*)in);
tmp = _mm_xor_si128 (tmp,sched[0]);
for (j=1; j<rnds; j++) tmp = _mm_aesenc_si128 (tmp,sched[j]);
tmp = _mm_aesenclast_si128 (tmp,sched[j]);
_mm_store_si128 ((__m128i*)out,tmp);
}
static inline void AES_decrypt(const unsigned char *in,
unsigned char *out, const AES_KEY *key)
{
int j,rnds=ROUNDS(key);
const __m128i *sched = ((__m128i *)(key->rd_key));
__m128i tmp = _mm_load_si128 ((__m128i*)in);
tmp = _mm_xor_si128 (tmp,sched[0]);
for (j=1; j<rnds; j++) tmp = _mm_aesdec_si128 (tmp,sched[j]);
tmp = _mm_aesdeclast_si128 (tmp,sched[j]);
_mm_store_si128 ((__m128i*)out,tmp);
}
static inline void AES_ecb_encrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
unsigned i,j,rnds=ROUNDS(key);
const __m128i *sched = ((__m128i *)(key->rd_key));
for (i=0; i<nblks; ++i)
blks[i] =_mm_xor_si128(blks[i], sched[0]);
for(j=1; j<rnds; ++j)
for (i=0; i<nblks; ++i)
blks[i] = _mm_aesenc_si128(blks[i], sched[j]);
for (i=0; i<nblks; ++i)
blks[i] =_mm_aesenclast_si128(blks[i], sched[j]);
}
static inline void AES_ecb_decrypt_blks(block *blks, unsigned nblks, AES_KEY *key) {
unsigned i,j,rnds=ROUNDS(key);
const __m128i *sched = ((__m128i *)(key->rd_key));
for (i=0; i<nblks; ++i)
blks[i] =_mm_xor_si128(blks[i], sched[0]);
for(j=1; j<rnds; ++j)
for (i=0; i<nblks; ++i)
blks[i] = _mm_aesdec_si128(blks[i], sched[j]);
for (i=0; i<nblks; ++i)
blks[i] =_mm_aesdeclast_si128(blks[i], sched[j]);
}
#define BPI 8 /* Number of blocks in buffer per ECB call */
/* Set to 4 for Westmere, 8 for Sandy Bridge */
#endif
/* ----------------------------------------------------------------------- */
/* Define OCB context structure. */
/* ----------------------------------------------------------------------- */
/*------------------------------------------------------------------------
/ 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.
/ 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 */
block Lstar; /* Memory correct */
block Ldollar; /* Memory correct */
block L[L_TABLE_SZ]; /* Memory correct */
block ad_checksum; /* Memory correct */
block ad_offset; /* Memory correct */
block cached_Top; /* Memory correct */
uint64_t KtopStr[3]; /* Register correct, each item */
uint32_t ad_blocks_processed;
uint32_t blocks_processed;
AES_KEY decrypt_key;
AES_KEY encrypt_key;
#if (OCB_TAG_LEN == 0)
unsigned tag_len;
#endif
};
/* ----------------------------------------------------------------------- */
/* L table lookup (or on-the-fly generation) */
/* ----------------------------------------------------------------------- */
#if L_TABLE_SZ_IS_ENOUGH
#define getL(_ctx, _tz) ((_ctx)->L[_tz])
#else
static block getL(const ae_ctx *ctx, unsigned tz)
{
if (tz < L_TABLE_SZ)
return ctx->L[tz];
else {
unsigned i;
/* Bring L[MAX] into registers, make it register correct */
block rval = swap_if_le(ctx->L[L_TABLE_SZ-1]);
rval = double_block(rval);
for (i=L_TABLE_SZ; i < tz; i++)
rval = double_block(rval);
return swap_if_le(rval); /* To memory correct */
}
}
#endif
/* ----------------------------------------------------------------------- */
/* Public functions */
/* ----------------------------------------------------------------------- */
/* 32-bit SSE2 and Altivec systems need to be forced to allocate memory
on 16-byte alignments. (I believe all major 64-bit systems do already.) */
/* Mosh uses its own AlignedBuffer class, not ae_allocate() or ae_free(). */
/* ----------------------------------------------------------------------- */
int ae_clear (ae_ctx *ctx) /* Zero ae_ctx and undo initialization */
{
memset(ctx, 0, sizeof(ae_ctx));
return AE_SUCCESS;
}
int ae_ctx_sizeof(void) { return (int) sizeof(ae_ctx); }
/* ----------------------------------------------------------------------- */
int ae_init(ae_ctx *ctx, const void *key, int key_len, int nonce_len, int tag_len)
{
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;
#endif
AES_set_encrypt_key((unsigned char *)key, key_len*8, &ctx->encrypt_key);
#if USE_AES_NI
AES_set_decrypt_key_fast(&ctx->decrypt_key,&ctx->encrypt_key);
#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);
tmp_blk = swap_if_le(ctx->Lstar);
tmp_blk = double_block(tmp_blk);
ctx->Ldollar = swap_if_le(tmp_blk);
tmp_blk = double_block(tmp_blk);
ctx->L[0] = swap_if_le(tmp_blk);
for (i = 1; i < L_TABLE_SZ; i++) {
tmp_blk = double_block(tmp_blk);
ctx->L[i] = swap_if_le(tmp_blk);
}
#if (OCB_TAG_LEN == 0)
ctx->tag_len = tag_len;
#else
(void) tag_len; /* Supress var not used error */
#endif
return AE_SUCCESS;
}
/* ----------------------------------------------------------------------- */
static block gen_offset_from_nonce(ae_ctx *ctx, const void *nonce)
{
const union { unsigned x; unsigned char endian; } little = { 1 };
union { uint32_t u32[4]; uint8_t u8[16]; block bl; } tmp;
unsigned idx;
/* Replace cached nonce Top if needed */
tmp.u32[0] = (little.endian?0x01000000:0x00000001);
tmp.u32[1] = ((uint32_t *)nonce)[0];
tmp.u32[2] = ((uint32_t *)nonce)[1];
tmp.u32[3] = ((uint32_t *)nonce)[2];
idx = (unsigned)(tmp.u8[15] & 0x3f); /* Get low 6 bits of nonce */
tmp.u8[15] = tmp.u8[15] & 0xc0; /* Zero low 6 bits of nonce */
if ( unequal_blocks(tmp.bl,ctx->cached_Top) ) { /* Cached? */
ctx->cached_Top = tmp.bl; /* Update cache, KtopStr */
AES_encrypt(tmp.u8, (unsigned char *)&ctx->KtopStr, &ctx->encrypt_key);
if (little.endian) { /* Make Register Correct */
ctx->KtopStr[0] = bswap64(ctx->KtopStr[0]);
ctx->KtopStr[1] = bswap64(ctx->KtopStr[1]);
}
ctx->KtopStr[2] = ctx->KtopStr[0] ^
(ctx->KtopStr[0] << 8) ^ (ctx->KtopStr[1] >> 56);
}
return gen_offset(ctx->KtopStr, idx);
}
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);
if (i) {
unsigned ad_block_num = ctx->ad_blocks_processed;
do {
block ta[BPI], oa[BPI];
ad_block_num += BPI;
tz = ntz(ad_block_num);
oa[0] = xor_block(ad_offset, ctx->L[0]);
ta[0] = xor_block(oa[0], adp[0]);
oa[1] = xor_block(oa[0], ctx->L[1]);
ta[1] = xor_block(oa[1], adp[1]);
oa[2] = xor_block(ad_offset, ctx->L[1]);
ta[2] = xor_block(oa[2], adp[2]);
#if BPI == 4
ad_offset = xor_block(oa[2], getL(ctx, tz));
ta[3] = xor_block(ad_offset, adp[3]);
#elif BPI == 8
oa[3] = xor_block(oa[2], ctx->L[2]);
ta[3] = xor_block(oa[3], adp[3]);
oa[4] = xor_block(oa[1], ctx->L[2]);
ta[4] = xor_block(oa[4], adp[4]);
oa[5] = xor_block(oa[0], ctx->L[2]);
ta[5] = xor_block(oa[5], adp[5]);
oa[6] = xor_block(ad_offset, ctx->L[2]);
ta[6] = xor_block(oa[6], adp[6]);
ad_offset = xor_block(oa[6], getL(ctx, tz));
ta[7] = xor_block(ad_offset, adp[7]);
#endif
AES_ecb_encrypt_blks(ta,BPI,&ctx->encrypt_key);
ad_checksum = xor_block(ad_checksum, ta[0]);
ad_checksum = xor_block(ad_checksum, ta[1]);
ad_checksum = xor_block(ad_checksum, ta[2]);
ad_checksum = xor_block(ad_checksum, ta[3]);
#if (BPI == 8)
ad_checksum = xor_block(ad_checksum, ta[4]);
ad_checksum = xor_block(ad_checksum, ta[5]);
ad_checksum = xor_block(ad_checksum, ta[6]);
ad_checksum = xor_block(ad_checksum, ta[7]);
#endif
adp += BPI;
} while (--i);
ctx->ad_blocks_processed = ad_block_num;
ctx->ad_offset = ad_offset;
ctx->ad_checksum = ad_checksum;
}
if (final) {
block ta[BPI];
/* Process remaining associated data, compute its tag contribution */
remaining = ((unsigned)ad_len) % (BPI*16);
if (remaining) {
k=0;
#if (BPI == 8)
if (remaining >= 64) {
tmp.bl = xor_block(ad_offset, ctx->L[0]);
ta[0] = xor_block(tmp.bl, adp[0]);
tmp.bl = xor_block(tmp.bl, ctx->L[1]);
ta[1] = xor_block(tmp.bl, adp[1]);
ad_offset = xor_block(ad_offset, ctx->L[1]);
ta[2] = xor_block(ad_offset, adp[2]);
ad_offset = xor_block(ad_offset, ctx->L[2]);
ta[3] = xor_block(ad_offset, adp[3]);
remaining -= 64;
k=4;
}
#endif
if (remaining >= 32) {
ad_offset = xor_block(ad_offset, ctx->L[0]);
ta[k] = xor_block(ad_offset, adp[k]);
ad_offset = xor_block(ad_offset, getL(ctx, ntz(k+2)));
ta[k+1] = xor_block(ad_offset, adp[k+1]);
remaining -= 32;
k+=2;
}
if (remaining >= 16) {
ad_offset = xor_block(ad_offset, ctx->L[0]);
ta[k] = xor_block(ad_offset, adp[k]);
remaining = remaining - 16;
++k;
}
if (remaining) {
ad_offset = xor_block(ad_offset,ctx->Lstar);
tmp.bl = zero_block();
memcpy(tmp.u8, adp+k, remaining);
tmp.u8[remaining] = (unsigned char)0x80u;
ta[k] = xor_block(ad_offset, tmp.bl);
++k;
}
AES_ecb_encrypt_blks(ta,k,&ctx->encrypt_key);
switch (k) {
#if (BPI == 8)
case 8: ad_checksum = xor_block(ad_checksum, ta[7]);
case 7: ad_checksum = xor_block(ad_checksum, ta[6]);
case 6: ad_checksum = xor_block(ad_checksum, ta[5]);
case 5: ad_checksum = xor_block(ad_checksum, ta[4]);
#endif
case 4: ad_checksum = xor_block(ad_checksum, ta[3]);
case 3: ad_checksum = xor_block(ad_checksum, ta[2]);
case 2: ad_checksum = xor_block(ad_checksum, ta[1]);
case 1: ad_checksum = xor_block(ad_checksum, ta[0]);
}
ctx->ad_checksum = ad_checksum;
}
}
}
/* ----------------------------------------------------------------------- */
int ae_encrypt(ae_ctx * ctx,
const void * nonce,
const void *pt,
int pt_len,
const void *ad,
int ad_len,
void *ct,
void *tag,
int final)
{
union { uint32_t u32[4]; uint8_t u8[16]; block bl; } tmp;
block offset, checksum;
unsigned i, k;
block * ctp = (block *)ct;
const block * ptp = (block *)pt;
/* Non-null nonce means start of new message, init per-message values */
if (nonce) {
ctx->offset = gen_offset_from_nonce(ctx, nonce);
ctx->ad_offset = ctx->checksum = zero_block();
ctx->ad_blocks_processed = ctx->blocks_processed = 0;
if (ad_len >= 0)
ctx->ad_checksum = zero_block();
}
/* Process associated data */
if (ad_len > 0)
process_ad(ctx, ad, ad_len, final);
/* Encrypt plaintext data BPI blocks at a time */
offset = ctx->offset;
checksum = ctx->checksum;
i = pt_len/(BPI*16);
if (i) {
block oa[BPI];
unsigned block_num = ctx->blocks_processed;
oa[BPI-1] = offset;
do {
block ta[BPI];
block_num += BPI;
oa[0] = xor_block(oa[BPI-1], ctx->L[0]);
ta[0] = xor_block(oa[0], ptp[0]);
checksum = xor_block(checksum, ptp[0]);
oa[1] = xor_block(oa[0], ctx->L[1]);
ta[1] = xor_block(oa[1], ptp[1]);
checksum = xor_block(checksum, ptp[1]);
oa[2] = xor_block(oa[1], ctx->L[0]);
ta[2] = xor_block(oa[2], ptp[2]);
checksum = xor_block(checksum, ptp[2]);
#if BPI == 4
oa[3] = xor_block(oa[2], getL(ctx, ntz(block_num)));
ta[3] = xor_block(oa[3], ptp[3]);
checksum = xor_block(checksum, ptp[3]);
#elif BPI == 8
oa[3] = xor_block(oa[2], ctx->L[2]);
ta[3] = xor_block(oa[3], ptp[3]);
checksum = xor_block(checksum, ptp[3]);
oa[4] = xor_block(oa[1], ctx->L[2]);
ta[4] = xor_block(oa[4], ptp[4]);
checksum = xor_block(checksum, ptp[4]);
oa[5] = xor_block(oa[0], ctx->L[2]);
ta[5] = xor_block(oa[5], ptp[5]);
checksum = xor_block(checksum, ptp[5]);
oa[6] = xor_block(oa[7], ctx->L[2]);
ta[6] = xor_block(oa[6], ptp[6]);
checksum = xor_block(checksum, ptp[6]);
oa[7] = xor_block(oa[6], getL(ctx, ntz(block_num)));
ta[7] = xor_block(oa[7], ptp[7]);
checksum = xor_block(checksum, ptp[7]);
#endif
AES_ecb_encrypt_blks(ta,BPI,&ctx->encrypt_key);
ctp[0] = xor_block(ta[0], oa[0]);
ctp[1] = xor_block(ta[1], oa[1]);
ctp[2] = xor_block(ta[2], oa[2]);
ctp[3] = xor_block(ta[3], oa[3]);
#if (BPI == 8)
ctp[4] = xor_block(ta[4], oa[4]);
ctp[5] = xor_block(ta[5], oa[5]);
ctp[6] = xor_block(ta[6], oa[6]);
ctp[7] = xor_block(ta[7], oa[7]);
#endif
ptp += BPI;
ctp += BPI;
} while (--i);
ctx->offset = offset = oa[BPI-1];
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 */
if (remaining) {
#if (BPI == 8)
if (remaining >= 64) {
oa[0] = xor_block(offset, ctx->L[0]);
ta[0] = xor_block(oa[0], ptp[0]);
checksum = xor_block(checksum, ptp[0]);
oa[1] = xor_block(oa[0], ctx->L[1]);
ta[1] = xor_block(oa[1], ptp[1]);
checksum = xor_block(checksum, ptp[1]);
oa[2] = xor_block(oa[1], ctx->L[0]);
ta[2] = xor_block(oa[2], ptp[2]);
checksum = xor_block(checksum, ptp[2]);
offset = oa[3] = xor_block(oa[2], ctx->L[2]);
ta[3] = xor_block(offset, ptp[3]);
checksum = xor_block(checksum, ptp[3]);
remaining -= 64;
k = 4;
}
#endif
if (remaining >= 32) {
oa[k] = xor_block(offset, ctx->L[0]);
ta[k] = xor_block(oa[k], ptp[k]);
checksum = xor_block(checksum, ptp[k]);
offset = oa[k+1] = xor_block(oa[k], ctx->L[1]);
ta[k+1] = xor_block(offset, ptp[k+1]);
checksum = xor_block(checksum, ptp[k+1]);
remaining -= 32;
k+=2;
}
if (remaining >= 16) {
offset = oa[k] = xor_block(offset, ctx->L[0]);
ta[k] = xor_block(offset, ptp[k]);
checksum = xor_block(checksum, ptp[k]);
remaining -= 16;
++k;
}
if (remaining) {
tmp.bl = zero_block();
memcpy(tmp.u8, ptp+k, remaining);
tmp.u8[remaining] = (unsigned char)0x80u;
checksum = xor_block(checksum, tmp.bl);
ta[k] = offset = xor_block(offset,ctx->Lstar);
++k;
}
}
offset = xor_block(offset, ctx->Ldollar); /* Part of tag gen */
ta[k] = xor_block(offset, checksum); /* Part of tag gen */
AES_ecb_encrypt_blks(ta,k+1,&ctx->encrypt_key);
offset = xor_block(ta[k], ctx->ad_checksum); /* Part of tag gen */
if (remaining) {
--k;
tmp.bl = xor_block(tmp.bl, ta[k]);
memcpy(ctp+k, tmp.u8, remaining);
}
switch (k) {
#if (BPI == 8)
case 7: ctp[6] = xor_block(ta[6], oa[6]);
case 6: ctp[5] = xor_block(ta[5], oa[5]);
case 5: ctp[4] = xor_block(ta[4], oa[4]);
case 4: ctp[3] = xor_block(ta[3], oa[3]);
#endif
case 3: ctp[2] = xor_block(ta[2], oa[2]);
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) {
#if (OCB_TAG_LEN == 16)
*(block *)tag = offset;
#elif (OCB_TAG_LEN > 0)
memcpy((char *)tag, &offset, OCB_TAG_LEN);
#else
memcpy((char *)tag, &offset, ctx->tag_len);