/* * This code is based on Ted Krovetz's ChaCha implementation; details below. * * Note that I've ripped out all of the code that wasn't suitable for doing * block-oriented operation, all (residual) support for 128-bit ChaCha keys, * all (partial) support for counter values over 32 bits, the ability to xor * the stream with a plaintext, and so on. * * Future versions of this might remove bigendian conversions too. DO NOT use * this code for your stream cipher: go back to the original source. (I got * this copy from SUPERCOP). */ /* Chacha implementation for 16-byte vectors by Ted Krovetz (ted@krovetz.net). * Assumes 32-bit int, 64-bit long long. Public domain. Modified: 2012.07.26. * Chacha is an improvement on the stream cipher Salsa, described at * http://cr.yp.to/papers.html#chacha */ #include #include #include "ottery-internal.h" /* Architecture-neutral way to specify 16-byte vector of ints */ typedef unsigned vec __attribute__ ((vector_size (16))); /* This implementation is designed for Neon, SSE and AltiVec machines. The * following specify how to do certain vector operations efficiently on * each architecture, using intrinsics. * This implementation supports parallel processing of multiple blocks, * including potentially using general-purpose registers. */ #if __ARM_NEON__ #include #define GPR_TOO 1 #define VBPI 2 #define ONE (vec)vsetq_lane_u32(1,vdupq_n_u32(0),0) #define NONCE(ctr,p) (vec)vcombine_u32(vcreate_u32(ctr),vcreate_u32(*(uint64_t *)p)) #define ROTV1(x) (vec)vextq_u32((uint32x4_t)x,(uint32x4_t)x,1) #define ROTV2(x) (vec)vextq_u32((uint32x4_t)x,(uint32x4_t)x,2) #define ROTV3(x) (vec)vextq_u32((uint32x4_t)x,(uint32x4_t)x,3) #define ROTW16(x) (vec)vrev32q_u16((uint16x8_t)x) #if __clang__ #define ROTW7(x) (x << ((vec){ 7, 7, 7, 7})) ^ (x >> ((vec){25,25,25,25})) #define ROTW8(x) (x << ((vec){ 8, 8, 8, 8})) ^ (x >> ((vec){24,24,24,24})) #define ROTW12(x) (x << ((vec){12,12,12,12})) ^ (x >> ((vec){20,20,20,20})) #else #define ROTW7(x) (vec)vsriq_n_u32(vshlq_n_u32((uint32x4_t)x,7),(uint32x4_t)x,25) #define ROTW8(x) (vec)vsriq_n_u32(vshlq_n_u32((uint32x4_t)x,8),(uint32x4_t)x,24) #define ROTW12(x) (vec)vsriq_n_u32(vshlq_n_u32((uint32x4_t)x,12),(uint32x4_t)x,20) #endif #elif __ALTIVEC__ #include #define GPR_TOO 1 #define VBPI 3 #define ONE ((vec){1,0,0,0}) #define NONCE(ctr,p) vec_sro(*(vec *)p, (vector char)(vec){0,0,0,8*8})+((vec){((ctr)&0xffffffff), (ctr)>>32, 0, 0}) #error "Don't use this code till it can be tested on altivec" #define REVW_BE(x) __builtin_bswap32(x) #define REVV_BE(x) vec_perm(x,x,(vector char){3,2,1,0,7,6,5,4,11,10,9,8,15,14,13,12}) #define ROTV1(x) vec_perm(x,x,(vector char){4,5,6,7,8,9,10,11,12,13,14,15,0,1,2,3}) #define ROTV2(x) vec_perm(x,x,(vector char){8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7}) #define ROTV3(x) vec_perm(x,x,(vector char){12,13,14,15,0,1,2,3,4,5,6,7,8,9,10,11}) #define ROTW7(x) vec_rl(x,vec_splat_u32(7)) #define ROTW8(x) vec_rl(x,vec_splat_u32(8)) #define ROTW12(x) vec_rl(x,vec_splat_u32(12)) #define ROTW16(x) vec_rl(x,vec_splat_u32(-16)) /* trick to get 16 */ #elif __SSE2__ #include #define GPR_TOO 0 #if __clang__ #define VBPI 4 #else #define VBPI 3 #endif #define ONE (vec)_mm_set_epi32(0,0,0,1) #define NONCE(ctr,p) (vec)(_mm_slli_si128(_mm_loadl_epi64((__m128i *)(p)),8)+_mm_set_epi64x(0,ctr)) #define ROTV1(x) (vec)_mm_shuffle_epi32((__m128i)x,_MM_SHUFFLE(0,3,2,1)) #define ROTV2(x) (vec)_mm_shuffle_epi32((__m128i)x,_MM_SHUFFLE(1,0,3,2)) #define ROTV3(x) (vec)_mm_shuffle_epi32((__m128i)x,_MM_SHUFFLE(2,1,0,3)) #define ROTW7(x) (vec)(_mm_slli_epi32((__m128i)x, 7) ^ _mm_srli_epi32((__m128i)x,25)) #define ROTW12(x) (vec)(_mm_slli_epi32((__m128i)x,12) ^ _mm_srli_epi32((__m128i)x,20)) #if __SSSE3__ #include #define ROTW8(x) (vec)_mm_shuffle_epi8((__m128i)x,_mm_set_epi8(14,13,12,15,10,9,8,11,6,5,4,7,2,1,0,3)) #define ROTW16(x) (vec)_mm_shuffle_epi8((__m128i)x,_mm_set_epi8(13,12,15,14,9,8,11,10,5,4,7,6,1,0,3,2)) #else #define ROTW8(x) (vec)(_mm_slli_epi32((__m128i)x, 8) ^ _mm_srli_epi32((__m128i)x,24)) #define ROTW16(x) (vec)(_mm_slli_epi32((__m128i)x,16) ^ _mm_srli_epi32((__m128i)x,16)) #endif #else #error -- Implementation supports only machines with neon, altivec or SSE2 #endif #ifndef REVV_BE #define REVV_BE(x) (x) #endif #ifndef REVW_BE #define REVW_BE(x) (x) #endif #define BPI (VBPI + GPR_TOO) /* Blocks computed per loop iteration */ #define DQROUND_VECTORS(a,b,c,d) \ a += b; d ^= a; d = ROTW16(d); \ c += d; b ^= c; b = ROTW12(b); \ a += b; d ^= a; d = ROTW8(d); \ c += d; b ^= c; b = ROTW7(b); \ b = ROTV1(b); c = ROTV2(c); d = ROTV3(d); \ a += b; d ^= a; d = ROTW16(d); \ c += d; b ^= c; b = ROTW12(b); \ a += b; d ^= a; d = ROTW8(d); \ c += d; b ^= c; b = ROTW7(b); \ b = ROTV3(b); c = ROTV2(c); d = ROTV1(d); #define QROUND_WORDS(a,b,c,d) \ a = a+b; d ^= a; d = d<<16 | d>>16; \ c = c+d; b ^= c; b = b<<12 | b>>20; \ a = a+b; d ^= a; d = d<< 8 | d>>24; \ c = c+d; b ^= c; b = b<< 7 | b>>25; #define WRITE(op, d, v0, v1, v2, v3) \ *(vec *)(op + d + 0) = REVV_BE(v0); \ *(vec *)(op + d + 4) = REVV_BE(v1); \ *(vec *)(op + d + 8) = REVV_BE(v2); \ *(vec *)(op + d + 12) = REVV_BE(v3); struct chacha_state_krovetz { __attribute__ ((aligned (16))) uint8_t key[32]; __attribute__ ((aligned (16))) uint8_t nonce[8]; }; #define LOOP_ITERATIONS 4 static inline int ottery_blocks_chacha_krovetz( const int chacha_rounds, uint8_t *out, uint32_t block_idx, struct chacha_state_krovetz *st) __attribute__((always_inline)); /** Generates 64 * BPI * LOOP_ITERATIONS bytes of output using the key and * nonce in st and the counter in block_idx, and store them in out. */ static inline int ottery_blocks_chacha_krovetz( const int chacha_rounds, uint8_t *out, uint32_t block_idx, struct chacha_state_krovetz *st) /* Assumes all pointers are aligned properly for vector reads */ { const unsigned char *k = st->key; const unsigned char *n = st->nonce; unsigned i, j, *op=(unsigned *)out, *kp, *np; __attribute__ ((aligned (16))) unsigned chacha_const[] = {0x61707865,0x3320646E,0x79622D32,0x6B206574}; #if ( __ARM_NEON__ || __SSE2__) kp = (unsigned *)k; np = (unsigned *)n; #else __attribute__ ((aligned (16))) unsigned key[8], nonce[2]; ((vec *)key)[0] = REVV_BE(((vec *)k)[0]); ((vec *)key)[1] = REVV_BE(((vec *)k)[1]); nonce[0] = REVW_BE(((unsigned *)n)[0]); nonce[1] = REVW_BE(((unsigned *)n)[1]); kp = (unsigned *)key; np = (unsigned *)nonce; #endif vec s0 = *(vec *)chacha_const; vec s1 = ((vec *)kp)[0]; vec s2 = ((vec *)kp)[1]; vec s3 = NONCE(block_idx, np); for (j = 0; j < LOOP_ITERATIONS; ++j) { vec v0,v1,v2,v3,v4,v5,v6,v7; v4 = v0 = s0; v5 = v1 = s1; v6 = v2 = s2; v3 = s3; v7 = v3 + ONE; #if VBPI > 2 vec v8,v9,v10,v11; v8 = v4; v9 = v5; v10 = v6; v11 = v7 + ONE; #endif #if VBPI > 3 vec v12,v13,v14,v15; v12 = v8; v13 = v9; v14 = v10; v15 = v11 + ONE; #endif #if GPR_TOO register unsigned x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; x0 = chacha_const[0]; x1 = chacha_const[1]; x2 = chacha_const[2]; x3 = chacha_const[3]; x4 = kp[0]; x5 = kp[1]; x6 = kp[2]; x7 = kp[3]; x8 = kp[4]; x9 = kp[5]; x10 = kp[6]; x11 = kp[7]; const uint64_t x_ctr = block_idx + BPI*iters+(BPI-1); x12 = x_ctr & 0xffffffff; x13 = x_ctr>>32; x14 = np[0]; x15 = np[1]; #endif for (i = chacha_rounds/2; i; i--) { DQROUND_VECTORS(v0,v1,v2,v3) DQROUND_VECTORS(v4,v5,v6,v7) #if VBPI > 2 DQROUND_VECTORS(v8,v9,v10,v11) #endif #if VBPI > 3 DQROUND_VECTORS(v12,v13,v14,v15) #endif #if GPR_TOO QROUND_WORDS( x0, x4, x8,x12) QROUND_WORDS( x1, x5, x9,x13) QROUND_WORDS( x2, x6,x10,x14) QROUND_WORDS( x3, x7,x11,x15) QROUND_WORDS( x0, x5,x10,x15) QROUND_WORDS( x1, x6,x11,x12) QROUND_WORDS( x2, x7, x8,x13) QROUND_WORDS( x3, x4, x9,x14) #endif } WRITE(op, 0, v0+s0, v1+s1, v2+s2, v3+s3) s3 += ONE; WRITE(op, 16, v4+s0, v5+s1, v6+s2, v7+s3) s3 += ONE; #if VBPI > 2 WRITE(op, 32, v8+s0, v9+s1, v10+s2, v11+s3) s3 += ONE; #endif #if VBPI > 3 WRITE(op, 48, v12+s0, v13+s1, v14+s2, v15+s3) s3 += ONE; #endif op += VBPI*16; #if GPR_TOO op[0] = REVW_BE((x0 + chacha_const[0])); op[1] = REVW_BE((x1 + chacha_const[1])); op[2] = REVW_BE((x2 + chacha_const[2])); op[3] = REVW_BE((x3 + chacha_const[3])); op[4] = REVW_BE((x4 + kp[0])); op[5] = REVW_BE((x5 + kp[1])); op[6] = REVW_BE((x6 + kp[2])); op[7] = REVW_BE((x7 + kp[3])); op[8] = REVW_BE((x8 + kp[4])); op[9] = REVW_BE((x9 + kp[5])); op[10] = REVW_BE((x10 + kp[6])); op[11] = REVW_BE((x11 + kp[7])); op[12] = REVW_BE((x12 + (x_ctr & 0xffffffff))); op[13] = REVW_BE((x13 + (x_ctr >> 32))); op[14] = REVW_BE((x14 + np[0])); op[15] = REVW_BE((x15 + np[1])); s3 += ONE; op += 16; #endif } return 0; } #define STATE_LEN (sizeof(struct chacha_state_krovetz)) #define STATE_BYTES 40 #define IDX_STEP (BPI * LOOP_ITERATIONS) #define OUTPUT_LEN (IDX_STEP * 64) static void chacha_krovetz_state_setup(void *state, const uint8_t *bytes) { struct chacha_state_krovetz *st = state; memcpy(st->key, bytes, 32); memcpy(st->nonce, bytes+32, 8); } static void chacha8_krovetz_generate(void *state, uint8_t *output, uint32_t idx) { struct chacha_state_krovetz *st = state; ottery_blocks_chacha_krovetz(8, output, idx * IDX_STEP, st); } static void chacha12_krovetz_generate(void *state, uint8_t *output, uint32_t idx) { struct chacha_state_krovetz *st = state; ottery_blocks_chacha_krovetz(12, output, idx * IDX_STEP, st); } static void chacha20_krovetz_generate(void *state, uint8_t *output, uint32_t idx) { struct chacha_state_krovetz *st = state; ottery_blocks_chacha_krovetz(20, output, idx * IDX_STEP, st); } #ifdef __SSSE3__ #define NEED_CPUCAP OTTERY_CPUCAP_SSSE3|OTTERY_CPUCAP_SIMD #define FLAV "-SSSE3" #else #define NEED_CPUCAP OTTERY_CPUCAP_SIMD #define FLAV "-DEFAULT" #endif #define PRF_CHACHA(r) { \ "CHACHA" #r, \ "CHACHA" #r "-SIMD", \ "CHACHA" #r "-SIMD" FLAV, \ STATE_LEN, \ STATE_BYTES, \ OUTPUT_LEN, \ NEED_CPUCAP, \ chacha_krovetz_state_setup, \ chacha ## r ## _krovetz_generate \ } #if defined OTTERY_BUILDING_SIMD1 const struct ottery_prf ottery_prf_chacha8_krovetz_1_ = PRF_CHACHA(8); const struct ottery_prf ottery_prf_chacha12_krovetz_1_ = PRF_CHACHA(12); const struct ottery_prf ottery_prf_chacha20_krovetz_1_ = PRF_CHACHA(20); #elif defined OTTERY_BUILDING_SIMD2 const struct ottery_prf ottery_prf_chacha8_krovetz_2_ = PRF_CHACHA(8); const struct ottery_prf ottery_prf_chacha12_krovetz_2_ = PRF_CHACHA(12); const struct ottery_prf ottery_prf_chacha20_krovetz_2_ = PRF_CHACHA(20); #else #error "Which PRF symbols am I supposed to define?" #endif