| /* |
| * AES-NI support functions |
| * |
| * Copyright (C) 2013, Brainspark B.V. |
| * |
| * This file is part of PolarSSL (http://www.polarssl.org) |
| * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> |
| * |
| * All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| /* |
| * [AES-WP] http://software.intel.com/en-us/articles/intel-advanced-encryption-standard-aes-instructions-set |
| * [CLMUL-WP] http://software.intel.com/en-us/articles/intel-carry-less-multiplication-instruction-and-its-usage-for-computing-the-gcm-mode/ |
| */ |
| |
| #include "polarssl/config.h" |
| |
| #if defined(POLARSSL_AESNI_C) |
| |
| #include "polarssl/aesni.h" |
| #include <stdio.h> |
| |
| #if defined(POLARSSL_HAVE_X86_64) |
| |
| /* |
| * AES-NI support detection routine |
| */ |
| int aesni_supports( unsigned int what ) |
| { |
| static int done = 0; |
| static unsigned int c = 0; |
| |
| if( ! done ) |
| { |
| asm( "movl $1, %%eax \n" |
| "cpuid \n" |
| : "=c" (c) |
| : |
| : "eax", "ebx", "edx" ); |
| done = 1; |
| } |
| |
| return( ( c & what ) != 0 ); |
| } |
| |
| /* |
| * AES-NI AES-ECB block en(de)cryption |
| */ |
| int aesni_crypt_ecb( aes_context *ctx, |
| int mode, |
| const unsigned char input[16], |
| unsigned char output[16] ) |
| { |
| asm( "movdqu (%3), %%xmm0 \n" // load input |
| "movdqu (%1), %%xmm1 \n" // load round key 0 |
| "pxor %%xmm1, %%xmm0 \n" // round 0 |
| "addq $16, %1 \n" // point to next round key |
| "subl $1, %0 \n" // normal rounds = nr - 1 |
| "test %2, %2 \n" // mode? |
| "jz 2f \n" // 0 = decrypt |
| |
| "1: \n" // encryption loop |
| "movdqu (%1), %%xmm1 \n" // load round key |
| "aesenc %%xmm1, %%xmm0 \n" // do round |
| "addq $16, %1 \n" // point to next round key |
| "subl $1, %0 \n" // loop |
| "jnz 1b \n" |
| "movdqu (%1), %%xmm1 \n" // load round key |
| "aesenclast %%xmm1, %%xmm0 \n" // last round |
| "jmp 3f \n" |
| |
| "2: \n" // decryption loop |
| "movdqu (%1), %%xmm1 \n" |
| "aesdec %%xmm1, %%xmm0 \n" |
| "addq $16, %1 \n" |
| "subl $1, %0 \n" |
| "jnz 2b \n" |
| "movdqu (%1), %%xmm1 \n" // load round key |
| "aesdeclast %%xmm1, %%xmm0 \n" // last round |
| |
| "3: \n" |
| "movdqu %%xmm0, (%4) \n" // export output |
| : |
| : "r" (ctx->nr), "r" (ctx->rk), "r" (mode), "r" (input), "r" (output) |
| : "memory", "cc", "xmm0", "xmm1" ); |
| |
| |
| return( 0 ); |
| } |
| |
| /* |
| * GCM multiplication: c = a times b in GF(2^128) |
| * Based on [CLMUL-WP] algorithms 1 (with equation 27) and 5. |
| */ |
| int aesni_gcm_mult( unsigned char c[16], |
| const unsigned char a[16], |
| const unsigned char b[16] ) |
| { |
| unsigned char aa[16], bb[16], cc[16]; |
| size_t i; |
| |
| /* The inputs are in big-endian order, so byte-reverse them */ |
| for( i = 0; i < 16; i++ ) |
| { |
| aa[i] = a[15 - i]; |
| bb[i] = b[15 - i]; |
| } |
| |
| asm( "movdqu (%0), %%xmm0 \n" // a1:a0 |
| "movdqu (%1), %%xmm1 \n" // b1:b0 |
| |
| /* |
| * Caryless multiplication xmm2:xmm1 = xmm0 * xmm1 |
| * using [CLMUL-WP] algorithm 1 (p. 13). |
| */ |
| "movdqa %%xmm1, %%xmm2 \n" // copy of b1:b0 |
| "movdqa %%xmm1, %%xmm3 \n" // same |
| "movdqa %%xmm1, %%xmm4 \n" // same |
| "pclmulqdq $0x00, %%xmm0, %%xmm1 \n" // a0*b0 = c1:c0 |
| "pclmulqdq $0x11, %%xmm0, %%xmm2 \n" // a1*b1 = d1:d0 |
| "pclmulqdq $0x10, %%xmm0, %%xmm3 \n" // a0*b1 = e1:e0 |
| "pclmulqdq $0x01, %%xmm0, %%xmm4 \n" // a1*b0 = f1:f0 |
| "pxor %%xmm3, %%xmm4 \n" // e1+f1:e0+f0 |
| "movdqa %%xmm4, %%xmm3 \n" // same |
| "psrldq $8, %%xmm4 \n" // 0:e1+f1 |
| "pslldq $8, %%xmm3 \n" // e0+f0:0 |
| "pxor %%xmm4, %%xmm2 \n" // d1:d0+e1+f1 |
| "pxor %%xmm3, %%xmm1 \n" // c1+e0+f1:c0 |
| |
| /* |
| * Now shift the result one bit to the left, |
| * taking advantage of [CLMUL-WP] eq 27 (p. 20) |
| */ |
| "movdqa %%xmm1, %%xmm3 \n" // r1:r0 |
| "movdqa %%xmm2, %%xmm4 \n" // r3:r2 |
| "psllq $1, %%xmm1 \n" // r1<<1:r0<<1 |
| "psllq $1, %%xmm2 \n" // r3<<1:r2<<1 |
| "psrlq $63, %%xmm3 \n" // r1>>63:r0>>63 |
| "psrlq $63, %%xmm4 \n" // r3>>63:r2>>63 |
| "movdqa %%xmm3, %%xmm5 \n" // r1>>63:r0>>63 |
| "pslldq $8, %%xmm3 \n" // r0>>63:0 |
| "pslldq $8, %%xmm4 \n" // r2>>63:0 |
| "psrldq $8, %%xmm5 \n" // 0:r1>>63 |
| "por %%xmm3, %%xmm1 \n" // r1<<1|r0>>63:r0<<1 |
| "por %%xmm4, %%xmm2 \n" // r3<<1|r2>>62:r2<<1 |
| "por %%xmm5, %%xmm2 \n" // r3<<1|r2>>62:r2<<1|r1>>63 |
| |
| /* |
| * Now reduce modulo the GCM polynomial x^128 + x^7 + x^2 + x + 1 |
| * using [CLMUL-WP] algorithm 5 (p. 20). |
| * Currently xmm2:xmm1 holds x3:x2:x1:x0 (already shifted). |
| */ |
| /* Step 2 (1) */ |
| "movdqa %%xmm1, %%xmm3 \n" // x1:x0 |
| "movdqa %%xmm1, %%xmm4 \n" // same |
| "movdqa %%xmm1, %%xmm5 \n" // same |
| "psllq $63, %%xmm3 \n" // x1<<63:x0<<63 = stuff:a |
| "psllq $62, %%xmm4 \n" // x1<<62:x0<<62 = stuff:b |
| "psllq $57, %%xmm5 \n" // x1<<57:x0<<57 = stuff:c |
| |
| /* Step 2 (2) */ |
| "pxor %%xmm4, %%xmm3 \n" // stuff:a+b |
| "pxor %%xmm5, %%xmm3 \n" // stuff:a+b+c |
| "pslldq $8, %%xmm3 \n" // a+b+c:0 |
| "pxor %%xmm3, %%xmm1 \n" // x1+a+b+c:x0 = d:x0 |
| |
| /* Steps 3 and 4 */ |
| "movdqa %%xmm1,%%xmm0 \n" // d:x0 |
| "movdqa %%xmm1,%%xmm4 \n" // same |
| "movdqa %%xmm1,%%xmm5 \n" // same |
| "psrlq $1, %%xmm0 \n" // e1:x0>>1 = e1:e0' |
| "psrlq $2, %%xmm4 \n" // f1:x0>>2 = f1:f0' |
| "psrlq $7, %%xmm5 \n" // g1:x0>>7 = g1:g0' |
| "pxor %%xmm4, %%xmm0 \n" // e1+f1:e0'+f0' |
| "pxor %%xmm5, %%xmm0 \n" // e1+f1+g1:e0'+f0'+g0' |
| // e0'+f0'+g0' is almost e0+f0+g0, except for some missing |
| // bits carried from d. Now get those bits back in. |
| "movdqa %%xmm1,%%xmm3 \n" // d:x0 |
| "movdqa %%xmm1,%%xmm4 \n" // same |
| "movdqa %%xmm1,%%xmm5 \n" // same |
| "psllq $63, %%xmm3 \n" // d<<63:stuff |
| "psllq $62, %%xmm4 \n" // d<<62:stuff |
| "psllq $57, %%xmm5 \n" // d<<57:stuff |
| "pxor %%xmm4, %%xmm3 \n" // d<<63+d<<62:stuff |
| "pxor %%xmm5, %%xmm3 \n" // missing bits of d:stuff |
| "psrldq $8, %%xmm3 \n" // 0:missing bits of d |
| "pxor %%xmm3, %%xmm0 \n" // e1+f1+g1:e0+f0+g0 |
| "pxor %%xmm1, %%xmm0 \n" // h1:h0 |
| "pxor %%xmm2, %%xmm0 \n" // x3+h1:x2+h0 |
| |
| "movdqu %%xmm0, (%2) \n" // done |
| : |
| : "r" (aa), "r" (bb), "r" (cc) |
| : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5" ); |
| |
| /* Now byte-reverse the outputs */ |
| for( i = 0; i < 16; i++ ) |
| c[i] = cc[15 - i]; |
| |
| return( 0 ); |
| } |
| |
| /* |
| * Compute decryption round keys from encryption round keys |
| */ |
| void aesni_inverse_key( unsigned char *invkey, |
| const unsigned char *fwdkey, int nr ) |
| { |
| unsigned char *ik = invkey; |
| const unsigned char *fk = fwdkey + 16 * nr; |
| |
| memcpy( ik, fk, 16 ); |
| |
| for( fk -= 16, ik += 16; fk > fwdkey; fk -= 16, ik += 16 ) |
| asm( "movdqu (%0), %%xmm0 \n" |
| "aesimc %%xmm0, %%xmm0 \n" |
| "movdqu %%xmm0, (%1) \n" |
| : |
| : "r" (fk), "r" (ik) |
| : "memory", "xmm0" ); |
| |
| memcpy( ik, fk, 16 ); |
| } |
| |
| #endif /* POLARSSL_HAVE_X86_64 */ |
| |
| #endif /* POLARSSL_AESNI_C */ |