/* * AES-NI support functions * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * [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 "common.h" #if defined(MBEDTLS_AESNI_C) #if defined(__has_feature) #if __has_feature(memory_sanitizer) #warning \ "MBEDTLS_AESNI_C is known to cause spurious error reports with some memory sanitizers as they do not understand the assembly code." #endif #endif #include "aesni.h" #include /* *INDENT-OFF* */ #ifndef asm #define asm __asm #endif /* *INDENT-ON* */ #if defined(MBEDTLS_HAVE_X86_64) /* * AES-NI support detection routine */ int mbedtls_aesni_has_support(unsigned int what) { static int done = 0; static unsigned int c = 0; if (!done) { asm ("movl $1, %%eax \n\t" "cpuid \n\t" : "=c" (c) : : "eax", "ebx", "edx"); done = 1; } return (c & what) != 0; } /* * Binutils needs to be at least 2.19 to support AES-NI instructions. * Unfortunately, a lot of users have a lower version now (2014-04). * Emit bytecode directly in order to support "old" version of gas. * * Opcodes from the Intel architecture reference manual, vol. 3. * We always use registers, so we don't need prefixes for memory operands. * Operand macros are in gas order (src, dst) as opposed to Intel order * (dst, src) in order to blend better into the surrounding assembly code. */ #define AESDEC ".byte 0x66,0x0F,0x38,0xDE," #define AESDECLAST ".byte 0x66,0x0F,0x38,0xDF," #define AESENC ".byte 0x66,0x0F,0x38,0xDC," #define AESENCLAST ".byte 0x66,0x0F,0x38,0xDD," #define AESIMC ".byte 0x66,0x0F,0x38,0xDB," #define AESKEYGENA ".byte 0x66,0x0F,0x3A,0xDF," #define PCLMULQDQ ".byte 0x66,0x0F,0x3A,0x44," #define xmm0_xmm0 "0xC0" #define xmm0_xmm1 "0xC8" #define xmm0_xmm2 "0xD0" #define xmm0_xmm3 "0xD8" #define xmm0_xmm4 "0xE0" #define xmm1_xmm0 "0xC1" #define xmm1_xmm2 "0xD1" /* * AES-NI AES-ECB block en(de)cryption */ int mbedtls_aesni_crypt_ecb(mbedtls_aes_context *ctx, int mode, const unsigned char input[16], unsigned char output[16]) { asm ("movdqu (%3), %%xmm0 \n\t" // load input "movdqu (%1), %%xmm1 \n\t" // load round key 0 "pxor %%xmm1, %%xmm0 \n\t" // round 0 "add $16, %1 \n\t" // point to next round key "subl $1, %0 \n\t" // normal rounds = nr - 1 "test %2, %2 \n\t" // mode? "jz 2f \n\t" // 0 = decrypt "1: \n\t" // encryption loop "movdqu (%1), %%xmm1 \n\t" // load round key AESENC xmm1_xmm0 "\n\t" // do round "add $16, %1 \n\t" // point to next round key "subl $1, %0 \n\t" // loop "jnz 1b \n\t" "movdqu (%1), %%xmm1 \n\t" // load round key AESENCLAST xmm1_xmm0 "\n\t" // last round "jmp 3f \n\t" "2: \n\t" // decryption loop "movdqu (%1), %%xmm1 \n\t" AESDEC xmm1_xmm0 "\n\t" // do round "add $16, %1 \n\t" "subl $1, %0 \n\t" "jnz 2b \n\t" "movdqu (%1), %%xmm1 \n\t" // load round key AESDECLAST xmm1_xmm0 "\n\t" // last round "3: \n\t" "movdqu %%xmm0, (%4) \n\t" // export output : : "r" (ctx->nr), "r" (ctx->buf + ctx->rk_offset), "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. */ void mbedtls_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\t" // a1:a0 "movdqu (%1), %%xmm1 \n\t" // b1:b0 /* * Caryless multiplication xmm2:xmm1 = xmm0 * xmm1 * using [CLMUL-WP] algorithm 1 (p. 13). */ "movdqa %%xmm1, %%xmm2 \n\t" // copy of b1:b0 "movdqa %%xmm1, %%xmm3 \n\t" // same "movdqa %%xmm1, %%xmm4 \n\t" // same PCLMULQDQ xmm0_xmm1 ",0x00 \n\t" // a0*b0 = c1:c0 PCLMULQDQ xmm0_xmm2 ",0x11 \n\t" // a1*b1 = d1:d0 PCLMULQDQ xmm0_xmm3 ",0x10 \n\t" // a0*b1 = e1:e0 PCLMULQDQ xmm0_xmm4 ",0x01 \n\t" // a1*b0 = f1:f0 "pxor %%xmm3, %%xmm4 \n\t" // e1+f1:e0+f0 "movdqa %%xmm4, %%xmm3 \n\t" // same "psrldq $8, %%xmm4 \n\t" // 0:e1+f1 "pslldq $8, %%xmm3 \n\t" // e0+f0:0 "pxor %%xmm4, %%xmm2 \n\t" // d1:d0+e1+f1 "pxor %%xmm3, %%xmm1 \n\t" // 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\t" // r1:r0 "movdqa %%xmm2, %%xmm4 \n\t" // r3:r2 "psllq $1, %%xmm1 \n\t" // r1<<1:r0<<1 "psllq $1, %%xmm2 \n\t" // r3<<1:r2<<1 "psrlq $63, %%xmm3 \n\t" // r1>>63:r0>>63 "psrlq $63, %%xmm4 \n\t" // r3>>63:r2>>63 "movdqa %%xmm3, %%xmm5 \n\t" // r1>>63:r0>>63 "pslldq $8, %%xmm3 \n\t" // r0>>63:0 "pslldq $8, %%xmm4 \n\t" // r2>>63:0 "psrldq $8, %%xmm5 \n\t" // 0:r1>>63 "por %%xmm3, %%xmm1 \n\t" // r1<<1|r0>>63:r0<<1 "por %%xmm4, %%xmm2 \n\t" // r3<<1|r2>>62:r2<<1 "por %%xmm5, %%xmm2 \n\t" // 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\t" // x1:x0 "movdqa %%xmm1, %%xmm4 \n\t" // same "movdqa %%xmm1, %%xmm5 \n\t" // same "psllq $63, %%xmm3 \n\t" // x1<<63:x0<<63 = stuff:a "psllq $62, %%xmm4 \n\t" // x1<<62:x0<<62 = stuff:b "psllq $57, %%xmm5 \n\t" // x1<<57:x0<<57 = stuff:c /* Step 2 (2) */ "pxor %%xmm4, %%xmm3 \n\t" // stuff:a+b "pxor %%xmm5, %%xmm3 \n\t" // stuff:a+b+c "pslldq $8, %%xmm3 \n\t" // a+b+c:0 "pxor %%xmm3, %%xmm1 \n\t" // x1+a+b+c:x0 = d:x0 /* Steps 3 and 4 */ "movdqa %%xmm1,%%xmm0 \n\t" // d:x0 "movdqa %%xmm1,%%xmm4 \n\t" // same "movdqa %%xmm1,%%xmm5 \n\t" // same "psrlq $1, %%xmm0 \n\t" // e1:x0>>1 = e1:e0' "psrlq $2, %%xmm4 \n\t" // f1:x0>>2 = f1:f0' "psrlq $7, %%xmm5 \n\t" // g1:x0>>7 = g1:g0' "pxor %%xmm4, %%xmm0 \n\t" // e1+f1:e0'+f0' "pxor %%xmm5, %%xmm0 \n\t" // e1+f1+g1:e0'+f0'+g0' // e0'+f0'+g0' is almost e0+f0+g0, ex\tcept for some missing // bits carried from d. Now get those\t bits back in. "movdqa %%xmm1,%%xmm3 \n\t" // d:x0 "movdqa %%xmm1,%%xmm4 \n\t" // same "movdqa %%xmm1,%%xmm5 \n\t" // same "psllq $63, %%xmm3 \n\t" // d<<63:stuff "psllq $62, %%xmm4 \n\t" // d<<62:stuff "psllq $57, %%xmm5 \n\t" // d<<57:stuff "pxor %%xmm4, %%xmm3 \n\t" // d<<63+d<<62:stuff "pxor %%xmm5, %%xmm3 \n\t" // missing bits of d:stuff "psrldq $8, %%xmm3 \n\t" // 0:missing bits of d "pxor %%xmm3, %%xmm0 \n\t" // e1+f1+g1:e0+f0+g0 "pxor %%xmm1, %%xmm0 \n\t" // h1:h0 "pxor %%xmm2, %%xmm0 \n\t" // x3+h1:x2+h0 "movdqu %%xmm0, (%2) \n\t" // 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; } /* * Compute decryption round keys from encryption round keys */ void mbedtls_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\t" AESIMC xmm0_xmm0 "\n\t" "movdqu %%xmm0, (%1) \n\t" : : "r" (fk), "r" (ik) : "memory", "xmm0"); } memcpy(ik, fk, 16); } /* * Key expansion, 128-bit case */ static void aesni_setkey_enc_128(unsigned char *rk, const unsigned char *key) { asm ("movdqu (%1), %%xmm0 \n\t" // copy the original key "movdqu %%xmm0, (%0) \n\t" // as round key 0 "jmp 2f \n\t" // skip auxiliary routine /* * Finish generating the next round key. * * On entry xmm0 is r3:r2:r1:r0 and xmm1 is X:stuff:stuff:stuff * with X = rot( sub( r3 ) ) ^ RCON. * * On exit, xmm0 is r7:r6:r5:r4 * with r4 = X + r0, r5 = r4 + r1, r6 = r5 + r2, r7 = r6 + r3 * and those are written to the round key buffer. */ "1: \n\t" "pshufd $0xff, %%xmm1, %%xmm1 \n\t" // X:X:X:X "pxor %%xmm0, %%xmm1 \n\t" // X+r3:X+r2:X+r1:r4 "pslldq $4, %%xmm0 \n\t" // r2:r1:r0:0 "pxor %%xmm0, %%xmm1 \n\t" // X+r3+r2:X+r2+r1:r5:r4 "pslldq $4, %%xmm0 \n\t" // etc "pxor %%xmm0, %%xmm1 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm1, %%xmm0 \n\t" // update xmm0 for next time! "add $16, %0 \n\t" // point to next round key "movdqu %%xmm0, (%0) \n\t" // write it "ret \n\t" /* Main "loop" */ "2: \n\t" AESKEYGENA xmm0_xmm1 ",0x01 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x02 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x04 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x08 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x10 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x20 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x40 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x80 \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x1B \n\tcall 1b \n\t" AESKEYGENA xmm0_xmm1 ",0x36 \n\tcall 1b \n\t" : : "r" (rk), "r" (key) : "memory", "cc", "0"); } /* * Key expansion, 192-bit case */ static void aesni_setkey_enc_192(unsigned char *rk, const unsigned char *key) { asm ("movdqu (%1), %%xmm0 \n\t" // copy original round key "movdqu %%xmm0, (%0) \n\t" "add $16, %0 \n\t" "movq 16(%1), %%xmm1 \n\t" "movq %%xmm1, (%0) \n\t" "add $8, %0 \n\t" "jmp 2f \n\t" // skip auxiliary routine /* * Finish generating the next 6 quarter-keys. * * On entry xmm0 is r3:r2:r1:r0, xmm1 is stuff:stuff:r5:r4 * and xmm2 is stuff:stuff:X:stuff with X = rot( sub( r3 ) ) ^ RCON. * * On exit, xmm0 is r9:r8:r7:r6 and xmm1 is stuff:stuff:r11:r10 * and those are written to the round key buffer. */ "1: \n\t" "pshufd $0x55, %%xmm2, %%xmm2 \n\t" // X:X:X:X "pxor %%xmm0, %%xmm2 \n\t" // X+r3:X+r2:X+r1:r4 "pslldq $4, %%xmm0 \n\t" // etc "pxor %%xmm0, %%xmm2 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm0, %%xmm2 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm2, %%xmm0 \n\t" // update xmm0 = r9:r8:r7:r6 "movdqu %%xmm0, (%0) \n\t" "add $16, %0 \n\t" "pshufd $0xff, %%xmm0, %%xmm2 \n\t" // r9:r9:r9:r9 "pxor %%xmm1, %%xmm2 \n\t" // stuff:stuff:r9+r5:r10 "pslldq $4, %%xmm1 \n\t" // r2:r1:r0:0 "pxor %%xmm2, %%xmm1 \n\t" // xmm1 = stuff:stuff:r11:r10 "movq %%xmm1, (%0) \n\t" "add $8, %0 \n\t" "ret \n\t" "2: \n\t" AESKEYGENA xmm1_xmm2 ",0x01 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x02 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x04 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x08 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x10 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x20 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x40 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x80 \n\tcall 1b \n\t" : : "r" (rk), "r" (key) : "memory", "cc", "0"); } /* * Key expansion, 256-bit case */ static void aesni_setkey_enc_256(unsigned char *rk, const unsigned char *key) { asm ("movdqu (%1), %%xmm0 \n\t" "movdqu %%xmm0, (%0) \n\t" "add $16, %0 \n\t" "movdqu 16(%1), %%xmm1 \n\t" "movdqu %%xmm1, (%0) \n\t" "jmp 2f \n\t" // skip auxiliary routine /* * Finish generating the next two round keys. * * On entry xmm0 is r3:r2:r1:r0, xmm1 is r7:r6:r5:r4 and * xmm2 is X:stuff:stuff:stuff with X = rot( sub( r7 )) ^ RCON * * On exit, xmm0 is r11:r10:r9:r8 and xmm1 is r15:r14:r13:r12 * and those have been written to the output buffer. */ "1: \n\t" "pshufd $0xff, %%xmm2, %%xmm2 \n\t" "pxor %%xmm0, %%xmm2 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm0, %%xmm2 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm0, %%xmm2 \n\t" "pslldq $4, %%xmm0 \n\t" "pxor %%xmm2, %%xmm0 \n\t" "add $16, %0 \n\t" "movdqu %%xmm0, (%0) \n\t" /* Set xmm2 to stuff:Y:stuff:stuff with Y = subword( r11 ) * and proceed to generate next round key from there */ AESKEYGENA xmm0_xmm2 ",0x00 \n\t" "pshufd $0xaa, %%xmm2, %%xmm2 \n\t" "pxor %%xmm1, %%xmm2 \n\t" "pslldq $4, %%xmm1 \n\t" "pxor %%xmm1, %%xmm2 \n\t" "pslldq $4, %%xmm1 \n\t" "pxor %%xmm1, %%xmm2 \n\t" "pslldq $4, %%xmm1 \n\t" "pxor %%xmm2, %%xmm1 \n\t" "add $16, %0 \n\t" "movdqu %%xmm1, (%0) \n\t" "ret \n\t" /* * Main "loop" - Generating one more key than necessary, * see definition of mbedtls_aes_context.buf */ "2: \n\t" AESKEYGENA xmm1_xmm2 ",0x01 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x02 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x04 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x08 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x10 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x20 \n\tcall 1b \n\t" AESKEYGENA xmm1_xmm2 ",0x40 \n\tcall 1b \n\t" : : "r" (rk), "r" (key) : "memory", "cc", "0"); } /* * Key expansion, wrapper */ int mbedtls_aesni_setkey_enc(unsigned char *rk, const unsigned char *key, size_t bits) { switch (bits) { case 128: aesni_setkey_enc_128(rk, key); break; case 192: aesni_setkey_enc_192(rk, key); break; case 256: aesni_setkey_enc_256(rk, key); break; default: return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH; } return 0; } #endif /* MBEDTLS_HAVE_X86_64 */ #endif /* MBEDTLS_AESNI_C */