/* cipher-gcm.c - Generic Galois Counter Mode implementation * Copyright (C) 2013 Dmitry Eremin-Solenikov * Copyright (C) 2013, 2018-2019 Jussi Kivilinna * * This file is part of Libgcrypt. * * Libgcrypt is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * Libgcrypt 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see . */ #include #include #include #include #include #include "g10lib.h" #include "cipher.h" #include "bufhelp.h" #include "./cipher-internal.h" static gcry_err_code_t _gcry_cipher_gcm_setiv_zero (gcry_cipher_hd_t c); /* Helper macro to force alignment to 16 or 64 bytes. */ #ifdef HAVE_GCC_ATTRIBUTE_ALIGNED # define ATTR_ALIGNED_64 __attribute__ ((aligned (64))) #else # define ATTR_ALIGNED_64 #endif #ifdef GCM_USE_INTEL_PCLMUL extern void _gcry_ghash_setup_intel_pclmul (gcry_cipher_hd_t c, unsigned int hw_features); #endif #ifdef GCM_USE_ARM_PMULL extern void _gcry_ghash_setup_armv8_ce_pmull (void *gcm_key, void *gcm_table); extern unsigned int _gcry_ghash_armv8_ce_pmull (void *gcm_key, byte *result, const byte *buf, size_t nblocks, void *gcm_table); extern unsigned int _gcry_polyval_armv8_ce_pmull (void *gcm_key, byte *result, const byte *buf, size_t nblocks, void *gcm_table); static void ghash_setup_armv8_ce_pmull (gcry_cipher_hd_t c) { _gcry_ghash_setup_armv8_ce_pmull(c->u_mode.gcm.u_ghash_key.key, c->u_mode.gcm.gcm_table); } static unsigned int ghash_armv8_ce_pmull (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { return _gcry_ghash_armv8_ce_pmull(c->u_mode.gcm.u_ghash_key.key, result, buf, nblocks, c->u_mode.gcm.gcm_table); } static unsigned int polyval_armv8_ce_pmull (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { return _gcry_polyval_armv8_ce_pmull(c->u_mode.gcm.u_ghash_key.key, result, buf, nblocks, c->u_mode.gcm.gcm_table); } #endif /* GCM_USE_ARM_PMULL */ #ifdef GCM_USE_ARM_NEON extern void _gcry_ghash_setup_armv7_neon (void *gcm_key); extern unsigned int _gcry_ghash_armv7_neon (void *gcm_key, byte *result, const byte *buf, size_t nblocks); static void ghash_setup_armv7_neon (gcry_cipher_hd_t c) { _gcry_ghash_setup_armv7_neon(c->u_mode.gcm.u_ghash_key.key); } static unsigned int ghash_armv7_neon (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { return _gcry_ghash_armv7_neon(c->u_mode.gcm.u_ghash_key.key, result, buf, nblocks); } #endif /* GCM_USE_ARM_NEON */ #ifdef GCM_USE_RISCV_ZBB_ZBC extern void _gcry_ghash_setup_riscv_zbb_zbc(gcry_cipher_hd_t c); extern unsigned int _gcry_ghash_riscv_zbb_zbc(gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks); extern unsigned int _gcry_polyval_riscv_zbb_zbc(gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks); #endif /* GCM_USE_RISCV_ZBB_ZBC */ #ifdef GCM_USE_RISCV_ZVKG extern int _gcry_ghash_setup_riscv_zvkg(gcry_cipher_hd_t c); extern unsigned int _gcry_ghash_riscv_zvkg(gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks); extern unsigned int _gcry_polyval_riscv_zvkg(gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks); #endif /* GCM_USE_RISCV_ZVKG */ #ifdef GCM_USE_AARCH64 extern void _gcry_ghash_setup_aarch64_simd(gcry_cipher_hd_t c); extern unsigned int _gcry_ghash_aarch64_simd(gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks); #endif /* GCM_USE_AARCH64 */ #ifdef GCM_USE_S390X_CRYPTO #include "asm-inline-s390x.h" static unsigned int ghash_s390x_kimd (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { u128_t params[2]; memcpy (¶ms[0], result, 16); memcpy (¶ms[1], c->u_mode.gcm.u_ghash_key.key, 16); kimd_execute (KMID_FUNCTION_GHASH, ¶ms, buf, nblocks * 16); memcpy (result, ¶ms[0], 16); wipememory (params, sizeof(params)); return 0; } #endif /* GCM_USE_S390X_CRYPTO*/ #ifdef GCM_USE_PPC_VPMSUM extern void _gcry_ghash_setup_ppc_vpmsum (void *gcm_table, void *gcm_key); /* result is 128-bits */ extern unsigned int _gcry_ghash_ppc_vpmsum (byte *result, void *gcm_table, const byte *buf, size_t nblocks); static void ghash_setup_ppc_vpmsum (gcry_cipher_hd_t c) { _gcry_ghash_setup_ppc_vpmsum(c->u_mode.gcm.gcm_table, c->u_mode.gcm.u_ghash_key.key); } static unsigned int ghash_ppc_vpmsum (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { return _gcry_ghash_ppc_vpmsum(result, c->u_mode.gcm.gcm_table, buf, nblocks); } #endif /* GCM_USE_PPC_VPMSUM */ #ifdef GCM_USE_TABLES static struct { volatile u32 counter_head; u32 cacheline_align[64 / 4 - 1]; u16 R[256]; volatile u32 counter_tail; } gcm_table ATTR_ALIGNED_64 = { 0, { 0, }, { 0x0000, 0x01c2, 0x0384, 0x0246, 0x0708, 0x06ca, 0x048c, 0x054e, 0x0e10, 0x0fd2, 0x0d94, 0x0c56, 0x0918, 0x08da, 0x0a9c, 0x0b5e, 0x1c20, 0x1de2, 0x1fa4, 0x1e66, 0x1b28, 0x1aea, 0x18ac, 0x196e, 0x1230, 0x13f2, 0x11b4, 0x1076, 0x1538, 0x14fa, 0x16bc, 0x177e, 0x3840, 0x3982, 0x3bc4, 0x3a06, 0x3f48, 0x3e8a, 0x3ccc, 0x3d0e, 0x3650, 0x3792, 0x35d4, 0x3416, 0x3158, 0x309a, 0x32dc, 0x331e, 0x2460, 0x25a2, 0x27e4, 0x2626, 0x2368, 0x22aa, 0x20ec, 0x212e, 0x2a70, 0x2bb2, 0x29f4, 0x2836, 0x2d78, 0x2cba, 0x2efc, 0x2f3e, 0x7080, 0x7142, 0x7304, 0x72c6, 0x7788, 0x764a, 0x740c, 0x75ce, 0x7e90, 0x7f52, 0x7d14, 0x7cd6, 0x7998, 0x785a, 0x7a1c, 0x7bde, 0x6ca0, 0x6d62, 0x6f24, 0x6ee6, 0x6ba8, 0x6a6a, 0x682c, 0x69ee, 0x62b0, 0x6372, 0x6134, 0x60f6, 0x65b8, 0x647a, 0x663c, 0x67fe, 0x48c0, 0x4902, 0x4b44, 0x4a86, 0x4fc8, 0x4e0a, 0x4c4c, 0x4d8e, 0x46d0, 0x4712, 0x4554, 0x4496, 0x41d8, 0x401a, 0x425c, 0x439e, 0x54e0, 0x5522, 0x5764, 0x56a6, 0x53e8, 0x522a, 0x506c, 0x51ae, 0x5af0, 0x5b32, 0x5974, 0x58b6, 0x5df8, 0x5c3a, 0x5e7c, 0x5fbe, 0xe100, 0xe0c2, 0xe284, 0xe346, 0xe608, 0xe7ca, 0xe58c, 0xe44e, 0xef10, 0xeed2, 0xec94, 0xed56, 0xe818, 0xe9da, 0xeb9c, 0xea5e, 0xfd20, 0xfce2, 0xfea4, 0xff66, 0xfa28, 0xfbea, 0xf9ac, 0xf86e, 0xf330, 0xf2f2, 0xf0b4, 0xf176, 0xf438, 0xf5fa, 0xf7bc, 0xf67e, 0xd940, 0xd882, 0xdac4, 0xdb06, 0xde48, 0xdf8a, 0xddcc, 0xdc0e, 0xd750, 0xd692, 0xd4d4, 0xd516, 0xd058, 0xd19a, 0xd3dc, 0xd21e, 0xc560, 0xc4a2, 0xc6e4, 0xc726, 0xc268, 0xc3aa, 0xc1ec, 0xc02e, 0xcb70, 0xcab2, 0xc8f4, 0xc936, 0xcc78, 0xcdba, 0xcffc, 0xce3e, 0x9180, 0x9042, 0x9204, 0x93c6, 0x9688, 0x974a, 0x950c, 0x94ce, 0x9f90, 0x9e52, 0x9c14, 0x9dd6, 0x9898, 0x995a, 0x9b1c, 0x9ade, 0x8da0, 0x8c62, 0x8e24, 0x8fe6, 0x8aa8, 0x8b6a, 0x892c, 0x88ee, 0x83b0, 0x8272, 0x8034, 0x81f6, 0x84b8, 0x857a, 0x873c, 0x86fe, 0xa9c0, 0xa802, 0xaa44, 0xab86, 0xaec8, 0xaf0a, 0xad4c, 0xac8e, 0xa7d0, 0xa612, 0xa454, 0xa596, 0xa0d8, 0xa11a, 0xa35c, 0xa29e, 0xb5e0, 0xb422, 0xb664, 0xb7a6, 0xb2e8, 0xb32a, 0xb16c, 0xb0ae, 0xbbf0, 0xba32, 0xb874, 0xb9b6, 0xbcf8, 0xbd3a, 0xbf7c, 0xbebe, }, 0 }; #define gcmR gcm_table.R static inline void prefetch_table(const void *tab, size_t len) { const volatile byte *vtab = tab; size_t i; for (i = 0; len - i >= 8 * 32; i += 8 * 32) { (void)vtab[i + 0 * 32]; (void)vtab[i + 1 * 32]; (void)vtab[i + 2 * 32]; (void)vtab[i + 3 * 32]; (void)vtab[i + 4 * 32]; (void)vtab[i + 5 * 32]; (void)vtab[i + 6 * 32]; (void)vtab[i + 7 * 32]; } for (; i < len; i += 32) { (void)vtab[i]; } (void)vtab[len - 1]; } static inline void do_prefetch_tables (const void *gcmM, size_t gcmM_size) { /* Modify counters to trigger copy-on-write and unsharing if physical pages * of look-up table are shared between processes. Modifying counters also * causes checksums for pages to change and hint same-page merging algorithm * that these pages are frequently changing. */ gcm_table.counter_head++; gcm_table.counter_tail++; /* Prefetch look-up tables to cache. */ prefetch_table(gcmM, gcmM_size); prefetch_table(&gcm_table, sizeof(gcm_table)); } #ifdef GCM_TABLES_USE_U64 static void bshift (u64 * b0, u64 * b1) { u64 t[2], mask; t[0] = *b0; t[1] = *b1; mask = -(t[1] & 1) & 0xe1; mask <<= 56; *b1 = (t[1] >> 1) ^ (t[0] << 63); *b0 = (t[0] >> 1) ^ mask; } static void do_fillM (unsigned char *h, u64 *M) { int i, j; M[0 + 0] = 0; M[0 + 16] = 0; M[8 + 0] = buf_get_be64 (h + 0); M[8 + 16] = buf_get_be64 (h + 8); for (i = 4; i > 0; i /= 2) { M[i + 0] = M[2 * i + 0]; M[i + 16] = M[2 * i + 16]; bshift (&M[i], &M[i + 16]); } for (i = 2; i < 16; i *= 2) for (j = 1; j < i; j++) { M[(i + j) + 0] = M[i + 0] ^ M[j + 0]; M[(i + j) + 16] = M[i + 16] ^ M[j + 16]; } for (i = 0; i < 16; i++) { M[i + 32] = (M[i + 0] >> 4) ^ ((u64) gcmR[(M[i + 16] & 0xf) << 4] << 48); M[i + 48] = (M[i + 16] >> 4) ^ (M[i + 0] << 60); } } static inline unsigned int do_ghash (unsigned char *result, const unsigned char *buf, const u64 *gcmM) { u64 V[2]; u64 tmp[2]; const u64 *M; u64 T; u32 A; int i; cipher_block_xor (V, result, buf, 16); V[0] = be_bswap64 (V[0]); V[1] = be_bswap64 (V[1]); /* First round can be manually tweaked based on fact that 'tmp' is zero. */ M = &gcmM[(V[1] & 0xf) + 32]; V[1] >>= 4; tmp[0] = M[0]; tmp[1] = M[16]; tmp[0] ^= gcmM[(V[1] & 0xf) + 0]; tmp[1] ^= gcmM[(V[1] & 0xf) + 16]; V[1] >>= 4; i = 6; while (1) { M = &gcmM[(V[1] & 0xf) + 32]; V[1] >>= 4; A = tmp[1] & 0xff; T = tmp[0]; tmp[0] = (T >> 8) ^ ((u64) gcmR[A] << 48) ^ gcmM[(V[1] & 0xf) + 0]; tmp[1] = (T << 56) ^ (tmp[1] >> 8) ^ gcmM[(V[1] & 0xf) + 16]; tmp[0] ^= M[0]; tmp[1] ^= M[16]; if (i == 0) break; V[1] >>= 4; --i; } i = 7; while (1) { M = &gcmM[(V[0] & 0xf) + 32]; V[0] >>= 4; A = tmp[1] & 0xff; T = tmp[0]; tmp[0] = (T >> 8) ^ ((u64) gcmR[A] << 48) ^ gcmM[(V[0] & 0xf) + 0]; tmp[1] = (T << 56) ^ (tmp[1] >> 8) ^ gcmM[(V[0] & 0xf) + 16]; tmp[0] ^= M[0]; tmp[1] ^= M[16]; if (i == 0) break; V[0] >>= 4; --i; } buf_put_be64 (result + 0, tmp[0]); buf_put_be64 (result + 8, tmp[1]); return (sizeof(V) + sizeof(T) + sizeof(tmp) + sizeof(int)*2 + sizeof(void*)*5); } #else /*!GCM_TABLES_USE_U64*/ static void bshift (u32 * M, int i) { u32 t[4], mask; t[0] = M[i * 4 + 0]; t[1] = M[i * 4 + 1]; t[2] = M[i * 4 + 2]; t[3] = M[i * 4 + 3]; mask = -(t[3] & 1) & 0xe1; M[i * 4 + 3] = (t[3] >> 1) ^ (t[2] << 31); M[i * 4 + 2] = (t[2] >> 1) ^ (t[1] << 31); M[i * 4 + 1] = (t[1] >> 1) ^ (t[0] << 31); M[i * 4 + 0] = (t[0] >> 1) ^ (mask << 24); } static void do_fillM (unsigned char *h, u32 *M) { int i, j; M[0 * 4 + 0] = 0; M[0 * 4 + 1] = 0; M[0 * 4 + 2] = 0; M[0 * 4 + 3] = 0; M[8 * 4 + 0] = buf_get_be32 (h + 0); M[8 * 4 + 1] = buf_get_be32 (h + 4); M[8 * 4 + 2] = buf_get_be32 (h + 8); M[8 * 4 + 3] = buf_get_be32 (h + 12); for (i = 4; i > 0; i /= 2) { M[i * 4 + 0] = M[2 * i * 4 + 0]; M[i * 4 + 1] = M[2 * i * 4 + 1]; M[i * 4 + 2] = M[2 * i * 4 + 2]; M[i * 4 + 3] = M[2 * i * 4 + 3]; bshift (M, i); } for (i = 2; i < 16; i *= 2) for (j = 1; j < i; j++) { M[(i + j) * 4 + 0] = M[i * 4 + 0] ^ M[j * 4 + 0]; M[(i + j) * 4 + 1] = M[i * 4 + 1] ^ M[j * 4 + 1]; M[(i + j) * 4 + 2] = M[i * 4 + 2] ^ M[j * 4 + 2]; M[(i + j) * 4 + 3] = M[i * 4 + 3] ^ M[j * 4 + 3]; } for (i = 0; i < 4 * 16; i += 4) { M[i + 0 + 64] = (M[i + 0] >> 4) ^ ((u64) gcmR[(M[i + 3] << 4) & 0xf0] << 16); M[i + 1 + 64] = (M[i + 1] >> 4) ^ (M[i + 0] << 28); M[i + 2 + 64] = (M[i + 2] >> 4) ^ (M[i + 1] << 28); M[i + 3 + 64] = (M[i + 3] >> 4) ^ (M[i + 2] << 28); } } static inline unsigned int do_ghash (unsigned char *result, const unsigned char *buf, const u32 *gcmM) { byte V[16]; u32 tmp[4]; u32 v; const u32 *M, *m; u32 T[3]; int i; cipher_block_xor (V, result, buf, 16); /* V is big-endian */ /* First round can be manually tweaked based on fact that 'tmp' is zero. */ i = 15; v = V[i]; M = &gcmM[(v & 0xf) * 4 + 64]; v = (v & 0xf0) >> 4; m = &gcmM[v * 4]; v = V[--i]; tmp[0] = M[0] ^ m[0]; tmp[1] = M[1] ^ m[1]; tmp[2] = M[2] ^ m[2]; tmp[3] = M[3] ^ m[3]; while (1) { M = &gcmM[(v & 0xf) * 4 + 64]; v = (v & 0xf0) >> 4; m = &gcmM[v * 4]; T[0] = tmp[0]; T[1] = tmp[1]; T[2] = tmp[2]; tmp[0] = (T[0] >> 8) ^ ((u32) gcmR[tmp[3] & 0xff] << 16) ^ m[0]; tmp[1] = (T[0] << 24) ^ (tmp[1] >> 8) ^ m[1]; tmp[2] = (T[1] << 24) ^ (tmp[2] >> 8) ^ m[2]; tmp[3] = (T[2] << 24) ^ (tmp[3] >> 8) ^ m[3]; tmp[0] ^= M[0]; tmp[1] ^= M[1]; tmp[2] ^= M[2]; tmp[3] ^= M[3]; if (i == 0) break; v = V[--i]; } buf_put_be32 (result + 0, tmp[0]); buf_put_be32 (result + 4, tmp[1]); buf_put_be32 (result + 8, tmp[2]); buf_put_be32 (result + 12, tmp[3]); return (sizeof(V) + sizeof(T) + sizeof(tmp) + sizeof(int)*2 + sizeof(void*)*6); } #endif /*!GCM_TABLES_USE_U64*/ #define fillM(c) \ do_fillM (c->u_mode.gcm.u_ghash_key.key, c->u_mode.gcm.gcm_table) #define GHASH(c, result, buf) do_ghash (result, buf, c->u_mode.gcm.gcm_table) #define prefetch_tables(c) \ do_prefetch_tables(c->u_mode.gcm.gcm_table, sizeof(c->u_mode.gcm.gcm_table)) #else static unsigned long bshift (unsigned long *b) { unsigned long c; int i; c = b[3] & 1; for (i = 3; i > 0; i--) { b[i] = (b[i] >> 1) | (b[i - 1] << 31); } b[i] >>= 1; return c; } static unsigned int do_ghash (unsigned char *hsub, unsigned char *result, const unsigned char *buf) { unsigned long V[4]; int i, j; byte *p; #ifdef WORDS_BIGENDIAN p = result; #else unsigned long T[4]; cipher_block_xor (V, result, buf, 16); for (i = 0; i < 4; i++) { V[i] = (V[i] & 0x00ff00ff) << 8 | (V[i] & 0xff00ff00) >> 8; V[i] = (V[i] & 0x0000ffff) << 16 | (V[i] & 0xffff0000) >> 16; } p = (byte *) T; #endif memset (p, 0, 16); for (i = 0; i < 16; i++) { for (j = 0x80; j; j >>= 1) { if (hsub[i] & j) cipher_block_xor (p, p, V, 16); if (bshift (V)) V[0] ^= 0xe1000000; } } #ifndef WORDS_BIGENDIAN for (i = 0, p = (byte *) T; i < 16; i += 4, p += 4) { result[i + 0] = p[3]; result[i + 1] = p[2]; result[i + 2] = p[1]; result[i + 3] = p[0]; } #endif return (sizeof(V) + sizeof(T) + sizeof(int)*2 + sizeof(void*)*5); } #define fillM(c) do { } while (0) #define GHASH(c, result, buf) do_ghash (c->u_mode.gcm.u_ghash_key.key, result, buf) #define prefetch_tables(c) do {} while (0) #endif /* !GCM_USE_TABLES */ static unsigned int ghash_internal (gcry_cipher_hd_t c, byte *result, const byte *buf, size_t nblocks) { const unsigned int blocksize = GCRY_GCM_BLOCK_LEN; unsigned int burn = 0; prefetch_tables (c); while (nblocks) { burn = GHASH (c, result, buf); buf += blocksize; nblocks--; } return burn + (burn ? 5*sizeof(void*) : 0); } static void setupM (gcry_cipher_hd_t c) { unsigned int features = _gcry_get_hw_features (); c->u_mode.gcm.ghash_fn = NULL; c->u_mode.gcm.polyval_fn = NULL; if (0) { (void)features; } #ifdef GCM_USE_INTEL_PCLMUL else if (features & HWF_INTEL_PCLMUL) { _gcry_ghash_setup_intel_pclmul (c, features); } #endif #ifdef GCM_USE_ARM_PMULL else if (features & HWF_ARM_PMULL) { c->u_mode.gcm.ghash_fn = ghash_armv8_ce_pmull; c->u_mode.gcm.polyval_fn = polyval_armv8_ce_pmull; ghash_setup_armv8_ce_pmull (c); } #endif #ifdef GCM_USE_ARM_NEON else if (features & HWF_ARM_NEON) { c->u_mode.gcm.ghash_fn = ghash_armv7_neon; ghash_setup_armv7_neon (c); } #endif #ifdef GCM_USE_AARCH64 else if (features & HWF_ARM_NEON) { c->u_mode.gcm.ghash_fn = _gcry_ghash_aarch64_simd; _gcry_ghash_setup_aarch64_simd (c); } #endif #ifdef GCM_USE_RISCV_ZVKG else if ((features & HWF_RISCV_IMAFDC) && (features & HWF_RISCV_B) /* Mandatory in RVA23U64 */ && (features & HWF_RISCV_V) /* Mandatory in RVA23U64 */ && (features & HWF_RISCV_ZVKG) /* Optional in RVA23U64 */ && _gcry_ghash_setup_riscv_zvkg (c)) { c->u_mode.gcm.ghash_fn = _gcry_ghash_riscv_zvkg; c->u_mode.gcm.polyval_fn = _gcry_polyval_riscv_zvkg; } #endif #ifdef GCM_USE_RISCV_ZBB_ZBC else if ((features & HWF_RISCV_IMAFDC) && (features & HWF_RISCV_ZBB) && (features & HWF_RISCV_ZBC)) { c->u_mode.gcm.ghash_fn = _gcry_ghash_riscv_zbb_zbc; c->u_mode.gcm.polyval_fn = _gcry_polyval_riscv_zbb_zbc; _gcry_ghash_setup_riscv_zbb_zbc (c); } #endif #ifdef GCM_USE_PPC_VPMSUM else if (features & HWF_PPC_VCRYPTO) { c->u_mode.gcm.ghash_fn = ghash_ppc_vpmsum; ghash_setup_ppc_vpmsum (c); } #endif #ifdef GCM_USE_S390X_CRYPTO else if (features & HWF_S390X_MSA) { if (kimd_query () & km_function_to_mask (KMID_FUNCTION_GHASH)) { c->u_mode.gcm.ghash_fn = ghash_s390x_kimd; } } #endif if (c->u_mode.gcm.ghash_fn == NULL) { c->u_mode.gcm.ghash_fn = ghash_internal; fillM (c); } } static inline void gcm_bytecounter_add (u32 ctr[2], size_t add) { if (sizeof(add) > sizeof(u32)) { u32 high_add = ((add >> 31) >> 1) & 0xffffffff; ctr[1] += high_add; } ctr[0] += add; if (ctr[0] >= add) return; ++ctr[1]; } static inline u32 gcm_add32_be128 (byte *ctr, unsigned int add) { /* 'ctr' must be aligned to four bytes. */ const unsigned int blocksize = GCRY_GCM_BLOCK_LEN; u32 *pval = (u32 *)(void *)(ctr + blocksize - sizeof(u32)); u32 val; val = be_bswap32(*pval) + add; *pval = be_bswap32(val); return val; /* return result as host-endian value */ } static inline int gcm_check_datalen (u32 ctr[2]) { /* len(plaintext) <= 2^39-256 bits == 2^36-32 bytes == 2^32-2 blocks */ if (ctr[1] > 0xfU) return 0; if (ctr[1] < 0xfU) return 1; if (ctr[0] <= 0xffffffe0U) return 1; return 0; } static inline int gcm_check_aadlen_or_ivlen (u32 ctr[2]) { /* len(aad/iv) <= 2^64-1 bits ~= 2^61-1 bytes */ if (ctr[1] > 0x1fffffffU) return 0; if (ctr[1] < 0x1fffffffU) return 1; if (ctr[0] <= 0xffffffffU) return 1; return 0; } static void do_ghash_buf(gcry_cipher_hd_t c, byte *hash, const byte *buf, size_t buflen, int do_padding) { unsigned int blocksize = GCRY_GCM_BLOCK_LEN; unsigned int unused = c->u_mode.gcm.mac_unused; ghash_fn_t ghash_fn = c->u_mode.gcm.ghash_fn; size_t nblocks, n; unsigned int burn = 0; if (buflen == 0 && (unused == 0 || !do_padding)) return; do { if (buflen > 0 && (buflen + unused < blocksize || unused > 0)) { n = blocksize - unused; n = n < buflen ? n : buflen; buf_cpy (&c->u_mode.gcm.macbuf[unused], buf, n); unused += n; buf += n; buflen -= n; } if (!buflen) { if (!do_padding && unused < blocksize) { break; } n = blocksize - unused; if (n > 0) { memset (&c->u_mode.gcm.macbuf[unused], 0, n); unused = blocksize; } } if (unused > 0) { gcry_assert (unused == blocksize); /* Process one block from macbuf. */ burn = ghash_fn (c, hash, c->u_mode.gcm.macbuf, 1); unused = 0; } nblocks = buflen / blocksize; if (nblocks) { burn = ghash_fn (c, hash, buf, nblocks); buf += blocksize * nblocks; buflen -= blocksize * nblocks; } } while (buflen > 0); c->u_mode.gcm.mac_unused = unused; if (burn) _gcry_burn_stack (burn); } static gcry_err_code_t gcm_ctr_encrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen, const byte *inbuf, size_t inbuflen) { gcry_err_code_t err = 0; while (inbuflen) { u32 nblocks_to_overflow; u32 num_ctr_increments; u32 curr_ctr_low; size_t currlen = inbuflen; byte ctr_copy[GCRY_GCM_BLOCK_LEN]; int fix_ctr = 0; /* GCM CTR increments only least significant 32-bits, without carry * to upper 96-bits of counter. Using generic CTR implementation * directly would carry 32-bit overflow to upper 96-bit. Detect * if input length is long enough to cause overflow, and limit * input length so that CTR overflow happen but updated CTR value is * not used to encrypt further input. After overflow, upper 96 bits * of CTR are restored to cancel out modification done by generic CTR * encryption. */ if (inbuflen > c->unused) { curr_ctr_low = gcm_add32_be128 (c->u_ctr.ctr, 0); /* Number of CTR increments this inbuflen would cause. */ num_ctr_increments = (inbuflen - c->unused) / GCRY_GCM_BLOCK_LEN + !!((inbuflen - c->unused) % GCRY_GCM_BLOCK_LEN); if ((u32)(num_ctr_increments + curr_ctr_low) < curr_ctr_low) { nblocks_to_overflow = 0xffffffffU - curr_ctr_low + 1; currlen = nblocks_to_overflow * GCRY_GCM_BLOCK_LEN + c->unused; if (currlen > inbuflen) { currlen = inbuflen; } fix_ctr = 1; cipher_block_cpy(ctr_copy, c->u_ctr.ctr, GCRY_GCM_BLOCK_LEN); } } err = _gcry_cipher_ctr_encrypt(c, outbuf, outbuflen, inbuf, currlen); if (err != 0) return err; if (fix_ctr) { /* Lower 32-bits of CTR should now be zero. */ gcry_assert(gcm_add32_be128 (c->u_ctr.ctr, 0) == 0); /* Restore upper part of CTR. */ buf_cpy(c->u_ctr.ctr, ctr_copy, GCRY_GCM_BLOCK_LEN - sizeof(u32)); wipememory(ctr_copy, sizeof(ctr_copy)); } inbuflen -= currlen; inbuf += currlen; outbuflen -= currlen; outbuf += currlen; } return err; } static gcry_err_code_t gcm_crypt_inner (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen, const byte *inbuf, size_t inbuflen, int encrypt) { gcry_err_code_t err; while (inbuflen) { size_t currlen = inbuflen; /* Use a bulk method if available. */ if (c->bulk.gcm_crypt) { /* Bulk method requires that there is no cached data. */ if (inbuflen >= GCRY_GCM_BLOCK_LEN && c->u_mode.gcm.mac_unused == 0) { size_t nblks = inbuflen / GCRY_GCM_BLOCK_LEN; size_t nleft; size_t ndone; nleft = c->bulk.gcm_crypt (c, outbuf, inbuf, nblks, encrypt); ndone = nblks - nleft; inbuf += ndone * GCRY_GCM_BLOCK_LEN; outbuf += ndone * GCRY_GCM_BLOCK_LEN; inbuflen -= ndone * GCRY_GCM_BLOCK_LEN; outbuflen -= ndone * GCRY_GCM_BLOCK_LEN; if (inbuflen == 0) break; currlen = inbuflen; } else if (c->u_mode.gcm.mac_unused > 0 && inbuflen >= GCRY_GCM_BLOCK_LEN + (16 - c->u_mode.gcm.mac_unused)) { /* Handle just enough data so that cache is depleted, and on * next loop iteration use bulk method. */ currlen = 16 - c->u_mode.gcm.mac_unused; gcry_assert(currlen); } } /* Since checksumming is done after/before encryption/decryption, * process input in 24KiB chunks to keep data loaded in L1 cache for * checksumming/decryption. However only do splitting if input is * large enough so that last chunks does not end up being short. */ if (currlen > 32 * 1024) currlen = 24 * 1024; if (!encrypt) do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, inbuf, currlen, 0); err = gcm_ctr_encrypt(c, outbuf, outbuflen, inbuf, currlen); if (err != 0) return err; if (encrypt) do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, outbuf, currlen, 0); outbuf += currlen; inbuf += currlen; outbuflen -= currlen; inbuflen -= currlen; } return 0; } gcry_err_code_t _gcry_cipher_gcm_encrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen, const byte *inbuf, size_t inbuflen) { if (c->spec->blocksize != GCRY_GCM_BLOCK_LEN) return GPG_ERR_CIPHER_ALGO; if (outbuflen < inbuflen) return GPG_ERR_BUFFER_TOO_SHORT; if (c->u_mode.gcm.datalen_over_limits) return GPG_ERR_INV_LENGTH; if (c->marks.tag || c->u_mode.gcm.ghash_data_finalized || !c->u_mode.gcm.ghash_fn) return GPG_ERR_INV_STATE; if (!c->marks.iv) _gcry_cipher_gcm_setiv_zero (c); if (c->u_mode.gcm.disallow_encryption_because_of_setiv_in_fips_mode) return GPG_ERR_INV_STATE; if (!c->u_mode.gcm.ghash_aad_finalized) { /* Start of encryption marks end of AAD stream. */ do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, NULL, 0, 1); c->u_mode.gcm.ghash_aad_finalized = 1; } gcm_bytecounter_add(c->u_mode.gcm.datalen, inbuflen); if (!gcm_check_datalen(c->u_mode.gcm.datalen)) { c->u_mode.gcm.datalen_over_limits = 1; return GPG_ERR_INV_LENGTH; } return gcm_crypt_inner (c, outbuf, outbuflen, inbuf, inbuflen, 1); } gcry_err_code_t _gcry_cipher_gcm_decrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen, const byte *inbuf, size_t inbuflen) { if (c->spec->blocksize != GCRY_GCM_BLOCK_LEN) return GPG_ERR_CIPHER_ALGO; if (outbuflen < inbuflen) return GPG_ERR_BUFFER_TOO_SHORT; if (c->u_mode.gcm.datalen_over_limits) return GPG_ERR_INV_LENGTH; if (c->marks.tag || c->u_mode.gcm.ghash_data_finalized || !c->u_mode.gcm.ghash_fn) return GPG_ERR_INV_STATE; if (!c->marks.iv) _gcry_cipher_gcm_setiv_zero (c); if (!c->u_mode.gcm.ghash_aad_finalized) { /* Start of decryption marks end of AAD stream. */ do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, NULL, 0, 1); c->u_mode.gcm.ghash_aad_finalized = 1; } gcm_bytecounter_add(c->u_mode.gcm.datalen, inbuflen); if (!gcm_check_datalen(c->u_mode.gcm.datalen)) { c->u_mode.gcm.datalen_over_limits = 1; return GPG_ERR_INV_LENGTH; } return gcm_crypt_inner (c, outbuf, outbuflen, inbuf, inbuflen, 0); } gcry_err_code_t _gcry_cipher_gcm_authenticate (gcry_cipher_hd_t c, const byte * aadbuf, size_t aadbuflen) { if (c->spec->blocksize != GCRY_GCM_BLOCK_LEN) return GPG_ERR_CIPHER_ALGO; if (c->u_mode.gcm.datalen_over_limits) return GPG_ERR_INV_LENGTH; if (c->marks.tag || c->u_mode.gcm.ghash_aad_finalized || c->u_mode.gcm.ghash_data_finalized || !c->u_mode.gcm.ghash_fn) return GPG_ERR_INV_STATE; if (!c->marks.iv) _gcry_cipher_gcm_setiv_zero (c); gcm_bytecounter_add(c->u_mode.gcm.aadlen, aadbuflen); if (!gcm_check_aadlen_or_ivlen(c->u_mode.gcm.aadlen)) { c->u_mode.gcm.datalen_over_limits = 1; return GPG_ERR_INV_LENGTH; } do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, aadbuf, aadbuflen, 0); return 0; } void _gcry_cipher_gcm_setupM (gcry_cipher_hd_t c) { setupM (c); } void _gcry_cipher_gcm_setkey (gcry_cipher_hd_t c) { memset (c->u_mode.gcm.u_ghash_key.key, 0, GCRY_GCM_BLOCK_LEN); c->spec->encrypt (&c->context.c, c->u_mode.gcm.u_ghash_key.key, c->u_mode.gcm.u_ghash_key.key); setupM (c); } static gcry_err_code_t _gcry_cipher_gcm_initiv (gcry_cipher_hd_t c, const byte *iv, size_t ivlen) { memset (c->u_mode.gcm.aadlen, 0, sizeof(c->u_mode.gcm.aadlen)); memset (c->u_mode.gcm.datalen, 0, sizeof(c->u_mode.gcm.datalen)); memset (c->u_mode.gcm.u_tag.tag, 0, GCRY_GCM_BLOCK_LEN); c->u_mode.gcm.datalen_over_limits = 0; c->u_mode.gcm.ghash_data_finalized = 0; c->u_mode.gcm.ghash_aad_finalized = 0; if (ivlen == 0) return GPG_ERR_INV_LENGTH; if (ivlen != GCRY_GCM_BLOCK_LEN - 4) { u32 iv_bytes[2] = {0, 0}; u32 bitlengths[2][2]; if (!c->u_mode.gcm.ghash_fn) return GPG_ERR_INV_STATE; memset(c->u_ctr.ctr, 0, GCRY_GCM_BLOCK_LEN); gcm_bytecounter_add(iv_bytes, ivlen); if (!gcm_check_aadlen_or_ivlen(iv_bytes)) { c->u_mode.gcm.datalen_over_limits = 1; return GPG_ERR_INV_LENGTH; } do_ghash_buf(c, c->u_ctr.ctr, iv, ivlen, 1); /* iv length, 64-bit */ bitlengths[1][1] = be_bswap32(iv_bytes[0] << 3); bitlengths[1][0] = be_bswap32((iv_bytes[0] >> 29) | (iv_bytes[1] << 3)); /* zeros, 64-bit */ bitlengths[0][1] = 0; bitlengths[0][0] = 0; do_ghash_buf(c, c->u_ctr.ctr, (byte*)bitlengths, GCRY_GCM_BLOCK_LEN, 1); wipememory (iv_bytes, sizeof iv_bytes); wipememory (bitlengths, sizeof bitlengths); } else { /* 96-bit IV is handled differently. */ memcpy (c->u_ctr.ctr, iv, ivlen); c->u_ctr.ctr[12] = c->u_ctr.ctr[13] = c->u_ctr.ctr[14] = 0; c->u_ctr.ctr[15] = 1; } c->spec->encrypt (&c->context.c, c->u_mode.gcm.tagiv, c->u_ctr.ctr); gcm_add32_be128 (c->u_ctr.ctr, 1); c->unused = 0; c->marks.iv = 1; c->marks.tag = 0; return 0; } gcry_err_code_t _gcry_cipher_gcm_setiv (gcry_cipher_hd_t c, const byte *iv, size_t ivlen) { c->marks.iv = 0; c->marks.tag = 0; return _gcry_cipher_gcm_initiv (c, iv, ivlen); } static gcry_err_code_t _gcry_cipher_gcm_setiv_zero (gcry_cipher_hd_t c) { static const unsigned char zerobuf[MAX_BLOCKSIZE]; c->u_mode.gcm.disallow_encryption_because_of_setiv_in_fips_mode = 0; if (fips_mode ()) { /* Direct invocation of GCM setiv in FIPS mode disables encryption. */ c->u_mode.gcm.disallow_encryption_because_of_setiv_in_fips_mode = 1; } return _gcry_cipher_gcm_setiv (c, zerobuf, GCRY_GCM_BLOCK_LEN); } #if 0 && TODO void _gcry_cipher_gcm_geniv (gcry_cipher_hd_t c, byte *ivout, size_t ivoutlen, const byte *nonce, size_t noncelen) { /* nonce: user provided part (might be null) */ /* noncelen: check if proper length (if nonce not null) */ /* ivout: iv used to initialize gcm, output to user */ /* ivoutlen: check correct size */ byte iv[IVLEN]; if (!ivout) return GPG_ERR_INV_ARG; if (ivoutlen != IVLEN) return GPG_ERR_INV_LENGTH; if (nonce != NULL && !is_nonce_ok_len(noncelen)) return GPG_ERR_INV_ARG; gcm_generate_iv(iv, nonce, noncelen); c->marks.iv = 0; c->marks.tag = 0; c->u_mode.gcm.disallow_encryption_because_of_setiv_in_fips_mode = 0; _gcry_cipher_gcm_initiv (c, iv, IVLEN); buf_cpy(ivout, iv, IVLEN); wipememory(iv, sizeof(iv)); } #endif static int is_tag_length_valid(size_t taglen) { switch (taglen) { /* Allowed tag lengths from NIST SP 800-38D. */ case 128 / 8: /* GCRY_GCM_BLOCK_LEN */ case 120 / 8: case 112 / 8: case 104 / 8: case 96 / 8: case 64 / 8: case 32 / 8: return 1; default: return 0; } } static gcry_err_code_t _gcry_cipher_gcm_tag (gcry_cipher_hd_t c, byte * outbuf, size_t outbuflen, int check) { if (!(is_tag_length_valid (outbuflen) || outbuflen >= GCRY_GCM_BLOCK_LEN)) return GPG_ERR_INV_LENGTH; if (c->u_mode.gcm.datalen_over_limits) return GPG_ERR_INV_LENGTH; if (!c->marks.tag) { u32 bitlengths[2][2]; if (!c->u_mode.gcm.ghash_fn) return GPG_ERR_INV_STATE; /* aad length */ bitlengths[0][1] = be_bswap32(c->u_mode.gcm.aadlen[0] << 3); bitlengths[0][0] = be_bswap32((c->u_mode.gcm.aadlen[0] >> 29) | (c->u_mode.gcm.aadlen[1] << 3)); /* data length */ bitlengths[1][1] = be_bswap32(c->u_mode.gcm.datalen[0] << 3); bitlengths[1][0] = be_bswap32((c->u_mode.gcm.datalen[0] >> 29) | (c->u_mode.gcm.datalen[1] << 3)); /* Finalize data-stream. */ do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, NULL, 0, 1); c->u_mode.gcm.ghash_aad_finalized = 1; c->u_mode.gcm.ghash_data_finalized = 1; /* Add bitlengths to tag. */ do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, (byte*)bitlengths, GCRY_GCM_BLOCK_LEN, 1); cipher_block_xor (c->u_mode.gcm.u_tag.tag, c->u_mode.gcm.tagiv, c->u_mode.gcm.u_tag.tag, GCRY_GCM_BLOCK_LEN); c->marks.tag = 1; wipememory (bitlengths, sizeof (bitlengths)); wipememory (c->u_mode.gcm.macbuf, GCRY_GCM_BLOCK_LEN); wipememory (c->u_mode.gcm.tagiv, GCRY_GCM_BLOCK_LEN); wipememory (c->u_mode.gcm.aadlen, sizeof (c->u_mode.gcm.aadlen)); wipememory (c->u_mode.gcm.datalen, sizeof (c->u_mode.gcm.datalen)); } if (!check) { if (outbuflen > GCRY_GCM_BLOCK_LEN) outbuflen = GCRY_GCM_BLOCK_LEN; /* NB: We already checked that OUTBUF is large enough to hold * the result or has valid truncated length. */ memcpy (outbuf, c->u_mode.gcm.u_tag.tag, outbuflen); } else { /* OUTBUFLEN gives the length of the user supplied tag in OUTBUF * and thus we need to compare its length first. */ if (!is_tag_length_valid (outbuflen) || !buf_eq_const (outbuf, c->u_mode.gcm.u_tag.tag, outbuflen)) return GPG_ERR_CHECKSUM; } return 0; } gcry_err_code_t _gcry_cipher_gcm_get_tag (gcry_cipher_hd_t c, unsigned char *outtag, size_t taglen) { /* Outputting authentication tag is part of encryption. */ if (c->u_mode.gcm.disallow_encryption_because_of_setiv_in_fips_mode) return GPG_ERR_INV_STATE; return _gcry_cipher_gcm_tag (c, outtag, taglen, 0); } gcry_err_code_t _gcry_cipher_gcm_check_tag (gcry_cipher_hd_t c, const unsigned char *intag, size_t taglen) { return _gcry_cipher_gcm_tag (c, (unsigned char *) intag, taglen, 1); }