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Diffstat (limited to 'plugins/MirOTR/Libgcrypt/cipher/cipher-gcm.c')
| -rw-r--r-- | plugins/MirOTR/Libgcrypt/cipher/cipher-gcm.c | 1180 |
1 files changed, 1180 insertions, 0 deletions
diff --git a/plugins/MirOTR/Libgcrypt/cipher/cipher-gcm.c b/plugins/MirOTR/Libgcrypt/cipher/cipher-gcm.c new file mode 100644 index 0000000000..457e337ac3 --- /dev/null +++ b/plugins/MirOTR/Libgcrypt/cipher/cipher-gcm.c @@ -0,0 +1,1180 @@ +/* cipher-gcm.c - Generic Galois Counter Mode implementation + * Copyright (C) 2013 Dmitry Eremin-Solenikov + * Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include "g10lib.h" +#include "cipher.h" +#include "ath.h" +#include "bufhelp.h" +#include "./cipher-internal.h" + +#ifdef GCM_USE_TABLES +static const u16 gcmR[256] = { + 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, +}; + +#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 : 0; + 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]; + } +} + +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; + + buf_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. */ + i = 15; + + M = &gcmM[(V[1] & 0xf)]; + V[1] >>= 4; + tmp[0] = (M[0] >> 4) ^ ((u64) gcmR[(M[16] & 0xf) << 4] << 48); + tmp[1] = (M[16] >> 4) ^ (M[0] << 60); + tmp[0] ^= gcmM[(V[1] & 0xf) + 0]; + tmp[1] ^= gcmM[(V[1] & 0xf) + 16]; + V[1] >>= 4; + + --i; + while (1) + { + M = &gcmM[(V[1] & 0xf)]; + 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] >> 4) ^ ((u64) gcmR[(M[16] & 0xf) << 4] << 48); + tmp[1] ^= (M[16] >> 4) ^ (M[0] << 60); + + if (i == 0) + break; + else if (i == 8) + V[1] = V[0]; + else + V[1] >>= 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 + +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 : 0; + + 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]; + } +} + +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; + + buf_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]; + v = (v & 0xf0) >> 4; + m = &gcmM[v * 4]; + v = V[--i]; + + tmp[0] = (M[0] >> 4) ^ ((u64) gcmR[(M[3] << 4) & 0xf0] << 16) ^ m[0]; + tmp[1] = (M[1] >> 4) ^ (M[0] << 28) ^ m[1]; + tmp[2] = (M[2] >> 4) ^ (M[1] << 28) ^ m[2]; + tmp[3] = (M[3] >> 4) ^ (M[2] << 28) ^ m[3]; + + while (1) + { + M = &gcmM[(v & 0xf) * 4]; + 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] >> 4) ^ ((u64) gcmR[(M[3] << 4) & 0xf0] << 16); + tmp[1] ^= (M[1] >> 4) ^ (M[0] << 28); + tmp[2] ^= (M[2] >> 4) ^ (M[1] << 28); + tmp[3] ^= (M[3] >> 4) ^ (M[2] << 28); + + 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 /* !HAVE_U64_TYPEDEF || SIZEOF_UNSIGNED_LONG != 8 */ + +#define fillM(c, h) do_fillM (h, c->u_mode.gcm.gcm_table) +#define GHASH(c, result, buf) do_ghash (result, buf, 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]; + + buf_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) + buf_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, h) do { } while (0) +#define GHASH(c, result, buf) do_ghash (c->u_mode.gcm.u_ghash_key.key, result, buf) + +#endif /* !GCM_USE_TABLES */ + + +#ifdef GCM_USE_INTEL_PCLMUL +/* + Intel PCLMUL ghash based on white paper: + "Intel® Carry-Less Multiplication Instruction and its Usage for Computing the + GCM Mode - Rev 2.01"; Shay Gueron, Michael E. Kounavis. + */ +static inline void gfmul_pclmul(void) +{ + /* Input: XMM0 and XMM1, Output: XMM1. Input XMM0 stays unmodified. + Input must be converted to little-endian. + */ + asm volatile (/* gfmul, xmm0 has operator a and xmm1 has operator b. */ + "pshufd $78, %%xmm0, %%xmm2\n\t" + "pshufd $78, %%xmm1, %%xmm4\n\t" + "pxor %%xmm0, %%xmm2\n\t" /* xmm2 holds a0+a1 */ + "pxor %%xmm1, %%xmm4\n\t" /* xmm4 holds b0+b1 */ + + "movdqa %%xmm0, %%xmm3\n\t" + "pclmulqdq $0, %%xmm1, %%xmm3\n\t" /* xmm3 holds a0*b0 */ + "movdqa %%xmm0, %%xmm6\n\t" + "pclmulqdq $17, %%xmm1, %%xmm6\n\t" /* xmm6 holds a1*b1 */ + "movdqa %%xmm3, %%xmm5\n\t" + "pclmulqdq $0, %%xmm2, %%xmm4\n\t" /* xmm4 holds (a0+a1)*(b0+b1) */ + + "pxor %%xmm6, %%xmm5\n\t" /* xmm5 holds a0*b0+a1*b1 */ + "pxor %%xmm5, %%xmm4\n\t" /* xmm4 holds a0*b0+a1*b1+(a0+a1)*(b0+b1) */ + "movdqa %%xmm4, %%xmm5\n\t" + "psrldq $8, %%xmm4\n\t" + "pslldq $8, %%xmm5\n\t" + "pxor %%xmm5, %%xmm3\n\t" + "pxor %%xmm4, %%xmm6\n\t" /* <xmm6:xmm3> holds the result of the + carry-less multiplication of xmm0 + by xmm1 */ + + /* shift the result by one bit position to the left cope for + the fact that bits are reversed */ + "movdqa %%xmm3, %%xmm4\n\t" + "movdqa %%xmm6, %%xmm5\n\t" + "pslld $1, %%xmm3\n\t" + "pslld $1, %%xmm6\n\t" + "psrld $31, %%xmm4\n\t" + "psrld $31, %%xmm5\n\t" + "movdqa %%xmm4, %%xmm1\n\t" + "pslldq $4, %%xmm5\n\t" + "pslldq $4, %%xmm4\n\t" + "psrldq $12, %%xmm1\n\t" + "por %%xmm4, %%xmm3\n\t" + "por %%xmm5, %%xmm6\n\t" + "por %%xmm6, %%xmm1\n\t" + + /* first phase of the reduction */ + "movdqa %%xmm3, %%xmm6\n\t" + "movdqa %%xmm3, %%xmm7\n\t" + "pslld $31, %%xmm6\n\t" /* packed right shifting << 31 */ + "movdqa %%xmm3, %%xmm5\n\t" + "pslld $30, %%xmm7\n\t" /* packed right shifting shift << 30 */ + "pslld $25, %%xmm5\n\t" /* packed right shifting shift << 25 */ + "pxor %%xmm7, %%xmm6\n\t" /* xor the shifted versions */ + "pxor %%xmm5, %%xmm6\n\t" + "movdqa %%xmm6, %%xmm7\n\t" + "pslldq $12, %%xmm6\n\t" + "psrldq $4, %%xmm7\n\t" + "pxor %%xmm6, %%xmm3\n\t" /* first phase of the reduction + complete */ + + /* second phase of the reduction */ + "movdqa %%xmm3, %%xmm2\n\t" + "movdqa %%xmm3, %%xmm4\n\t" + "psrld $1, %%xmm2\n\t" /* packed left shifting >> 1 */ + "movdqa %%xmm3, %%xmm5\n\t" + "psrld $2, %%xmm4\n\t" /* packed left shifting >> 2 */ + "psrld $7, %%xmm5\n\t" /* packed left shifting >> 7 */ + "pxor %%xmm4, %%xmm2\n\t" /* xor the shifted versions */ + "pxor %%xmm5, %%xmm2\n\t" + "pxor %%xmm7, %%xmm2\n\t" + "pxor %%xmm2, %%xmm3\n\t" + "pxor %%xmm3, %%xmm1\n\t" /* the result is in xmm1 */ + ::: "cc" ); +} + +#ifdef __x86_64__ +static inline void gfmul_pclmul_aggr4(void) +{ + /* Input: + H¹: XMM0 X_i : XMM6 + H²: XMM8 X_(i-1) : XMM3 + H³: XMM9 X_(i-2) : XMM2 + H⁴: XMM10 X_(i-3)⊕Y_(i-4): XMM1 + Output: + Y_i: XMM1 + Inputs XMM0 stays unmodified. + Input must be converted to little-endian. + */ + asm volatile (/* perform clmul and merge results... */ + "pshufd $78, %%xmm10, %%xmm11\n\t" + "pshufd $78, %%xmm1, %%xmm12\n\t" + "pxor %%xmm10, %%xmm11\n\t" /* xmm11 holds 4:a0+a1 */ + "pxor %%xmm1, %%xmm12\n\t" /* xmm12 holds 4:b0+b1 */ + + "pshufd $78, %%xmm9, %%xmm13\n\t" + "pshufd $78, %%xmm2, %%xmm14\n\t" + "pxor %%xmm9, %%xmm13\n\t" /* xmm13 holds 3:a0+a1 */ + "pxor %%xmm2, %%xmm14\n\t" /* xmm14 holds 3:b0+b1 */ + + "pshufd $78, %%xmm8, %%xmm5\n\t" + "pshufd $78, %%xmm3, %%xmm15\n\t" + "pxor %%xmm8, %%xmm5\n\t" /* xmm1 holds 2:a0+a1 */ + "pxor %%xmm3, %%xmm15\n\t" /* xmm2 holds 2:b0+b1 */ + + "movdqa %%xmm10, %%xmm4\n\t" + "movdqa %%xmm9, %%xmm7\n\t" + "pclmulqdq $0, %%xmm1, %%xmm4\n\t" /* xmm4 holds 4:a0*b0 */ + "pclmulqdq $0, %%xmm2, %%xmm7\n\t" /* xmm7 holds 3:a0*b0 */ + "pclmulqdq $17, %%xmm10, %%xmm1\n\t" /* xmm1 holds 4:a1*b1 */ + "pclmulqdq $17, %%xmm9, %%xmm2\n\t" /* xmm9 holds 3:a1*b1 */ + "pclmulqdq $0, %%xmm11, %%xmm12\n\t" /* xmm12 holds 4:(a0+a1)*(b0+b1) */ + "pclmulqdq $0, %%xmm13, %%xmm14\n\t" /* xmm14 holds 3:(a0+a1)*(b0+b1) */ + + "pshufd $78, %%xmm0, %%xmm10\n\t" + "pshufd $78, %%xmm6, %%xmm11\n\t" + "pxor %%xmm0, %%xmm10\n\t" /* xmm10 holds 1:a0+a1 */ + "pxor %%xmm6, %%xmm11\n\t" /* xmm11 holds 1:b0+b1 */ + + "pxor %%xmm4, %%xmm7\n\t" /* xmm7 holds 3+4:a0*b0 */ + "pxor %%xmm2, %%xmm1\n\t" /* xmm1 holds 3+4:a1*b1 */ + "pxor %%xmm14, %%xmm12\n\t" /* xmm12 holds 3+4:(a0+a1)*(b0+b1) */ + + "movdqa %%xmm8, %%xmm13\n\t" + "pclmulqdq $0, %%xmm3, %%xmm13\n\t" /* xmm13 holds 2:a0*b0 */ + "pclmulqdq $17, %%xmm8, %%xmm3\n\t" /* xmm3 holds 2:a1*b1 */ + "pclmulqdq $0, %%xmm5, %%xmm15\n\t" /* xmm15 holds 2:(a0+a1)*(b0+b1) */ + + "pxor %%xmm13, %%xmm7\n\t" /* xmm7 holds 2+3+4:a0*b0 */ + "pxor %%xmm3, %%xmm1\n\t" /* xmm1 holds 2+3+4:a1*b1 */ + "pxor %%xmm15, %%xmm12\n\t" /* xmm12 holds 2+3+4:(a0+a1)*(b0+b1) */ + + "movdqa %%xmm0, %%xmm3\n\t" + "pclmulqdq $0, %%xmm6, %%xmm3\n\t" /* xmm3 holds 1:a0*b0 */ + "pclmulqdq $17, %%xmm0, %%xmm6\n\t" /* xmm6 holds 1:a1*b1 */ + "movdqa %%xmm11, %%xmm4\n\t" + "pclmulqdq $0, %%xmm10, %%xmm4\n\t" /* xmm4 holds 1:(a0+a1)*(b0+b1) */ + + "pxor %%xmm7, %%xmm3\n\t" /* xmm3 holds 1+2+3+4:a0*b0 */ + "pxor %%xmm1, %%xmm6\n\t" /* xmm6 holds 1+2+3+4:a1*b1 */ + "pxor %%xmm12, %%xmm4\n\t" /* xmm4 holds 1+2+3+4:(a0+a1)*(b0+b1) */ + + /* aggregated reduction... */ + "movdqa %%xmm3, %%xmm5\n\t" + "pxor %%xmm6, %%xmm5\n\t" /* xmm5 holds a0*b0+a1*b1 */ + "pxor %%xmm5, %%xmm4\n\t" /* xmm4 holds a0*b0+a1*b1+(a0+a1)*(b0+b1) */ + "movdqa %%xmm4, %%xmm5\n\t" + "psrldq $8, %%xmm4\n\t" + "pslldq $8, %%xmm5\n\t" + "pxor %%xmm5, %%xmm3\n\t" + "pxor %%xmm4, %%xmm6\n\t" /* <xmm6:xmm3> holds the result of the + carry-less multiplication of xmm0 + by xmm1 */ + + /* shift the result by one bit position to the left cope for + the fact that bits are reversed */ + "movdqa %%xmm3, %%xmm4\n\t" + "movdqa %%xmm6, %%xmm5\n\t" + "pslld $1, %%xmm3\n\t" + "pslld $1, %%xmm6\n\t" + "psrld $31, %%xmm4\n\t" + "psrld $31, %%xmm5\n\t" + "movdqa %%xmm4, %%xmm1\n\t" + "pslldq $4, %%xmm5\n\t" + "pslldq $4, %%xmm4\n\t" + "psrldq $12, %%xmm1\n\t" + "por %%xmm4, %%xmm3\n\t" + "por %%xmm5, %%xmm6\n\t" + "por %%xmm6, %%xmm1\n\t" + + /* first phase of the reduction */ + "movdqa %%xmm3, %%xmm6\n\t" + "movdqa %%xmm3, %%xmm7\n\t" + "pslld $31, %%xmm6\n\t" /* packed right shifting << 31 */ + "movdqa %%xmm3, %%xmm5\n\t" + "pslld $30, %%xmm7\n\t" /* packed right shifting shift << 30 */ + "pslld $25, %%xmm5\n\t" /* packed right shifting shift << 25 */ + "pxor %%xmm7, %%xmm6\n\t" /* xor the shifted versions */ + "pxor %%xmm5, %%xmm6\n\t" + "movdqa %%xmm6, %%xmm7\n\t" + "pslldq $12, %%xmm6\n\t" + "psrldq $4, %%xmm7\n\t" + "pxor %%xmm6, %%xmm3\n\t" /* first phase of the reduction + complete */ + + /* second phase of the reduction */ + "movdqa %%xmm3, %%xmm2\n\t" + "movdqa %%xmm3, %%xmm4\n\t" + "psrld $1, %%xmm2\n\t" /* packed left shifting >> 1 */ + "movdqa %%xmm3, %%xmm5\n\t" + "psrld $2, %%xmm4\n\t" /* packed left shifting >> 2 */ + "psrld $7, %%xmm5\n\t" /* packed left shifting >> 7 */ + "pxor %%xmm4, %%xmm2\n\t" /* xor the shifted versions */ + "pxor %%xmm5, %%xmm2\n\t" + "pxor %%xmm7, %%xmm2\n\t" + "pxor %%xmm2, %%xmm3\n\t" + "pxor %%xmm3, %%xmm1\n\t" /* the result is in xmm1 */ + :::"cc"); +} +#endif + +#endif /*GCM_USE_INTEL_PCLMUL*/ + + +static unsigned int +ghash (gcry_cipher_hd_t c, byte *result, const byte *buf, + size_t nblocks) +{ + const unsigned int blocksize = GCRY_GCM_BLOCK_LEN; + unsigned int burn; + + if (nblocks == 0) + return 0; + + if (0) + ; +#ifdef GCM_USE_INTEL_PCLMUL + else if (c->u_mode.gcm.use_intel_pclmul) + { + static const unsigned char be_mask[16] __attribute__ ((aligned (16))) = + { 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 }; + + /* Preload hash and H1. */ + asm volatile ("movdqu %[hash], %%xmm1\n\t" + "movdqa %[hsub], %%xmm0\n\t" + "pshufb %[be_mask], %%xmm1\n\t" /* be => le */ + : + : [hash] "m" (*result), [be_mask] "m" (*be_mask), + [hsub] "m" (*c->u_mode.gcm.u_ghash_key.key)); + +#ifdef __x86_64__ + if (nblocks >= 4) + { + do + { + asm volatile ("movdqa %[be_mask], %%xmm4\n\t" + "movdqu 0*16(%[buf]), %%xmm5\n\t" + "movdqu 1*16(%[buf]), %%xmm2\n\t" + "movdqu 2*16(%[buf]), %%xmm3\n\t" + "movdqu 3*16(%[buf]), %%xmm6\n\t" + "pshufb %%xmm4, %%xmm5\n\t" /* be => le */ + + /* Load H2, H3, H4. */ + "movdqu 2*16(%[h_234]), %%xmm10\n\t" + "movdqu 1*16(%[h_234]), %%xmm9\n\t" + "movdqu 0*16(%[h_234]), %%xmm8\n\t" + + "pxor %%xmm5, %%xmm1\n\t" + "pshufb %%xmm4, %%xmm2\n\t" /* be => le */ + "pshufb %%xmm4, %%xmm3\n\t" /* be => le */ + "pshufb %%xmm4, %%xmm6\n\t" /* be => le */ + : + : [buf] "r" (buf), [be_mask] "m" (*be_mask), + [h_234] "r" (c->u_mode.gcm.gcm_table)); + + gfmul_pclmul_aggr4 (); + + buf += 4 * blocksize; + nblocks -= 4; + } + while (nblocks >= 4); + + /* Clear used x86-64/XMM registers. */ + asm volatile( "pxor %%xmm8, %%xmm8\n\t" + "pxor %%xmm9, %%xmm9\n\t" + "pxor %%xmm10, %%xmm10\n\t" + "pxor %%xmm11, %%xmm11\n\t" + "pxor %%xmm12, %%xmm12\n\t" + "pxor %%xmm13, %%xmm13\n\t" + "pxor %%xmm14, %%xmm14\n\t" + "pxor %%xmm15, %%xmm15\n\t" + ::: "cc" ); + } +#endif + + while (nblocks--) + { + asm volatile ("movdqu %[buf], %%xmm2\n\t" + "pshufb %[be_mask], %%xmm2\n\t" /* be => le */ + "pxor %%xmm2, %%xmm1\n\t" + : + : [buf] "m" (*buf), [be_mask] "m" (*be_mask)); + + gfmul_pclmul (); + + buf += blocksize; + } + + /* Store hash. */ + asm volatile ("pshufb %[be_mask], %%xmm1\n\t" /* be => le */ + "movdqu %%xmm1, %[hash]\n\t" + : [hash] "=m" (*result) + : [be_mask] "m" (*be_mask)); + + /* Clear used registers. */ + asm volatile( "pxor %%xmm0, %%xmm0\n\t" + "pxor %%xmm1, %%xmm1\n\t" + "pxor %%xmm2, %%xmm2\n\t" + "pxor %%xmm3, %%xmm3\n\t" + "pxor %%xmm4, %%xmm4\n\t" + "pxor %%xmm5, %%xmm5\n\t" + "pxor %%xmm6, %%xmm6\n\t" + "pxor %%xmm7, %%xmm7\n\t" + ::: "cc" ); + burn = 0; + } +#endif + else + { + 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, byte *h) +{ + if (0) + ; +#ifdef GCM_USE_INTEL_PCLMUL + else if (_gcry_get_hw_features () & HWF_INTEL_PCLMUL) + { + u64 tmp[2]; + + c->u_mode.gcm.use_intel_pclmul = 1; + + /* Swap endianness of hsub. */ + tmp[0] = buf_get_be64(c->u_mode.gcm.u_ghash_key.key + 8); + tmp[1] = buf_get_be64(c->u_mode.gcm.u_ghash_key.key + 0); + buf_cpy (c->u_mode.gcm.u_ghash_key.key, tmp, GCRY_GCM_BLOCK_LEN); + +#ifdef __x86_64__ + asm volatile ("movdqu %[h_1], %%xmm0\n\t" + "movdqa %%xmm0, %%xmm1\n\t" + : + : [h_1] "m" (*tmp)); + + gfmul_pclmul (); /* H•H => H² */ + + asm volatile ("movdqu %%xmm1, 0*16(%[h_234])\n\t" + "movdqa %%xmm1, %%xmm8\n\t" + : + : [h_234] "r" (c->u_mode.gcm.gcm_table) + : "memory"); + + gfmul_pclmul (); /* H•H² => H³ */ + + asm volatile ("movdqa %%xmm8, %%xmm0\n\t" + "movdqu %%xmm1, 1*16(%[h_234])\n\t" + "movdqa %%xmm8, %%xmm1\n\t" + : + : [h_234] "r" (c->u_mode.gcm.gcm_table) + : "memory"); + + gfmul_pclmul (); /* H²•H² => H⁴ */ + + asm volatile ("movdqu %%xmm1, 2*16(%[h_234])\n\t" + : + : [h_234] "r" (c->u_mode.gcm.gcm_table) + : "memory"); + + /* Clear used registers. */ + asm volatile( "pxor %%xmm0, %%xmm0\n\t" + "pxor %%xmm1, %%xmm1\n\t" + "pxor %%xmm2, %%xmm2\n\t" + "pxor %%xmm3, %%xmm3\n\t" + "pxor %%xmm4, %%xmm4\n\t" + "pxor %%xmm5, %%xmm5\n\t" + "pxor %%xmm6, %%xmm6\n\t" + "pxor %%xmm7, %%xmm7\n\t" + "pxor %%xmm8, %%xmm8\n\t" + ::: "cc" ); +#endif + + wipememory (tmp, sizeof(tmp)); + } +#endif + else + fillM (c, h); +} + + +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; + size_t nblocks, n; + unsigned int burn = 0; + + if (buflen == 0 && (unused == 0 || !do_padding)) + return; + + do + { + if (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) + break; + + while (unused < blocksize) + c->u_mode.gcm.macbuf[unused++] = 0; + } + + if (unused > 0) + { + gcry_assert (unused == blocksize); + + /* Process one block from macbuf. */ + burn = ghash (c, hash, c->u_mode.gcm.macbuf, 1); + unused = 0; + } + + nblocks = buflen / blocksize; + + if (nblocks) + { + burn = ghash (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); +} + + +gcry_err_code_t +_gcry_cipher_gcm_encrypt (gcry_cipher_hd_t c, + byte *outbuf, size_t outbuflen, + const byte *inbuf, size_t inbuflen) +{ + static const unsigned char zerobuf[MAX_BLOCKSIZE]; + gcry_err_code_t err; + + 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) + return GPG_ERR_INV_STATE; + + if (!c->marks.iv) + _gcry_cipher_gcm_setiv (c, zerobuf, GCRY_GCM_BLOCK_LEN); + + 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; + } + + err = _gcry_cipher_ctr_encrypt(c, outbuf, outbuflen, inbuf, inbuflen); + if (err != 0) + return err; + + do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, outbuf, inbuflen, 0); + + return 0; +} + + +gcry_err_code_t +_gcry_cipher_gcm_decrypt (gcry_cipher_hd_t c, + byte *outbuf, size_t outbuflen, + const byte *inbuf, size_t inbuflen) +{ + static const unsigned char zerobuf[MAX_BLOCKSIZE]; + + 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) + return GPG_ERR_INV_STATE; + + if (!c->marks.iv) + _gcry_cipher_gcm_setiv (c, zerobuf, GCRY_GCM_BLOCK_LEN); + + 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; + } + + do_ghash_buf(c, c->u_mode.gcm.u_tag.tag, inbuf, inbuflen, 0); + + return _gcry_cipher_ctr_encrypt(c, outbuf, outbuflen, inbuf, inbuflen); +} + + +gcry_err_code_t +_gcry_cipher_gcm_authenticate (gcry_cipher_hd_t c, + const byte * aadbuf, size_t aadbuflen) +{ + static const unsigned char zerobuf[MAX_BLOCKSIZE]; + + 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) + return GPG_ERR_INV_STATE; + + if (!c->marks.iv) + _gcry_cipher_gcm_setiv (c, zerobuf, GCRY_GCM_BLOCK_LEN); + + 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_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, c->u_mode.gcm.u_ghash_key.key); +} + + +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]; + + 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; + 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_initiv (c, iv, ivlen); +} + + +#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 gcry_err_code_t +_gcry_cipher_gcm_tag (gcry_cipher_hd_t c, + byte * outbuf, size_t outbuflen, int check) +{ + if (outbuflen < GCRY_GCM_BLOCK_LEN) + return GPG_ERR_BUFFER_TOO_SHORT; + if (c->u_mode.gcm.datalen_over_limits) + return GPG_ERR_INV_LENGTH; + + if (!c->marks.tag) + { + u32 bitlengths[2][2]; + + /* 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); + buf_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) + { + memcpy (outbuf, c->u_mode.gcm.u_tag.tag, outbuflen); + return GPG_ERR_NO_ERROR; + } + else + { + return buf_eq_const(outbuf, c->u_mode.gcm.u_tag.tag, outbuflen) ? + GPG_ERR_NO_ERROR : 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); +} |