1 /** 2 * \file gcm.h 3 * 4 * \brief This file contains GCM definitions and functions. 5 * 6 * The Galois/Counter Mode (GCM) for 128-bit block ciphers is defined 7 * in <em>D. McGrew, J. Viega, The Galois/Counter Mode of Operation 8 * (GCM), Natl. Inst. Stand. Technol.</em> 9 * 10 * For more information on GCM, see <em>NIST SP 800-38D: Recommendation for 11 * Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC</em>. 12 * 13 */ 14 /* 15 * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved 16 * SPDX-License-Identifier: Apache-2.0 17 * 18 * Licensed under the Apache License, Version 2.0 (the "License"); you may 19 * not use this file except in compliance with the License. 20 * You may obtain a copy of the License at 21 * 22 * http://www.apache.org/licenses/LICENSE-2.0 23 * 24 * Unless required by applicable law or agreed to in writing, software 25 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 26 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 27 * See the License for the specific language governing permissions and 28 * limitations under the License. 29 * 30 * This file is part of Mbed TLS (https://tls.mbed.org) 31 */ 32 33 #ifndef MBEDTLS_GCM_ALT_H 34 #define MBEDTLS_GCM_ALT_H 35 36 #if defined(MBEDTLS_GCM_ALT) 37 38 /** 39 * \brief The GCM context structure. 40 */ 41 typedef struct mbedtls_gcm_context 42 { 43 mbedtls_cipher_context_t cipher_ctx; /*!< The cipher context used. */ 44 uint64_t HL[16]; /*!< Precalculated HTable low. */ 45 uint64_t HH[16]; /*!< Precalculated HTable high. */ 46 uint64_t len; /*!< The total length of the encrypted data. */ 47 uint64_t add_len; /*!< The total length of the additional data. */ 48 unsigned char base_ectr[16]; /*!< The first ECTR for tag. */ 49 unsigned char y[16]; /*!< The Y working value. */ 50 unsigned char buf[16]; /*!< The buf working value. */ 51 int mode; /*!< The operation to perform: 52 #MBEDTLS_GCM_ENCRYPT or 53 #MBEDTLS_GCM_DECRYPT. */ 54 } 55 mbedtls_gcm_context; 56 57 #endif /* !MBEDTLS_GCM_ALT */ 58 59 #endif /* gcm_alt.h */ 60