Hannes Tschofenig
/
aes-gcm-test-program
Example program to test AES-GCM functionality. Used for a workshop
Diff: SSL/include/polarssl/gcm.h
- Revision:
- 0:796d0f61a05b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/SSL/include/polarssl/gcm.h Thu Sep 27 06:34:22 2018 +0000 @@ -0,0 +1,221 @@ +/** + * \file gcm.h + * + * \brief Galois/Counter mode for 128-bit block ciphers + * + * Copyright (C) 2006-2013, 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. + */ +#ifndef POLARSSL_GCM_H +#define POLARSSL_GCM_H + +#include "cipher.h" + +#if defined(_MSC_VER) && !defined(EFIX64) && !defined(EFI32) +#include <basetsd.h> +typedef UINT32 uint32_t; +typedef UINT64 uint64_t; +#else +#include <stdint.h> +#endif + +#define GCM_ENCRYPT 1 +#define GCM_DECRYPT 0 + +#define POLARSSL_ERR_GCM_AUTH_FAILED -0x0012 /**< Authenticated decryption failed. */ +#define POLARSSL_ERR_GCM_BAD_INPUT -0x0014 /**< Bad input parameters to function. */ + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \brief GCM context structure + */ +typedef struct { + cipher_context_t cipher_ctx;/*!< cipher context used */ + uint64_t HL[16]; /*!< Precalculated HTable */ + uint64_t HH[16]; /*!< Precalculated HTable */ + uint64_t len; /*!< Total data length */ + uint64_t add_len; /*!< Total add length */ + unsigned char base_ectr[16];/*!< First ECTR for tag */ + unsigned char y[16]; /*!< Y working value */ + unsigned char buf[16]; /*!< buf working value */ + int mode; /*!< Encrypt or Decrypt */ +} +gcm_context; + +/** + * \brief GCM initialization (encryption) + * + * \param ctx GCM context to be initialized + * \param cipher cipher to use (a 128-bit block cipher) + * \param key encryption key + * \param keysize must be 128, 192 or 256 + * + * \return 0 if successful, or a cipher specific error code + */ +int gcm_init( gcm_context *ctx, cipher_id_t cipher, const unsigned char *key, + unsigned int keysize ); + +/** + * \brief GCM buffer encryption/decryption using a block cipher + * + * \note On encryption, the output buffer can be the same as the input buffer. + * On decryption, the output buffer cannot be the same as input buffer. + * If buffers overlap, the output buffer must trail at least 8 bytes + * behind the input buffer. + * + * \param ctx GCM context + * \param mode GCM_ENCRYPT or GCM_DECRYPT + * \param length length of the input data + * \param iv initialization vector + * \param iv_len length of IV + * \param add additional data + * \param add_len length of additional data + * \param input buffer holding the input data + * \param output buffer for holding the output data + * \param tag_len length of the tag to generate + * \param tag buffer for holding the tag + * + * \return 0 if successful + */ +int gcm_crypt_and_tag( gcm_context *ctx, + int mode, + size_t length, + const unsigned char *iv, + size_t iv_len, + const unsigned char *add, + size_t add_len, + const unsigned char *input, + unsigned char *output, + size_t tag_len, + unsigned char *tag ); + +/** + * \brief GCM buffer authenticated decryption using a block cipher + * + * \note On decryption, the output buffer cannot be the same as input buffer. + * If buffers overlap, the output buffer must trail at least 8 bytes + * behind the input buffer. + * + * \param ctx GCM context + * \param length length of the input data + * \param iv initialization vector + * \param iv_len length of IV + * \param add additional data + * \param add_len length of additional data + * \param tag buffer holding the tag + * \param tag_len length of the tag + * \param input buffer holding the input data + * \param output buffer for holding the output data + * + * \return 0 if successful and authenticated, + * POLARSSL_ERR_GCM_AUTH_FAILED if tag does not match + */ +int gcm_auth_decrypt( gcm_context *ctx, + size_t length, + const unsigned char *iv, + size_t iv_len, + const unsigned char *add, + size_t add_len, + const unsigned char *tag, + size_t tag_len, + const unsigned char *input, + unsigned char *output ); + +/** + * \brief Generic GCM stream start function + * + * \param ctx GCM context + * \param mode GCM_ENCRYPT or GCM_DECRYPT + * \param iv initialization vector + * \param iv_len length of IV + * \param add additional data (or NULL if length is 0) + * \param add_len length of additional data + * + * \return 0 if successful + */ +int gcm_starts( gcm_context *ctx, + int mode, + const unsigned char *iv, + size_t iv_len, + const unsigned char *add, + size_t add_len ); + +/** + * \brief Generic GCM update function. Encrypts/decrypts using the + * given GCM context. Expects input to be a multiple of 16 + * bytes! Only the last call before gcm_finish() can be less + * than 16 bytes! + * + * \note On decryption, the output buffer cannot be the same as input buffer. + * If buffers overlap, the output buffer must trail at least 8 bytes + * behind the input buffer. + * + * \param ctx GCM context + * \param length length of the input data + * \param input buffer holding the input data + * \param output buffer for holding the output data + * + * \return 0 if successful or POLARSSL_ERR_GCM_BAD_INPUT + */ +int gcm_update( gcm_context *ctx, + size_t length, + const unsigned char *input, + unsigned char *output ); + +/** + * \brief Generic GCM finalisation function. Wraps up the GCM stream + * and generates the tag. The tag can have a maximum length of + * 16 bytes. + * + * \param ctx GCM context + * \param tag buffer for holding the tag (may be NULL if tag_len is 0) + * \param tag_len length of the tag to generate + * + * \return 0 if successful or POLARSSL_ERR_GCM_BAD_INPUT + */ +int gcm_finish( gcm_context *ctx, + unsigned char *tag, + size_t tag_len ); + +/** + * \brief Free a GCM context and underlying cipher sub-context + * + * \param ctx GCM context to free + */ +void gcm_free( gcm_context *ctx ); + +/** + * \brief Checkup routine + * + * \return 0 if successful, or 1 if the test failed + */ +int gcm_self_test( int verbose ); + +#ifdef __cplusplus +} +#endif + +#endif /* gcm.h */ + +