diff options
Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/crypto/axtls_aes.c')
| -rw-r--r-- | contrib/syslinux-4.02/gpxe/src/crypto/axtls_aes.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/crypto/axtls_aes.c b/contrib/syslinux-4.02/gpxe/src/crypto/axtls_aes.c new file mode 100644 index 0000000..8bd3758 --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/crypto/axtls_aes.c @@ -0,0 +1,158 @@ +/* + * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>. + * + * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <string.h> +#include <errno.h> +#include <byteswap.h> +#include <gpxe/crypto.h> +#include <gpxe/cbc.h> +#include <gpxe/aes.h> +#include "crypto/axtls/crypto.h" + +/** @file + * + * AES algorithm + * + */ + +/** + * Set key + * + * @v ctx Context + * @v key Key + * @v keylen Key length + * @ret rc Return status code + */ +static int aes_setkey ( void *ctx, const void *key, size_t keylen ) { + struct aes_context *aes_ctx = ctx; + AES_MODE mode; + void *iv; + + switch ( keylen ) { + case ( 128 / 8 ): + mode = AES_MODE_128; + break; + case ( 256 / 8 ): + mode = AES_MODE_256; + break; + default: + return -EINVAL; + } + + /* IV is not a relevant concept at this stage; use a dummy + * value that will have no side-effects. + */ + iv = &aes_ctx->axtls_ctx.iv; + + AES_set_key ( &aes_ctx->axtls_ctx, key, iv, mode ); + + aes_ctx->decrypting = 0; + + return 0; +} + +/** + * Set initialisation vector + * + * @v ctx Context + * @v iv Initialisation vector + */ +static void aes_setiv ( void *ctx __unused, const void *iv __unused ) { + /* Nothing to do */ +} + +/** + * Call AXTLS' AES_encrypt() or AES_decrypt() functions + * + * @v axtls_ctx AXTLS AES context + * @v src Data to process + * @v dst Buffer for output + * @v func AXTLS AES function to call + */ +static void aes_call_axtls ( AES_CTX *axtls_ctx, const void *src, void *dst, + void ( * func ) ( const AES_CTX *axtls_ctx, + uint32_t *data ) ){ + const uint32_t *srcl = src; + uint32_t *dstl = dst; + unsigned int i; + + /* AXTLS' AES_encrypt() and AES_decrypt() functions both + * expect to deal with an array of four dwords in host-endian + * order. + */ + for ( i = 0 ; i < 4 ; i++ ) + dstl[i] = ntohl ( srcl[i] ); + func ( axtls_ctx, dstl ); + for ( i = 0 ; i < 4 ; i++ ) + dstl[i] = htonl ( dstl[i] ); +} + +/** + * Encrypt data + * + * @v ctx Context + * @v src Data to encrypt + * @v dst Buffer for encrypted data + * @v len Length of data + */ +static void aes_encrypt ( void *ctx, const void *src, void *dst, + size_t len ) { + struct aes_context *aes_ctx = ctx; + + assert ( len == AES_BLOCKSIZE ); + if ( aes_ctx->decrypting ) + assert ( 0 ); + aes_call_axtls ( &aes_ctx->axtls_ctx, src, dst, AES_encrypt ); +} + +/** + * Decrypt data + * + * @v ctx Context + * @v src Data to decrypt + * @v dst Buffer for decrypted data + * @v len Length of data + */ +static void aes_decrypt ( void *ctx, const void *src, void *dst, + size_t len ) { + struct aes_context *aes_ctx = ctx; + + assert ( len == AES_BLOCKSIZE ); + if ( ! aes_ctx->decrypting ) { + AES_convert_key ( &aes_ctx->axtls_ctx ); + aes_ctx->decrypting = 1; + } + aes_call_axtls ( &aes_ctx->axtls_ctx, src, dst, AES_decrypt ); +} + +/** Basic AES algorithm */ +struct cipher_algorithm aes_algorithm = { + .name = "aes", + .ctxsize = sizeof ( struct aes_context ), + .blocksize = AES_BLOCKSIZE, + .setkey = aes_setkey, + .setiv = aes_setiv, + .encrypt = aes_encrypt, + .decrypt = aes_decrypt, +}; + +/* AES with cipher-block chaining */ +CBC_CIPHER ( aes_cbc, aes_cbc_algorithm, + aes_algorithm, struct aes_context, AES_BLOCKSIZE ); |