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-rw-r--r--src/crypto/axtls_aes.c231
1 files changed, 208 insertions, 23 deletions
diff --git a/src/crypto/axtls_aes.c b/src/crypto/axtls_aes.c
index a19ad3c42..04d274d35 100644
--- a/src/crypto/axtls_aes.c
+++ b/src/crypto/axtls_aes.c
@@ -1,17 +1,65 @@
-#include "crypto/axtls/crypto.h"
+/*
+ * 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.
+ */
+
#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"
-struct aes_cbc_context {
- AES_CTX ctx;
+/** @file
+ *
+ * AES algorithm
+ *
+ */
+
+/** Basic AES blocksize */
+#define AES_BLOCKSIZE 16
+
+/****************************************************************************
+ *
+ * Basic AES algorithm (independent of mode of operation)
+ *
+ ****************************************************************************
+ */
+
+/** AES context */
+struct aes_context {
+ /** AES context for AXTLS */
+ AES_CTX axtls_ctx;
+ /** Cipher is being used for decrypting */
int decrypting;
};
-static int aes_cbc_setkey ( void *ctx, const void *key, size_t keylen ) {
- struct aes_cbc_context *aesctx = ctx;
+/**
+ * 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 ):
@@ -24,45 +72,182 @@ static int aes_cbc_setkey ( void *ctx, const void *key, size_t keylen ) {
return -EINVAL;
}
- AES_set_key ( &aesctx->ctx, key, aesctx->ctx.iv, mode );
+ /* 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 );
- aesctx->decrypting = 0;
+ aes_ctx->decrypting = 0;
return 0;
}
-static void aes_cbc_setiv ( void *ctx, const void *iv ) {
- struct aes_cbc_context *aesctx = ctx;
+/**
+ * Set initialisation vector
+ *
+ * @v ctx Context
+ * @v iv Initialisation vector
+ */
+static void aes_setiv ( void *ctx __unused, const void *iv __unused ) {
+ /* Nothing to do */
+}
- memcpy ( aesctx->ctx.iv, iv, sizeof ( aesctx->ctx.iv ) );
+/**
+ * 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] );
}
-static void aes_cbc_encrypt ( void *ctx, const void *data, void *dst,
- size_t len ) {
- struct aes_cbc_context *aesctx = ctx;
+/**
+ * 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;
- if ( aesctx->decrypting )
+ 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 */
+static 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)
+ *
+ ****************************************************************************
+ */
+
+/** AES with CBC context */
+struct aes_cbc_context {
+ /** AES context */
+ struct aes_context aes_ctx;
+ /** CBC context */
+ uint8_t cbc_ctx[AES_BLOCKSIZE];
+};
+
+/**
+ * Set key
+ *
+ * @v ctx Context
+ * @v key Key
+ * @v keylen Key length
+ * @ret rc Return status code
+ */
+static int aes_cbc_setkey ( void *ctx, const void *key, size_t keylen ) {
+ struct aes_cbc_context *aes_cbc_ctx = ctx;
- AES_cbc_encrypt ( &aesctx->ctx, data, dst, len );
+ return cbc_setkey ( ctx, key, keylen, &aes_algorithm,
+ &aes_cbc_ctx->cbc_ctx );
}
-static void aes_cbc_decrypt ( void *ctx, const void *data, void *dst,
+/**
+ * Set initialisation vector
+ *
+ * @v ctx Context
+ * @v iv Initialisation vector
+ */
+static void aes_cbc_setiv ( void *ctx, const void *iv ) {
+ struct aes_cbc_context *aes_cbc_ctx = ctx;
+
+ cbc_setiv ( ctx, iv, &aes_algorithm, &aes_cbc_ctx->cbc_ctx );
+}
+
+/**
+ * Encrypt data
+ *
+ * @v ctx Context
+ * @v src Data to encrypt
+ * @v dst Buffer for encrypted data
+ * @v len Length of data
+ */
+static void aes_cbc_encrypt ( void *ctx, const void *src, void *dst,
size_t len ) {
- struct aes_cbc_context *aesctx = ctx;
+ struct aes_cbc_context *aes_cbc_ctx = ctx;
- if ( ! aesctx->decrypting ) {
- AES_convert_key ( &aesctx->ctx );
- aesctx->decrypting = 1;
- }
+ cbc_encrypt ( &aes_cbc_ctx->aes_ctx, src, dst, len,
+ &aes_algorithm, &aes_cbc_ctx->cbc_ctx );
+}
+
+/**
+ * Decrypt data
+ *
+ * @v ctx Context
+ * @v src Data to decrypt
+ * @v dst Buffer for decrypted data
+ * @v len Length of data
+ */
+static void aes_cbc_decrypt ( void *ctx, const void *src, void *dst,
+ size_t len ) {
+ struct aes_cbc_context *aes_cbc_ctx = ctx;
- AES_cbc_decrypt ( &aesctx->ctx, data, dst, len );
+ cbc_decrypt ( &aes_cbc_ctx->aes_ctx, src, dst, len,
+ &aes_algorithm, &aes_cbc_ctx->cbc_ctx );
}
+/* AES with cipher-block chaining */
struct cipher_algorithm aes_cbc_algorithm = {
.name = "aes_cbc",
.ctxsize = sizeof ( struct aes_cbc_context ),
- .blocksize = 16,
+ .blocksize = AES_BLOCKSIZE,
.setkey = aes_cbc_setkey,
.setiv = aes_cbc_setiv,
.encrypt = aes_cbc_encrypt,
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2026-02-27 17:12:58 +0100