axtls_aes.c File Reference

AES algorithm. More...

#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"

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
static int	aes_setkey (void *ctx, const void *key, size_t keylen)
	Set key.
static void	aes_setiv (void *ctx __unused, const void *iv __unused)
	Set initialisation vector.
static void	aes_call_axtls (AES_CTX *axtls_ctx, const void *src, void *dst, void(*func)(const AES_CTX *axtls_ctx, uint32_t *data))
	Call AXTLS' AES_encrypt() or AES_decrypt() functions.
static void	aes_encrypt (void *ctx, const void *src, void *dst, size_t len)
	Encrypt data.
static void	aes_decrypt (void *ctx, const void *src, void *dst, size_t len)
	Decrypt data.
	CBC_CIPHER (aes_cbc, aes_cbc_algorithm, aes_algorithm, struct aes_context, AES_BLOCKSIZE)
Variables
struct cipher_algorithm	aes_algorithm
	Basic AES algorithm.

---

Detailed Description

AES algorithm.

Definition in file axtls_aes.c.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static int aes_setkey	(	void *	ctx,
		const void *	key,
		size_t	keylen
	)			[static]

Set key.

Parameters:

	ctx	Context
	key	Key
	keylen	Key length

Return values:

rc

Return status code

Definition at line 43 of file axtls_aes.c.

References AES_MODE_128, AES_MODE_256, AES_set_key(), aes_context::axtls_ctx, aes_context::decrypting, EINVAL, and aes_key_st::iv.

                                                                    {
        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;
}

static void aes_setiv	(	void *ctx	__unused,
		const void *iv	__unused
	)			[static]

Set initialisation vector.

Parameters:

	ctx	Context
	iv	Initialisation vector

Definition at line 77 of file axtls_aes.c.

                                                                      {
        /* Nothing to do */
}

static void aes_call_axtls	(	AES_CTX *	axtls_ctx,
		const void *	src,
		void *	dst,
		void(*)(const AES_CTX *axtls_ctx, uint32_t *data)	func
	)			[static]

Call AXTLS' AES_encrypt() or AES_decrypt() functions.

Parameters:

	axtls_ctx	AXTLS AES context
	src	Data to process
	dst	Buffer for output
	func	AXTLS AES function to call

Definition at line 89 of file axtls_aes.c.

References htonl, and ntohl.

Referenced by aes_decrypt(), and aes_encrypt().

                                                                 {
        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_encrypt	(	void *	ctx,
		const void *	src,
		void *	dst,
		size_t	len
	)			[static]

Encrypt data.

Parameters:

	ctx	Context
	src	Data to encrypt
	dst	Buffer for encrypted data
	len	Length of data

Definition at line 115 of file axtls_aes.c.

References AES_BLOCKSIZE, aes_call_axtls(), AES_encrypt(), assert, aes_context::axtls_ctx, and aes_context::decrypting.

                                       {
        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 );
}

static void aes_decrypt	(	void *	ctx,
		const void *	src,
		void *	dst,
		size_t	len
	)			[static]

Decrypt data.

Parameters:

	ctx	Context
	src	Data to decrypt
	dst	Buffer for decrypted data
	len	Length of data

Definition at line 133 of file axtls_aes.c.

References AES_BLOCKSIZE, aes_call_axtls(), AES_convert_key(), AES_decrypt(), assert, aes_context::axtls_ctx, and aes_context::decrypting.

                                       {
        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 );
}

CBC_CIPHER	(	aes_cbc	,
		aes_cbc_algorithm	,
		aes_algorithm	,
		struct aes_context	,
		AES_BLOCKSIZE
	)

---

Variable Documentation

struct cipher_algorithm aes_algorithm

Initial value:

 {
        .name = "aes",
        .ctxsize = sizeof ( struct aes_context ),
        .blocksize = AES_BLOCKSIZE,
        .setkey = aes_setkey,
        .setiv = aes_setiv,
        .encrypt = aes_encrypt,
        .decrypt = aes_decrypt,
}

Basic AES algorithm.

Definition at line 146 of file axtls_aes.c.

Referenced by aes_unwrap(), aes_wrap(), ccmp_cbc_mac(), ccmp_ctr_xor(), ccmp_feed_cbc_mac(), and ccmp_init().