69 lines
1.5 KiB
C
69 lines
1.5 KiB
C
#include <stdio.h>
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#include <string.h>
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#include <stddef.h>
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#include <sys/types.h>
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#include <freeswan.h>
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#include "constants.h"
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#include "defs.h"
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#include "log.h"
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#include "libaes/aes_cbc.h"
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#include "alg_info.h"
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#include "ike_alg.h"
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#define AES_CBC_BLOCK_SIZE (128/BITS_PER_BYTE)
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#define AES_KEY_MIN_LEN 128
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#define AES_KEY_DEF_LEN 128
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#define AES_KEY_MAX_LEN 256
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static void
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do_aes(u_int8_t *buf, size_t buf_len, u_int8_t *key, size_t key_size, u_int8_t *iv, bool enc)
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{
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aes_context aes_ctx;
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char iv_bak[AES_CBC_BLOCK_SIZE];
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char *new_iv = NULL; /* logic will avoid copy to NULL */
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aes_set_key(&aes_ctx, key, key_size, 0);
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/*
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* my AES cbc does not touch passed IV (optimization for
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* ESP handling), so I must "emulate" des-like IV
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* crunching
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*/
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if (!enc)
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memcpy(new_iv=iv_bak, (char*) buf + buf_len - AES_CBC_BLOCK_SIZE
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, AES_CBC_BLOCK_SIZE);
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AES_cbc_encrypt(&aes_ctx, buf, buf, buf_len, iv, enc);
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if (enc)
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new_iv = (char*) buf + buf_len-AES_CBC_BLOCK_SIZE;
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memcpy(iv, new_iv, AES_CBC_BLOCK_SIZE);
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}
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struct encrypt_desc algo_aes =
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{
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algo_type: IKE_ALG_ENCRYPT,
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algo_id: OAKLEY_AES_CBC,
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algo_next: NULL,
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enc_ctxsize: sizeof(aes_context),
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enc_blocksize: AES_CBC_BLOCK_SIZE,
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keyminlen: AES_KEY_MIN_LEN,
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keydeflen: AES_KEY_DEF_LEN,
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keymaxlen: AES_KEY_MAX_LEN,
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do_crypt: do_aes,
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};
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int ike_alg_aes_init(void);
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int
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ike_alg_aes_init(void)
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{
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int ret = ike_alg_register_enc(&algo_aes);
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return ret;
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}
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/*
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IKE_ALG_INIT_NAME: ike_alg_aes_init
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*/
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