71 lines
1.7 KiB
C
71 lines
1.7 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 "libserpent/serpent_cbc.h"
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#include "alg_info.h"
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#include "ike_alg.h"
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#define SERPENT_CBC_BLOCK_SIZE (128/BITS_PER_BYTE)
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#define SERPENT_KEY_MIN_LEN 128
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#define SERPENT_KEY_DEF_LEN 128
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#define SERPENT_KEY_MAX_LEN 256
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static void
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do_serpent(u_int8_t *buf, size_t buf_size, u_int8_t *key, size_t key_size, u_int8_t *iv, bool enc)
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{
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serpent_context serpent_ctx;
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char iv_bak[SERPENT_CBC_BLOCK_SIZE];
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char *new_iv = NULL; /* logic will avoid copy to NULL */
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serpent_set_key(&serpent_ctx, key, key_size);
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/*
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* my SERPENT 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,
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(char*) buf + buf_size-SERPENT_CBC_BLOCK_SIZE,
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SERPENT_CBC_BLOCK_SIZE);
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serpent_cbc_encrypt(&serpent_ctx, buf, buf, buf_size, iv, enc);
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if (enc)
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new_iv = (char*) buf + buf_size-SERPENT_CBC_BLOCK_SIZE;
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memcpy(iv, new_iv, SERPENT_CBC_BLOCK_SIZE);
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}
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struct encrypt_desc encrypt_desc_serpent =
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{
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algo_type: IKE_ALG_ENCRYPT,
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algo_id: OAKLEY_SERPENT_CBC,
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algo_next: NULL,
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enc_ctxsize: sizeof(struct serpent_context),
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enc_blocksize: SERPENT_CBC_BLOCK_SIZE,
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keyminlen: SERPENT_KEY_MIN_LEN,
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keydeflen: SERPENT_KEY_DEF_LEN,
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keymaxlen: SERPENT_KEY_MAX_LEN,
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do_crypt: do_serpent,
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};
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int ike_alg_serpent_init(void);
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int
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ike_alg_serpent_init(void)
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{
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int ret = ike_alg_register_enc(&encrypt_desc_serpent);
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return ret;
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}
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/*
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IKE_ALG_INIT_NAME: ike_alg_serpent_init
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*/
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