87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
/*
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* Copyright (c) 2016, Intel Corporation
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* Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <crypto/ecdh.h>
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#include <crypto/kpp.h>
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#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short))
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static inline u8 *ecdh_pack_data(void *dst, const void *src, size_t sz)
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{
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memcpy(dst, src, sz);
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return dst + sz;
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}
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static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
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{
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memcpy(dst, src, sz);
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return src + sz;
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}
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int crypto_ecdh_key_len(const struct ecdh *params)
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{
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return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
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}
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EXPORT_SYMBOL_GPL(crypto_ecdh_key_len);
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int crypto_ecdh_encode_key(char *buf, unsigned int len,
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const struct ecdh *params)
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{
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u8 *ptr = buf;
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struct kpp_secret secret = {
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.type = CRYPTO_KPP_SECRET_TYPE_ECDH,
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.len = len
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};
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if (unlikely(!buf))
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return -EINVAL;
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if (len != crypto_ecdh_key_len(params))
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return -EINVAL;
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ptr = ecdh_pack_data(ptr, &secret, sizeof(secret));
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ptr = ecdh_pack_data(ptr, ¶ms->curve_id, sizeof(params->curve_id));
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ptr = ecdh_pack_data(ptr, ¶ms->key_size, sizeof(params->key_size));
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ecdh_pack_data(ptr, params->key, params->key_size);
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return 0;
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}
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EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key);
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int crypto_ecdh_decode_key(const char *buf, unsigned int len,
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struct ecdh *params)
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{
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const u8 *ptr = buf;
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struct kpp_secret secret;
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if (unlikely(!buf || len < ECDH_KPP_SECRET_MIN_SIZE))
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return -EINVAL;
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ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret));
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if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH)
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return -EINVAL;
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ptr = ecdh_unpack_data(¶ms->curve_id, ptr, sizeof(params->curve_id));
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ptr = ecdh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size));
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if (secret.len != crypto_ecdh_key_len(params))
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return -EINVAL;
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/* Don't allocate memory. Set pointer to data
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* within the given buffer
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*/
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params->key = (void *)ptr;
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return 0;
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}
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EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key);
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