31 lines
776 B
C
31 lines
776 B
C
/* Copyright 2015 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "dcrypto.h"
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#include "cryptoc/p256.h"
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#include "cryptoc/util.h"
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static const p256_int p256_one = P256_ONE;
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/*
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* Key selection based on FIPS-186-4, section B.4.2 (Key Pair
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* Generation by Testing Candidates).
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*/
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int DCRYPTO_p256_key_from_bytes(p256_int *x, p256_int *y, p256_int *d,
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const uint8_t key_bytes[P256_NBYTES])
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{
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p256_int key;
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p256_from_bin(key_bytes, &key);
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if (p256_cmp(&SECP256r1_nMin2, &key) < 0)
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return 0;
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p256_add(&key, &p256_one, d);
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always_memset(&key, 0, sizeof(key));
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if (x == NULL || y == NULL)
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return 1;
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return dcrypto_p256_base_point_mul(d, x, y);
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}
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