52 lines
1.6 KiB
C
52 lines
1.6 KiB
C
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/* Edwards curve signature system
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* Daniel Beer <dlbeer@gmail.com>, 22 Apr 2014
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*
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* This file is in the public domain.
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*/
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#ifndef EDSIGN_H_
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#define EDSIGN_H_
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#include <stdint.h>
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#include <stddef.h>
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/* This is the Ed25519 signature system, as described in:
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*
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* Daniel J. Bernstein, Niels Duif, Tanja Lange, Peter Schwabe, Bo-Yin
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* Yang. High-speed high-security signatures. Journal of Cryptographic
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* Engineering 2 (2012), 77-89. Document ID:
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* a1a62a2f76d23f65d622484ddd09caf8. URL:
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* http://cr.yp.to/papers.html#ed25519. Date: 2011.09.26.
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*
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* The format and calculation of signatures is compatible with the
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* Ed25519 implementation in SUPERCOP. Note, however, that our secret
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* keys are half the size: we don't store a copy of the public key in
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* the secret key (we generate it on demand).
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*/
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/* Any string of 32 random bytes is a valid secret key. There is no
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* clamping of bits, because we don't use the key directly as an
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* exponent (the exponent is derived from part of a key expansion).
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*/
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#define EDSIGN_SECRET_KEY_SIZE 32
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/* Given a secret key, produce the public key (a packed Edwards-curve
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* point).
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*/
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#define EDSIGN_PUBLIC_KEY_SIZE 32
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void edsign_sec_to_pub(uint8_t *pub, const uint8_t *secret);
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/* Produce a signature for a message. */
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#define EDSIGN_SIGNATURE_SIZE 64
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void edsign_sign(uint8_t *signature, const uint8_t *pub,
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const uint8_t *secret,
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const uint8_t *message, size_t len);
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/* Verify a message signature. Returns non-zero if ok. */
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uint8_t edsign_verify(const uint8_t *signature, const uint8_t *pub,
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const uint8_t *message, size_t len);
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#endif
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