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Diffstat (limited to 'src/secp256k1/src/ecmult.h')
-rw-r--r-- | src/secp256k1/src/ecmult.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/src/secp256k1/src/ecmult.h b/src/secp256k1/src/ecmult.h new file mode 100644 index 0000000000..c9b198239d --- /dev/null +++ b/src/secp256k1/src/ecmult.h @@ -0,0 +1,48 @@ +/********************************************************************** + * Copyright (c) 2013, 2014, 2017 Pieter Wuille, Andrew Poelstra * + * Distributed under the MIT software license, see the accompanying * + * file COPYING or http://www.opensource.org/licenses/mit-license.php.* + **********************************************************************/ + +#ifndef SECP256K1_ECMULT_H +#define SECP256K1_ECMULT_H + +#include "num.h" +#include "group.h" +#include "scalar.h" +#include "scratch.h" + +typedef struct { + /* For accelerating the computation of a*P + b*G: */ + secp256k1_ge_storage (*pre_g)[]; /* odd multiples of the generator */ +#ifdef USE_ENDOMORPHISM + secp256k1_ge_storage (*pre_g_128)[]; /* odd multiples of 2^128*generator */ +#endif +} secp256k1_ecmult_context; + +static const size_t SECP256K1_ECMULT_CONTEXT_PREALLOCATED_SIZE; +static void secp256k1_ecmult_context_init(secp256k1_ecmult_context *ctx); +static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, void **prealloc); +static void secp256k1_ecmult_context_finalize_memcpy(secp256k1_ecmult_context *dst, const secp256k1_ecmult_context *src); +static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context *ctx); +static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context *ctx); + +/** Double multiply: R = na*A + ng*G */ +static void secp256k1_ecmult(const secp256k1_ecmult_context *ctx, secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_scalar *na, const secp256k1_scalar *ng); + +typedef int (secp256k1_ecmult_multi_callback)(secp256k1_scalar *sc, secp256k1_ge *pt, size_t idx, void *data); + +/** + * Multi-multiply: R = inp_g_sc * G + sum_i ni * Ai. + * Chooses the right algorithm for a given number of points and scratch space + * size. Resets and overwrites the given scratch space. If the points do not + * fit in the scratch space the algorithm is repeatedly run with batches of + * points. If no scratch space is given then a simple algorithm is used that + * simply multiplies the points with the corresponding scalars and adds them up. + * Returns: 1 on success (including when inp_g_sc is NULL and n is 0) + * 0 if there is not enough scratch space for a single point or + * callback returns 0 + */ +static int secp256k1_ecmult_multi_var(const secp256k1_callback* error_callback, const secp256k1_ecmult_context *ctx, secp256k1_scratch *scratch, secp256k1_gej *r, const secp256k1_scalar *inp_g_sc, secp256k1_ecmult_multi_callback cb, void *cbdata, size_t n); + +#endif /* SECP256K1_ECMULT_H */ |