/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */ #ifndef _UECC_VLI_H_ #define _UECC_VLI_H_ #include "uECC.h" #include "types.h" /* Functions for raw large-integer manipulation. These are only available if uECC.c is compiled with uECC_ENABLE_VLI_API defined to 1. */ #ifndef uECC_ENABLE_VLI_API #define uECC_ENABLE_VLI_API 0 #endif #ifdef __cplusplus extern "C" { #endif #if uECC_ENABLE_VLI_API void uECC_vli_clear(uECC_word_t *vli, wordcount_t num_words); /* Constant-time comparison to zero - secure way to compare long integers */ /* Returns 1 if vli == 0, 0 otherwise. */ uECC_word_t uECC_vli_isZero(const uECC_word_t *vli, wordcount_t num_words); /* Returns nonzero if bit 'bit' of vli is set. */ uECC_word_t uECC_vli_testBit(const uECC_word_t *vli, bitcount_t bit); /* Counts the number of bits required to represent vli. */ bitcount_t uECC_vli_numBits(const uECC_word_t *vli, const wordcount_t max_words); /* Sets dest = src. */ void uECC_vli_set(uECC_word_t *dest, const uECC_word_t *src, wordcount_t num_words); /* Constant-time comparison function - secure way to compare long integers */ /* Returns one if left == right, zero otherwise */ uECC_word_t uECC_vli_equal(const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); /* Constant-time comparison function - secure way to compare long integers */ /* Returns sign of left - right, in constant time. */ cmpresult_t uECC_vli_cmp(const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); /* Computes vli = vli >> 1. */ void uECC_vli_rshift1(uECC_word_t *vli, wordcount_t num_words); /* Computes result = left + right, returning carry. Can modify in place. */ uECC_word_t uECC_vli_add(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); /* Computes result = left - right, returning borrow. Can modify in place. */ uECC_word_t uECC_vli_sub(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); /* Computes result = left * right. Result must be 2 * num_words long. */ void uECC_vli_mult(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, wordcount_t num_words); /* Computes result = left^2. Result must be 2 * num_words long. */ void uECC_vli_square(uECC_word_t *result, const uECC_word_t *left, wordcount_t num_words); /* Computes result = (left + right) % mod. Assumes that left < mod and right < mod, and that result does not overlap mod. */ void uECC_vli_modAdd(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, const uECC_word_t *mod, wordcount_t num_words); /* Computes result = (left - right) % mod. Assumes that left < mod and right < mod, and that result does not overlap mod. */ void uECC_vli_modSub(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, const uECC_word_t *mod, wordcount_t num_words); /* Computes result = product % mod, where product is 2N words long. Currently only designed to work for mod == curve->p or curve_n. */ void uECC_vli_mmod(uECC_word_t *result, uECC_word_t *product, const uECC_word_t *mod, wordcount_t num_words); /* Calculates result = product (mod curve->p), where product is up to 2 * curve->num_words long. */ void uECC_vli_mmod_fast(uECC_word_t *result, uECC_word_t *product, uECC_Curve curve); /* Computes result = (left * right) % mod. Currently only designed to work for mod == curve->p or curve_n. */ void uECC_vli_modMult(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, const uECC_word_t *mod, wordcount_t num_words); /* Computes result = (left * right) % curve->p. */ void uECC_vli_modMult_fast(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *right, uECC_Curve curve); /* Computes result = left^2 % mod. Currently only designed to work for mod == curve->p or curve_n. */ void uECC_vli_modSquare(uECC_word_t *result, const uECC_word_t *left, const uECC_word_t *mod, wordcount_t num_words); /* Computes result = left^2 % curve->p. */ void uECC_vli_modSquare_fast(uECC_word_t *result, const uECC_word_t *left, uECC_Curve curve); /* Computes result = (1 / input) % mod.*/ void uECC_vli_modInv(uECC_word_t *result, const uECC_word_t *input, const uECC_word_t *mod, wordcount_t num_words); #if uECC_SUPPORT_COMPRESSED_POINT /* Calculates a = sqrt(a) (mod curve->p) */ void uECC_vli_mod_sqrt(uECC_word_t *a, uECC_Curve curve); #endif /* Converts an integer in uECC native format to big-endian bytes. */ void uECC_vli_nativeToBytes(uint8_t *bytes, int num_bytes, const uECC_word_t *native); /* Converts big-endian bytes to an integer in uECC native format. */ void uECC_vli_bytesToNative(uECC_word_t *native, const uint8_t *bytes, int num_bytes); unsigned uECC_curve_num_words(uECC_Curve curve); unsigned uECC_curve_num_bytes(uECC_Curve curve); unsigned uECC_curve_num_bits(uECC_Curve curve); unsigned uECC_curve_num_n_words(uECC_Curve curve); unsigned uECC_curve_num_n_bytes(uECC_Curve curve); unsigned uECC_curve_num_n_bits(uECC_Curve curve); const uECC_word_t *uECC_curve_p(uECC_Curve curve); const uECC_word_t *uECC_curve_n(uECC_Curve curve); const uECC_word_t *uECC_curve_G(uECC_Curve curve); const uECC_word_t *uECC_curve_b(uECC_Curve curve); int uECC_valid_point(const uECC_word_t *point, uECC_Curve curve); /* Multiplies a point by a scalar. Points are represented by the X coordinate followed by the Y coordinate in the same array, both coordinates are curve->num_words long. Note that scalar must be curve->num_n_words long (NOT curve->num_words). */ void uECC_point_mult(uECC_word_t *result, const uECC_word_t *point, const uECC_word_t *scalar, uECC_Curve curve); /* Generates a random integer in the range 0 < random < top. Both random and top have num_words words. */ int uECC_generate_random_int(uECC_word_t *random, const uECC_word_t *top, wordcount_t num_words); #endif /* uECC_ENABLE_VLI_API */ #ifdef __cplusplus } /* end of extern "C" */ #endif #endif /* _UECC_VLI_H_ */