/**************************************************************************** * include/crypto/bn.h * This is free and unencumbered software released into the public domain. * Anyone is free to copy, modify, publish, use, compile, sell, or * distribute this software, either in source code form or as a compiled * binary, for any purpose, commercial or non-commercial, and by any * means. * In jurisdictions that recognize copyright laws, the author or authors * of this software dedicate any and all copyright interest in the * software to the public domain. We make this dedication for the benefit * of the public at large and to the detriment of our heirs and * successors. We intend this dedication to be an overt act of * relinquishment in perpetuity of all present and future rights to this * software under copyright law. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * For more information, please refer to ****************************************************************************/ #ifndef __INCLUDE_CRYPTO_BIGNUM_H #define __INCLUDE_CRYPTO_BIGNUM_H /* Big number library - arithmetic on multiple-precision unsigned integers. * * This library is an implementation of arithmetic on arbitrarily large * integers. * * The difference between this and other implementations, is that the data * structure * has optimal memory utilization (i.e. a 1024 bit integer takes up 128 bytes * RAM), * and all memory is allocated statically: no dynamic allocation for better * or worse. * * Primary goals are correctness, clarity of code and clean, portable * implementation. * Secondary goal is a memory footprint small enough to make it suitable for * use in * embedded applications. * * * The current state is correct functionality and adequate performance. * There may well be room for performance-optimizations and improvements. */ /**************************************************************************** * Included Files ****************************************************************************/ #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* This macro defines the word size in bytes of the array that constitues the * big-number data structure. */ #define WORD_SIZE 1 /* Size of big-numbers in bytes */ #define BN_ARRAY_SIZE (256 / WORD_SIZE) /* Data type of array in structure */ #define DTYPE uint8_t /* Data-type larger than DTYPE, for holding intermediate results of * calculations */ #define DTYPE_TMP uint32_t /* bitmask for getting MSB */ #define DTYPE_MSB ((DTYPE_TMP)(0x80)) /* sprintf format string */ #define SPRINTF_FORMAT_STR "%.02x" #define SSCANF_FORMAT_STR "%2hhx" /* Max value of integer type */ #define MAX_VAL ((DTYPE_TMP)0xFF) /**************************************************************************** * Public Types ****************************************************************************/ /* Data-holding structure: array of DTYPEs */ struct bn { DTYPE array[BN_ARRAY_SIZE]; }; /* Tokens returned by bignum_cmp() for value comparison */ enum { SMALLER = -1, EQUAL = 0, LARGER = 1 }; /**************************************************************************** * Public Functions Prototype ****************************************************************************/ /* Initialization functions: */ void bignum_init(FAR struct bn *n); void bignum_from_int(FAR struct bn *n, DTYPE_TMP i); int bignum_to_int(FAR struct bn *n); void bignum_from_string(FAR struct bn *n, FAR char *str, int nbytes); void bignum_to_string(FAR struct bn *n, FAR char *str, int maxsize); /* Basic arithmetic operations: */ /* c = a + b */ void bignum_add(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a - b */ void bignum_sub(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a * b */ void bignum_mul(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a / b */ void bignum_div(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a % b */ void bignum_mod(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a / b, d = a % b */ void bignum_divmod(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c, FAR struct bn *d); /* Bitwise operations: */ /* c = a & b */ void bignum_and(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a | b */ void bignum_or(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* c = a ^ b */ void bignum_xor(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* b = a << nbits */ void bignum_lshift(FAR struct bn *a, FAR struct bn *b, int nbits); /* b = a >> nbits */ void bignum_rshift(FAR struct bn *a, FAR struct bn *b, int nbits); /* Special operators and comparison */ /* Compare: returns LARGER, EQUAL or SMALLER */ int bignum_cmp(FAR struct bn *a, FAR struct bn *b); /* For comparison with zero */ int bignum_is_zero(FAR struct bn *n); /* Increment: add one to n */ void bignum_inc(FAR struct bn *n); /* Decrement: subtract one from n */ void bignum_dec(FAR struct bn *n); /* Calculate a^b -- e.g. 2^10 => 1024 */ void bignum_pow(FAR struct bn *a, FAR struct bn *b, FAR struct bn *c); /* Integer square root -- e.g. isqrt(5) => 2 */ void bignum_isqrt(FAR struct bn *a, FAR struct bn *b); /* Copy src into dst -- dst := src */ void bignum_assign(FAR struct bn *dst, FAR struct bn *src); /* CRK_EXP_MOD algorithm */ void pow_mod_faster(FAR struct bn *a, FAR struct bn *b, FAR struct bn *n, FAR struct bn *res); #endif /* __INCLUDE_CRYPTO_BIGNUM_H */