/* See LICENSE file for copyright and license details. */ /* Warning: libzahl is not thread-safe. */ /* Caution: Do not use libzahl for cryptographic applications, use a specialised library. */ #ifndef ZAHL_H #define ZAHL_H 1 #include #include #include #include #include "zahl-internals.h" /* This structure should be considered opaque. */ typedef struct { int sign; #if INT_MAX != LONG_MAX int padding__; #endif size_t used; size_t alloced; zahl_char_t *chars; } z_t[1]; enum zprimality { NONPRIME = 0, /* The number is definitely composite. */ PROBABLY_PRIME, /* The number is probably prime. */ PRIME /* The number is definitely prime. */ }; enum zranddev { FAST_RANDOM = 0, /* Random numbers are generated directly from /dev/urandom. */ SECURE_RANDOM, /* Random numbers are generated directly from /dev/random. */ DEFAULT_RANDOM, /* Select the default random number generator. */ FASTEST_RANDOM, /* Select the fastest random number generator. */ LIBC_RAND_RANDOM, /* Use rand(3). */ LIBC_RANDOM_RANDOM, /* Use random(3). */ LIBC_RAND48_RANDOM /* Use lrand48(3). */ }; enum zranddist { QUASIUNIFORM = 0, /* Almost uniformly random, per the usual recommendation. */ UNIFORM, /* Actually uniformly random. */ MODUNIFORM /* Almost uniformly random, using the naïve approach of modulation. */ }; enum zerror { ZERROR_ERRNO_SET = 0, /* Please refer to errno. */ ZERROR_0_POW_0, /* Indeterminate form: 0:th power of 0. (Translatable to EDOM.) */ ZERROR_0_DIV_0, /* Indeterminate form: 0 divided by 0. (Translatable to EDOM.) */ ZERROR_DIV_0, /* Undefined result: Division by 0. (Translatable to EDOM.) */ ZERROR_NEGATIVE /* Argument must be non-negative. (Translatable to EDOM or EINVAL.) */ }; /* The parameters in the functions below are numbers a, b, c, ... */ /* Library initialisation and destruction. */ void zsetup(jmp_buf); /* Prepare libzahl for use. */ void zunsetup(void); /* Free resources used by libzahl */ /* Memory functions. */ ZAHL_INLINE void zinit(z_t); /* Prepare a for use. */ ZAHL_INLINE void zswap(z_t, z_t); /* (a, b) := (b, a) */ void zfree(z_t); /* Free resources in a. */ size_t zsave(z_t, void *); /* Store a into b (if !!b), and return number of written bytes. */ size_t zload(z_t, const void *); /* Restore a from b, and return number of read bytes. */ /* Assignment functions. */ void zset(z_t, z_t); /* a := b */ void zsetu(z_t, uint64_t); /* a := b */ ZAHL_INLINE void zseti(z_t, int64_t); /* a := b */ /* Comparison functions. */ ZAHL_INLINE int zcmp(z_t, z_t); /* signum (a - b) */ ZAHL_INLINE int zcmpu(z_t, uint64_t); /* signum (a - b) */ ZAHL_INLINE int zcmpi(z_t, int64_t); /* signum (a - b) */ ZAHL_INLINE int zcmpmag(z_t, z_t); /* signum (|a| - |b|) */ /* Arithmetic functions. */ ZAHL_INLINE void zabs(z_t, z_t); /* a := |b| */ ZAHL_INLINE void zneg(z_t, z_t); /* a := -b */ void zadd(z_t, z_t, z_t); /* a := b + c */ void zsub(z_t, z_t, z_t); /* a := b - c */ void zmul(z_t, z_t, z_t); /* a := b * c */ void zmodmul(z_t, z_t, z_t, z_t); /* a := (b * c) % d */ void zdiv(z_t, z_t, z_t); /* a := b / c */ void zdivmod(z_t, z_t, z_t, z_t); /* a := c / d, b = c % d */ void zmod(z_t, z_t, z_t); /* a := b % c */ void zsqr(z_t, z_t); /* a := b² */ void zmodsqr(z_t, z_t, z_t); /* a := b² % c */ void zpow(z_t, z_t, z_t); /* a := b ↑ c */ void zmodpow(z_t, z_t, z_t, z_t); /* a := (b ↑ c) % d */ void zpowu(z_t, z_t, unsigned long long int); void zmodpowu(z_t, z_t, unsigned long long int, z_t); /* These are used internally and may be removed in a future version. */ void zadd_unsigned(z_t, z_t, z_t); /* a := |b| + |c| */ void zsub_unsigned(z_t, z_t, z_t); /* a := |b| - |c| */ void zadd_unsigned_assign(z_t, z_t); /* a := |a| + |b| */ void zsub_nonnegative_assign(z_t, z_t); /* a := a - b, assuming a ≥ b ≥ 0 */ void zsub_positive_assign(z_t, z_t); /* a := a - b, assuming a > b > 0 */ /* Bitwise operations. */ void zand(z_t, z_t, z_t); /* a := b & c */ void zor(z_t, z_t, z_t); /* a := b | c */ void zxor(z_t, z_t, z_t); /* a := b ^ c */ void znot(z_t, z_t); /* a := ~b */ void zlsh(z_t, z_t, size_t); /* a := b << c */ void zrsh(z_t, z_t, size_t); /* a := b >> c */ void ztrunc(z_t, z_t, size_t); /* a := b & ((1 << c) - 1) */ void zsplit(z_t, z_t, z_t, size_t); /* a := c >> d, b := c - (a << d) */ ZAHL_INLINE int zbtest(z_t, size_t); /* (a >> b) & 1 */ ZAHL_INLINE size_t zlsb(z_t); /* Index of first set bit, SIZE_MAX if none are set. */ ZAHL_INLINE size_t zbits(z_t); /* ⌊log₂ |a|⌋ + 1, 1 if a = 0 */ /* If d > 0: a := b | (1 << c), if d = 0: a := b & ~(1 << c), if d < 0: a := b ^ (1 << c) */ ZAHL_INLINE void zbset(z_t, z_t, size_t, int); /* Number theory. */ ZAHL_INLINE int zeven(z_t); /* Is a even? */ ZAHL_INLINE int zodd(z_t); /* Is a odd? */ ZAHL_INLINE int zeven_nonzero(z_t); /* Is a even? Assumes a ≠ 0. */ ZAHL_INLINE int zodd_nonzero(z_t); /* Is a odd? Assumes a ≠ 0. */ ZAHL_INLINE int zzero(z_t); /* Is a zero? */ ZAHL_INLINE int zsignum(z_t); /* a/|a|, 0 if a is zero. */ void zgcd(z_t, z_t, z_t); /* a := gcd(b, c) */ /* NONPRIME if b ∉ ℙ, PROBABLY_PRIME, if b ∈ ℙ with (1 − 4↑−c) certainty, 2 if PRIME ∈ ℙ. * If NONPRIME is returned the witness of b's compositeness is stored in a. */ enum zprimality zptest(z_t, z_t, int); /* Random number generation. */ /* Pick a randomly from [0, d] ∩ ℤ. */ void zrand(z_t, enum zranddev, enum zranddist, z_t); /* String conversion. */ char *zstr(z_t, char *); /* Write a in decimal onto b. */ int zsets(z_t, const char *); /* a := b */ /* Length of a in radix b. */ size_t zstr_length(z_t, unsigned long long int); /* Error handling functions. */ enum zerror zerror(const char **); /* Return the current error code, and unless !a, a description in *a. */ void zperror(const char *); /* Identical to perror(3p) except it supports libzahl errors. */ #include "zahl-inlines.h" #endif