diff options
Diffstat (limited to 'libtommath/bn_mp_prime_is_prime.c')
-rw-r--r-- | libtommath/bn_mp_prime_is_prime.c | 105 |
1 files changed, 25 insertions, 80 deletions
diff --git a/libtommath/bn_mp_prime_is_prime.c b/libtommath/bn_mp_prime_is_prime.c index 6af5c2c..7f9fc0b 100644 --- a/libtommath/bn_mp_prime_is_prime.c +++ b/libtommath/bn_mp_prime_is_prime.c @@ -1,16 +1,7 @@ #include "tommath_private.h" #ifdef BN_MP_PRIME_IS_PRIME_C -/* LibTomMath, multiple-precision integer library -- Tom St Denis - * - * LibTomMath is a library that provides multiple-precision - * integer arithmetic as well as number theoretic functionality. - * - * The library was designed directly after the MPI library by - * Michael Fromberger but has been written from scratch with - * additional optimizations in place. - * - * SPDX-License-Identifier: Unlicense - */ +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ /* portable integer log of two with small footprint */ static unsigned int s_floor_ilog2(int value) @@ -23,61 +14,58 @@ static unsigned int s_floor_ilog2(int value) } -int mp_prime_is_prime(const mp_int *a, int t, int *result) +mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result) { mp_int b; - int ix, err, res, p_max = 0, size_a, len; + int ix, p_max = 0, size_a, len; + mp_bool res; + mp_err err; unsigned int fips_rand, mask; /* default to no */ *result = MP_NO; - /* valid value of t? */ - if (t > PRIME_SIZE) { - return MP_VAL; - } - /* Some shortcuts */ /* N > 3 */ if (a->used == 1) { if ((a->dp[0] == 0u) || (a->dp[0] == 1u)) { - *result = 0; + *result = MP_NO; return MP_OKAY; } if (a->dp[0] == 2u) { - *result = 1; + *result = MP_YES; return MP_OKAY; } } /* N must be odd */ - if (mp_iseven(a) == MP_YES) { + if (MP_IS_EVEN(a)) { return MP_OKAY; } /* N is not a perfect square: floor(sqrt(N))^2 != N */ if ((err = mp_is_square(a, &res)) != MP_OKAY) { return err; } - if (res != 0) { + if (res != MP_NO) { return MP_OKAY; } /* is the input equal to one of the primes in the table? */ - for (ix = 0; ix < PRIME_SIZE; ix++) { - if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) { + for (ix = 0; ix < PRIVATE_MP_PRIME_TAB_SIZE; ix++) { + if (mp_cmp_d(a, s_mp_prime_tab[ix]) == MP_EQ) { *result = MP_YES; return MP_OKAY; } } #ifdef MP_8BIT /* The search in the loop above was exhaustive in this case */ - if ((a->used == 1) && (PRIME_SIZE >= 31)) { + if ((a->used == 1) && (PRIVATE_MP_PRIME_TAB_SIZE >= 31)) { return MP_OKAY; } #endif /* first perform trial division */ - if ((err = mp_prime_is_divisible(a, &res)) != MP_OKAY) { + if ((err = s_mp_prime_is_divisible(a, &res)) != MP_OKAY) { return err; } @@ -114,10 +102,10 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result) /* * Both, the Frobenius-Underwood test and the the Lucas-Selfridge test are quite - * slow so if speed is an issue, define LTM_USE_FIPS_ONLY to use M-R tests with + * slow so if speed is an issue, define LTM_USE_ONLY_MR to use M-R tests with * bases 2, 3 and t random bases. */ -#ifndef LTM_USE_FIPS_ONLY +#ifndef LTM_USE_ONLY_MR if (t >= 0) { /* * Use a Frobenius-Underwood test instead of the Lucas-Selfridge test for @@ -149,44 +137,14 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result) } /* - abs(t) extra rounds of M-R to extend the range of primes it can find if t < 0. Only recommended if the input range is known to be < 3317044064679887385961981 - It uses the bases for a deterministic M-R test if input < 3317044064679887385961981 + It uses the bases necessary for a deterministic M-R test if the input is + smaller than 3317044064679887385961981 The caller has to check the size. - - Not for cryptographic use because with known bases strong M-R pseudoprimes can - be constructed. Use at least one M-R test with a random base (t >= 1). - - The 1119 bit large number - - 80383745745363949125707961434194210813883768828755814583748891752229742737653\ - 33652186502336163960045457915042023603208766569966760987284043965408232928738\ - 79185086916685732826776177102938969773947016708230428687109997439976544144845\ - 34115587245063340927902227529622941498423068816854043264575340183297861112989\ - 60644845216191652872597534901 - - has been constructed by F. Arnault (F. Arnault, "Rabin-Miller primality test: - composite numbers which pass it.", Mathematics of Computation, 1995, 64. Jg., - Nr. 209, S. 355-361), is a semiprime with the two factors - - 40095821663949960541830645208454685300518816604113250877450620473800321707011\ - 96242716223191597219733582163165085358166969145233813917169287527980445796800\ - 452592031836601 - - 20047910831974980270915322604227342650259408302056625438725310236900160853505\ - 98121358111595798609866791081582542679083484572616906958584643763990222898400\ - 226296015918301 - - and it is a strong pseudoprime to all forty-six prime M-R bases up to 200 - - It does not fail the strong Bailley-PSP test as implemented here, it is just - given as an example, if not the reason to use the BPSW-test instead of M-R-tests - with a sequence of primes 2...n. - + TODO: can be made a bit finer grained but comparing is not free. */ if (t < 0) { - t = -t; /* Sorenson, Jonathan; Webster, Jonathan (2015). "Strong Pseudoprimes to Twelve Prime Bases". @@ -212,18 +170,9 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result) } } - /* for compatibility with the current API (well, compatible within a sign's width) */ - if (p_max < t) { - p_max = t; - } - - if (p_max > PRIME_SIZE) { - err = MP_VAL; - goto LBL_B; - } /* we did bases 2 and 3 already, skip them */ for (ix = 2; ix < p_max; ix++) { - mp_set(&b, ltm_prime_tab[ix]); + mp_set(&b, s_mp_prime_tab[ix]); if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) { goto LBL_B; } @@ -296,19 +245,19 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result) * One 8-bit digit is too small, so concatenate two if the size of * unsigned int allows for it. */ - if (((sizeof(unsigned int) * CHAR_BIT)/2) >= (sizeof(mp_digit) * CHAR_BIT)) { + if ((MP_SIZEOF_BITS(unsigned int)/2) >= MP_SIZEOF_BITS(mp_digit)) { if ((err = mp_rand(&b, 1)) != MP_OKAY) { goto LBL_B; } - fips_rand <<= sizeof(mp_digit) * CHAR_BIT; + fips_rand <<= MP_SIZEOF_BITS(mp_digit); fips_rand |= (unsigned int) b.dp[0]; fips_rand &= mask; } #endif - if (fips_rand > (unsigned int)(INT_MAX - DIGIT_BIT)) { - len = INT_MAX / DIGIT_BIT; + if (fips_rand > (unsigned int)(INT_MAX - MP_DIGIT_BIT)) { + len = INT_MAX / MP_DIGIT_BIT; } else { - len = (((int)fips_rand + DIGIT_BIT) / DIGIT_BIT); + len = (((int)fips_rand + MP_DIGIT_BIT) / MP_DIGIT_BIT); } /* Unlikely. */ if (len < 0) { @@ -363,7 +312,3 @@ LBL_B: } #endif - -/* ref: HEAD -> master, tag: v1.1.0 */ -/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ -/* commit time: 2019-01-28 20:32:32 +0100 */ |