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author | 2015-09-04 07:35:06 +0000 | |
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committer | 2015-09-04 07:35:06 +0000 | |
commit | ca6aa8198d2335f8c326c3dd4d26bf5899064214 (patch) | |
tree | 6274a2d971fc0cac0896efe8583927d0190e3d20 /moon-abe/pbc-0.5.14/ecc/mpc.c | |
parent | 92fd2dbfb672d7b2b1cdfd5dd5cf89f7716b3e12 (diff) | |
parent | 3baeb11a8fbcfcdbc31976d421f17b85503b3ecd (diff) |
Merge "init attribute-based encryption"
Diffstat (limited to 'moon-abe/pbc-0.5.14/ecc/mpc.c')
-rw-r--r-- | moon-abe/pbc-0.5.14/ecc/mpc.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/moon-abe/pbc-0.5.14/ecc/mpc.c b/moon-abe/pbc-0.5.14/ecc/mpc.c new file mode 100644 index 00000000..e5341f99 --- /dev/null +++ b/moon-abe/pbc-0.5.14/ecc/mpc.c @@ -0,0 +1,122 @@ +//GMP based complex floats +#include <stdio.h> +#include <gmp.h> +#include "mpc.h" + +//(a+bi)(c+di) = ac - bd + ((a+b)(c+d) - ac - bd)i +void mpc_mul(mpc_t res, mpc_t z0, mpc_t z1) +{ + mpf_t ac, bd, f0; + mpf_init(ac); + mpf_init(bd); + mpf_init(f0); + mpf_mul(ac, z0->a, z1->a); + mpf_mul(bd, z0->b, z1->b); + mpf_add(f0, z0->a, z0->b); + mpf_add(res->b, z1->a, z1->b); + mpf_mul(res->b, res->b, f0); + mpf_sub(res->b, res->b, ac); + mpf_sub(res->b, res->b, bd); + mpf_sub(res->a, ac, bd); + mpf_clear(f0); + mpf_clear(ac); + mpf_clear(bd); +} + +void mpc_mul_2exp(mpc_t res, mpc_t z, unsigned long int e) +{ + mpf_mul_2exp(res->a, z->a, e); + mpf_mul_2exp(res->b, z->b, e); +} + +//(a+bi)^2 = (a-b)(a+b) + 2abi +void mpc_sqr(mpc_t res, mpc_t z) +{ + mpf_t f0, f1; + mpf_init(f0); + mpf_init(f1); + mpf_add(f0, z->a, z->b); + mpf_sub(f1, z->a, z->b); + mpf_mul(f0, f0, f1); + mpf_mul(f1, z->a, z->b); + mpf_set(res->a, f0); + mpf_add(res->b, f1, f1); + mpf_clear(f0); + mpf_clear(f1); +} + +//1/(a+bi) = (1/(a^2 + b^2))(a-bi) +//naive. TODO: use one that is less prone to (over/under)flows/precision loss +void mpc_inv(mpc_t res, mpc_t z) +{ + mpf_t f0, f1; + mpf_init(f0); + mpf_init(f1); + mpf_mul(f0, z->a, z->a); + mpf_mul(f1, z->b, z->b); + mpf_add(f0, f0, f1); + mpf_ui_div(f0, 1, f0); + mpf_mul(res->a, z->a, f0); + mpf_neg(f0, f0); + mpf_mul(res->b, z->b, f0); + mpf_clear(f0); + mpf_clear(f1); +} + +void mpc_div(mpc_t res, mpc_t z0, mpc_t z1) +{ + mpc_t c0; + mpc_init(c0); + mpc_inv(c0, z1); + mpc_mul(res, z0, c0); + mpc_clear(c0); +} + +size_t mpc_out_str(FILE *stream, int base, size_t n_digits, mpc_t op) +{ + size_t result, status; + result = mpf_out_str(stream, base, n_digits, op->a); + if (!result) return 0; + if (mpf_sgn(op->b) >= 0) { + if (EOF == fputc('+', stream)) return 0; + result++; + } + status = mpf_out_str(stream, base, n_digits, op->b); + if (!status) return 0; + if (EOF == fputc('i', stream)) return 0; + return result + status + 1; +} + +void mpc_pow_ui(mpc_t res, mpc_t z, unsigned int n) +{ + unsigned int m; + mpc_t z0; + mpc_init(z0); + + //set m to biggest power of 2 less than n + for (m = 1; m <= n; m <<= 1); + m >>= 1; + + mpf_set_ui(z0->a, 1); + mpf_set_ui(z0->b, 0); + while (m) { + mpc_mul(z0, z0, z0); + if (m & n) { + mpc_mul(z0, z0, z); + } + m >>= 1; + } + mpc_set(res, z0); + mpc_clear(z0); +} + +void mpc_muli(mpc_t res, mpc_t z) +{ + //i(a+bi) = -b + ai + mpf_t f0; + mpf_init(f0); + mpf_neg(f0, z->b); + mpf_set(res->b, z->a); + mpf_set(res->a, f0); + mpf_clear(f0); +} |