// Copyright 2007,2008,2010 Segher Boessenkool // Licensed under the terms of the GNU GPL, version 2 // http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt // Updated and simplified for use by Kirk Engine - July 2011 #include #include // Include definitions from kirk header #include "kirk_engine.h" void bn_print(char *name, u8 *a, u32 n) { u32 i; printf("%s = ", name); for (i = 0; i < n; i++) printf("%02x", a[i]); printf("\n"); } static void bn_zero(u8 *d, u32 n) { memset(d, 0, n); } void bn_copy(u8 *d, u8 *a, u32 n) { memcpy(d, a, n); } int bn_compare(u8 *a, u8 *b, u32 n) { u32 i; for (i = 0; i < n; i++) { if (a[i] < b[i]) return -1; if (a[i] > b[i]) return 1; } return 0; } static u8 bn_add_1(u8 *d, u8 *a, u8 *b, u32 n) { u32 i; u32 dig; u8 c; c = 0; for (i = n - 1; i < n; i--) { dig = a[i] + b[i] + c; c = dig >> 8; d[i] = dig; } return c; } static u8 bn_sub_1(u8 *d, u8 *a, u8 *b, u32 n) { u32 i; u32 dig; u8 c; c = 1; for (i = n - 1; i < n; i--) { dig = a[i] + 255 - b[i] + c; c = dig >> 8; d[i] = dig; } return 1 - c; } void bn_reduce(u8 *d, u8 *N, u32 n) { if (bn_compare(d, N, n) >= 0) bn_sub_1(d, d, N, n); } void bn_add(u8 *d, u8 *a, u8 *b, u8 *N, u32 n) { if (bn_add_1(d, a, b, n)) bn_sub_1(d, d, N, n); bn_reduce(d, N, n); } void bn_sub(u8 *d, u8 *a, u8 *b, u8 *N, u32 n) { if (bn_sub_1(d, a, b, n)) bn_add_1(d, d, N, n); } static const u8 inv256[0x80] = { 0x01, 0xab, 0xcd, 0xb7, 0x39, 0xa3, 0xc5, 0xef, 0xf1, 0x1b, 0x3d, 0xa7, 0x29, 0x13, 0x35, 0xdf, 0xe1, 0x8b, 0xad, 0x97, 0x19, 0x83, 0xa5, 0xcf, 0xd1, 0xfb, 0x1d, 0x87, 0x09, 0xf3, 0x15, 0xbf, 0xc1, 0x6b, 0x8d, 0x77, 0xf9, 0x63, 0x85, 0xaf, 0xb1, 0xdb, 0xfd, 0x67, 0xe9, 0xd3, 0xf5, 0x9f, 0xa1, 0x4b, 0x6d, 0x57, 0xd9, 0x43, 0x65, 0x8f, 0x91, 0xbb, 0xdd, 0x47, 0xc9, 0xb3, 0xd5, 0x7f, 0x81, 0x2b, 0x4d, 0x37, 0xb9, 0x23, 0x45, 0x6f, 0x71, 0x9b, 0xbd, 0x27, 0xa9, 0x93, 0xb5, 0x5f, 0x61, 0x0b, 0x2d, 0x17, 0x99, 0x03, 0x25, 0x4f, 0x51, 0x7b, 0x9d, 0x07, 0x89, 0x73, 0x95, 0x3f, 0x41, 0xeb, 0x0d, 0xf7, 0x79, 0xe3, 0x05, 0x2f, 0x31, 0x5b, 0x7d, 0xe7, 0x69, 0x53, 0x75, 0x1f, 0x21, 0xcb, 0xed, 0xd7, 0x59, 0xc3, 0xe5, 0x0f, 0x11, 0x3b, 0x5d, 0xc7, 0x49, 0x33, 0x55, 0xff, }; static void bn_mon_muladd_dig(u8 *d, u8 *a, u8 b, u8 *N, u32 n) { u32 dig; u32 i; u8 z = -(d[n-1] + a[n-1]*b) * inv256[N[n-1]/2]; dig = d[n-1] + a[n-1]*b + N[n-1]*z; dig >>= 8; for (i = n - 2; i < n; i--) { dig += d[i] + a[i]*b + N[i]*z; d[i+1] = dig; dig >>= 8; } d[0] = dig; dig >>= 8; if (dig) bn_sub_1(d, d, N, n); bn_reduce(d, N, n); } void bn_mon_mul(u8 *d, u8 *a, u8 *b, u8 *N, u32 n) { u8 t[512]; u32 i; bn_zero(t, n); for (i = n - 1; i < n; i--) bn_mon_muladd_dig(t, a, b[i], N, n); bn_copy(d, t, n); } void bn_to_mon(u8 *d, u8 *N, u32 n) { u32 i; for (i = 0; i < 8*n; i++) bn_add(d, d, d, N, n); } void bn_from_mon(u8 *d, u8 *N, u32 n) { u8 t[512]; bn_zero(t, n); t[n-1] = 1; bn_mon_mul(d, d, t, N, n); } static void bn_mon_exp(u8 *d, u8 *a, u8 *N, u32 n, u8 *e, u32 en) { u8 t[512]; u32 i; u8 mask; bn_zero(d, n); d[n-1] = 1; bn_to_mon(d, N, n); for (i = 0; i < en; i++) for (mask = 0x80; mask != 0; mask >>= 1) { bn_mon_mul(t, d, d, N, n); if ((e[i] & mask) != 0) bn_mon_mul(d, t, a, N, n); else bn_copy(d, t, n); } } void bn_mon_inv(u8 *d, u8 *a, u8 *N, u32 n) { u8 t[512], s[512]; bn_zero(s, n); s[n-1] = 2; bn_sub_1(t, N, s, n); bn_mon_exp(d, a, N, n, t, n); }