#include "crypto_decode_1013x7177.h" /* auto-generated; do not edit */ #define int16 int16_t #define uint16 uint16_t #define uint32 uint32_t #define uint64 uint64_t /* CPU division instruction typically takes time depending on x. This software is designed to take time independent of x. Time still varies depending on m; user must ensure that m is constant. Time also varies on CPUs where multiplication is variable-time. There could be more CPU issues. There could also be compiler issues. */ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) { uint32 v = 0x80000000; uint32 qpart; uint32 mask; v /= m; /* caller guarantees m > 0 */ /* caller guarantees m < 16384 */ /* vm <= 2^31 <= vm+m-1 */ /* xvm <= 2^31 x <= xvm+x(m-1) */ *q = 0; qpart = (uint32) ((x * (uint64)v) >> 31); /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */ /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */ /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */ /* 0 <= 2^31 newx <= (2^31-1)m + x(m-1) */ /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */ /* 0 <= newx <= (1-1/2^31)(2^14-1) + (2^32-1)((2^14-1)-1)/2^31 */ x -= qpart * m; *q += qpart; /* x <= 49146 */ qpart = (uint32) ((x * (uint64)v) >> 31); /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */ /* 0 <= newx <= m + 49146(2^14-1)/2^31 */ /* 0 <= newx <= m + 0.4 */ /* 0 <= newx <= m */ x -= qpart * m; *q += qpart; /* x <= m */ x -= m; *q += 1; mask = (~(x >> 31) + 1); x += mask & (uint32)m; *q += mask; /* x < m */ *r = (uint16) x; } static uint16 uint32_mod_uint14(uint32 x, uint16 m) { uint32 q; uint16 r; uint32_divmod_uint14(&q, &r, x, m); return r; } void PQCLEAN_SNTRUP1013_CLEAN_crypto_decode_1013x7177(void *v, const unsigned char *s) { int16 *R0 = v; uint16 R1[507], R2[254], R3[127], R4[64], R5[32], R6[16], R7[8], R8[4], R9[2], R10[1]; long long i; uint16 r0; uint32 r1, r2; s += PQCLEAN_SNTRUP1013_CLEAN_crypto_decode_1013x7177_STRBYTES; r1 = 0; r1 = (r1 << 8) | *--s; r1 = (r1 << 8) | *--s; r1 = uint32_mod_uint14(r1, 274); /* needed only for invalid inputs */ R10[0] = (uint16) r1; r2 = R10[0]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 91); R9[0] = r0; r1 = uint32_mod_uint14(r1, 769); /* needed only for invalid inputs */ R9[1] = (uint16) r1; r2 = R9[1]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 152); R8[2] = r0; r1 = uint32_mod_uint14(r1, 1294); /* needed only for invalid inputs */ R8[3] = (uint16) r1; r2 = R9[0]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 152); R8[0] = r0; r1 = uint32_mod_uint14(r1, 152); /* needed only for invalid inputs */ R8[1] = (uint16) r1; r2 = R8[3]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 197); R7[6] = r0; r1 = uint32_mod_uint14(r1, 1681); /* needed only for invalid inputs */ R7[7] = (uint16) r1; for (i = 2; i >= 0; --i) { r2 = R8[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 197); R7[2 * i] = r0; r1 = uint32_mod_uint14(r1, 197); /* needed only for invalid inputs */ R7[2 * i + 1] = (uint16) r1; } r2 = R7[7]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 3586); R6[14] = r0; r1 = uint32_mod_uint14(r1, 120); /* needed only for invalid inputs */ R6[15] = (uint16) r1; for (i = 6; i >= 0; --i) { r2 = R7[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 3586); R6[2 * i] = r0; r1 = uint32_mod_uint14(r1, 3586); /* needed only for invalid inputs */ R6[2 * i + 1] = (uint16) r1; } r2 = R6[15]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 958); R5[30] = r0; r1 = uint32_mod_uint14(r1, 8200); /* needed only for invalid inputs */ R5[31] = (uint16) r1; for (i = 14; i >= 0; --i) { r2 = R6[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 958); R5[2 * i] = r0; r1 = uint32_mod_uint14(r1, 958); /* needed only for invalid inputs */ R5[2 * i + 1] = (uint16) r1; } r2 = R5[31]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 7921); R4[62] = r0; r1 = uint32_mod_uint14(r1, 265); /* needed only for invalid inputs */ R4[63] = (uint16) r1; for (i = 30; i >= 0; --i) { r2 = R5[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 7921); R4[2 * i] = r0; r1 = uint32_mod_uint14(r1, 7921); /* needed only for invalid inputs */ R4[2 * i + 1] = (uint16) r1; } R3[126] = R4[63]; for (i = 62; i >= 0; --i) { r2 = R4[i]; uint32_divmod_uint14(&r1, &r0, r2, 89); R3[2 * i] = r0; r1 = uint32_mod_uint14(r1, 89); /* needed only for invalid inputs */ R3[2 * i + 1] = (uint16) r1; } r2 = R3[126]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 2414); R2[252] = r0; r1 = uint32_mod_uint14(r1, 7177); /* needed only for invalid inputs */ R2[253] = (uint16) r1; for (i = 125; i >= 0; --i) { r2 = R3[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 2414); R2[2 * i] = r0; r1 = uint32_mod_uint14(r1, 2414); /* needed only for invalid inputs */ R2[2 * i + 1] = (uint16) r1; } R1[506] = R2[253]; for (i = 252; i >= 0; --i) { r2 = R2[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 786); R1[2 * i] = r0; r1 = uint32_mod_uint14(r1, 786); /* needed only for invalid inputs */ R1[2 * i + 1] = (uint16) r1; } R0[1012] = (int16) (R1[506] - 3588); for (i = 505; i >= 0; --i) { r2 = R1[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 7177); R0[2 * i] = (int16) (r0 - 3588); r1 = uint32_mod_uint14(r1, 7177); /* needed only for invalid inputs */ R0[2 * i + 1] = (int16) (r1 - 3588); } }