#include "crypto_decode_953x6343.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_SNTRUP953_CLEAN_crypto_decode_953x6343(void *v, const unsigned char *s) { int16 *R0 = v; uint16 R1[477], R2[239], R3[120], R4[60], R5[30], R6[15], R7[8], R8[4], R9[2], R10[1]; long long i; uint16 r0; uint32 r1, r2; s += PQCLEAN_SNTRUP953_CLEAN_crypto_decode_953x6343_STRBYTES; r1 = 0; r1 = (r1 << 8) | *--s; r1 = (r1 << 8) | *--s; r1 = uint32_mod_uint14(r1, 12558); /* needed only for invalid inputs */ R10[0] = (uint16) r1; r2 = R10[0]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 2383); R9[0] = r0; r1 = uint32_mod_uint14(r1, 1349); /* needed only for invalid inputs */ R9[1] = (uint16) r1; r2 = R9[1]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 781); R8[2] = r0; r1 = uint32_mod_uint14(r1, 442); /* needed only for invalid inputs */ R8[3] = (uint16) r1; r2 = R9[0]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 781); R8[0] = r0; r1 = uint32_mod_uint14(r1, 781); /* needed only for invalid inputs */ R8[1] = (uint16) r1; r2 = R8[3]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 447); R7[6] = r0; r1 = uint32_mod_uint14(r1, 253); /* 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, 447); R7[2 * i] = r0; r1 = uint32_mod_uint14(r1, 447); /* needed only for invalid inputs */ R7[2 * i + 1] = (uint16) r1; } R6[14] = R7[7]; for (i = 6; i >= 0; --i) { r2 = R7[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 338); R6[2 * i] = r0; r1 = uint32_mod_uint14(r1, 338); /* needed only for invalid inputs */ R6[2 * i + 1] = (uint16) r1; } r2 = R6[14]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 4701); R5[28] = r0; r1 = uint32_mod_uint14(r1, 3519); /* needed only for invalid inputs */ R5[29] = (uint16) r1; for (i = 13; i >= 0; --i) { r2 = R6[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 4701); R5[2 * i] = r0; r1 = uint32_mod_uint14(r1, 4701); /* needed only for invalid inputs */ R5[2 * i + 1] = (uint16) r1; } r2 = R5[29]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 1097); R4[58] = r0; r1 = uint32_mod_uint14(r1, 821); /* needed only for invalid inputs */ R4[59] = (uint16) r1; for (i = 28; i >= 0; --i) { r2 = R5[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 1097); R4[2 * i] = r0; r1 = uint32_mod_uint14(r1, 1097); /* needed only for invalid inputs */ R4[2 * i + 1] = (uint16) r1; } r2 = R4[59]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 8476); R3[118] = r0; r1 = uint32_mod_uint14(r1, 6343); /* needed only for invalid inputs */ R3[119] = (uint16) r1; for (i = 58; i >= 0; --i) { r2 = R4[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 8476); R3[2 * i] = r0; r1 = uint32_mod_uint14(r1, 8476); /* needed only for invalid inputs */ R3[2 * i + 1] = (uint16) r1; } R2[238] = R3[119]; for (i = 118; i >= 0; --i) { r2 = R3[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 1473); R2[2 * i] = r0; r1 = uint32_mod_uint14(r1, 1473); /* needed only for invalid inputs */ R2[2 * i + 1] = (uint16) r1; } R1[476] = R2[238]; for (i = 237; i >= 0; --i) { r2 = R2[i]; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 614); R1[2 * i] = r0; r1 = uint32_mod_uint14(r1, 614); /* needed only for invalid inputs */ R1[2 * i + 1] = (uint16) r1; } R0[952] = (int16) (R1[476] - 3171); for (i = 475; i >= 0; --i) { r2 = R1[i]; r2 = (r2 << 8) | *--s; r2 = (r2 << 8) | *--s; uint32_divmod_uint14(&r1, &r0, r2, 6343); R0[2 * i] = (int16) (r0 - 3171); r1 = uint32_mod_uint14(r1, 6343); /* needed only for invalid inputs */ R0[2 * i + 1] = (int16) (r1 - 3171); } }