X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshbn.c;h=afc38a0bb2b5dfd056a50fae8483fa7dd020e6ba;hb=90c7b1562ce540d38f688492543467cc4dfa983c;hp=9d69b38588aba720ae1856dde3b308e9dc8f3e41;hpb=f2bbeca400edae9429f274cc47ee434816bb7306;p=PuTTY.git diff --git a/sshbn.c b/sshbn.c index 9d69b385..afc38a0b 100644 --- a/sshbn.c +++ b/sshbn.c @@ -6,93 +6,12 @@ #include #include #include +#include +#include #include "misc.h" -/* - * Usage notes: - * * Do not call the DIVMOD_WORD macro with expressions such as array - * subscripts, as some implementations object to this (see below). - * * Note that none of the division methods below will cope if the - * quotient won't fit into BIGNUM_INT_BITS. Callers should be careful - * to avoid this case. - * If this condition occurs, in the case of the x86 DIV instruction, - * an overflow exception will occur, which (according to a correspondent) - * will manifest on Windows as something like - * 0xC0000095: Integer overflow - * The C variant won't give the right answer, either. - */ - -#if defined __GNUC__ && defined __i386__ -typedef unsigned long BignumInt; -typedef unsigned long long BignumDblInt; -#define BIGNUM_INT_MASK 0xFFFFFFFFUL -#define BIGNUM_TOP_BIT 0x80000000UL -#define BIGNUM_INT_BITS 32 -#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2) -#define DIVMOD_WORD(q, r, hi, lo, w) \ - __asm__("div %2" : \ - "=d" (r), "=a" (q) : \ - "r" (w), "d" (hi), "a" (lo)) -#elif defined _MSC_VER && defined _M_IX86 -typedef unsigned __int32 BignumInt; -typedef unsigned __int64 BignumDblInt; -#define BIGNUM_INT_MASK 0xFFFFFFFFUL -#define BIGNUM_TOP_BIT 0x80000000UL -#define BIGNUM_INT_BITS 32 -#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2) -/* Note: MASM interprets array subscripts in the macro arguments as - * assembler syntax, which gives the wrong answer. Don't supply them. - * */ -#define DIVMOD_WORD(q, r, hi, lo, w) do { \ - __asm mov edx, hi \ - __asm mov eax, lo \ - __asm div w \ - __asm mov r, edx \ - __asm mov q, eax \ -} while(0) -#elif defined _LP64 -/* 64-bit architectures can do 32x32->64 chunks at a time */ -typedef unsigned int BignumInt; -typedef unsigned long BignumDblInt; -#define BIGNUM_INT_MASK 0xFFFFFFFFU -#define BIGNUM_TOP_BIT 0x80000000U -#define BIGNUM_INT_BITS 32 -#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2) -#define DIVMOD_WORD(q, r, hi, lo, w) do { \ - BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \ - q = n / w; \ - r = n % w; \ -} while (0) -#elif defined _LLP64 -/* 64-bit architectures in which unsigned long is 32 bits, not 64 */ -typedef unsigned long BignumInt; -typedef unsigned long long BignumDblInt; -#define BIGNUM_INT_MASK 0xFFFFFFFFUL -#define BIGNUM_TOP_BIT 0x80000000UL -#define BIGNUM_INT_BITS 32 -#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2) -#define DIVMOD_WORD(q, r, hi, lo, w) do { \ - BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \ - q = n / w; \ - r = n % w; \ -} while (0) -#else -/* Fallback for all other cases */ -typedef unsigned short BignumInt; -typedef unsigned long BignumDblInt; -#define BIGNUM_INT_MASK 0xFFFFU -#define BIGNUM_TOP_BIT 0x8000U -#define BIGNUM_INT_BITS 16 -#define MUL_WORD(w1, w2) ((BignumDblInt)w1 * w2) -#define DIVMOD_WORD(q, r, hi, lo, w) do { \ - BignumDblInt n = (((BignumDblInt)hi) << BIGNUM_INT_BITS) | lo; \ - q = n / w; \ - r = n % w; \ -} while (0) -#endif - -#define BIGNUM_INT_BYTES (BIGNUM_INT_BITS / 8) +#include "sshbn.h" #define BIGNUM_INTERNAL typedef BignumInt *Bignum; @@ -101,6 +20,7 @@ typedef BignumInt *Bignum; BignumInt bnZero[1] = { 0 }; BignumInt bnOne[2] = { 1, 1 }; +BignumInt bnTen[2] = { 1, 10 }; /* * The Bignum format is an array of `BignumInt'. The first @@ -116,13 +36,15 @@ BignumInt bnOne[2] = { 1, 1 }; * nonzero. */ -Bignum Zero = bnZero, One = bnOne; +Bignum Zero = bnZero, One = bnOne, Ten = bnTen; static Bignum newbn(int length) { - Bignum b = snewn(length + 1, BignumInt); - if (!b) - abort(); /* FIXME */ + Bignum b; + + assert(length >= 0 && length < INT_MAX / BIGNUM_INT_BITS); + + b = snewn(length + 1, BignumInt); memset(b, 0, (length + 1) * sizeof(*b)); b[0] = length; return b; @@ -154,7 +76,11 @@ void freebn(Bignum b) Bignum bn_power_2(int n) { - Bignum ret = newbn(n / BIGNUM_INT_BITS + 1); + Bignum ret; + + assert(n >= 0); + + ret = newbn(n / BIGNUM_INT_BITS + 1); bignum_set_bit(ret, n, 1); return ret; } @@ -589,7 +515,7 @@ static void monty_reduce(BignumInt *x, const BignumInt *n, } static void internal_add_shifted(BignumInt *number, - unsigned n, int shift) + BignumInt n, int shift) { int word = 1 + (shift / BIGNUM_INT_BITS); int bshift = shift % BIGNUM_INT_BITS; @@ -598,6 +524,7 @@ static void internal_add_shifted(BignumInt *number, addend = (BignumDblInt)n << bshift; while (addend) { + assert(word <= number[0]); addend += number[word]; number[word] = (BignumInt) addend & BIGNUM_INT_MASK; addend >>= BIGNUM_INT_BITS; @@ -619,11 +546,11 @@ static void internal_mod(BignumInt *a, int alen, BignumInt *m, int mlen, BignumInt *quot, int qshift) { - BignumInt m0, m1; - unsigned int h; + BignumInt m0, m1, h; int i, k; m0 = m[0]; + assert(m0 >> (BIGNUM_INT_BITS-1) == 1); if (mlen > 1) m1 = m[1]; else @@ -631,7 +558,7 @@ static void internal_mod(BignumInt *a, int alen, for (i = 0; i <= alen - mlen; i++) { BignumDblInt t; - unsigned int q, r, c, ai1; + BignumInt q, r, c, ai1; if (i == 0) { h = 0; @@ -686,7 +613,7 @@ static void internal_mod(BignumInt *a, int alen, for (k = mlen - 1; k >= 0; k--) { t = MUL_WORD(q, m[k]); t += c; - c = (unsigned)(t >> BIGNUM_INT_BITS); + c = (BignumInt)(t >> BIGNUM_INT_BITS); if ((BignumInt) t > a[i + k]) c++; a[i + k] -= (BignumInt) t; @@ -769,7 +696,7 @@ Bignum modpow_simple(Bignum base_in, Bignum exp, Bignum mod) /* Skip leading zero bits of exp. */ i = 0; j = BIGNUM_INT_BITS-1; - while (i < (int)exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) { + while (i < (int)exp[0] && (exp[exp[0] - i] & ((BignumInt)1 << j)) == 0) { j--; if (j < 0) { i++; @@ -782,7 +709,7 @@ Bignum modpow_simple(Bignum base_in, Bignum exp, Bignum mod) while (j >= 0) { internal_mul(a + mlen, a + mlen, b, mlen, scratch); internal_mod(b, mlen * 2, m, mlen, NULL, 0); - if ((exp[exp[0] - i] & (1 << j)) != 0) { + if ((exp[exp[0] - i] & ((BignumInt)1 << j)) != 0) { internal_mul(b + mlen, n, a, mlen, scratch); internal_mod(a, mlen * 2, m, mlen, NULL, 0); } else { @@ -815,20 +742,15 @@ Bignum modpow_simple(Bignum base_in, Bignum exp, Bignum mod) result[0]--; /* Free temporary arrays */ - for (i = 0; i < 2 * mlen; i++) - a[i] = 0; + smemclr(a, 2 * mlen * sizeof(*a)); sfree(a); - for (i = 0; i < scratchlen; i++) - scratch[i] = 0; + smemclr(scratch, scratchlen * sizeof(*scratch)); sfree(scratch); - for (i = 0; i < 2 * mlen; i++) - b[i] = 0; + smemclr(b, 2 * mlen * sizeof(*b)); sfree(b); - for (i = 0; i < mlen; i++) - m[i] = 0; + smemclr(m, mlen * sizeof(*m)); sfree(m); - for (i = 0; i < mlen; i++) - n[i] = 0; + smemclr(n, mlen * sizeof(*n)); sfree(n); freebn(base); @@ -873,6 +795,7 @@ Bignum modpow(Bignum base_in, Bignum exp, Bignum mod) len = mod[0]; r = bn_power_2(BIGNUM_INT_BITS * len); inv = modinv(mod, r); + assert(inv); /* cannot fail, since mod is odd and r is a power of 2 */ /* * Multiply the base by r mod n, to get it into Montgomery @@ -923,7 +846,7 @@ Bignum modpow(Bignum base_in, Bignum exp, Bignum mod) /* Skip leading zero bits of exp. */ i = 0; j = BIGNUM_INT_BITS-1; - while (i < (int)exp[0] && (exp[exp[0] - i] & (1 << j)) == 0) { + while (i < (int)exp[0] && (exp[exp[0] - i] & ((BignumInt)1 << j)) == 0) { j--; if (j < 0) { i++; @@ -936,7 +859,7 @@ Bignum modpow(Bignum base_in, Bignum exp, Bignum mod) while (j >= 0) { internal_mul(a + len, a + len, b, len, scratch); monty_reduce(b, n, mninv, scratch, len); - if ((exp[exp[0] - i] & (1 << j)) != 0) { + if ((exp[exp[0] - i] & ((BignumInt)1 << j)) != 0) { internal_mul(b + len, x, a, len, scratch); monty_reduce(a, n, mninv, scratch, len); } else { @@ -965,23 +888,17 @@ Bignum modpow(Bignum base_in, Bignum exp, Bignum mod) result[0]--; /* Free temporary arrays */ - for (i = 0; i < scratchlen; i++) - scratch[i] = 0; + smemclr(scratch, scratchlen * sizeof(*scratch)); sfree(scratch); - for (i = 0; i < 2 * len; i++) - a[i] = 0; + smemclr(a, 2 * len * sizeof(*a)); sfree(a); - for (i = 0; i < 2 * len; i++) - b[i] = 0; + smemclr(b, 2 * len * sizeof(*b)); sfree(b); - for (i = 0; i < len; i++) - mninv[i] = 0; + smemclr(mninv, len * sizeof(*mninv)); sfree(mninv); - for (i = 0; i < len; i++) - n[i] = 0; + smemclr(n, len * sizeof(*n)); sfree(n); - for (i = 0; i < len; i++) - x[i] = 0; + smemclr(x, len * sizeof(*x)); sfree(x); return result; @@ -999,6 +916,12 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod) int pqlen, mlen, rlen, i, j; Bignum result; + /* + * The most significant word of mod needs to be non-zero. It + * should already be, but let's make sure. + */ + assert(mod[mod[0]] != 0); + /* Allocate m of size mlen, copy mod to m */ /* We use big endian internally */ mlen = mod[0]; @@ -1018,6 +941,13 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod) pqlen = (p[0] > q[0] ? p[0] : q[0]); + /* + * Make sure that we're allowing enough space. The shifting below + * will underflow the vectors we allocate if pqlen is too small. + */ + if (2*pqlen <= mlen) + pqlen = mlen/2 + 1; + /* Allocate n of size pqlen, copy p to n */ n = snewn(pqlen, BignumInt); i = pqlen - p[0]; @@ -1064,25 +994,49 @@ Bignum modmul(Bignum p, Bignum q, Bignum mod) result[0]--; /* Free temporary arrays */ - for (i = 0; i < scratchlen; i++) - scratch[i] = 0; + smemclr(scratch, scratchlen * sizeof(*scratch)); sfree(scratch); - for (i = 0; i < 2 * pqlen; i++) - a[i] = 0; + smemclr(a, 2 * pqlen * sizeof(*a)); sfree(a); - for (i = 0; i < mlen; i++) - m[i] = 0; + smemclr(m, mlen * sizeof(*m)); sfree(m); - for (i = 0; i < pqlen; i++) - n[i] = 0; + smemclr(n, pqlen * sizeof(*n)); sfree(n); - for (i = 0; i < pqlen; i++) - o[i] = 0; + smemclr(o, pqlen * sizeof(*o)); sfree(o); return result; } +Bignum modsub(const Bignum a, const Bignum b, const Bignum n) +{ + Bignum a1, b1, ret; + + if (bignum_cmp(a, n) >= 0) a1 = bigmod(a, n); + else a1 = a; + if (bignum_cmp(b, n) >= 0) b1 = bigmod(b, n); + else b1 = b; + + if (bignum_cmp(a1, b1) >= 0) /* a >= b */ + { + ret = bigsub(a1, b1); + } + else + { + /* Handle going round the corner of the modulus without having + * negative support in Bignum */ + Bignum tmp = bigsub(n, b1); + assert(tmp); + ret = bigadd(tmp, a1); + freebn(tmp); + } + + if (a != a1) freebn(a1); + if (b != b1) freebn(b1); + + return ret; +} + /* * Compute p % mod. * The most significant word of mod MUST be non-zero. @@ -1096,6 +1050,12 @@ static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient) int mshift; int plen, mlen, i, j; + /* + * The most significant word of mod needs to be non-zero. It + * should already be, but let's make sure. + */ + assert(mod[mod[0]] != 0); + /* Allocate m of size mlen, copy mod to m */ /* We use big endian internally */ mlen = mod[0]; @@ -1147,11 +1107,9 @@ static void bigdivmod(Bignum p, Bignum mod, Bignum result, Bignum quotient) } /* Free temporary arrays */ - for (i = 0; i < mlen; i++) - m[i] = 0; + smemclr(m, mlen * sizeof(*m)); sfree(m); - for (i = 0; i < plen; i++) - n[i] = 0; + smemclr(n, plen * sizeof(*n)); sfree(n); } @@ -1171,6 +1129,8 @@ Bignum bignum_from_bytes(const unsigned char *data, int nbytes) Bignum result; int w, i; + assert(nbytes >= 0 && nbytes < INT_MAX/8); + w = (nbytes + BIGNUM_INT_BYTES - 1) / BIGNUM_INT_BYTES; /* bytes->words */ result = newbn(w); @@ -1178,14 +1138,93 @@ Bignum bignum_from_bytes(const unsigned char *data, int nbytes) result[i] = 0; for (i = nbytes; i--;) { unsigned char byte = *data++; - result[1 + i / BIGNUM_INT_BYTES] |= byte << (8*i % BIGNUM_INT_BITS); + result[1 + i / BIGNUM_INT_BYTES] |= + (BignumInt)byte << (8*i % BIGNUM_INT_BITS); + } + + bn_restore_invariant(result); + return result; +} + +Bignum bignum_from_bytes_le(const unsigned char *data, int nbytes) +{ + Bignum result; + int w, i; + + assert(nbytes >= 0 && nbytes < INT_MAX/8); + + w = (nbytes + BIGNUM_INT_BYTES - 1) / BIGNUM_INT_BYTES; /* bytes->words */ + + result = newbn(w); + for (i = 1; i <= w; i++) + result[i] = 0; + for (i = 0; i < nbytes; ++i) { + unsigned char byte = *data++; + result[1 + i / BIGNUM_INT_BYTES] |= + (BignumInt)byte << (8*i % BIGNUM_INT_BITS); + } + + bn_restore_invariant(result); + return result; +} + +Bignum bignum_from_decimal(const char *decimal) +{ + Bignum result = copybn(Zero); + + while (*decimal) { + Bignum tmp, tmp2; + + if (!isdigit((unsigned char)*decimal)) { + freebn(result); + return 0; + } + + tmp = bigmul(result, Ten); + tmp2 = bignum_from_long(*decimal - '0'); + result = bigadd(tmp, tmp2); + freebn(tmp); + freebn(tmp2); + + decimal++; } - while (result[0] > 1 && result[result[0]] == 0) - result[0]--; return result; } +Bignum bignum_random_in_range(const Bignum lower, const Bignum upper) +{ + Bignum ret = NULL; + unsigned char *bytes; + int upper_len = bignum_bitcount(upper); + int upper_bytes = upper_len / 8; + int upper_bits = upper_len % 8; + if (upper_bits) ++upper_bytes; + + bytes = snewn(upper_bytes, unsigned char); + do { + int i; + + if (ret) freebn(ret); + + for (i = 0; i < upper_bytes; ++i) + { + bytes[i] = (unsigned char)random_byte(); + } + /* Mask the top to reduce failure rate to 50/50 */ + if (upper_bits) + { + bytes[i - 1] &= 0xFF >> (8 - upper_bits); + } + + ret = bignum_from_bytes(bytes, upper_bytes); + } while (bignum_cmp(ret, lower) < 0 || bignum_cmp(ret, upper) > 0); + smemclr(bytes, upper_bytes); + sfree(bytes); + + return ret; +} + /* * Read an SSH-1-format bignum from a data buffer. Return the number * of bytes consumed, or -1 if there wasn't enough data. @@ -1247,7 +1286,7 @@ int ssh2_bignum_length(Bignum bn) */ int bignum_byte(Bignum bn, int i) { - if (i >= (int)(BIGNUM_INT_BYTES * bn[0])) + if (i < 0 || i >= (int)(BIGNUM_INT_BYTES * bn[0])) return 0; /* beyond the end */ else return (bn[i / BIGNUM_INT_BYTES + 1] >> @@ -1259,7 +1298,7 @@ int bignum_byte(Bignum bn, int i) */ int bignum_bit(Bignum bn, int i) { - if (i >= (int)(BIGNUM_INT_BITS * bn[0])) + if (i < 0 || i >= (int)(BIGNUM_INT_BITS * bn[0])) return 0; /* beyond the end */ else return (bn[i / BIGNUM_INT_BITS + 1] >> (i % BIGNUM_INT_BITS)) & 1; @@ -1270,11 +1309,11 @@ int bignum_bit(Bignum bn, int i) */ void bignum_set_bit(Bignum bn, int bitnum, int value) { - if (bitnum >= (int)(BIGNUM_INT_BITS * bn[0])) - abort(); /* beyond the end */ - else { + if (bitnum < 0 || bitnum >= (int)(BIGNUM_INT_BITS * bn[0])) { + if (value) abort(); /* beyond the end */ + } else { int v = bitnum / BIGNUM_INT_BITS + 1; - int mask = 1 << (bitnum % BIGNUM_INT_BITS); + BignumInt mask = (BignumInt)1 << (bitnum % BIGNUM_INT_BITS); if (value) bn[v] |= mask; else @@ -1306,7 +1345,18 @@ int ssh1_write_bignum(void *data, Bignum bn) int bignum_cmp(Bignum a, Bignum b) { int amax = a[0], bmax = b[0]; - int i = (amax > bmax ? amax : bmax); + int i; + + /* Annoyingly we have two representations of zero */ + if (amax == 1 && a[amax] == 0) + amax = 0; + if (bmax == 1 && b[bmax] == 0) + bmax = 0; + + assert(amax == 0 || a[amax] != 0); + assert(bmax == 0 || b[bmax] != 0); + + i = (amax > bmax ? amax : bmax); while (i) { BignumInt aval = (i > amax ? 0 : a[i]); BignumInt bval = (i > bmax ? 0 : b[i]); @@ -1328,6 +1378,8 @@ Bignum bignum_rshift(Bignum a, int shift) int i, shiftw, shiftb, shiftbb, bits; BignumInt ai, ai1; + assert(shift >= 0); + bits = bignum_bitcount(a) - shift; ret = newbn((bits + BIGNUM_INT_BITS - 1) / BIGNUM_INT_BITS); @@ -1347,6 +1399,44 @@ Bignum bignum_rshift(Bignum a, int shift) return ret; } +/* + * Left-shift one bignum to form another. + */ +Bignum bignum_lshift(Bignum a, int shift) +{ + Bignum ret; + int bits, shiftWords, shiftBits; + + assert(shift >= 0); + + bits = bignum_bitcount(a) + shift; + ret = newbn((bits + BIGNUM_INT_BITS - 1) / BIGNUM_INT_BITS); + + shiftWords = shift / BIGNUM_INT_BITS; + shiftBits = shift % BIGNUM_INT_BITS; + + if (shiftBits == 0) + { + memcpy(&ret[1 + shiftWords], &a[1], sizeof(BignumInt) * a[0]); + } + else + { + int i; + BignumInt carry = 0; + + /* Remember that Bignum[0] is length, so add 1 */ + for (i = shiftWords + 1; i < ((int)a[0]) + shiftWords + 1; ++i) + { + BignumInt from = a[i - shiftWords]; + ret[i] = (from << shiftBits) | carry; + carry = from >> (BIGNUM_INT_BITS - shiftBits); + } + if (carry) ret[i] = carry; + } + + return ret; +} + /* * Non-modular multiplication and addition. */ @@ -1398,8 +1488,7 @@ Bignum bigmuladd(Bignum a, Bignum b, Bignum addend) } ret[0] = maxspot; - for (i = 0; i < wslen; i++) - workspace[i] = 0; + smemclr(workspace, wslen * sizeof(*workspace)); sfree(workspace); return ret; } @@ -1583,6 +1672,8 @@ Bignum bigdiv(Bignum a, Bignum b) { Bignum q = newbn(a[0]); bigdivmod(a, b, NULL, q); + while (q[0] > 1 && q[q[0]] == 0) + q[0]--; return q; } @@ -1593,6 +1684,8 @@ Bignum bigmod(Bignum a, Bignum b) { Bignum r = newbn(b[0]); bigdivmod(a, b, r, NULL); + while (r[0] > 1 && r[r[0]] == 0) + r[0]--; return r; } @@ -1629,12 +1722,31 @@ Bignum modinv(Bignum number, Bignum modulus) Bignum x = copybn(One); int sign = +1; + assert(number[number[0]] != 0); + assert(modulus[modulus[0]] != 0); + while (bignum_cmp(b, One) != 0) { - Bignum t = newbn(b[0]); - Bignum q = newbn(a[0]); + Bignum t, q; + + if (bignum_cmp(b, Zero) == 0) { + /* + * Found a common factor between the inputs, so we cannot + * return a modular inverse at all. + */ + freebn(b); + freebn(a); + freebn(xp); + freebn(x); + return NULL; + } + + t = newbn(b[0]); + q = newbn(a[0]); bigdivmod(a, b, t, q); while (t[0] > 1 && t[t[0]] == 0) t[0]--; + while (q[0] > 1 && q[q[0]] == 0) + q[0]--; freebn(a); a = b; b = t; @@ -1750,6 +1862,7 @@ char *bignum_decimal(Bignum x) /* * Done. */ + smemclr(workspace, x[0] * sizeof(*workspace)); sfree(workspace); return ret; } @@ -1761,13 +1874,13 @@ char *bignum_decimal(Bignum x) #include /* - * gcc -g -O0 -DTESTBN -o testbn sshbn.c misc.c -I unix -I charset + * gcc -Wall -g -O0 -DTESTBN -o testbn sshbn.c misc.c conf.c tree234.c unix/uxmisc.c -I. -I unix -I charset * * Then feed to this program's standard input the output of * testdata/bignum.py . */ -void modalfatalbox(char *p, ...) +void modalfatalbox(const char *p, ...) { va_list ap; fprintf(stderr, "FATAL ERROR: "); @@ -1778,6 +1891,12 @@ void modalfatalbox(char *p, ...) exit(1); } +int random_byte(void) +{ + modalfatalbox("random_byte called in testbn"); + return 0; +} + #define fromxdigit(c) ( (c)>'9' ? ((c)&0xDF) - 'A' + 10 : (c) - '0' ) int main(int argc, char **argv) @@ -1864,11 +1983,49 @@ int main(int argc, char **argv) freebn(b); freebn(c); freebn(p); + } else if (!strcmp(buf, "modmul")) { + Bignum a, b, m, c, p; + + if (ptrnum != 4) { + printf("%d: modmul with %d parameters, expected 4\n", + line, ptrnum); + exit(1); + } + a = bignum_from_bytes(ptrs[0], ptrs[1]-ptrs[0]); + b = bignum_from_bytes(ptrs[1], ptrs[2]-ptrs[1]); + m = bignum_from_bytes(ptrs[2], ptrs[3]-ptrs[2]); + c = bignum_from_bytes(ptrs[3], ptrs[4]-ptrs[3]); + p = modmul(a, b, m); + + if (bignum_cmp(c, p) == 0) { + passes++; + } else { + char *as = bignum_decimal(a); + char *bs = bignum_decimal(b); + char *ms = bignum_decimal(m); + char *cs = bignum_decimal(c); + char *ps = bignum_decimal(p); + + printf("%d: fail: %s * %s mod %s gave %s expected %s\n", + line, as, bs, ms, ps, cs); + fails++; + + sfree(as); + sfree(bs); + sfree(ms); + sfree(cs); + sfree(ps); + } + freebn(a); + freebn(b); + freebn(m); + freebn(c); + freebn(p); } else if (!strcmp(buf, "pow")) { Bignum base, expt, modulus, expected, answer; if (ptrnum != 4) { - printf("%d: mul with %d parameters, expected 4\n", line, ptrnum); + printf("%d: pow with %d parameters, expected 4\n", line, ptrnum); exit(1); }