From: Simon Tatham Date: Sat, 6 Jun 2015 13:52:29 +0000 (+0100) Subject: Move BignumInt definitions into a header file. X-Git-Tag: 0.65~11 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=e6679d46022a8fb8ddb41af29e5c2684f68a7ef2;p=PuTTY.git Move BignumInt definitions into a header file. This allows files other than sshbn.c to work with the primitives necessary to build multi-word arithmetic functions satisfying all of PuTTY's portability constraints. (cherry picked from commit 2c60070aad2d959a9e7e850523352c23c6aa7009) Cherry-picker's notes: required on this branch because it's a dependency of f8b27925eee6a37df107a7cd2e718e997a52516e which we want. --- diff --git a/sshbn.c b/sshbn.c index b1ea5d63..953f06b5 100644 --- a/sshbn.c +++ b/sshbn.c @@ -10,90 +10,7 @@ #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; diff --git a/sshbn.h b/sshbn.h new file mode 100644 index 00000000..3d15b948 --- /dev/null +++ b/sshbn.h @@ -0,0 +1,92 @@ +/* + * sshbn.h: the assorted conditional definitions of BignumInt and + * multiply/divide macros used throughout the bignum code to treat + * numbers as arrays of the most conveniently sized word for the + * target machine. Exported so that other code (e.g. poly1305) can use + * it too. + */ + +/* + * 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)