1257 lines
39 KiB
PHP
1257 lines
39 KiB
PHP
; mpint.inc - Multi precision integer procedures
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;
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; Copyright (C) 2015-2021 Jeffrey Amelynck
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;
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; This program is free software: you can redistribute it and/or modify
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; it under the terms of the GNU General Public License as published by
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; the Free Software Foundation, either version 3 of the License, or
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; (at your option) any later version.
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;
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; This program is distributed in the hope that it will be useful,
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; but WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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; GNU General Public License for more details.
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;
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; You should have received a copy of the GNU General Public License
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; along with this program. If not, see <http://www.gnu.org/licenses/>.
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; Note:
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;
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; These procedures have been designed to work with unsigned integers.
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; For compatibility reasons, the highest bit must always be 0.
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;
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; You have been warned!
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MPINT_MAX_LEN = MAX_BITS/8
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;;===========================================================================;;
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proc mpint_to_little_endian uses esi edi ecx, dst, src ;/////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Convert big endian MPINT to little endian MPINT. ;;
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;;---------------------------------------------------------------------------;;
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;> src = pointer to big endian MPINT ;;
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;> dst = pointer to buffer for little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< eax = MPINT number length ;;
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;;===========================================================================;;
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mov esi, [src]
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mov edi, [dst]
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; Load length dword
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lodsd
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; Convert to little endian
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bswap eax
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stosd
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test eax, eax
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jz .zero
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; Copy data, convert to little endian meanwhile
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push eax
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add esi, eax
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dec esi
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mov ecx, eax
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std
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@@:
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lodsb
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mov byte[edi], al
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inc edi
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dec ecx
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jnz @r
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cld
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pop eax
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.zero:
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ret
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endp
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;;===========================================================================;;
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proc mpint_to_big_endian uses esi edi ecx, dst, src ;////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Convert little endian MPINT to big endian MPINT. ;;
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;;---------------------------------------------------------------------------;;
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;> src = pointer to little endian MPINT ;;
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;> dst = pointer to buffer for big endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< eax = MPINT number length ;;
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;;===========================================================================;;
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mov esi, [src]
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mov edi, [dst]
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; Load length dword
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lodsd
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test eax, eax
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jz .zero
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mov ecx, eax
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add esi, eax
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dec esi
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push eax ; we'll return length to the caller later
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bswap eax
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stosd
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; Copy data, convert to big endian meanwhile
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std
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@@:
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lodsb
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mov byte[edi], al
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inc edi
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dec ecx
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jnz @r
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cld
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pop eax
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ret
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.zero:
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stosd ; Number 0 has 0 data bytes
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ret
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endp
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;;===========================================================================;;
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proc mpint_print uses ecx esi eax, src ;/////////////////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Print MPINT to the debug board. ;;
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;;---------------------------------------------------------------------------;;
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;> src = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< - ;;
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;;===========================================================================;;
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DEBUGF 1, "0x"
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mov esi, [src]
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mov ecx, [esi]
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test ecx, ecx
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jz .zero
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lea esi, [esi + ecx + 4 - 1]
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pushf
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std
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.loop:
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lodsb
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DEBUGF 1, "%x", eax:2
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dec ecx
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jnz .loop
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DEBUGF 1, "\n"
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popf
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ret
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.zero:
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DEBUGF 1, "00\n"
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ret
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endp
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;;===========================================================================;;
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proc mpint_bits uses esi ecx, dst ;//////////////////////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Count the number of bits in the MPINT ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< eax = highest order bit number + 1 ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_bits(0x%x): ", [dst]
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mov esi, [dst]
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mov eax, [esi]
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test eax, eax
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jz .zero
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add esi, 4-1
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; Find highest order byte
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.byteloop:
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cmp byte[esi+eax], 0
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jne .nz
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dec eax
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jnz .byteloop
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.zero:
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DEBUGF 1, "%u\n", eax
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ret
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.nz:
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mov cl, byte[esi+eax]
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; multiply (eax - 1) by 8 to get nr of bits before this byte
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dec eax
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shl eax, 3
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; Now shift bits of the highest order byte right, until the byte reaches zero, counting bits meanwhile
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.bitloop:
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inc eax
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shr cl, 1
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jnz .bitloop
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DEBUGF 1, "%u\n", eax
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ret
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endp
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;;===========================================================================;;
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proc mpint_bytes uses esi, dst ;/////////////////////////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Count the number of bytes in the MPINT ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< eax = highest order byte number + 1 ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_bytes(0x%x): ", [dst]
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mov esi, [dst]
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mov eax, [esi]
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test eax, eax
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jz .done
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add esi, 4-1
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; Find highest order byte
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.byteloop:
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cmp byte[esi+eax], 0
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jne .done
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dec eax
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jnz .byteloop
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.done:
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DEBUGF 1, "%u\n", eax
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ret
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endp
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;;===========================================================================;;
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proc mpint_cmp uses esi edi edx ecx ebx eax, src, dst ;//////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Compare two MPINTS. ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;> src = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< flags are set as for single precision CMP instruction ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_cmp(0x%x, 0x%x)\n", [dst], [src]
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; First, check the size of both numbers
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stdcall mpint_bytes, [dst]
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mov ecx, eax
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stdcall mpint_bytes, [src]
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; If one number has more bytes, it is bigger
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cmp eax, ecx
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jne .got_answer
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; If both numbers have 0 bytes, they are equal
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test ecx, ecx
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jz .got_answer
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; Numbers have equal amount of bytes
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; Start comparing from the MSB towards the LSB
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mov esi, [src]
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mov edi, [dst]
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lea esi, [esi + 4 + ecx]
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lea edi, [edi + 4 + ecx]
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; If remaining bytes is not divisible by 4, compare only one byte at a time
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.loop_1:
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test ecx, 111b
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jz .done_1
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dec esi
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dec edi
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mov al, byte[esi]
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cmp al, byte[edi]
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jne .got_answer
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dec ecx
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jmp .loop_1
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; Remaining bytes is divisable by 8, compare dwords
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.done_1:
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shr ecx, 3
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jz .got_answer
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align 8
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.loop_8:
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lea esi, [esi-8]
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lea edi, [edi-8]
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mov eax, [esi+04]
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mov ebx, [esi+00]
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cmp eax, [edi+04]
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jne .got_answer
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cmp ebx, [edi+00]
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jne .got_answer
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dec ecx
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jnz .loop_8
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.got_answer:
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ret
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endp
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;;===========================================================================;;
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proc mpint_mov uses esi edi edx ecx ebx eax, dst, src ;//////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Copy MPINT. ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to buffer for little endian MPINT ;;
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;> src = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< dst = src ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_mov(0x%x, 0x%x)\n", [dst], [src]
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mov esi, [src]
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mov edi, [dst]
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mov ecx, [esi] ; Get dword count + 1
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add ecx, 7 ;
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shr ecx, 2 ;
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mov edx, ecx
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shr ecx, 3
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test ecx, ecx
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jz .no32
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align 8
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.loop32:
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mov eax, [esi+00]
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mov ebx, [esi+04]
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mov [edi+00], eax
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mov [edi+04], ebx
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mov eax, [esi+08]
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mov ebx, [esi+12]
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mov [edi+08], eax
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mov [edi+12], ebx
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mov eax, [esi+16]
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mov ebx, [esi+20]
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mov [edi+16], eax
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mov [edi+20], ebx
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mov eax, [esi+24]
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mov ebx, [esi+28]
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mov [edi+24], eax
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mov [edi+28], ebx
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lea esi, [esi+32]
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lea edi, [edi+32]
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dec ecx
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jnz .loop32
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.no32:
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test edx, 100b
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jz .no16
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mov eax, [esi+00]
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mov ebx, [esi+04]
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mov [edi+00], eax
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mov [edi+04], ebx
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mov eax, [esi+08]
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mov ebx, [esi+12]
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mov [edi+08], eax
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mov [edi+12], ebx
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lea esi, [esi+16]
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lea edi, [edi+16]
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.no16:
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test edx, 010b
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jz .no8
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mov eax, [esi+00]
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mov ebx, [esi+04]
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mov [edi+00], eax
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mov [edi+04], ebx
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lea esi, [esi+08]
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lea edi, [edi+08]
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.no8:
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test edx, 001b
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jz .no4
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mov eax, [esi+00]
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mov [edi+00], eax
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.no4:
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ret
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endp
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;;===========================================================================;;
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proc mpint_shl1 uses edi ecx, dst ;//////////////////////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Shift little endian MPINT one bit to the left. ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< dst = dst SHL 1 ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_shl1(0x%x)\n", [dst]
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mov edi, [dst]
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mov ecx, [edi]
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test ecx, 11b
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jnz .adjust_needed
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shr ecx, 2
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jz .done
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.length_ok:
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add edi, 4
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; Do the lowest order dword first
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shl dword[edi], 1
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lea edi, [edi+4]
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dec ecx
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jz .done
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; And the remaining dwords
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.loop:
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rcl dword[edi], 1
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lea edi, [edi+4]
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dec ecx
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jnz .loop
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.done:
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jc .carry
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test dword[edi-4], 0x10000000
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jnz .add0
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ret
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.carry:
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mov ecx, [dst]
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cmp dword[ecx], MPINT_MAX_LEN
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je .ovf
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add dword[ecx], 4
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mov dword[edi], 1
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ret
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.add0:
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mov ecx, [dst]
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cmp dword[ecx], MPINT_MAX_LEN
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je .ovf
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add dword[ecx], 4
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mov dword[edi], 0
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ret
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.ovf:
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int3
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;;;;
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ret
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.adjust_needed:
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add ecx, 3
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and ecx, not 3
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stdcall mpint_grow, edi, ecx
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jmp .length_ok
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endp
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;;===========================================================================;;
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proc mpint_shr1 uses edi ecx, dst ;//////////////////////////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Shift little endian MPINT one bit to the right. ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< dst = dst SHR 1 ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_shr1(0x%x)\n", [dst]
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mov edi, [dst]
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mov ecx, [edi]
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test ecx, 11b
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jnz .adjust_needed
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.length_ok:
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shr ecx, 2
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jz .done
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lea edi, [edi+ecx*4]
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; Do the highest order dword first
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shr dword[edi], 1
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lea edi, [edi-4]
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dec ecx
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jz .done
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; And the remaining dwords
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.loop:
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rcr dword[edi], 1
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lea edi, [edi-4]
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dec ecx
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jnz .loop
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.done:
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ret
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.adjust_needed:
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add ecx, 3
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and ecx, not 3
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stdcall mpint_grow, edi, ecx
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jmp .length_ok
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endp
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;;===========================================================================;;
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proc mpint_shl uses eax ebx ecx edx esi edi, dst, shift ;////////////////////;;
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;;---------------------------------------------------------------------------;;
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;? Left shift little endian MPINT by x bits. ;;
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;;---------------------------------------------------------------------------;;
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;> dst = pointer to little endian MPINT ;;
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;> shift = number of bits to shift the MPINT ;;
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;;---------------------------------------------------------------------------;;
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;< - ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_shl(0x%x, %u)\n", [dst], [shift]
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; Calculate new size
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stdcall mpint_bits, [dst]
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add eax, [shift]
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shr eax, 3
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cmp eax, MPINT_MAX_LEN
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jae .overflow ;;
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inc eax
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mov esi, [dst]
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mov [esi], eax
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mov ecx, [shift]
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shr ecx, 3 ; 8 bits in one byte
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add esi, MPINT_MAX_LEN+4-4
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mov edi, esi
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and ecx, not 11b
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sub esi, ecx
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mov edx, MPINT_MAX_LEN/4-1
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shr ecx, 2 ; 4 bytes in one dword
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push ecx
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sub edx, ecx
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mov ecx, [shift]
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and ecx, 11111b
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std
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.loop:
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lodsd
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mov ebx, [esi]
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shld eax, ebx, cl
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stosd
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dec edx
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jnz .loop
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lodsd
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shl eax, cl
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stosd
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; fill the LSBs with zeros
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pop ecx
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test ecx, ecx
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jz @f
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xor eax, eax
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rep stosd
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@@:
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cld
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ret
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.zero:
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mov eax, [dst]
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mov dword[eax], 0
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ret
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.overflow:
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int3
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ret
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endp
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;;===========================================================================;;
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proc mpint_shlmov uses eax ebx ecx edx esi edi, dst, src, shift ;////////////;;
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;;---------------------------------------------------------------------------;;
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;? Left shift by x bits and copy little endian MPINT. ;;
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;;---------------------------------------------------------------------------;;
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;> src = pointer to little endian MPINT ;;
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;> dst = pointer to little endian MPINT ;;
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;> shift = number of bits to shift the MPINT to the left ;;
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;;---------------------------------------------------------------------------;;
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;< dst = src SHL shift ;;
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;;===========================================================================;;
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DEBUGF 1, "mpint_shlmov(0x%x, 0x%x, %u)\n", [dst], [src], [shift]
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stdcall mpint_bits, [src]
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test eax, eax
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jz .zero
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add eax, [shift]
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shr eax, 3
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inc eax
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mov edi, [dst]
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mov [edi], eax
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cmp eax, MPINT_MAX_LEN
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jae .overflow
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mov esi, [src]
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add esi, MPINT_MAX_LEN+4-4
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add edi, MPINT_MAX_LEN+4-4
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mov ecx, [shift]
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shr ecx, 3 ; 8 bits in one byte
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and ecx, not 11b
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sub esi, ecx
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mov edx, MPINT_MAX_LEN/4-1
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shr ecx, 2 ; 4 bytes in one dword
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push ecx
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sub edx, ecx
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mov ecx, [shift]
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and ecx, 11111b
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std
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.loop:
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lodsd
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mov ebx, [esi]
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shld eax, ebx, cl
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stosd
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dec edx
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jnz .loop
|
|
lodsd
|
|
shl eax, cl
|
|
stosd
|
|
|
|
; fill the lsb bytes with zeros
|
|
pop ecx
|
|
test ecx, ecx
|
|
jz @f
|
|
xor eax, eax
|
|
rep stosd
|
|
@@:
|
|
cld
|
|
ret
|
|
|
|
.zero:
|
|
mov eax, [dst]
|
|
mov dword[eax], 0
|
|
ret
|
|
|
|
.overflow:
|
|
int3
|
|
ret
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_add uses esi edi edx ecx ebx eax, dst, src ;//////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Add a little endian MPINT to another little endian MPINT. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> src = pointer to little endian MPINT ;;
|
|
;> dst = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< dst = dst + src ;;
|
|
;;===========================================================================;;
|
|
|
|
locals
|
|
dd_cnt dd ?
|
|
endl
|
|
|
|
DEBUGF 1, "mpint_add(0x%x, 0x%x)\n", [dst], [src]
|
|
|
|
; Grow both numbers to same 4-byte boundary, if not already the case
|
|
mov esi, [src]
|
|
mov edi, [dst]
|
|
mov ecx, [esi]
|
|
test ecx, 11b
|
|
jnz .adjust_needed
|
|
cmp ecx, [edi]
|
|
jne .adjust_needed
|
|
|
|
; Do the additions
|
|
.length_ok:
|
|
add esi, 4
|
|
add edi, 4
|
|
shr ecx, 2
|
|
jz .done
|
|
mov eax, ecx
|
|
and eax, 111b
|
|
mov [dd_cnt], eax
|
|
shr ecx, 3
|
|
test ecx, ecx ; Clear carry flag
|
|
jz .no32
|
|
|
|
.loop32:
|
|
mov eax, [esi+00]
|
|
mov edx, [esi+04]
|
|
adc [edi+00], eax
|
|
adc [edi+04], edx
|
|
|
|
mov eax, [esi+08]
|
|
mov edx, [esi+12]
|
|
adc [edi+08], eax
|
|
adc [edi+12], edx
|
|
|
|
mov eax, [esi+16]
|
|
mov edx, [esi+20]
|
|
adc [edi+16], eax
|
|
adc [edi+20], edx
|
|
|
|
mov eax, [esi+24]
|
|
mov edx, [esi+28]
|
|
adc [edi+24], eax
|
|
adc [edi+28], edx
|
|
|
|
lea esi, [esi + 32]
|
|
lea edi, [edi + 32]
|
|
dec ecx
|
|
jnz .loop32
|
|
|
|
.no32:
|
|
mov ecx, [dd_cnt]
|
|
dec ecx
|
|
js .check_ovf
|
|
inc ecx
|
|
.dword_loop:
|
|
mov eax, [esi+0]
|
|
adc [edi+0], eax
|
|
lea esi, [esi + 4]
|
|
lea edi, [edi + 4]
|
|
dec ecx
|
|
jnz .dword_loop
|
|
|
|
.check_ovf:
|
|
jc .add_1 ; Carry
|
|
test byte[edi-1], 0x80
|
|
jnz .add_0 ; Currently highest bit set
|
|
.done:
|
|
ret
|
|
|
|
; Highest bit was set, add a 0 byte as MSB if possible
|
|
.add_0:
|
|
mov ecx, [dst]
|
|
cmp dword[ecx], MPINT_MAX_LEN
|
|
jae .ovf_0
|
|
mov byte[edi], 0
|
|
inc dword[ecx]
|
|
ret
|
|
|
|
.ovf_0:
|
|
int3
|
|
clc
|
|
; TODO: set overflow flag?
|
|
ret
|
|
|
|
; Carry bit was set, add a 1 byte as MSB if possible
|
|
.add_1:
|
|
mov ecx, [dst]
|
|
cmp dword[ecx], MPINT_MAX_LEN
|
|
jae .ovf_1
|
|
mov byte[edi], 1
|
|
inc dword[ecx]
|
|
ret
|
|
|
|
.ovf_1:
|
|
int3
|
|
stc
|
|
; TODO: set overflow flag?
|
|
ret
|
|
|
|
.adjust_needed:
|
|
; mov ecx, [esi]
|
|
mov eax, [edi]
|
|
; find the maximum of the two in ecx
|
|
mov edx, ecx
|
|
sub edx, eax
|
|
sbb ebx, ebx
|
|
and ebx, edx
|
|
sub ecx, ebx
|
|
; align to 4 byte boundary
|
|
add ecx, 3
|
|
and ecx, not 3
|
|
; adjust both mpints
|
|
stdcall mpint_grow, esi, ecx
|
|
stdcall mpint_grow, edi, ecx
|
|
jmp .length_ok
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_sub uses esi edi edx ecx ebx eax, dst, src ;//////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Subtract a little endian MPINT to another little endian MPINT. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> src = pointer to little endian MPINT ;;
|
|
;> dst = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< dst = dst - src ;;
|
|
;;===========================================================================;;
|
|
|
|
locals
|
|
dd_cnt dd ?
|
|
endl
|
|
|
|
DEBUGF 1, "mpint_sub(0x%x, 0x%x)\n", [dst], [src]
|
|
|
|
; Grow both numbers to same 4-byte boundary, if not already the case
|
|
mov esi, [src]
|
|
mov edi, [dst]
|
|
mov ecx, [esi]
|
|
test ecx, 11b
|
|
jnz .adjust_needed
|
|
cmp ecx, [edi]
|
|
jne .adjust_needed
|
|
|
|
; Do the subtractions
|
|
.length_ok:
|
|
add esi, 4
|
|
add edi, 4
|
|
shr ecx, 2
|
|
jz .done
|
|
mov eax, ecx
|
|
and eax, 111b
|
|
mov [dd_cnt], eax
|
|
shr ecx, 3
|
|
test ecx, ecx ; Clear carry flag
|
|
jz .no32
|
|
|
|
.loop32:
|
|
mov eax, [esi+00]
|
|
mov edx, [esi+04]
|
|
sbb [edi+00], eax
|
|
sbb [edi+04], edx
|
|
|
|
mov eax, [esi+08]
|
|
mov edx, [esi+12]
|
|
sbb [edi+08], eax
|
|
sbb [edi+12], edx
|
|
|
|
mov eax, [esi+16]
|
|
mov edx, [esi+20]
|
|
sbb [edi+16], eax
|
|
sbb [edi+20], edx
|
|
|
|
mov eax, [esi+24]
|
|
mov edx, [esi+28]
|
|
sbb [edi+24], eax
|
|
sbb [edi+28], edx
|
|
|
|
lea esi, [esi + 32]
|
|
lea edi, [edi + 32]
|
|
dec ecx
|
|
jnz .loop32
|
|
|
|
.no32:
|
|
mov ecx, [dd_cnt]
|
|
dec ecx
|
|
js .done
|
|
inc ecx
|
|
.dword_loop:
|
|
mov eax, [esi+0]
|
|
sbb [edi+0], eax
|
|
lea esi, [esi + 4]
|
|
lea edi, [edi + 4]
|
|
dec ecx
|
|
jnz .dword_loop
|
|
|
|
.done:
|
|
ret
|
|
|
|
.adjust_needed:
|
|
; mov ecx, [esi]
|
|
mov eax, [edi]
|
|
; find the maximum of the two in ecx
|
|
mov edx, ecx
|
|
sub edx, eax
|
|
sbb ebx, ebx
|
|
and ebx, edx
|
|
sub ecx, ebx
|
|
; align to 4 byte boundary
|
|
add ecx, 3
|
|
and ecx, not 3
|
|
; adjust both mpints
|
|
stdcall mpint_grow, esi, ecx
|
|
stdcall mpint_grow, edi, ecx
|
|
jmp .length_ok
|
|
|
|
endp
|
|
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_shrink uses eax edi, dst ;////////////////////////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Get rid of unnescessary leading zeroes on a little endian MPINT. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> src = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< ;;
|
|
;;===========================================================================;;
|
|
|
|
DEBUGF 1, "mpint_shrink(0x%x)\n", [dst]
|
|
|
|
stdcall mpint_bits, [dst]
|
|
shr eax, 3
|
|
inc eax
|
|
mov edi, [dst]
|
|
mov [edi], eax
|
|
|
|
ret
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_grow uses eax edi ecx, dst, length ;//////////////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Add leading zeroes on a little endian MPINT. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> src = pointer to little endian MPINT ;;
|
|
;> length = total length of the new MPINT in bytes ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< ;;
|
|
;;===========================================================================;;
|
|
|
|
DEBUGF 1, "mpint_grow(0x%x, %u): ", [dst], [length]
|
|
|
|
mov edi, [dst]
|
|
mov eax, [edi]
|
|
mov ecx, [length]
|
|
sub ecx, eax
|
|
jbe .dontgrow
|
|
lea edi, [edi + 4 + eax]
|
|
xor al, al
|
|
rep stosb
|
|
mov eax, [length]
|
|
mov edi, [dst]
|
|
mov [edi], eax
|
|
DEBUGF 1, "ok\n"
|
|
ret
|
|
|
|
.dontgrow:
|
|
DEBUGF 1, "already large enough!\n"
|
|
ret
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_mul uses eax ebx ecx edx esi edi, dst, a, b ;///////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Multiply a little endian MPINT with another little endian MPINT and store ;;
|
|
;? in a third one. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> dst = pointer to little endian MPINT ;;
|
|
;> a = pointer to little endian MPINT ;;
|
|
;> b = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< dst = a * b ;;
|
|
;;===========================================================================;;
|
|
|
|
locals
|
|
asize dd ?
|
|
bsize dd ?
|
|
counter dd ?
|
|
esp_ dd ?
|
|
endl
|
|
|
|
DEBUGF 1, "mpint_mul(0x%x, 0x%x, 0x%x)\n", [dst], [a], [b]
|
|
|
|
; Grow both numbers to individual 4-byte boundary, if not already the case
|
|
mov esi, [a]
|
|
mov edx, [b]
|
|
mov ecx, [esi]
|
|
mov ebx, [edx]
|
|
test ecx, 11b
|
|
jnz .adjust_needed
|
|
test ebx, 11b
|
|
jnz .adjust_needed
|
|
.length_ok:
|
|
|
|
; Must have Asize >= Bsize.
|
|
cmp ebx, ecx
|
|
ja .swap_a_b
|
|
.conditions_ok:
|
|
|
|
; D size will be A size + B size
|
|
lea eax, [ebx + ecx]
|
|
cmp eax, MPINT_MAX_LEN
|
|
ja .ovf
|
|
|
|
; [Asize] = number of dwords in x
|
|
shr ecx, 2
|
|
jz .zero
|
|
mov [asize], ecx
|
|
; esi = x ptr
|
|
add esi, 4
|
|
|
|
; [Bsize] = number of dwords in y
|
|
shr ebx, 2
|
|
jz .zero
|
|
mov [bsize], ebx
|
|
; edx = y ptr (temporarily)
|
|
add edx, 4
|
|
|
|
; store D size
|
|
mov edi, [dst]
|
|
mov [edi], eax
|
|
; edi = D ptr
|
|
add edi, 4
|
|
|
|
; Use esp as frame pointer instead of ebp
|
|
; ! Use the stack with extreme caution from here on !
|
|
mov [esp_], esp
|
|
mov esp, ebp
|
|
|
|
; ebp = B ptr
|
|
mov ebp, edx
|
|
|
|
; Do the first multiplication
|
|
mov eax, [esi] ; load A[0]
|
|
mul dword[ebp] ; multiply by B[0]
|
|
mov [edi], eax ; store to D[0]
|
|
; mov ecx, [Asize] ; Asize
|
|
dec ecx ; if Asize = 1, Bsize = 1 too
|
|
jz .done
|
|
|
|
; Prepare to enter loop1
|
|
mov eax, [asize-ebp+esp]
|
|
|
|
mov ebx, edx
|
|
lea esi, [esi + eax * 4] ; make A ptr point at end
|
|
lea edi, [edi + eax * 4] ; offset D ptr by Asize
|
|
neg ecx ; negate j size/index for inner loop
|
|
xor eax, eax ; clear carry
|
|
|
|
align 8
|
|
.loop1:
|
|
adc ebx, 0
|
|
mov eax, [esi + ecx * 4] ; load next dword at A[j]
|
|
mul dword[ebp]
|
|
add eax, ebx
|
|
mov [edi + ecx * 4], eax
|
|
inc ecx
|
|
mov ebx, edx
|
|
jnz .loop1
|
|
|
|
adc ebx, 0
|
|
mov eax, [bsize-ebp+esp]
|
|
mov [edi], ebx ; most significant dword of the product
|
|
add edi, 4 ; increment dst
|
|
dec eax
|
|
jz .skip
|
|
mov [counter-ebp+esp], eax ; set index i to Bsize
|
|
|
|
.outer:
|
|
add ebp, 4 ; make ebp point to next B dword
|
|
mov ecx, [asize-ebp+esp]
|
|
neg ecx
|
|
xor ebx, ebx
|
|
|
|
.loop2:
|
|
adc ebx, 0
|
|
mov eax, [esi + ecx * 4]
|
|
mul dword[ebp]
|
|
add eax, ebx
|
|
mov ebx, [edi + ecx * 4]
|
|
adc edx, 0
|
|
add ebx, eax
|
|
mov [edi + ecx * 4], ebx
|
|
inc ecx
|
|
mov ebx, edx
|
|
jnz .loop2
|
|
|
|
adc ebx, 0
|
|
|
|
mov [edi], ebx
|
|
add edi, 4
|
|
mov eax, [counter-ebp+esp]
|
|
dec eax
|
|
mov [counter-ebp+esp], eax
|
|
jnz .outer
|
|
|
|
.skip:
|
|
; restore esp, ebp
|
|
mov ebp, esp
|
|
mov esp, [esp_]
|
|
|
|
ret
|
|
|
|
.done:
|
|
mov [edi+4], edx ; store to D[1]
|
|
; restore esp, ebp
|
|
mov ebp, esp
|
|
mov esp, [esp_]
|
|
|
|
ret
|
|
|
|
.ovf:
|
|
int3
|
|
|
|
.zero:
|
|
mov eax, [dst]
|
|
mov dword[eax], 0
|
|
|
|
ret
|
|
|
|
.adjust_needed:
|
|
; align to 4 byte boundary
|
|
add ecx, 3
|
|
and ecx, not 3
|
|
add ebx, 3
|
|
and ebx, not 3
|
|
; adjust both mpints
|
|
stdcall mpint_grow, esi, ecx
|
|
stdcall mpint_grow, edx, ebx
|
|
jmp .length_ok
|
|
|
|
.swap_a_b:
|
|
mov eax, esi
|
|
mov esi, edx
|
|
mov edx, eax
|
|
|
|
mov eax, ebx
|
|
mov ebx, ecx
|
|
mov ecx, eax
|
|
jmp .conditions_ok
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_mod uses eax ebx ecx, dst, m ;////////////////////////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Find the modulo (remainder after division) of dst by mod. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> dst = pointer to little endian MPINT ;;
|
|
;> mod = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< dst = dst MOD m ;;
|
|
;;===========================================================================;;
|
|
|
|
locals
|
|
mpint_tmp rb MPINT_MAX_LEN+4
|
|
endl
|
|
|
|
DEBUGF 1, "mpint_mod(0x%x, 0x%x)\n", [dst], [m]
|
|
|
|
stdcall mpint_cmp, [m], [dst]
|
|
ja .done ; if mod > dst, dst = dst
|
|
je .zero ; if mod == dst, dst = 0
|
|
|
|
; left shift mod until the high order bits of mod and dst are aligned
|
|
|
|
stdcall mpint_bits, [dst]
|
|
mov ecx, eax
|
|
stdcall mpint_bits, [m]
|
|
test eax, eax
|
|
jz .zero ; if mod is zero, return
|
|
sub ecx, eax
|
|
lea ebx, [mpint_tmp]
|
|
stdcall mpint_shlmov, ebx, [m], ecx
|
|
inc ecx
|
|
|
|
; For every bit in dst (starting from the high order bit):
|
|
.bitloop:
|
|
stdcall mpint_cmp, [dst], ebx ; If dst > mpint_tmp
|
|
jb @f
|
|
stdcall mpint_sub, [dst], ebx ; dst = dst - mpint_tmp
|
|
@@:
|
|
dec ecx
|
|
jz .done
|
|
|
|
stdcall mpint_shr1, ebx ; mpint = mpint >> 1
|
|
jmp .bitloop
|
|
|
|
.done:
|
|
; adjust size of dst so it is no larger than mod
|
|
mov ebx, [dst]
|
|
mov ecx, [ebx] ; current size
|
|
mov eax, [m]
|
|
mov eax, [eax] ; size of mod
|
|
cmp ecx, eax
|
|
jb .ret
|
|
mov [ebx], eax
|
|
.ret:
|
|
ret
|
|
|
|
.zero:
|
|
mov ebx, [dst]
|
|
mov dword[ebx], 0
|
|
ret
|
|
|
|
endp
|
|
|
|
;;===========================================================================;;
|
|
proc mpint_modexp uses edi eax ebx ecx edx, dst, b, e, m ;///////////////////;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;? Find the modulo (remainder after division) of dst by mod. ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;> dst = pointer to buffer for little endian MPINT ;;
|
|
;> base = pointer to little endian MPINT ;;
|
|
;> exp = pointer to little endian MPINT ;;
|
|
;> mod = pointer to little endian MPINT ;;
|
|
;;---------------------------------------------------------------------------;;
|
|
;< dst = b ** e MOD m ;;
|
|
;;===========================================================================;;
|
|
|
|
locals
|
|
mpint_tmp rb MPINT_MAX_LEN+4
|
|
endl
|
|
|
|
DEBUGF 1, "mpint_modexp(0x%x, 0x%x, 0x%x, 0x%x)\n", [dst], [b], [e], [m]
|
|
|
|
; If mod is zero, return
|
|
stdcall mpint_bytes, [m]
|
|
test eax, eax
|
|
jz .mod_zero
|
|
test eax, 3
|
|
jnz .grow_mod
|
|
.modsize_ok:
|
|
|
|
; Find highest order byte in exponent
|
|
stdcall mpint_bytes, [e]
|
|
test eax, eax
|
|
jz .exp_zero
|
|
mov ecx, eax
|
|
mov edi, [e]
|
|
lea edi, [edi + 4 + ecx - 1]
|
|
|
|
; Find the highest order bit in this byte
|
|
mov al, [edi]
|
|
test al, al
|
|
jz .invalid
|
|
mov bl, 9
|
|
@@:
|
|
dec bl
|
|
shl al, 1
|
|
jnc @r
|
|
|
|
; Make pointer to tmp mpint for convenient access
|
|
lea edx, [mpint_tmp]
|
|
|
|
; Initialise result to base, to take care of the highest order bit
|
|
stdcall mpint_mov, [dst], [b]
|
|
dec bl
|
|
jz .next_byte
|
|
.bit_loop:
|
|
; For each bit, square result
|
|
stdcall mpint_mov, edx, [dst]
|
|
stdcall mpint_mul, [dst], edx, edx
|
|
stdcall mpint_mod, [dst], [m]
|
|
|
|
; If the bit is set, multiply result by the base
|
|
shl al, 1
|
|
jnc .next_bit
|
|
stdcall mpint_mov, edx, [dst]
|
|
stdcall mpint_mul, [dst], [b], edx
|
|
stdcall mpint_mod, [dst], [m]
|
|
.next_bit:
|
|
dec bl
|
|
jnz .bit_loop
|
|
.next_byte:
|
|
dec ecx
|
|
jz .done
|
|
dec edi
|
|
mov al, [edi]
|
|
mov bl, 8
|
|
jmp .bit_loop
|
|
.done:
|
|
ret
|
|
|
|
.mod_zero:
|
|
DEBUGF 3, "modexp with modulo 0\n"
|
|
; if mod is zero, result = 0
|
|
mov eax, [dst]
|
|
mov dword[eax], 0
|
|
ret
|
|
|
|
.exp_zero:
|
|
DEBUGF 3, "modexp with exponent 0\n"
|
|
; if exponent is zero, result = 1
|
|
mov eax, [dst]
|
|
mov dword[eax], 1
|
|
mov byte[eax+4], 1
|
|
ret
|
|
|
|
.invalid:
|
|
DEBUGF 3, "modexp: Invalid input!\n"
|
|
ret
|
|
|
|
.grow_mod:
|
|
add eax, 3
|
|
and eax, not 3
|
|
stdcall mpint_grow, [m], eax
|
|
jmp .modsize_ok
|
|
|
|
endp
|
|
|