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Added UPX_MAGIC2_LE32 as an additional magic number for the original

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packheader as stored in the stubs.

committer: mfx <mfx> 979754722 +0000
This commit is contained in:
Markus F.X.J. Oberhumer 2001-01-17 18:05:22 +00:00
parent ad4bf703f0
commit 4322931d97
4 changed files with 49 additions and 19 deletions
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47
src/packhead.cpp
View File

@ -99,7 +99,7 @@ int PackHeader::getPackHeaderSize() const
/*************************************************************************
//
// see stub/header.ash
**************************************************************************/
void PackHeader::putPackHeader(upx_bytep p)
@ -108,32 +108,34 @@ void PackHeader::putPackHeader(upx_bytep p)
throwBadLoader();
#else
assert(get_le32(p) == UPX_MAGIC_LE32);
int size = 0;
if (get_le32(p+4) != UPX_MAGIC2_LE32)
{
printf("%x %x\n", get_le32(p+4), UPX_MAGIC2_LE32);
throwBadLoader();
}
p[4] = (unsigned char) version;
p[5] = (unsigned char) format;
p[6] = (unsigned char) method;
p[7] = (unsigned char) level;
int size = 0;
int old_chksum = 0;
// the new variable length header
if (format < 128)
{
set_le32(p+8,u_adler);
set_le32(p+12,c_adler);
if (format == UPX_F_DOS_COM || format == UPX_F_DOS_SYS)
{
size = 22;
old_chksum = get_packheader_checksum(p, size - 1);
set_le16(p+16,u_len);
set_le16(p+18,c_len);
p[20] = (unsigned char) filter;
size = 22;
}
else if (format == UPX_F_DOS_EXE)
{
size = 27;
old_chksum = get_packheader_checksum(p, size - 1);
set_le24(p+16,u_len);
set_le24(p+19,c_len);
set_le24(p+22,u_file_size);
p[25] = (unsigned char) filter;
size = 27;
}
else if (format == UPX_F_DOS_EXEH)
{
@ -141,17 +143,22 @@ void PackHeader::putPackHeader(upx_bytep p)
}
else
{
size = 32;
old_chksum = get_packheader_checksum(p, size - 1);
set_le32(p+16,u_len);
set_le32(p+20,c_len);
set_le32(p+24,u_file_size);
p[28] = (unsigned char) filter;
p[29] = (unsigned char) filter_cto;
p[30] = 0;
size = 32;
}
set_le32(p+8,u_adler);
set_le32(p+12,c_adler);
}
else
{
size = 32;
old_chksum = get_packheader_checksum(p, size - 1);
set_be32(p+8,u_len);
set_be32(p+12,c_len);
set_be32(p+16,u_adler);
@ -160,11 +167,25 @@ void PackHeader::putPackHeader(upx_bytep p)
p[28] = (unsigned char) filter;
p[29] = (unsigned char) filter_cto;
p[30] = 0;
size = 32;
}
// store header_checksum
p[4] = (unsigned char) version;
p[5] = (unsigned char) format;
p[6] = (unsigned char) method;
p[7] = (unsigned char) level;
// header_checksum
assert(size == getPackHeaderSize());
// check old header_checksum
if (p[size - 1] != 0)
{
if (p[size - 1] != old_chksum)
{
printf("old_checksum: %d %d\n", p[size - 1], old_chksum);
throwBadLoader();
}
}
// store new header_checksum
p[size - 1] = get_packheader_checksum(p, size - 1);
#endif /* UNUPX */
}

13
src/stub/header.ash
View File

@ -28,11 +28,16 @@
; ------------- HEADER ------------- ; __UPX1HEAD__
db 'UPX!' ; 0 magic
db 85,80,88,33 ; 0 UPX_MAGIC_LE32
%if 0
db 0 ; 4 version
db 0 ; 5 type (com,sys,...)
db 0 ; 5 format
db 0 ; 6 compression method
db 0 ; 7 compression level
%else
; another magic for PackHeader::putPackHeader
db 161,216,208,213 ; UPX_MAGIC2_LE32
%endif
dd 0 ; 8 uncompressed adler32
dd 0 ; 12 compressed adler32
@ -52,9 +57,9 @@
dd 0 ; 20 compressed len
dd 0 ; 24 original file size
db 0 ; 28 filter id
db 0 ; 29 cto (for filters 0x21..0x29)
db 0 ; 29 filter cto
db 0 ; unsused
db 0 ; 31 header checksum
db 45 ; 31 header checksum
%endif

7
src/stub/l_tos.s
View File

@ -288,8 +288,11 @@ clear_bss_end:
align4
dc.b 'UPX!' ; magic
dc.l 0,0,0,0,0,0,0 ; 28 bytes - #include "header.ash"
; 32 bytes - #include "header.ash"
dc.b 85,80,88,33 ; UPX_MAGIC_LE32
dc.b 161,216,208,213 ; UPX_MAGIC2_LE32
dc.l 0,0,0,0,0 ; 20 bytes
dc.b 0,0,0,45
; end of text segment - size is a multiple of 4

1
src/unupx.h
View File

@ -88,6 +88,7 @@ typedef unsigned upx_uint32;
#define UPX_MAGIC_LE32 0x21585055 /* "UPX!" */
#define UPX_MAGIC2_LE32 0xD5D0D8A1
/*************************************************************************