void PackHeader::putPackHeader(upx_bytep p)
{
assert(get_le32(p) == UPX_MAGIC_LE32);
if (get_le32(p+4) != UPX_MAGIC2_LE32)
{
//fprintf(stderr, "MAGIC2_LE32: %x %x\n", get_le32(p+4), UPX_MAGIC2_LE32);
throwBadLoader();
}
int size = 0;
int old_chksum = 0;
// the new variable length header
if (format < 128)
{
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;
}
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;
}
else if (format == UPX_F_DOS_EXEH)
{
throwInternalError("invalid format");
}
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;
assert(n_mru == 0 || (n_mru >= 2 && n_mru <= 256));
p[30] = (unsigned char) (n_mru ? n_mru - 1 : 0);
}
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);
set_be32(p+20,c_adler);
set_be32(p+24,u_file_size);
p[28] = (unsigned char) filter;
p[29] = (unsigned char) filter_cto;
assert(n_mru == 0 || (n_mru >= 2 && n_mru <= 256));
p[30] = (unsigned char) (n_mru ? n_mru - 1 : 0);
}
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);
}
int find_be32(const void *b, int blen, unsigned what)
{
unsigned char w[4];
set_be32(w, what);
return find(b, blen, w, 4);
}
