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Calculate correct PE checksum instead of setting it to 0.

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Patch provided by Roland Schwingel.
This commit is contained in:
Per Allansson 2013-03-07 07:26:56 +01:00
parent 7485a6b7a4
commit 09c664791b
2 changed files with 28 additions and 2 deletions
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1
TODO
View File

@ -4,7 +4,6 @@
- verify signatures - verify signatures
- remove mmap usage to increase portability - remove mmap usage to increase portability
- tests - tests
- calculate correct PE checksum instead of setting it to 0
- fix other stuff marked 'XXX' - fix other stuff marked 'XXX'
- free memory properly :) - free memory properly :)

29
osslsigncode.c
View File

@ -534,6 +534,32 @@ static void get_indirect_data_blob(u_char **blob, int *len, const EVP_MD *md, in
i2d_SpcIndirectDataContent(idc, &p); i2d_SpcIndirectDataContent(idc, &p);
} }
static void recalc_pe_checksum(BIO *outdata, unsigned int peheader)
{
unsigned int checkSum = 0;
unsigned short val;
unsigned int size = 0;
/* First set current checksum to 0. */
(void)BIO_seek(outdata, peheader + 88);
BIO_write(outdata, &checkSum, 4);
/* recalc checksum. */
(void)BIO_seek(outdata, 0);
while (BIO_read(outdata, &val, 2) == 2) {
checkSum += val;
checkSum = 0xffff & (checkSum + (checkSum >> 0x10));
size += 2;
}
checkSum = 0xffff & (checkSum + (checkSum >> 0x10));
checkSum += size;
/* write back checksum. */
(void)BIO_seek(outdata, peheader + 88);
BIO_write(outdata, &checkSum, 4);
}
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
BIO *btmp, *sigdata, *hash, *outdata; BIO *btmp, *sigdata, *hash, *outdata;
@ -751,7 +777,7 @@ int main(int argc, char **argv)
} }
/* Create outdata file */ /* Create outdata file */
outdata = BIO_new_file(outfile, "wb"); outdata = BIO_new_file(outfile, "w+b");
if (outdata == NULL) if (outdata == NULL)
DO_EXIT_1("Failed to create file: %s\n", outfile); DO_EXIT_1("Failed to create file: %s\n", outfile);
@ -991,6 +1017,7 @@ int main(int argc, char **argv)
BIO_write(outdata, buf, 4); BIO_write(outdata, buf, 4);
PUT_UINT32_LE(len+8+padlen, buf); PUT_UINT32_LE(len+8+padlen, buf);
BIO_write(outdata, buf, 4); BIO_write(outdata, buf, 4);
recalc_pe_checksum(outdata, peheader);
} else { } else {
(void)BIO_seek(outdata, 0x30); (void)BIO_seek(outdata, 0x30);
PUT_UINT32_LE(len+padlen, buf); PUT_UINT32_LE(len+padlen, buf);