I needed to see someone about my shoulder/neck injury. On the recommendation of a coworker, I went to see Dr. Jon Dickinson. He seems to be very nice, knowledgeable, and happily explains what he’s observing, rather than just writing a prescription.
Dickinson, Jon A, MD
California Pacific Ortho and Sports Med
3838 California St Rm 715
San Francisco, CA 94118
(415) 668-8010
I just took a fun test to determine how good I am at discriminating colors. Lower values are better. My results:
Your score: 8 Gender: Male Age range: 30-39 Best score for your gender and age range: 0 Highest score for your gender and age range: 1464
Neat! Take the test here.
We needed to modify the resources of an installer and then apply an Authenticode signature. Unfortunately, it already had a signature on it, and modifying the resources of an executable with a signature results in a corrupted signature. The Microsoft signing tools cannot recover from this situation, so:
It is not possible to re-sign a file after modifying its resources.
However, it is possible to remove the existing signature, modify the binary, and then apply a new signature. There are two approaches (which almost certainly amount to the same thing):
Your Certificate Authority will supply one of the following:
For the second and third case, these file must be converted to a Personal Information Exchange (.pfx), using the Pvk2Pfx.exe tool.
Syntax for .spc conversion:
pvk2pfx -pvk filename.pvk -pi password -spc filename.spc -pfx output.pfx
The syntax is identical for .cer conversion:
pvk2pfx -pvk filename.pvk -pi password -spc filename.cer -pfx output.pfx
Signtool.exe can be used to sign executables (.exe) and Dynamic Link Libraries (.DLL).
signtool.exe sign /v /f filename.pvk /p password executable
signtool.exe sign /v /f filename.pvk /p password /t timeurl executable
Where timeurl is the URL of your Certificate Authority’s timestamp server (e.g. http://timestamp.verisign.com/scripts/timestamp.dll for VeriSign)
signtool verify /pa executable
/pa indicates that the “Default Authenticode” verification policy is used. Omitting the switch will cause the verification to fail, which does not necessarily mean that a given file isn’t Authenticode signed.
While investigating Authenticode, I become curious about the Portable Executable format. This is the file format used by all Windows executables.
Here is a good overview in the context of .Net. And here is the referenced image which is missing from that post (originally http://jfmasmtuts.blowsearch.ws/Ch2/peheader2.jpg):
This missing image turns out to be part of a fantastic overview of the PE architecture. While the original article appears to be long gone, it lives on in an archive (and as a PDF in my own archive).
Here is a significantly more dry introduction, from MSDN.
With CAPICOM deprecated, MSDN suggests using the mssign32.dll functions. There are two fundamental problems with this:
Well, at least I can do something about #2. Here is a minimal version of a header file for mssign32.dll. It includes direct function declarations, as well as function pointer typedefs.
The function pointers can be used with LoadLibrary/GetProcAddress to dynamically call the functions, as in:
SignerSignPtr pSignerSign =
(SignerSignPtr)GetProcAddress(hModule, "SignerSign");