Test Key Signing

re: Test Key Signing

Kevin Westhead — Wed, 26 Oct 2005 02:59:50 GMT

"Note that you need to register the test public key only, attempting to register the full keypair will result in the message: 'The public key supplied for test signing is invalid.'"

Doesn't this mean that the line

D:\src>sn -Vr assembly.dll testKey.snk

should actually be

D:\src>sn -Vr assembly.dll testPublicKey.snk

You also mentioned a couple of problems with managing test keys. Is this feature currently in use on the CLR and BCL teams? If so, how are they managing their test keys?

re: Test Key Signing

shawnfa — Sat, 05 Nov 2005 02:42:20 GMT

Hi Kevin -- you're write, I meant to register the public key, and I've updated it.

This feature is not currently used by the CLR and BCL teams (we used delay signing for Whidbey), but we could move towards it in the future.

-Shawn

Delay signing and VS 2005 challenges

Teucer's Quiver — Mon, 13 Feb 2006 18:57:37 GMT

re: Test Key Signing

hevean — Thu, 15 Mar 2007 14:45:48 GMT

Hi all,

what's the different between 'sn -TS....' and 'sn -Ra'. and what's the different between the re-signed .dll file via 'sn -TS....' and via 'sn -TS....'.

Thanks :)

re: Test Key Signing

shawnfa — Fri, 16 Mar 2007 01:37:56 GMT

SN -TS test signs an assembly as I described in this post. That means the assembly will not load unless the machine has registerd the test key pair for that assembly.

SN -Ra re-signs an assembly, leaving it with a valid signature. Since the signature is valid, it does not require any special configuration to verify on the user's machine.

-Shawn

re: Test Key Signing

Steve — Mon, 14 May 2007 23:58:46 GMT

Am I trying to understand the world of digital signing, so I'm probably missing something ... but if an internal signing authority can resign a delay signed or test signed assembly, what prevents a malicious person from re-signing an assembly that I have deployed? Does this imply that there needs to be some link between the test and official keys? I assume there is some way to re-sign a delay signed assembly with a different public key if the original key is lost or compromised?

re: Test Key Signing

shawnfa — Tue, 15 May 2007 18:31:40 GMT

Hi Steve,

The intent is that you never deploy a test signed assembly. Once you are ready to ship your final bits, then you'll apply the real signature. This signature can only be calculated if you have both the private and public key for the assembly.

A third party could of course resign your assembly with their own key. This would have the effect of changing the public key of the assembly however, which gives the assembly an entirely different identity.

-Shawn

(The link between the test key and the public key that you mention is kept in the registry in the skip verification entries by the way.)

re: Test Key Signing

Steve — Tue, 15 May 2007 22:30:40 GMT

Hello again,

Thanks for your reply. I have a situation where I inherited a project that was delay signed but I only have the public key - the original key pair is not available. The assemblies have not been deployed, so I am trying to find out what my options are when deployment time comes. I tried generating another key pair and delay signed a test assembly that was previous signed with the original public key with the new public key. When I tried to use this test assembly it would load, saying it had been tampered with. Do you know how I can resolve this issue? Thanks again,

Steve

re: Test Key Signing

shawnfa — Wed, 23 May 2007 18:52:29 GMT

If you've lost the private key for the assembly's public key, your only option is to generate a new key pair to sign the assemblies with. This will of course end up changing the identity of the assemblies -- however if we allowed anyone to sign assemblies who did not have the corresponding private key, this would totally invalidate the purpose of the signatures :-)

-Shawn

David DeWinter » The AllowPartiallyTrustedCallersAttribute (APTCA) – #6

Fri, 22 May 2009 04:14:55 GMT

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