Code Access Security - Evidence

Evidence

Evidence can be any information associated with an assembly. The default evidences that are used by .NET code access security are:

  • Application directory - The directory in which an assembly resides.
  • Publisher - The assembly's publisher's digital signature (requires the assembly to be signed via Authenticode).
  • URL - the complete URL where the assembly was launched from
  • Site - The hostname of the URL/Remote Domain/VPN.
  • Zone - the security zone where the assembly resides
  • Hash - a cryptographic hash of the assembly, which identifies a specific version.
  • Strong Name - a combination of the assembly name, version and public key of the signing key used to sign the assembly. The signing key is not an X509 certificate, but a custom key pair generated by the strong naming tool, SN.EXE or by Visual Studio.

A developer can use custom evidence (so-called assembly evidence) but this requires writing a security assembly and in version 1.1 of .NET this facility does not work.

Evidence based on a hash of the assembly is easily obtained in code. For example in C#, evidence may be obtained by the following code clause:

this.GetType.Assembly.Evidence

Read more about this topic:  Code Access Security

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