How can I check the digital signature of an .exe or .dll in Perl?

Question

I'm trying to find a way to script (preferably in Perl) - a check to see if an .exe or .dll is digitally signed - if anyone has an easy direction to point me, I'd appreciate it.

Answer 1

An idea is to translate the sample program on MSDN using Win32::API.

Update: I took a stab at translating the sample program from MSDN. For some reason, the call keeps returning 0x800B0001 (=TRUST_E_PROVIDER_UNKNOWN) for files that verify correctly with the Win32 sample code. I am posting the script here in case someone can spot my error.

Note that I have no idea how to memset the structures although it should not matter. More importantly, I think the problem is with the way I am constructing the GUID for WINTRUST_ACTION_GENERIC_VERIFY_V2 and/or the way I am passing it.

#!/usr/bin/perl

use strict;
use warnings;

use Win32; # for GetLastError
use Win32::API;
use Win32::API::Struct;
use Win32::API::Type;

use Readonly;

Readonly::Hash my %TRUST_E => (
    NOSIGNATURE          => sprintf('%8.8X', 0x800B0100),
    SUBJECT_FORM_UNKNOWN => sprintf('%8.8X', 0x800B0003),
    PROVIDER_UNKNOWN     => sprintf('%8.8X', 0x800B0001),
    EXPLICIT_DISTRUST    => sprintf('%8.8X', 0x800B0111),
    SUBJECT_NOT_TRUSTED  => sprintf('%8.8X', 0x800B0004),
    ACTION_UNKNOWN       => sprintf('%8.8X', 0x800B0002),
);

Readonly::Hash my %WTD => (
    UI_ALL    => 1,
    UI_NONE   => 2,
    UI_NOBAD  => 3,
    UI_NOGOOD => 4,

    REVOKE_NONE       => 0x00000000,
    REVOKE_WHOLECHAIN => 0x00000001,

    CHOICE_FILE    => 1,
    CHOICE_CATALOG => 2,
    CHOICE_BLOB    => 3,
    CHOICE_SIGNER  => 4,
    CHOICE_CERT    => 5,

    PROV_FLAGS_MASK                      => 0x0000FFFF,
    USE_IE4_TRUST_FLAG                   => 0x00000001,
    NO_IE4_CHAIN_FLAG                    => 0x00000002,
    NO_POLICY_USAGE_FLAG                 => 0x00000004,
    REVOCATION_CHECK_NONE                => 0x00000010,
    REVOCATION_CHECK_END_CERT            => 0x00000020,
    REVOCATION_CHECK_CHAIN               => 0x00000040,
    REVOCATION_CHECK_CHAIN_EXCLUDE_ROOT  => 0x00000080,
    SAFER_FLAG                           => 0x00000100,
    HASH_ONLY_FLAG                       => 0x00000200,
    USE_DEFAULT_OSVER_CHECK              => 0x00000400,
    LIFETIME_SIGNING_FLAG                => 0x00000800,
    CACHE_ONLY_URL_RETRIEVAL             => 0x00001000,

    STATEACTION_IGNORE           => 0x00000000,
    STATEACTION_VERIFY           => 0x00000001,
    STATEACTION_CLOSE            => 0x00000002,
    STATEACTION_AUTO_CACHE       => 0x00000003,
    STATEACTION_AUTO_CACHE_FLUSH => 0x00000004,

    UICONTEXT_EXECUTE => 0,
    UICONTEXT_INSTALL => 1,
);

typedef Win32::API::Struct GUID => qw{
    DWORD Data1;
    WORD  Data2;
    WORD  Data3;
    BYTE  Data4[8];
};

typedef Win32::API::Struct WINTRUST_FILE_INFO => qw{
      DWORD   cbStruct;
      LPCWSTR pcwszFilePath;
      HANDLE  hFile;
      GUID    *pgKnownSubject;
};

typedef Win32::API::Struct WINTRUST_DATA_FILE_INFO => qw{
    DWORD  cbStruct;
    LPVOID pPolicyCallbackData;
    LPVOID pSIPClientData;
    DWORD  dwUIChoice;
    DWORD  fdwRevocationChecks;
    DWORD  dwUnionChoice;
    PWINTRUST_FILE_INFO pFile;
    DWORD  dwStateAction;
    HANDLE hWVTStateData;
    PWCHAR pwszURLReference;
    DWORD  dwProvFlags;
    DWORD  dwUIContext;
};

for my $file ( @ARGV ) {
    printf "%s: %s\n", $file, VerifyEmbeddedSignature($file);
}

sub VerifyEmbeddedSignature {
    my ($file) = @_;

    # From SoftPub.h '00AAC56B-CD44-11d0-8CC2-00C04FC295EE'
    # 0xaac56b 0xcd44 0x11d0 0x8c 0xc2 0x0 0xc0 0x4f 0xc2 0x95 0xee

    my $WINTRUST_ACTION_GENERIC_VERIFY_V2
        = Win32::API::Struct->new('GUID');
    $WINTRUST_ACTION_GENERIC_VERIFY_V2->{Data1} = 0xaac56b;
    $WINTRUST_ACTION_GENERIC_VERIFY_V2->{Data2} = 0xcd44;
    $WINTRUST_ACTION_GENERIC_VERIFY_V2->{Data3} = 0x11d0;
    $WINTRUST_ACTION_GENERIC_VERIFY_V2->{Data4} = [
        0x8c, 0xc2, 0x0, 0xc0, 0x4f, 0xc2, 0x95, 0xee,
    ];

    my $FileData = Win32::API::Struct->new('WINTRUST_FILE_INFO');

    $FileData->{cbStruct} = $FileData->sizeof;
    $FileData->{pcwszFilePath}  = $file;
    $FileData->{hFile}          = undef;
    $FileData->{pgKnownSubject} = undef;

    my $WinTrustData = Win32::API::Struct->new(
        'WINTRUST_DATA_FILE_INFO');

    $WinTrustData->{cbStruct} = $WinTrustData->sizeof;
    $WinTrustData->{pPolicyCallbackData} = undef;
    $WinTrustData->{pSIPClientData}      = undef;
    $WinTrustData->{dwUIChoice}          = $WTD{UI_NONE};
    $WinTrustData->{fdwRevocationChecks} = $WTD{REVOKE_NONE};
    $WinTrustData->{dwUnionChoice}       = $WTD{CHOICE_FILE};
    $WinTrustData->{dwStateAction}       = 0;
    $WinTrustData->{hWVTStateData}       = undef;
    $WinTrustData->{pwszURLReference}    = undef;
    $WinTrustData->{dwProvFlags}         = $WTD{SAFER_FLAG};
    $WinTrustData->{dwUIContext}         = 0;
    $WinTrustData->{pFile}               = $FileData;

    my $WinVerifyTrust = Win32::API->new(
        wintrust => q{LONG WinVerifyTrust(
            HWND hWnd,
            GUID *pgActionID,
            LPVOID pWVTData)
        }
    );

    my $status = sprintf('0x%8.8X', $WinVerifyTrust->Call(
        -1,
        $WINTRUST_ACTION_GENERIC_VERIFY_V2,
        $WinTrustData,
    ));

    warn "$status\n";

    if ($status eq sprintf '0x%8.8X', 0) {
         return 'signed and the signature was verified';
    }
    elsif ($status eq $TRUST_E{SUBJECT_NOT_TRUSTED}) {
        return 'The subject failed the specified verification action';
    }
    elsif ($status eq $TRUST_E{PROVIDER_UNKNOWN}) {
        return 'The trust provider is not recognized on this system';
    }
    elsif ($status eq $TRUST_E{ACTION_UNKNOWN}) {
        return 'The trust provider does not support the specified action';
    }
    elsif ($status eq $TRUST_E{SUBJECT_FORM_UNKNOWN}) {
        return
        'The trust provider does not support the form ' .
        'specified for the subject';
    }
    else {
        return "Error code: $status";
    }

    return;
}