CAT to TXT Converter

CAT to TXT Conversion Explained

Converting Security catalog files (.CAT) to plain text files (.TXT) is a one-way extraction process. A .CAT file is a binary cryptographic file used by Microsoft Windows to digitally sign a collection of files. When you convert .CAT to .TXT, you extract the embedded metadata—such as file names, cryptographic hashes (thumbprints), and digital certificate details—into a human-readable format.

People convert .CAT to .TXT to audit driver packages, verify hash algorithms, or document software signatures without needing specialized cryptographic tools. You gain universal readability and the ability to search the file contents using standard text editors. However, you lose all cryptographic validity. A .TXT file cannot be used by the Windows operating system to verify file integrity or pass Driver Signature Enforcement. If your goal is to install a driver or verify a system file, converting to text is a bad idea; you must keep the original .CAT file.

Typical Tasks and Users

This conversion is highly specific to security and system administration workflows. Common users include:

• System Administrators: Auditing Windows driver packages to ensure they use modern hashing algorithms like SHA-256 instead of deprecated SHA-1.
• Security Analysts: Extracting file hashes from a catalog to cross-reference them with threat intelligence databases or malware logs.
• Reverse Engineers: Inspecting the Certificate Trust List (CTL) within a software package to identify the original publisher and timestamp countersignatures.
• Software Developers: Generating readable logs of their signed release artifacts to store in version control systems like Git.

Software & Tool Support

Because .CAT files use a binary ASN.1 DER-encoded structure (specifically PKCS #7 / CMS), standard text editors cannot read them. You must use specialized tools to parse and extract the text:

• Windows SDK: Microsoft provides command-line tools like signtool.exe to verify catalogs, though extracting raw text requires specific command flags.
• PowerShell: The built-in Get-AuthenticodeSignature cmdlet can read .CAT files and output signature details to the console, which can be piped to a .TXT file.
• OpenSSL: The free, open-source OpenSSL library can parse ASN.1 structures using the asn1parse or pkcs7 commands to dump the binary contents into readable text.
• Windows Cryptographic Shell: Double-clicking a .CAT file in Windows opens a GUI to view the contents, but it lacks a native "export to text" feature.

Pros and Cons of the Conversion

Pros:

• Universal Compatibility: Any device, operating system, or text editor can open a .TXT file.
• Searchability: You can easily use tools like grep or standard search functions to find specific file names or hash values.
• Transparency: Exposes the hidden binary contents of the catalog, making it easy to read the Subject, Issuer, and valid date ranges of the signing certificate.

Cons:

• Loss of Functionality: The resulting .TXT file is strictly an informational report. It cannot enforce security policies.
• One-Way Process: You cannot convert the .TXT file back into a .CAT file. Creating a valid .CAT requires the original files, a .CDF (Catalog Definition File), the MakeCat tool, and a private key to re-sign it.
• Loss of Binary Structure: The strict ASN.1 hierarchical structure is flattened into plain text, which cannot be parsed by cryptographic APIs.

Conversion Difficulties & Why Convert.Guru

The primary technical difficulty in this conversion is parsing the Abstract Syntax Notation One (ASN.1) encoding. A .CAT file is not a simple list; it is a complex cryptographic container. To convert it accurately, a tool must decode the Object Identifiers (OIDs), extract the Certificate Trust List, format the binary hash values into readable hexadecimal strings, and handle nested timestamp signatures. If a parser fails to recognize a specific OID, it may output gibberish or drop critical file hashes entirely.

Convert.Guru handles this complex parsing pipeline automatically. When you use Convert.Guru to convert cat to txt, the platform safely decodes the PKCS #7 structure and extracts the relevant metadata—file names, hash algorithms, thumbprints, and signer information—into a clean, structured text layout. It eliminates the need to install the heavy Windows SDK or write complex OpenSSL command-line scripts.

CAT vs. TXT: What is the better choice?

Which format should you choose?

You should choose .CAT when distributing Windows software, drivers, or firmware updates. The operating system strictly requires the binary .CAT file to verify that the accompanying files have not been tampered with since they were signed.

You should choose .TXT only when you need a human-readable report of the catalog's contents. It is the better choice for compliance documentation, security auditing, or sharing hash lists with colleagues who do not have access to Windows cryptographic tools. Avoid this conversion entirely if you are trying to bypass driver signature enforcement or modify the catalog contents.

Conclusion

Converting .CAT to .TXT is a highly specialized process that transforms a binary security token into a readable text report. While this conversion makes it incredibly easy to audit file hashes and certificate metadata, the critical limitation is that the resulting text file loses all cryptographic authority and cannot be used by Windows for verification. For security analysts and administrators who need quick, accurate visibility into Windows catalog files without wrestling with command-line utilities, Convert.Guru provides a reliable and instant extraction tool.