Certificate File Workbench
Untangle a certificate bundle with real signature checks, explicit trust anchors and downloadable files. Private keys are optional and require a separate local-processing choice.
How we build a check
This workbench processes supported inputs locally. We test calculations, file structure and generated artifacts using independent readers or known fixtures where available. The example runs the same processing path as a supplied input; it does not stand in for checking your own result.
Editorial responsibility
KitForma maintains this tool and its guides. The source notes on the tool page link to the supporting documentation. We do not claim affiliation with the referenced hardware manufacturers or platforms. Review date: 2026-10-18.
Limits and updates
16 files / 4 MiB combined / 32 objects; ASN.1 depth 32 and 20,000 nodes; browser worker 60 seconds, cancellable. Definite-length PEM/DER X.509 and PKCS10, RSA and P-256/P-384/P-521 PKCS8/PKCS1/SEC1 keys, password-MAC PFX. PBES2/PBKDF2 AES-CBC only (up to 1,000,000 iterations; PFX MAC up to 100,000). No legacy RC2/3DES, PKCS7/P7B, SSH keys, EdDSA/DSA private keys, multiple private keys, live server/revocation checks or public CA issuance. Use trusted local software for keys if your security policy forbids browser handling. If a specification changes or a result appears incorrect, send the relevant source URL and a non-sensitive reproduction to kitforma@outlook.com.
Open-source components
The tools use self-hosted open-source components appropriate to each format, including PDF.js, pdf-lib, fflate, SheetJS, MediaInfo by MediaArea.net SARL and others. Component versions and licenses. MediaInfo license · fflate license.