X.509 Certificate (PEM) Inspector
X.509 Certificate (PEM) Inspector: Parses ASN.1 DER sequence, decodes X.509 v3 fields, extracts Subject Alternative Names (SAN), and validates dates.
About this x.509 certificate (pem) inspector
Parses ASN.1 DER sequence, decodes X.509 v3 fields, extracts Subject Alternative Names (SAN), and validates dates Runs entirely in-memory using Web Crypto primitives to keep sensitive tokens, certificates, and cryptographic keys secure from third-party interception.
Encoding & cryptographic principles
Parses a supplied PEM certificate and reports its exposed subject, issuer, serial number, validity fields, signature algorithm, extension types, and self-signed result. A parser result is not certificate-chain, hostname, or revocation validation.
Worked verification example
Scenario: Parse one complete demonstration PEM certificate and report its encoded fields.
Sample input:
Processing: Parses the certificate and reports serial, subject, issuer, validity dates, algorithm, extension types, and self-signed status. Parsed does not mean trusted, current, or hostname-valid.
Illustrative output:
Security parameters & input constraints
valid:true means the certificate parsed, not that it is trusted, in date, hostname-matched or unrevoked. The self-signed flag is not a trust decision. No live TLS, CA chain, OCSP or CRL check is performed.
Cryptographic digests, encoded strings, and signatures generated by X.509 Certificate (PEM) Inspector should be verified against target authentication systems before production use.
Client-side Web Crypto boundary
Key derivation, hashing, and encoding in X.509 Certificate (PEM) Inspector execute in local memory using Web Crypto APIs without remote socket transmission.
Cryptographic specifications & RFC standards
Technical specifications and cryptographic RFC standards governing algorithms and key representations:
X.509 Certificate (PEM) Inspector verification · Audit standards
How to use it
- Paste a PEM X.509 certificate.
- Parse it locally and extract serial, subject, issuer, validity dates, signature algorithm, extensions and self-signed check.
- Read valid:true with parsed metadata or valid:false with an error in JSON.
Frequently asked questions
What does X.509 Certificate Inspector return?+
It trims the supplied certificate text and tries to parse it. A successful result has `valid: true`, `certificateType: "X.509"`, serial number, subject, issuer, ISO dates, signature algorithm, extension type names, and `selfSigned`; a parsing failure returns `valid: false` and `error`.
What can I inspect from a PEM certificate?+
Paste a PEM certificate. The result exposes its encoded subject, issuer, validity dates, signature algorithm, listed extension types, and whether the parser considers it self-signed.
Does `valid: true` establish trust?+
No. It establishes that this parser read the supplied certificate. Chain building, hostname matching, revocation, current time, and relying-party policy require separate checks.
Can it repair or fetch certificate material?+
No. It inspects only the supplied text. It does not reconstruct PEM, fetch intermediates, contact a CA, or issue a certificate.