Keys, Certificates & Tokens
RSA Verifier
Verify an RSA PKCS#1 v1.5 signature against a message and public key. Supports SHA-256, SHA-384, and SHA-512 with Base64 or hex input.
This tool runs open-source code from CyberChef by GCHQ (Apache License 2.0). See open-source credits.
Verification checks the signature against the exact message bytes, selected digest, and supplied RSA public key.
The result reports Verified OK or Verification Failure.
- Check a signature made with openssl dgst -sha256 -sign before you trust the file.
Verify a signature of Hello
Input: The Base64 signature of Hello from RSA Signer
Settings: RSA Public Key (PEM) from the same test pair; Signature format Base64. Message Hello; Message format UTF8; Message Digest Algorithm SHA-256.
Result: Verified OK
Changing Message to Hello! returns Verification Failure with the same signature.
Match message bytes, digest, and signature scheme
- Paste the signature with its format and the public PEM key.
- Enter Message and select its format.
- Match Message Digest Algorithm to the signer, then select Verify.
- RSA-PSS signatures are unsupported.
- SHA-1 is a legacy verification option.
- A successful check does not establish who owns the key.