redis/redis-py · error · ConnectionError

no certificate found for ssl peer

Error message

no certificate found for ssl peer

What it means

Error "no certificate found for ssl peer" thrown in redis/redis-py.

Source

Thrown at redis/ocsp.py:199

        self.PORT = port
        self.CA_CERTS = ca_certs

    def _bin2ascii(self, der):
        """Convert SSL certificates in a binary (DER) format to ASCII PEM."""

        pem = ssl.DER_cert_to_PEM_cert(der)
        cert = x509.load_pem_x509_certificate(pem.encode(), backends.default_backend())
        return cert

    def components_from_socket(self):
        """This function returns the certificate, primary issuer, and primary ocsp
        server in the chain for a socket already wrapped with ssl.
        """

        # convert the binary certificate to text
        der = self.SOCK.getpeercert(True)
        if der is False:
            raise ConnectionError("no certificate found for ssl peer")
        cert = self._bin2ascii(der)
        return self._certificate_components(cert)

    def _certificate_components(self, cert):
        """Given an SSL certificate, retract the useful components for
        validating the certificate status with an OCSP server.

        Args:
            cert ([bytes]): A PEM encoded ssl certificate
        """

        try:
            aia = cert.extensions.get_extension_for_oid(
                x509.oid.ExtensionOID.AUTHORITY_INFORMATION_ACCESS
            ).value
        except cryptography.x509.extensions.ExtensionNotFound:
            raise ConnectionError("No AIA information present in ssl certificate")

View on GitHub (pinned to da03cdc7e8)

When it happens

Trigger: Thrown at redis/ocsp.py:199 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/c5abbe61137089e8.json. Report an issue: GitHub.