ruby/rubygems · error · Gem::Security::Exception

missing signing certificate

Error message

missing signing certificate

What it means

Error "missing signing certificate" thrown in ruby/rubygems.

Source

Thrown at lib/rubygems/security/policy.rb:87

  end

  ##
  # Verifies that +data+ matches the +signature+ created by +public_key+ and
  # the +digest+ algorithm.

  def check_data(public_key, digest, signature, data)
    raise Gem::Security::Exception, "invalid signature" unless
      public_key.verify digest, signature, data.digest

    true
  end

  ##
  # Ensures that +signer+ is valid for +time+ and was signed by the +issuer+.
  # If the +issuer+ is +nil+ no verification is performed.

  def check_cert(signer, issuer, time)
    raise Gem::Security::Exception, "missing signing certificate" unless
      signer

    message = "certificate #{signer.subject}"

    if (not_before = signer.not_before) && not_before > time
      raise Gem::Security::Exception,
            "#{message} not valid before #{not_before}"
    end

    if (not_after = signer.not_after) && not_after < time
      raise Gem::Security::Exception, "#{message} not valid after #{not_after}"
    end

    if issuer && !signer.verify(issuer.public_key)
      raise Gem::Security::Exception,
            "#{message} was not issued by #{issuer.subject}"
    end

View on GitHub (pinned to 86cbb817a3)

Solutions

1. Re-sign the gem so it includes the signing certificate in its chain

When it happens

Trigger: Thrown at lib/rubygems/security/policy.rb:87 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• SSL/TLS and certificate errors — how TLS handshakes and certificate validation fail.

AI-assisted analysis of ruby/rubygems@86cbb817a3 (2026-08-23). Data as JSON: /api/errors/bf9f81c3ebc2f366. Report an issue: GitHub.