# module OpenSSL::SSL

Use `SSLContext` to set up the parameters for a TLS (former `SSL`) connection. Both client and server TLS connections are supported, `SSLSocket` and `SSLServer` may be used in conjunction with an instance of `SSLContext` to set up connections.

### Constants

OP_ALL
OP_ALLOW_CLIENT_RENEGOTIATION
OP_ALLOW_NO_DHE_KEX
OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
OP_CIPHER_SERVER_PREFERENCE
OP_CISCO_ANYCONNECT
OP_CLEANSE_PLAINTEXT
OP_COOKIE_EXCHANGE
OP_CRYPTOPRO_TLSEXT_BUG
OP_DISABLE_TLSEXT_CA_NAMES
OP_DONT_INSERT_EMPTY_FRAGMENTS
OP_ENABLE_KTLS
OP_ENABLE_MIDDLEBOX_COMPAT
OP_EPHEMERAL_RSA

  Deprecated in `OpenSSL` 1.0.1k and 1.0.2.

OP_IGNORE_UNEXPECTED_EOF
OP_LEGACY_SERVER_CONNECT
OP_MICROSOFT_BIG_SSLV3_BUFFER

  Deprecated in `OpenSSL` 1.1.0.

OP_MICROSOFT_SESS_ID_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_MSIE_SSLV2_RSA_PADDING

  Deprecated in `OpenSSL` 0.9.7h and 0.9.8b.

OP_NETSCAPE_CA_DN_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_NETSCAPE_CHALLENGE_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG

  Deprecated in `OpenSSL` 0.9.8q and 1.0.0c.

OP_NO_ANTI_REPLAY
OP_NO_COMPRESSION
OP_NO_ENCRYPT_THEN_MAC
OP_NO_QUERY_MTU
OP_NO_RENEGOTIATION
OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
OP_NO_SSLv2

  Deprecated in `OpenSSL` 1.1.0.

OP_NO_SSLv3
OP_NO_TICKET
OP_NO_TLSv1
OP_NO_TLSv1_1
OP_NO_TLSv1_2
OP_NO_TLSv1_3
OP_PKCS1_CHECK_1

  Deprecated in `OpenSSL` 1.0.1.

OP_PKCS1_CHECK_2

  Deprecated in `OpenSSL` 1.0.1.

OP_PRIORITIZE_CHACHA
OP_SAFARI_ECDHE_ECDSA_BUG
OP_SINGLE_DH_USE

  Deprecated in `OpenSSL` 1.1.0.

OP_SINGLE_ECDH_USE

  Deprecated in `OpenSSL` 1.1.0.

OP_SSLEAY_080_CLIENT_DH_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_SSLREF2_REUSE_CERT_TYPE_BUG

  Deprecated in `OpenSSL` 1.0.1h and 1.0.2.

OP_TLSEXT_PADDING
OP_TLS_BLOCK_PADDING_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_TLS_D5_BUG

  Deprecated in `OpenSSL` 1.1.0.

OP_TLS_ROLLBACK_BUG
SSL2_VERSION

  `SSL` 2.0

SSL3_VERSION

  `SSL` 3.0

TLS1_1_VERSION

  TLS 1.1

TLS1_2_VERSION

  TLS 1.2

TLS1_3_VERSION

  TLS 1.3

TLS1_VERSION

  TLS 1.0

VERIFY_CLIENT_ONCE
VERIFY_FAIL_IF_NO_PEER_CERT
VERIFY_NONE
VERIFY_PEER

### Public Class Methods

verify_certificate_identity (cert, hostname)
Source

    # File ext/openssl/lib/openssl/ssl.rb, line 313
    def verify_certificate_identity(cert, hostname)
      should_verify_common_name = true
      cert.extensions.each{|ext|
        next if ext.oid != "subjectAltName"
        ostr = OpenSSL::ASN1.decode(ext.to_der).value.last
        sequence = OpenSSL::ASN1.decode(ostr.value)
        sequence.value.each{|san|
          case san.tag
          when 2 # dNSName in GeneralName (RFC5280)
            should_verify_common_name = false
            return true if verify_hostname(hostname, san.value)
          when 7 # iPAddress in GeneralName (RFC5280)
            should_verify_common_name = false
            if san.value.size == 4 || san.value.size == 16
              begin
                return true if san.value == IPAddr.new(hostname).hton
              rescue IPAddr::InvalidAddressError
              end
            end
          end
        }
      }
      if should_verify_common_name
        cert.subject.to_a.each{|oid, value|
          if oid == "CN"
            return true if verify_hostname(hostname, value)
          end
        }
      end
      return false
    end

### Private Instance Methods

verify_certificate_identity (cert, hostname)
Source

    # File ext/openssl/lib/openssl/ssl.rb, line 313
    def verify_certificate_identity(cert, hostname)
      should_verify_common_name = true
      cert.extensions.each{|ext|
        next if ext.oid != "subjectAltName"
        ostr = OpenSSL::ASN1.decode(ext.to_der).value.last
        sequence = OpenSSL::ASN1.decode(ostr.value)
        sequence.value.each{|san|
          case san.tag
          when 2 # dNSName in GeneralName (RFC5280)
            should_verify_common_name = false
            return true if verify_hostname(hostname, san.value)
          when 7 # iPAddress in GeneralName (RFC5280)
            should_verify_common_name = false
            if san.value.size == 4 || san.value.size == 16
              begin
                return true if san.value == IPAddr.new(hostname).hton
              rescue IPAddr::InvalidAddressError
              end
            end
          end
        }
      }
      if should_verify_common_name
        cert.subject.to_a.each{|oid, value|
          if oid == "CN"
            return true if verify_hostname(hostname, value)
          end
        }
      end
      return false
    end