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SSL context options

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SSL context option listing

Description

Context options for ssl:// and tls:// transports.

Options

peer_namestring

Peer name to be used. If this value is not set, then the name is guessed based on the hostname used when opening the stream.

verify_peerbool

Require verification of SSL certificate used.

Defaults to true.

verify_peer_namebool

Require verification of peer name.

Defaults to true.

allow_self_signedbool

Allow self-signed certificates. Requires verify_peer.

Defaults to false

cafilestring

Location of Certificate Authority file on local filesystem which should be used with the verify_peer context option to authenticate the identity of the remote peer.

capathstring

If cafile is not specified or if the certificate is not found there, the directory pointed to by capath is searched for a suitable certificate. capath must be a correctly hashed certificate directory.

local_certstring

Path to local certificate file on filesystem. It must be a PEM encoded file which contains your certificate and private key. It can optionally contain the certificate chain of issuers. The private key also may be contained in a separate file specified by local_pk.

local_pkstring

Path to local private key file on filesystem in case of separate files for certificate (local_cert) and private key.

passphrasestring

Passphrase with which your local_cert file was encoded.

verify_depthint

Abort if the certificate chain is too deep.

Defaults to no verification.

ciphersstring

Sets the list of available ciphers. The format of the string is described in ciphers(1).

Defaults to DEFAULT.

capture_peer_certbool

If set to true a peer_certificate context option will be created containing the peer certificate.

capture_peer_cert_chainbool

If set to true a peer_certificate_chain context option will be created containing the certificate chain.

SNI_enabledbool

If set to true server name indication will be enabled. Enabling SNI allows multiple certificates on the same IP address.

SNI_server_certsarray

An array of server names and their corresponding certificates to be used for SNI. The keys are the server names and the values are the paths to the certificate files on the local filesystem. The certificate files must be PEM encoded and contain both the certificate and private key.

Available as of PHP 5.6.0.

alpn_protocolsarray

An array of application layer protocol names to be used for ALPN (Application-Layer Protocol Negotiation). The values are the protocol names as strings (e.g. "http/1.1", "h2").

Available as of PHP 7.0.0 and OpenSSL 1.0.2.

no_ticketbool

If set, disable TLS session tickets. This can help to enhance security by providing Perfect Forward Secrecy (PFS).

Available as of PHP 5.3.6.

disable_compressionbool

If set, disable TLS compression. This can help mitigate the CRIME attack vector.

peer_fingerprintstring | array

Aborts when the remote certificate digest doesn't match the specified hash.

When a string is used, the length will determine which hashing algorithm is applied, either "md5" (32) or "sha1" (40).

When an array is used, the keys indicate the hashing algorithm name and each corresponding value is the expected digest.

security_levelint

Sets the security level. If not specified the library default security level is used. The security levels are described in SSL_CTX_get_security_level(3).

Available as of PHP 7.2.0 and OpenSSL 1.1.0.

min_proto_versionint

Sets the minimum protocol version allowed. If not specified the library default minimum protocol version is used. The protocol versions are described in SSL_CTX_set_min_proto_version(3).

Available as of PHP 7.3.0 and OpenSSL 1.1.0.

max_proto_versionint

Sets the maximum protocol version allowed. If not specified the library default maximum protocol version is used. The protocol versions are described in SSL_CTX_set_max_proto_version(3).

Available as of PHP 7.3.0 and OpenSSL 1.1.0.

Changelog

Version	Description
7.3.0	Added `min_proto_version` and `max_proto_version`. Requires OpenSSL >= 1.1.0.
7.2.0	Added `security_level`. Requires OpenSSL >= 1.1.0.
7.0.0	Added `alpn_protocols`. Requires OpenSSL >= 1.0.2.
5.6.0	Added `SNI_server_certs`.
5.3.6	Added `no_ticket`.

Notes

Note

Because ssl:// is the underlying transport for the https:// and ftps:// wrappers, any context options which apply to ssl:// also apply to https:// and ftps://.