Some systems (most notably certain versions of Linux) do not support the secondary stderr stream of rexec/rshell. For these systems, you must turn stderr off. Any stderr output will then be provided through stdout.

The default value for this configuration setting is True.

This configuration setting indicates the maximum amount of characters that the class will store in the stderr property. The default value is -1, which indicates there is no maximum. A value of zero (0) will disable accumulation of stderr in the stderr property, although the on_stderr event will still continue to fire.

This configuration setting indicates the maximum amount of characters that the class will store in the stdout property. The default value is -1, which indicates there is no maximum. A value of zero (0) will disable accumulation of stdout in the stdout property, although the on_stdout event will still continue to fire.

The default value is zero, which instructs the class to use a random port. Use this property with caution. If you supply a value, it must be an available port on the system or an error will be returned.

Some systems do not support secondary stderr streams. Please refer to the EnableStderr configuration setting for more information.

When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the class will use timeout for establishing a connection and transmitting/receiving data.

This configuration setting is provided for use by classs that do not directly expose Firewall properties.

If a FirewallHost is given, requested connections will be authenticated through the specified firewall when connecting.

If the FirewallHost setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the FirewallHost setting is set to the corresponding address. If the search is not successful, an error is returned.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

If FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the given firewall. If the authentication fails, the class fails with an error.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

The FirewallPort is set automatically when FirewallType is set to a valid value.

Note: This configuration setting is provided for use by classs that do not directly expose Firewall properties.

The appropriate values are as follows:

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

If the FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the Firewall. If the authentication fails, the class fails with an error.

Note: This setting is provided for use by classs that do not directly expose Firewall properties.

When set, TCPKeepAlive will automatically be set to True. A TCP keep-alive packet will be sent after a period of inactivity as defined by KeepAliveTime. If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This configuration setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. This system default if this value is not specified here is 1 second.

Note: This value is not applicable in macOS.

When set, TCPKeepAlive will automatically be set to True. By default, the operating system will determine the time a connection is idle before a Transmission Control Protocol (TCP) keep-alive packet is sent. This system default if this value is not specified here is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds.

This property controls how a connection is closed. The default is True.

In the case that Linger is True (default), two scenarios determine how long the connection will linger. In the first, if LingerTime is 0 (default), the system will attempt to send pending data for a connection until the default IP timeout expires.

In the second scenario, if LingerTime is a positive value, the system will attempt to send pending data until the specified LingerTime is reached. If this attempt fails, then the system will reset the connection.

The default behavior (which is also the default mode for stream sockets) might result in a long delay in closing the connection. Although the class returns control immediately, the system could hold system resources until all pending data are sent (even after your application closes).

Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you sent (e.g., by a client acknowledgment), setting this property to False might be the appropriate course of action.

LingerTime is the time, in seconds, the socket connection will linger. This value is 0 by default, which means it will use the default IP timeout.

The local_host setting contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the local_host setting shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

This must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by local_port after the connection is established.

local_port cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This; setting is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxLineLength is the size of an internal buffer, which holds received data while waiting for an eol string.

If an eol string is found in the input stream before MaxLineLength bytes are received, the on_data_in event is fired with the EOL parameter set to True, and the buffer is reset.

If no eol is found, and MaxLineLength bytes are accumulated in the buffer, the on_data_in event is fired with the EOL parameter set to False, and the buffer is reset.

The minimum value for MaxLineLength is 256 bytes. The default value is 2048 bytes.

This configuration setting can be used to throttle outbound TCP traffic. Set this to the number of bytes to be sent per second. By default, this is not set and there is no limit.

This configuration setting optionally specifies a semicolon-separated list of hostnames or IP addresses to bypass when a proxy is in use. When requests are made to hosts specified in this property, the proxy will not be used. For instance:

www.google.com;www.nsoftware.com

If set to True, the socket's keep-alive option is enabled and keep-alive packets will be sent periodically to maintain the connection. Set KeepAliveTime and KeepAliveInterval to configure the timing of the keep-alive packets.

Note: This value is not applicable in Java.

When true, the socket will send all data that is ready to send at once. When false, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm.

By default, this config is set to false.

When set to 0 (default), the class will use IPv4 exclusively. When set to 1, the class will use IPv6 exclusively. To instruct the class to prefer IPv6 addresses, but use IPv4 if IPv6 is not supported on the system, this setting should be set to 2. The default value is 0. Possible values are:

When ssl_provider is set to Internal, this setting controls whether SSL packets should be logged. By default, this setting is False, as it is only useful for debugging purposes.

When enabled, SSL packet logs are output using the on_ssl_status event, which will fire each time an SSL packet is sent or received.

Enabling this setting has no effect if ssl_provider is set to Platform.

This functionality is available only when the provider is OpenSSL.

The path set by this property should point to a directory containing CA certificates in PEM format. The files each contain one CA certificate. The files are looked up by the CA subject name hash value, which must hence be available. If more than one CA certificate with the same name hash value exist, the extension must be different (e.g. 9d66eef0.0, 9d66eef0.1 etc). OpenSSL recommends to use the c_rehash utility to create the necessary links. Please refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details.

This functionality is available only when the provider is OpenSSL.

The file set by this property should contain a list of CA certificates in PEM format. The file can contain several CA certificates identified by

-----BEGIN CERTIFICATE-----

... (CA certificate in base64 encoding) ...

-----END CERTIFICATE-----

sequences. Before, between, and after the certificates text is allowed which can be used e.g. for descriptions of the certificates. Please refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details.

This functionality is available only when the provider is OpenSSL.

The format of this string is described in the OpenSSL man page ciphers(1) section "CIPHER LIST FORMAT". Please refer to it for details. The default string "DEFAULT" is determined at compile time and is normally equivalent to "ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH".

This functionality is available only when the provider is OpenSSL.

By default OpenSSL uses the device file "/dev/urandom" to seed the PRNG and setting OpenSSLPrngSeedData is not required. If set, the string specified is used to seed the PRNG.

If set to true, the class will reuse the context if and only if the following criteria are met:

• The target host name is the same.
• The system cache entry has not expired (default timeout is 10 hours).
• The application process that calls the function is the same.
• The logon session is the same.
• The instance of the class is the same.

This setting specifies the paths on disk to CA certificate files on Unix/Linux.

The value is formatted as a list of paths separated by semicolons. The class will check for the existence of each file in the order specified. When a file is found the CA certificates within the file will be loaded and used to determine the validity of server or client certificates.

The default value is:

/etc/ssl/ca-bundle.pem;/etc/pki/tls/certs/ca-bundle.crt;/etc/ssl/certs/ca-certificates.crt;/etc/pki/tls/cacert.pem

This setting specifies one or more CA certificates to be included in the request when performing SSL client authentication. Some servers require the entire chain, including CA certificates, to be presented when performing SSL client authentication. The value of this setting is a newline (CrLf) separated list of certificates. For instance:

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

This setting specifies whether the class will check the Certificate Revocation List specified by the server certificate. If set to 1 or 2, the class will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The class will then make HTTP requests to each CRL endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation the class fails with an error.

When set to 0 (default) the CRL check will not be performed by the class. When set to 1, it will attempt to perform the CRL check, but will continue without an error if the server's certificate does not support CRL. When set to 2, it will perform the CRL check and will throw an error if CRL is not supported.

This configuration setting is only supported in the Java, C#, and C++ editions. In the C++ edition, it is only supported on Windows operating systems.

This setting specifies whether the class will use OCSP to check the validity of the server certificate. If set to 1 or 2, the class will first obtain the OCSP URL from the server certificate's OCSP extension. The class will then locate the issuing certificate and make an HTTP request to the OCSP endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation the class fails with an error.

When set to 0 (default) the class will not perform an OCSP check. When set to 1, it will attempt to perform the OCSP check, but will continue without an error if the server's certificate does not support OCSP. When set to 2, it will perform the OCSP check and will throw an error if OCSP is not supported.

This configuration setting is only supported in the Java, C#, and C++ editions. In the C++ edition, it is only supported on Windows operating systems.

This minimum cipher strength largely dependent on the security modules installed on the system. If the cipher strength specified is not supported, an error will be returned when connections are initiated.

Please note that this setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the on_ssl_status event.

Use this setting with caution. Requesting a lower cipher strength than necessary could potentially cause serious security vulnerabilities in your application.

When the provider is OpenSSL, SSLCipherStrength is currently not supported. This functionality is instead made available through the OpenSSLCipherList config setting.

The enabled cipher suites to be used in SSL negotiation.

By default, the enabled cipher suites will include all available ciphers ("*").

The special value "*" means that the class will pick all of the supported cipher suites. If SSLEnabledCipherSuites is set to any other value, only the specified cipher suites will be considered.

Multiple cipher suites are separated by semicolons.

Example values when ssl_provider is set to Platform:

 
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obj.config("SSLEnabledCipherSuites=*");
obj.config("SSLEnabledCipherSuites=CALG_AES_256");
obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES");

• CALG_3DES
• CALG_3DES_112
• CALG_AES
• CALG_AES_128
• CALG_AES_192
• CALG_AES_256
• CALG_AGREEDKEY_ANY
• CALG_CYLINK_MEK
• CALG_DES
• CALG_DESX
• CALG_DH_EPHEM
• CALG_DH_SF
• CALG_DSS_SIGN
• CALG_ECDH
• CALG_ECDH_EPHEM
• CALG_ECDSA
• CALG_ECMQV
• CALG_HASH_REPLACE_OWF
• CALG_HUGHES_MD5
• CALG_HMAC
• CALG_KEA_KEYX
• CALG_MAC
• CALG_MD2
• CALG_MD4
• CALG_MD5
• CALG_NO_SIGN
• CALG_OID_INFO_CNG_ONLY
• CALG_OID_INFO_PARAMETERS
• CALG_PCT1_MASTER
• CALG_RC2
• CALG_RC4
• CALG_RC5
• CALG_RSA_KEYX
• CALG_RSA_SIGN
• CALG_SCHANNEL_ENC_KEY
• CALG_SCHANNEL_MAC_KEY
• CALG_SCHANNEL_MASTER_HASH
• CALG_SEAL
• CALG_SHA
• CALG_SHA1
• CALG_SHA_256
• CALG_SHA_384
• CALG_SHA_512
• CALG_SKIPJACK
• CALG_SSL2_MASTER
• CALG_SSL3_MASTER
• CALG_SSL3_SHAMD5
• CALG_TEK
• CALG_TLS1_MASTER
• CALG_TLS1PRF

 
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obj.config("SSLEnabledCipherSuites=*");
obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA");
obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA;TLS_DH_ANON_WITH_AES_128_CBC_SHA");

• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
• TLS_RSA_WITH_AES_256_GCM_SHA384
• TLS_RSA_WITH_AES_128_GCM_SHA256
• TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256
• TLS_DHE_DSS_WITH_AES_256_GCM_SHA384
• TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256
• TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
• TLS_DHE_DSS_WITH_AES_128_GCM_SHA256
• TLS_DH_RSA_WITH_AES_128_GCM_SHA256 (Not Recommended)
• TLS_DH_RSA_WITH_AES_256_GCM_SHA384 (Not Recommended)
• TLS_DH_DSS_WITH_AES_128_GCM_SHA256 (Not Recommended)
• TLS_DH_DSS_WITH_AES_256_GCM_SHA384 (Not Recommended)
• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
• TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
• TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384
• TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
• TLS_RSA_WITH_AES_256_CBC_SHA256
• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
• TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384
• TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
• TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
• TLS_RSA_WITH_AES_128_CBC_SHA256
• TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256
• TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256
• TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
• TLS_RSA_WITH_AES_256_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
• TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA
• TLS_DHE_RSA_WITH_AES_256_CBC_SHA
• TLS_ECDH_RSA_WITH_AES_256_CBC_SHA
• TLS_DHE_DSS_WITH_AES_256_CBC_SHA
• TLS_RSA_WITH_AES_128_CBC_SHA
• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
• TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA
• TLS_ECDH_RSA_WITH_AES_128_CBC_SHA
• TLS_DHE_RSA_WITH_AES_128_CBC_SHA
• TLS_DHE_DSS_WITH_AES_128_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA
• TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA
• TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
• TLS_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_RSA_WITH_DES_CBC_SHA
• TLS_DHE_RSA_WITH_DES_CBC_SHA
• TLS_DHE_DSS_WITH_DES_CBC_SHA
• TLS_RSA_WITH_RC4_128_MD5
• TLS_RSA_WITH_RC4_128_SHA

When TLS 1.3 is negotiated (see SSLEnabledProtocols) only the following cipher suites are supported:

• TLS_AES_256_GCM_SHA384
• TLS_CHACHA20_POLY1305_SHA256
• TLS_AES_128_GCM_SHA256

SSLEnabledCipherSuites is used together with SSLCipherStrength.

Used to enable/disable the supported security protocols.

Not all supported protocols are enabled by default (the value of this setting is 4032). If you want more granular control over the enabled protocols, you can set this property to the binary 'OR' of one or more of the following values:

SSLEnabledProtocols - TLS 1.3 Notes

By default when TLS 1.3 is enabled the class will use the internal TLS implementation when the ssl_provider is set to Automatic for all editions.

In editions which are designed to run on Windows ssl_provider can be set to Platform to use the platform implementation instead of the internal implementation. When configured in this manner, please note that the platform provider is only supported on Windows 11 / Windows Server 2022 and up. The default internal provider is available on all platforms and is not restricted to any specific OS version.

If set to 1 (Platform provider) please be aware of the following notes:

• The platform provider is only available on Windows 11 / Windows Server 2022 and up.
• SSLEnabledCipherSuites and other similar SSL configuration settings are not supported.
• If SSLEnabledProtocols includes both TLS 1.3 and TLS 1.2 the above restrictions are still applicable even if TLS 1.2 is negotiated. Enabling TLS 1.3 with the platform provider changes the implementation used for all TLS versions.

SSLEnabledProtocols: SSL2 and SSL3 Notes:

SSL 2.0 and 3.0 are not supported by the class when the ssl_provider is set to internal. To use SSL 2.0 or SSL 3.0, the platform security API must have the protocols enabled and ssl_provider needs to be set to platform.

This setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This setting is True by default, but can be set to False to disable the extension.

This setting is only applicable when ssl_provider is set to Internal.

This setting specifies whether the Encoded parameter of the on_ssl_server_authentication event contains the full certificate chain. By default this value is False and only the leaf certificate will be present in the Encoded parameter of the on_ssl_server_authentication event.

If set to True all certificates returned by the server will be present in the Encoded parameter of the on_ssl_server_authentication event. This includes the leaf certificate, any intermediate certificate, and the root certificate.

This setting optionally specifies the full path to a file on disk where per-session secrets are stored for debugging purposes.

When set, the class will save the session secrets in the same format as the SSLKEYLOGFILE environment variable functionality used by most major browsers and tools such as Chrome, Firefox, and cURL. This file can then be used in tools such as Wireshark to decrypt TLS traffice for debugging purposes. When writing to this file the class will only append, it will not overwrite previous values.

Note: This setting is only applicable when ssl_provider is set to Internal.

Returns the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedCipher[connId]");

Returns the strength of the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g.TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedCipherStrength[connId]");

Returns the cipher suite negotiated during the SSL handshake represented as a single string.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedCipherSuite[connId]");

Returns the key exchange algorithm negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedKeyExchange[connId]");

Returns the strenghth of the key exchange algorithm negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedKeyExchangeStrength[connId]");

Returns the protocol version negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example:

 
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server.Config("SSLNegotiatedVersion[connId]");

The following flags are defined (specified in hexadecimal notation). They can be or-ed together to exclude multiple conditions:

This functionality is currently not available when the provider is OpenSSL.

This setting optionally specifies one or more CA certificates to be used when verifying the server certificate. When verifying the server's certificate the certificates trusted by the system will be used as part of the verification process. If the server's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This setting should only be set if the server's CA certificates are not already trusted on the system and cannot be installed to the trusted system store.

The value of this setting is a newline (CrLf) separated list of certificates. For instance:

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

This setting specifies the allowed server certificate signature algorithms when ssl_provider is set to Internal and SSLEnabledProtocols is set to allow TLS 1.2.

When specified the class will verify that the server certificate signature algorithm is among the values specified in this setting. If the server certificate signature algorithm is unsupported the class fails with an error.

The format of this value is a comma separated list of hash-signature combinations. For instance:

 
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component.SSLProvider = TCPClientSSLProviders.sslpInternal;
component.Config("SSLEnabledProtocols=3072"); //TLS 1.2
component.Config("TLS12SignatureAlgorithms=sha256-rsa,sha256-dsa,sha1-rsa,sha1-dsa");

In order to not restrict the server's certificate signature algorithm, specify an empty string as the value for this setting, which will cause the signature_algorithms TLS 1.2 extension to not be sent.

This setting specifies a comma separated list of named groups used in TLS 1.2 for ECC.

The default value is ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1.

When using TLS 1.2 and ssl_provider is set to Internal, the values refer to the supported groups for ECC. The following values are supported:

• "ecdhe_secp256r1" (default)
• "ecdhe_secp384r1" (default)
• "ecdhe_secp521r1" (default)

This setting specifies a comma separated list of named groups used in TLS 1.3 for key exchange. The groups specified here will have key share data pregenerated locally before establishing a connection. This can prevent an additional round trip during the handshake if the group is supported by the server.

The default value is set to balance common supported groups and the computational resources required to generate key shares. As a result only some groups are included by default in this setting.

Note: All supported groups can always be used during the handshake even if not listed here, but if a group is used which is not present in this list it will incur an additional round trip and time to generate the key share for that group.

In most cases this setting does not need to be modified. This should only be modified if there is a specific reason to do so.

The default value is ecdhe_x25519,ecdhe_secp256r1,ecdhe_secp384r1,ffdhe_2048,ffdhe_3072

The values are ordered from most preferred to least preferred. The following values are supported:

• "ecdhe_x25519" (default)
• "ecdhe_x448"
• "ecdhe_secp256r1" (default)
• "ecdhe_secp384r1" (default)
• "ecdhe_secp521r1"
• "ffdhe_2048" (default)
• "ffdhe_3072" (default)
• "ffdhe_4096"
• "ffdhe_6144"
• "ffdhe_8192"

This setting holds a comma separated list of allowed signature algorithms. Possible values are:

• "ed25519" (default)
• "ed448" (default)
• "ecdsa_secp256r1_sha256" (default)
• "ecdsa_secp384r1_sha384" (default)
• "ecdsa_secp521r1_sha512" (default)
• "rsa_pkcs1_sha256" (default)
• "rsa_pkcs1_sha384" (default)
• "rsa_pkcs1_sha512" (default)
• "rsa_pss_sha256" (default)
• "rsa_pss_sha384" (default)
• "rsa_pss_sha512" (default)

This setting specifies a comma separated list of named groups used in TLS 1.3 for key exchange. This setting should only be modified if there is a specific reason to do so.

The default value is ecdhe_x25519,ecdhe_x448,ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1,ffdhe_2048,ffdhe_3072,ffdhe_4096,ffdhe_6144,ffdhe_8192

The values are ordered from most preferred to least preferred. The following values are supported:

• "ecdhe_x25519" (default)
• "ecdhe_x448" (default)
• "ecdhe_secp256r1" (default)
• "ecdhe_secp384r1" (default)
• "ecdhe_secp521r1" (default)
• "ffdhe_2048" (default)
• "ffdhe_3072" (default)
• "ffdhe_4096" (default)
• "ffdhe_6144" (default)
• "ffdhe_8192" (default)

If AbsoluteTimeout is set to True, any method which does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for UDP ports.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g. headers for custom authentication schemes).

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

When queried, this setting will return a string containing information about the product's build.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

• Product: The product the license is for.
• Product Key: The key the license was generated from.
• License Source: Where the license was found (e.g., RuntimeLicense, License File).
• License Type: The type of license installed (e.g., Royalty Free, Single Server).
• Last Valid Build: The last valid build number for which the license will work.

In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to True to mask sensitive data. The default is True.

This setting only works on these classes: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.

If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True.

If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20.

When set to False, the class will use the system security libraries by default to perform cryptographic functions where applicable.

Setting this configuration setting to True tells the class to use the internal implementation instead of using the system security libraries.

On Windows, this setting is set to False by default. On Linux/macOS, this setting is set to True by default.

To use the system security libraries for Linux, OpenSSL support must be enabled. For more information on how to enable OpenSSL, please refer to the OpenSSL Notes section.