doc/man3/SSL_CTX_set_tlsext_use_srtp.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 SSL_CTX_set_tlsext_use_srtp,
 SSL_set_tlsext_use_srtp,
 SSL_get_srtp_profiles,
 SSL_get_selected_srtp_profile
 - Configure and query SRTP support

 =head1 SYNOPSIS

  #include <openssl/srtp.h>

  int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles);
  int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);

  STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *ssl);
  SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s);

 =head1 DESCRIPTION

 SRTP is the Secure Real-Time Transport Protocol. OpenSSL implements support for
 the "use_srtp" DTLS extension defined in RFC5764. This provides a mechanism for
 establishing SRTP keying material, algorithms and parameters using DTLS. This
 capability may be used as part of an implementation that conforms to RFC5763.
 OpenSSL does not implement SRTP itself or RFC5763. Note that OpenSSL does not
 support the use of SRTP Master Key Identifiers (MKIs). Also note that this
 extension is only supported in DTLS. Any SRTP configuration will be ignored if a
 TLS connection is attempted.

 An OpenSSL client wishing to send the "use_srtp" extension should call
 SSL_CTX_set_tlsext_use_srtp() to set its use for all SSL objects subsequently
 created from an SSL_CTX. Alternatively a client may call
 SSL_set_tlsext_use_srtp() to set its use for an individual SSL object. The
 B<profiles> parameters should point to a NUL-terminated, colon delimited list of
 SRTP protection profile names.

 The currently supported protection profile names are:

 =over 4

 =item SRTP_AES128_CM_SHA1_80

 This corresponds to SRTP_AES128_CM_HMAC_SHA1_80 defined in RFC5764.

 =item SRTP_AES128_CM_SHA1_32

 This corresponds to SRTP_AES128_CM_HMAC_SHA1_32 defined in RFC5764.

 =item SRTP_AEAD_AES_128_GCM

 This corresponds to the profile of the same name defined in RFC7714.

 =item SRTP_AEAD_AES_256_GCM

 This corresponds to the profile of the same name defined in RFC7714.

 =back

 Supplying an unrecognised protection profile name will result in an error.

 An OpenSSL server wishing to support the "use_srtp" extension should also call
 SSL_CTX_set_tlsext_use_srtp() or SSL_set_tlsext_use_srtp() to indicate the
 protection profiles that it is willing to negotiate.

 The currently configured list of protection profiles for either a client or a
 server can be obtained by calling SSL_get_srtp_profiles(). This returns a stack
 of SRTP_PROTECTION_PROFILE objects. The memory pointed to in the return value of
 this function should not be freed by the caller.

 After a handshake has been completed the negotiated SRTP protection profile (if
 any) can be obtained (on the client or the server) by calling
 SSL_get_selected_srtp_profile(). This function will return NULL if no SRTP
 protection profile was negotiated. The memory returned from this function should
 not be freed by the caller.

 If an SRTP protection profile has been successfully negotiated then the SRTP
 keying material (on both the client and server) should be obtained via a call to
 L<SSL_export_keying_material(3)>. This call should provide a label value of
 "EXTRACTOR-dtls_srtp" and a NULL context value (use_context is 0). The total
 length of keying material obtained should be equal to two times the sum of the
 master key length and the salt length as defined for the protection profile in
 use. This provides the client write master key, the server write master key, the
 client write master salt and the server write master salt in that order.

 =head1 RETURN VALUES

 SSL_CTX_set_tlsext_use_srtp() and SSL_set_tlsext_use_srtp() return 0 on success
 or 1 on error.

 SSL_get_srtp_profiles() returns a stack of SRTP_PROTECTION_PROFILE objects on
 success or NULL on error or if no protection profiles have been configured.

 SSL_get_selected_srtp_profile() returns a pointer to an SRTP_PROTECTION_PROFILE
 object if one has been negotiated or NULL otherwise.

 =head1 SEE ALSO

 L<ssl(7)>,
 L<SSL_export_keying_material(3)>

 =head1 COPYRIGHT

 Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.

 =cut
	=pod

	=head1 NAME

	SSL_CTX_set_tlsext_use_srtp,
	SSL_set_tlsext_use_srtp,
	SSL_get_srtp_profiles,
	SSL_get_selected_srtp_profile
	- Configure and query SRTP support

	=head1 SYNOPSIS

	#include <openssl/srtp.h>

	int SSL_CTX_set_tlsext_use_srtp(SSL_CTX ctx, const char profiles);
	int SSL_set_tlsext_use_srtp(SSL ssl, const char profiles);

	STACK_OF(SRTP_PROTECTION_PROFILE) SSL_get_srtp_profiles(SSL ssl);
	SRTP_PROTECTION_PROFILE SSL_get_selected_srtp_profile(SSL s);

	=head1 DESCRIPTION

	SRTP is the Secure Real-Time Transport Protocol. OpenSSL implements support for
	the "use_srtp" DTLS extension defined in RFC5764. This provides a mechanism for
	establishing SRTP keying material, algorithms and parameters using DTLS. This
	capability may be used as part of an implementation that conforms to RFC5763.
	OpenSSL does not implement SRTP itself or RFC5763. Note that OpenSSL does not
	support the use of SRTP Master Key Identifiers (MKIs). Also note that this
	extension is only supported in DTLS. Any SRTP configuration will be ignored if a
	TLS connection is attempted.

	An OpenSSL client wishing to send the "use_srtp" extension should call
	SSL_CTX_set_tlsext_use_srtp() to set its use for all SSL objects subsequently
	created from an SSL_CTX. Alternatively a client may call
	SSL_set_tlsext_use_srtp() to set its use for an individual SSL object. The
	B<profiles> parameters should point to a NUL-terminated, colon delimited list of
	SRTP protection profile names.

	The currently supported protection profile names are:

	=over 4

	=item SRTP_AES128_CM_SHA1_80

	This corresponds to SRTP_AES128_CM_HMAC_SHA1_80 defined in RFC5764.

	=item SRTP_AES128_CM_SHA1_32

	This corresponds to SRTP_AES128_CM_HMAC_SHA1_32 defined in RFC5764.

	=item SRTP_AEAD_AES_128_GCM

	This corresponds to the profile of the same name defined in RFC7714.

	=item SRTP_AEAD_AES_256_GCM

	This corresponds to the profile of the same name defined in RFC7714.

	=back

	Supplying an unrecognised protection profile name will result in an error.

	An OpenSSL server wishing to support the "use_srtp" extension should also call
	SSL_CTX_set_tlsext_use_srtp() or SSL_set_tlsext_use_srtp() to indicate the
	protection profiles that it is willing to negotiate.

	The currently configured list of protection profiles for either a client or a
	server can be obtained by calling SSL_get_srtp_profiles(). This returns a stack
	of SRTP_PROTECTION_PROFILE objects. The memory pointed to in the return value of
	this function should not be freed by the caller.

	After a handshake has been completed the negotiated SRTP protection profile (if
	any) can be obtained (on the client or the server) by calling
	SSL_get_selected_srtp_profile(). This function will return NULL if no SRTP
	protection profile was negotiated. The memory returned from this function should
	not be freed by the caller.

	If an SRTP protection profile has been successfully negotiated then the SRTP
	keying material (on both the client and server) should be obtained via a call to
	L<SSL_export_keying_material(3)>. This call should provide a label value of
	"EXTRACTOR-dtls_srtp" and a NULL context value (use_context is 0). The total
	length of keying material obtained should be equal to two times the sum of the
	master key length and the salt length as defined for the protection profile in
	use. This provides the client write master key, the server write master key, the
	client write master salt and the server write master salt in that order.

	=head1 RETURN VALUES

	SSL_CTX_set_tlsext_use_srtp() and SSL_set_tlsext_use_srtp() return 0 on success
	or 1 on error.

	SSL_get_srtp_profiles() returns a stack of SRTP_PROTECTION_PROFILE objects on
	success or NULL on error or if no protection profiles have been configured.

	SSL_get_selected_srtp_profile() returns a pointer to an SRTP_PROTECTION_PROFILE
	object if one has been negotiated or NULL otherwise.

	=head1 SEE ALSO

	L<ssl(7)>,
	L<SSL_export_keying_material(3)>

	=head1 COPYRIGHT

	Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

	Licensed under the Apache License 2.0 (the "License"). You may not use
	this file except in compliance with the License. You can obtain a copy
	in the file LICENSE in the source distribution or at
	L<https://www.openssl.org/source/license.html>.

	=cut