doc/man7/provider.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 provider - OpenSSL operation implementation providers

 =head1 SYNOPSIS

 =for openssl generic

 #include <openssl/provider.h>

 =head1 DESCRIPTION

 =head2 General

 This page contains information useful to provider authors.

 A I<provider>, in OpenSSL terms, is a unit of code that provides one
 or more implementations for various operations for diverse algorithms
 that one might want to perform.

 An I<operation> is something one wants to do, such as encryption and
 decryption, key derivation, MAC calculation, signing and verification,
 etc.

 An I<algorithm> is a named method to perform an operation.
 Very often, the algorithms revolve around cryptographic operations,
 but may also revolve around other types of operation, such as managing
 certain types of objects.

 See L<crypto(7)> for further details.

 =head2 Provider

 A I<provider> offers an initialization function, as a set of base
 functions in the form of an B<OSSL_DISPATCH> array, and by extension,
 a set of B<OSSL_ALGORITHM>s (see L<openssl-core.h(7)>).
 It may be a dynamically loadable module, or may be built-in, in
 OpenSSL libraries or in the application.
 If it's a dynamically loadable module, the initialization function
 must be named C<OSSL_provider_init> and must be exported.
 If it's built-in, the initialization function may have any name.

 The initialization function must have the following signature:

  int NAME(const OSSL_CORE_HANDLE *handle,
           const OSSL_DISPATCH *in, const OSSL_DISPATCH **out,
           void **provctx);

 I<handle> is the OpenSSL library object for the provider, and works
 as a handle for everything the OpenSSL libraries need to know about
 the provider.
 For the provider itself, it is passed to some of the functions given in the
 dispatch array I<in>.

 I<in> is a dispatch array of base functions offered by the OpenSSL
 libraries, and the available functions are further described in
 L<provider-base(7)>.

 I<*out> must be assigned a dispatch array of base functions that the
 provider offers to the OpenSSL libraries.
 The functions that may be offered are further described in
 L<provider-base(7)>, and they are the central means of communication
 between the OpenSSL libraries and the provider.

 I<*provctx> should be assigned a provider specific context to allow
 the provider multiple simultaneous uses.
 This pointer will be passed to various operation functions offered by
 the provider.

 Note that the provider will not be made available for applications to use until
 the initialization function has completed and returned successfully.

 One of the functions the provider offers to the OpenSSL libraries is
 the central mechanism for the OpenSSL libraries to get access to
 operation implementations for diverse algorithms.
 Its referred to with the number B<OSSL_FUNC_PROVIDER_QUERY_OPERATION>
 and has the following signature:

  const OSSL_ALGORITHM *provider_query_operation(void *provctx,
                                                 int operation_id,
                                                 const int *no_store);

 I<provctx> is the provider specific context that was passed back by
 the initialization function.

 I<operation_id> is an operation identity (see L</Operations> below).

 I<no_store> is a flag back to the OpenSSL libraries which, when
 nonzero, signifies that the OpenSSL libraries will not store a
 reference to the returned data in their internal store of
 implementations.

 The returned B<OSSL_ALGORITHM> is the foundation of any OpenSSL
 library API that uses providers for their implementation, most
 commonly in the I<fetching> type of functions
 (see L<crypto(7)/ALGORITHM FETCHING>).

 =head2 Operations

 Operations are referred to with numbers, via macros with names
 starting with C<OSSL_OP_>.

 With each operation comes a set of defined function types that a
 provider may or may not offer, depending on its needs.

 Currently available operations are:

 =over 4

 =item Digests

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_MD>.
 The number for this operation is B<OSSL_OP_DIGEST>.
 The functions the provider can offer are described in
 L<provider-digest(7)>.

 =item Symmetric ciphers

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_CIPHER>.
 The number for this operation is B<OSSL_OP_CIPHER>.
 The functions the provider can offer are described in
 L<provider-cipher(7)>.

 =item Message Authentication Code (MAC)

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_MAC>.
 The number for this operation is B<OSSL_OP_MAC>.
 The functions the provider can offer are described in
 L<provider-mac(7)>.

 =item Key Derivation Function (KDF)

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_KDF>.
 The number for this operation is B<OSSL_OP_KDF>.
 The functions the provider can offer are described in
 L<provider-kdf(7)>.

 =item Key Exchange

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_KEYEXCH>.
 The number for this operation is B<OSSL_OP_KEYEXCH>.
 The functions the provider can offer are described in
 L<provider-keyexch(7)>.

 =item Asymmetric Ciphers

 In the OpenSSL libraries, the corresponding method object is
 B<EVP_ASYM_CIPHER>.
 The number for this operation is B<OSSL_OP_ASYM_CIPHER>.
 The functions the provider can offer are described in
 L<provider-asym_cipher(7)>.

 =item Asymmetric Key Encapsulation

 In the OpenSSL libraries, the corresponding method object is B<EVP_KEM>.
 The number for this operation is B<OSSL_OP_KEM>.
 The functions the provider can offer are described in L<provider-kem(7)>.

 =item Encoding

 In the OpenSSL libraries, the corresponding method object is
 B<OSSL_ENCODER>.
 The number for this operation is B<OSSL_OP_ENCODER>.
 The functions the provider can offer are described in
 L<provider-encoder(7)>.

 =item Decoding

 In the OpenSSL libraries, the corresponding method object is
 B<OSSL_DECODER>.
 The number for this operation is B<OSSL_OP_DECODER>.
 The functions the provider can offer are described in
 L<provider-decoder(7)>.

 =item Random Number Generation

 The number for this operation is B<OSSL_OP_RAND>.
 The functions the provider can offer for random number generation are described
 in L<provider-rand(7)>.

 =item Key Management

 The number for this operation is B<OSSL_OP_KEYMGMT>.
 The functions the provider can offer for key management are described in
 L<provider-keymgmt(7)>.

 =item Signing and Signature Verification

 The number for this operation is B<OSSL_OP_SIGNATURE>.
 The functions the provider can offer for digital signatures are described in
 L<provider-signature(7)>.

 =item Store Management

 The number for this operation is B<OSSL_OP_STORE>.
 The functions the provider can offer for store management are described in
 L<provider-storemgmt(7)>.

 =back

 =head3 Algorithm naming

 Algorithm names are case insensitive. Any particular algorithm can have multiple
 aliases associated with it. The canonical OpenSSL naming scheme follows this
 format:

 ALGNAME[VERSION?][-SUBNAME[VERSION?]?][-SIZE?][-MODE?]

 VERSION is only present if there are multiple versions of an algorithm (e.g.
 MD2, MD4, MD5).  It may be omitted if there is only one version.

 SUBNAME may be present where multiple algorithms are combined together,
 e.g. MD5-SHA1.

 SIZE is only present if multiple versions of an algorithm exist with different
 sizes (e.g. AES-128-CBC, AES-256-CBC)

 MODE is only present where applicable.

 Other aliases may exist for example where standards bodies or common practice
 use alternative names or names that OpenSSL has used historically.

 =head1 OPENSSL PROVIDERS

 OpenSSL provides a number of its own providers. These are the default, base,
 fips, legacy and null providers. See L<crypto(7)> for an overview of these
 providers.

 =head1 SEE ALSO

 L<EVP_DigestInit_ex(3)>, L<EVP_EncryptInit_ex(3)>,
 L<OSSL_LIB_CTX(3)>,
 L<EVP_set_default_properties(3)>,
 L<EVP_MD_fetch(3)>,
 L<EVP_CIPHER_fetch(3)>,
 L<EVP_KEYMGMT_fetch(3)>,
 L<openssl-core.h(7)>,
 L<provider-base(7)>,
 L<provider-digest(7)>,
 L<provider-cipher(7)>,
 L<provider-keyexch(7)>

 =head1 HISTORY

 The concept of providers and everything surrounding them was
 introduced in OpenSSL 3.0.

 =head1 COPYRIGHT

 Copyright 2019-2022 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

	provider - OpenSSL operation implementation providers

	=head1 SYNOPSIS

	=for openssl generic

	#include <openssl/provider.h>

	=head1 DESCRIPTION

	=head2 General

	This page contains information useful to provider authors.

	A I<provider>, in OpenSSL terms, is a unit of code that provides one
	or more implementations for various operations for diverse algorithms
	that one might want to perform.

	An I<operation> is something one wants to do, such as encryption and
	decryption, key derivation, MAC calculation, signing and verification,
	etc.

	An I<algorithm> is a named method to perform an operation.
	Very often, the algorithms revolve around cryptographic operations,
	but may also revolve around other types of operation, such as managing
	certain types of objects.

	See L<crypto(7)> for further details.

	=head2 Provider

	A I<provider> offers an initialization function, as a set of base
	functions in the form of an B<OSSL_DISPATCH> array, and by extension,
	a set of B<OSSL_ALGORITHM>s (see L<openssl-core.h(7)>).
	It may be a dynamically loadable module, or may be built-in, in
	OpenSSL libraries or in the application.
	If it's a dynamically loadable module, the initialization function
	must be named C<OSSL_provider_init> and must be exported.
	If it's built-in, the initialization function may have any name.

	The initialization function must have the following signature:

	int NAME(const OSSL_CORE_HANDLE *handle,
	const OSSL_DISPATCH in, const OSSL_DISPATCH *out,
	void **provctx);

	I<handle> is the OpenSSL library object for the provider, and works
	as a handle for everything the OpenSSL libraries need to know about
	the provider.
	For the provider itself, it is passed to some of the functions given in the
	dispatch array I<in>.

	I<in> is a dispatch array of base functions offered by the OpenSSL
	libraries, and the available functions are further described in
	L<provider-base(7)>.

	I<*out> must be assigned a dispatch array of base functions that the
	provider offers to the OpenSSL libraries.
	The functions that may be offered are further described in
	L<provider-base(7)>, and they are the central means of communication
	between the OpenSSL libraries and the provider.

	I<*provctx> should be assigned a provider specific context to allow
	the provider multiple simultaneous uses.
	This pointer will be passed to various operation functions offered by
	the provider.

	Note that the provider will not be made available for applications to use until
	the initialization function has completed and returned successfully.

	One of the functions the provider offers to the OpenSSL libraries is
	the central mechanism for the OpenSSL libraries to get access to
	operation implementations for diverse algorithms.
	Its referred to with the number B<OSSL_FUNC_PROVIDER_QUERY_OPERATION>
	and has the following signature:

	const OSSL_ALGORITHM provider_query_operation(void provctx,
	int operation_id,
	const int *no_store);

	I<provctx> is the provider specific context that was passed back by
	the initialization function.

	I<operation_id> is an operation identity (see L</Operations> below).

	I<no_store> is a flag back to the OpenSSL libraries which, when
	nonzero, signifies that the OpenSSL libraries will not store a
	reference to the returned data in their internal store of
	implementations.

	The returned B<OSSL_ALGORITHM> is the foundation of any OpenSSL
	library API that uses providers for their implementation, most
	commonly in the I<fetching> type of functions
	(see L<crypto(7)/ALGORITHM FETCHING>).

	=head2 Operations

	Operations are referred to with numbers, via macros with names
	starting with C<OSSL_OP_>.

	With each operation comes a set of defined function types that a
	provider may or may not offer, depending on its needs.

	Currently available operations are:

	=over 4

	=item Digests

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_MD>.
	The number for this operation is B<OSSL_OP_DIGEST>.
	The functions the provider can offer are described in
	L<provider-digest(7)>.

	=item Symmetric ciphers

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_CIPHER>.
	The number for this operation is B<OSSL_OP_CIPHER>.
	The functions the provider can offer are described in
	L<provider-cipher(7)>.

	=item Message Authentication Code (MAC)

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_MAC>.
	The number for this operation is B<OSSL_OP_MAC>.
	The functions the provider can offer are described in
	L<provider-mac(7)>.

	=item Key Derivation Function (KDF)

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_KDF>.
	The number for this operation is B<OSSL_OP_KDF>.
	The functions the provider can offer are described in
	L<provider-kdf(7)>.

	=item Key Exchange

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_KEYEXCH>.
	The number for this operation is B<OSSL_OP_KEYEXCH>.
	The functions the provider can offer are described in
	L<provider-keyexch(7)>.

	=item Asymmetric Ciphers

	In the OpenSSL libraries, the corresponding method object is
	B<EVP_ASYM_CIPHER>.
	The number for this operation is B<OSSL_OP_ASYM_CIPHER>.
	The functions the provider can offer are described in
	L<provider-asym_cipher(7)>.

	=item Asymmetric Key Encapsulation

	In the OpenSSL libraries, the corresponding method object is B<EVP_KEM>.
	The number for this operation is B<OSSL_OP_KEM>.
	The functions the provider can offer are described in L<provider-kem(7)>.

	=item Encoding

	In the OpenSSL libraries, the corresponding method object is
	B<OSSL_ENCODER>.
	The number for this operation is B<OSSL_OP_ENCODER>.
	The functions the provider can offer are described in
	L<provider-encoder(7)>.

	=item Decoding

	In the OpenSSL libraries, the corresponding method object is
	B<OSSL_DECODER>.
	The number for this operation is B<OSSL_OP_DECODER>.
	The functions the provider can offer are described in
	L<provider-decoder(7)>.

	=item Random Number Generation

	The number for this operation is B<OSSL_OP_RAND>.
	The functions the provider can offer for random number generation are described
	in L<provider-rand(7)>.

	=item Key Management

	The number for this operation is B<OSSL_OP_KEYMGMT>.
	The functions the provider can offer for key management are described in
	L<provider-keymgmt(7)>.

	=item Signing and Signature Verification

	The number for this operation is B<OSSL_OP_SIGNATURE>.
	The functions the provider can offer for digital signatures are described in
	L<provider-signature(7)>.

	=item Store Management

	The number for this operation is B<OSSL_OP_STORE>.
	The functions the provider can offer for store management are described in
	L<provider-storemgmt(7)>.

	=back

	=head3 Algorithm naming

	Algorithm names are case insensitive. Any particular algorithm can have multiple
	aliases associated with it. The canonical OpenSSL naming scheme follows this
	format:

	ALGNAME[VERSION?][-SUBNAME[VERSION?]?][-SIZE?][-MODE?]

	VERSION is only present if there are multiple versions of an algorithm (e.g.
	MD2, MD4, MD5). It may be omitted if there is only one version.

	SUBNAME may be present where multiple algorithms are combined together,
	e.g. MD5-SHA1.

	SIZE is only present if multiple versions of an algorithm exist with different
	sizes (e.g. AES-128-CBC, AES-256-CBC)

	MODE is only present where applicable.

	Other aliases may exist for example where standards bodies or common practice
	use alternative names or names that OpenSSL has used historically.

	=head1 OPENSSL PROVIDERS

	OpenSSL provides a number of its own providers. These are the default, base,
	fips, legacy and null providers. See L<crypto(7)> for an overview of these
	providers.

	=head1 SEE ALSO

	L<EVP_DigestInit_ex(3)>, L<EVP_EncryptInit_ex(3)>,
	L<OSSL_LIB_CTX(3)>,
	L<EVP_set_default_properties(3)>,
	L<EVP_MD_fetch(3)>,
	L<EVP_CIPHER_fetch(3)>,
	L<EVP_KEYMGMT_fetch(3)>,
	L<openssl-core.h(7)>,
	L<provider-base(7)>,
	L<provider-digest(7)>,
	L<provider-cipher(7)>,
	L<provider-keyexch(7)>

	=head1 HISTORY

	The concept of providers and everything surrounding them was
	introduced in OpenSSL 3.0.

	=head1 COPYRIGHT

	Copyright 2019-2022 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