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

 =pod

 =head1 NAME

 provider-mac - The mac library E<lt>-E<gt> provider functions

 =head1 SYNOPSIS

 =for openssl multiple includes

  #include <openssl/core_dispatch.h>
  #include <openssl/core_names.h>

  /*
   * None of these are actual functions, but are displayed like this for
   * the function signatures for functions that are offered as function
   * pointers in OSSL_DISPATCH arrays.
   */

  /* Context management */
  void *OSSL_FUNC_mac_newctx(void *provctx);
  void OSSL_FUNC_mac_freectx(void *mctx);
  void *OSSL_FUNC_mac_dupctx(void *src);

  /* Encryption/decryption */
  int OSSL_FUNC_mac_init(void *mctx, unsigned char *key, size_t keylen,
                         const OSSL_PARAM params[]);
  int OSSL_FUNC_mac_update(void *mctx, const unsigned char *in, size_t inl);
  int OSSL_FUNC_mac_final(void *mctx, unsigned char *out, size_t *outl, size_t outsize);

  /* MAC parameter descriptors */
  const OSSL_PARAM *OSSL_FUNC_mac_gettable_params(void *provctx);
  const OSSL_PARAM *OSSL_FUNC_mac_gettable_ctx_params(void *mctx, void *provctx);
  const OSSL_PARAM *OSSL_FUNC_mac_settable_ctx_params(void *mctx, void *provctx);

  /* MAC parameters */
  int OSSL_FUNC_mac_get_params(OSSL_PARAM params[]);
  int OSSL_FUNC_mac_get_ctx_params(void *mctx, OSSL_PARAM params[]);
  int OSSL_FUNC_mac_set_ctx_params(void *mctx, const OSSL_PARAM params[]);

 =head1 DESCRIPTION

 This documentation is primarily aimed at provider authors. See L<provider(7)>
 for further information.

 The MAC operation enables providers to implement mac algorithms and make
 them available to applications via the API functions L<EVP_MAC_init(3)>,
 L<EVP_MAC_update(3)> and L<EVP_MAC_final(3)>.

 All "functions" mentioned here are passed as function pointers between
 F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays via
 B<OSSL_ALGORITHM> arrays that are returned by the provider's
 provider_query_operation() function
 (see L<provider-base(7)/Provider Functions>).

 All these "functions" have a corresponding function type definition
 named B<OSSL_FUNC_{name}_fn>, and a helper function to retrieve the
 function pointer from an B<OSSL_DISPATCH> element named
 B<OSSL_FUNC_{name}>.
 For example, the "function" OSSL_FUNC_mac_newctx() has these:

  typedef void *(OSSL_OSSL_FUNC_mac_newctx_fn)(void *provctx);
  static ossl_inline OSSL_OSSL_FUNC_mac_newctx_fn
      OSSL_FUNC_mac_newctx(const OSSL_DISPATCH *opf);

 B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
 macros in L<openssl-core_dispatch.h(7)>, as follows:

  OSSL_FUNC_mac_newctx               OSSL_FUNC_MAC_NEWCTX
  OSSL_FUNC_mac_freectx              OSSL_FUNC_MAC_FREECTX
  OSSL_FUNC_mac_dupctx               OSSL_FUNC_MAC_DUPCTX

  OSSL_FUNC_mac_init                 OSSL_FUNC_MAC_INIT
  OSSL_FUNC_mac_update               OSSL_FUNC_MAC_UPDATE
  OSSL_FUNC_mac_final                OSSL_FUNC_MAC_FINAL

  OSSL_FUNC_mac_get_params           OSSL_FUNC_MAC_GET_PARAMS
  OSSL_FUNC_mac_get_ctx_params       OSSL_FUNC_MAC_GET_CTX_PARAMS
  OSSL_FUNC_mac_set_ctx_params       OSSL_FUNC_MAC_SET_CTX_PARAMS

  OSSL_FUNC_mac_gettable_params      OSSL_FUNC_MAC_GETTABLE_PARAMS
  OSSL_FUNC_mac_gettable_ctx_params  OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS
  OSSL_FUNC_mac_settable_ctx_params  OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS

 A mac algorithm implementation may not implement all of these functions.
 In order to be a consistent set of functions, at least the following functions
 must be implemented: OSSL_FUNC_mac_newctx(), OSSL_FUNC_mac_freectx(), OSSL_FUNC_mac_init(),
 OSSL_FUNC_mac_update(), OSSL_FUNC_mac_final().
 All other functions are optional.

 =head2 Context Management Functions

 OSSL_FUNC_mac_newctx() should create and return a pointer to a provider side
 structure for holding context information during a mac operation.
 A pointer to this context will be passed back in a number of the other mac
 operation function calls.
 The parameter I<provctx> is the provider context generated during provider
 initialisation (see L<provider(7)>).

 OSSL_FUNC_mac_freectx() is passed a pointer to the provider side mac context in
 the I<mctx> parameter.
 If it receives NULL as I<mctx> value, it should not do anything other than
 return.
 This function should free any resources associated with that context.

 OSSL_FUNC_mac_dupctx() should duplicate the provider side mac context in the
 I<mctx> parameter and return the duplicate copy.

 =head2 Encryption/Decryption Functions

 OSSL_FUNC_mac_init() initialises a mac operation given a newly created provider
 side mac context in the I<mctx> parameter.  The I<params> are set before setting
 the MAC I<key> of I<keylen> bytes.

 OSSL_FUNC_mac_update() is called to supply data for MAC computation of a previously
 initialised mac operation.
 The I<mctx> parameter contains a pointer to a previously initialised provider
 side context.
 OSSL_FUNC_mac_update() may be called multiple times for a single mac operation.

 OSSL_FUNC_mac_final() completes the MAC computation started through previous
 OSSL_FUNC_mac_init() and OSSL_FUNC_mac_update() calls.
 The I<mctx> parameter contains a pointer to the provider side context.
 The resulting MAC should be written to I<out> and the amount of data written
 to I<*outl>, which should not exceed I<outsize> bytes.
 The same expectations apply to I<outsize> as documented for
 L<EVP_MAC_final(3)>.

 =head2 Mac Parameters

 See L<OSSL_PARAM(3)> for further details on the parameters structure used by
 these functions.

 OSSL_FUNC_mac_get_params() gets details of parameter values associated with the
 provider algorithm and stores them in I<params>.

 OSSL_FUNC_mac_set_ctx_params() sets mac parameters associated with the given
 provider side mac context I<mctx> to I<params>.
 Any parameter settings are additional to any that were previously set.
 Passing NULL for I<params> should return true.

 OSSL_FUNC_mac_get_ctx_params() gets details of currently set parameter values
 associated with the given provider side mac context I<mctx> and stores them
 in I<params>.
 Passing NULL for I<params> should return true.

 OSSL_FUNC_mac_gettable_params(), OSSL_FUNC_mac_gettable_ctx_params(),
 and OSSL_FUNC_mac_settable_ctx_params() all return constant B<OSSL_PARAM>
 arrays as descriptors of the parameters that OSSL_FUNC_mac_get_params(),
 OSSL_FUNC_mac_get_ctx_params(), and OSSL_FUNC_mac_set_ctx_params()
 can handle, respectively.  OSSL_FUNC_mac_gettable_ctx_params() and
 OSSL_FUNC_mac_settable_ctx_params() will return the parameters associated
 with the provider side context I<mctx> in its current state if it is
 not NULL.  Otherwise, they return the parameters associated with the
 provider side algorithm I<provctx>.

 All MAC implementations are expected to handle the following parameters:

 =over 4

 =item with OSSL_FUNC_set_ctx_params():

 =over 4

 =item "key" (B<OSSL_MAC_PARAM_KEY>) <octet string>

 Sets the key in the associated MAC ctx.  This is identical to passing a I<key>
 argument to the OSSL_FUNC_mac_init() function.

 =back

 =item with OSSL_FUNC_get_params():

 =over 4

 =item "size" (B<OSSL_MAC_PARAM_SIZE>) <integer>

 Can be used to get the default MAC size (which might be the only allowable
 MAC size for the implementation).

 Note that some implementations allow setting the size that the resulting MAC
 should have as well, see the documentation of the implementation.

 =back

 =over 4

 =item "size" (B<OSSL_MAC_PARAM_BLOCK_SIZE>) <integer>

 Can be used to get the MAC block size (if supported by the algorithm).

 =back

 =back

 =head1 NOTES

 The MAC life-cycle is described in L<life_cycle-rand(7)>.  Providers should
 ensure that the various transitions listed there are supported.  At some point
 the EVP layer will begin enforcing the listed transitions.

 =head1 RETURN VALUES

 OSSL_FUNC_mac_newctx() and OSSL_FUNC_mac_dupctx() should return the newly created
 provider side mac context, or NULL on failure.

 OSSL_FUNC_mac_init(), OSSL_FUNC_mac_update(), OSSL_FUNC_mac_final(), OSSL_FUNC_mac_get_params(),
 OSSL_FUNC_mac_get_ctx_params() and OSSL_FUNC_mac_set_ctx_params() should return 1 for
 success or 0 on error.

 OSSL_FUNC_mac_gettable_params(), OSSL_FUNC_mac_gettable_ctx_params() and
 OSSL_FUNC_mac_settable_ctx_params() should return a constant B<OSSL_PARAM>
 array, or NULL if none is offered.

 =head1 SEE ALSO

 L<provider(7)>,
 L<EVP_MAC-BLAKE2(7)>, L<EVP_MAC-CMAC(7)>, L<EVP_MAC-GMAC(7)>,
 L<EVP_MAC-HMAC(7)>, L<EVP_MAC-KMAC(7)>, L<EVP_MAC-Poly1305(7)>,
 L<EVP_MAC-Siphash(7)>,
 L<life_cycle-mac(7)>, L<EVP_MAC(3)>

 =head1 HISTORY

 The provider MAC interface was introduced in OpenSSL 3.0.

 =head1 COPYRIGHT

 Copyright 2019-2021 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-mac - The mac library E<lt>-E<gt> provider functions

	=head1 SYNOPSIS

	=for openssl multiple includes

	#include <openssl/core_dispatch.h>
	#include <openssl/core_names.h>

	/*
	* None of these are actual functions, but are displayed like this for
	* the function signatures for functions that are offered as function
	* pointers in OSSL_DISPATCH arrays.
	*/

	/* Context management */
	void OSSL_FUNC_mac_newctx(void provctx);
	void OSSL_FUNC_mac_freectx(void *mctx);
	void OSSL_FUNC_mac_dupctx(void src);

	/* Encryption/decryption */
	int OSSL_FUNC_mac_init(void mctx, unsigned char key, size_t keylen,
	const OSSL_PARAM params[]);
	int OSSL_FUNC_mac_update(void mctx, const unsigned char in, size_t inl);
	int OSSL_FUNC_mac_final(void mctx, unsigned char out, size_t *outl, size_t outsize);

	/* MAC parameter descriptors */
	const OSSL_PARAM OSSL_FUNC_mac_gettable_params(void provctx);
	const OSSL_PARAM OSSL_FUNC_mac_gettable_ctx_params(void mctx, void *provctx);
	const OSSL_PARAM OSSL_FUNC_mac_settable_ctx_params(void mctx, void *provctx);

	/* MAC parameters */
	int OSSL_FUNC_mac_get_params(OSSL_PARAM params[]);
	int OSSL_FUNC_mac_get_ctx_params(void *mctx, OSSL_PARAM params[]);
	int OSSL_FUNC_mac_set_ctx_params(void *mctx, const OSSL_PARAM params[]);

	=head1 DESCRIPTION

	This documentation is primarily aimed at provider authors. See L<provider(7)>
	for further information.

	The MAC operation enables providers to implement mac algorithms and make
	them available to applications via the API functions L<EVP_MAC_init(3)>,
	L<EVP_MAC_update(3)> and L<EVP_MAC_final(3)>.

	All "functions" mentioned here are passed as function pointers between
	F<libcrypto> and the provider in B<OSSL_DISPATCH> arrays via
	B<OSSL_ALGORITHM> arrays that are returned by the provider's
	provider_query_operation() function
	(see L<provider-base(7)/Provider Functions>).

	All these "functions" have a corresponding function type definition
	named B<OSSL_FUNC_{name}_fn>, and a helper function to retrieve the
	function pointer from an B<OSSL_DISPATCH> element named
	B<OSSL_FUNC_{name}>.
	For example, the "function" OSSL_FUNC_mac_newctx() has these:

	typedef void (OSSL_OSSL_FUNC_mac_newctx_fn)(void provctx);
	static ossl_inline OSSL_OSSL_FUNC_mac_newctx_fn
	OSSL_FUNC_mac_newctx(const OSSL_DISPATCH *opf);

	B<OSSL_DISPATCH> arrays are indexed by numbers that are provided as
	macros in L<openssl-core_dispatch.h(7)>, as follows:

	OSSL_FUNC_mac_newctx OSSL_FUNC_MAC_NEWCTX
	OSSL_FUNC_mac_freectx OSSL_FUNC_MAC_FREECTX
	OSSL_FUNC_mac_dupctx OSSL_FUNC_MAC_DUPCTX

	OSSL_FUNC_mac_init OSSL_FUNC_MAC_INIT
	OSSL_FUNC_mac_update OSSL_FUNC_MAC_UPDATE
	OSSL_FUNC_mac_final OSSL_FUNC_MAC_FINAL

	OSSL_FUNC_mac_get_params OSSL_FUNC_MAC_GET_PARAMS
	OSSL_FUNC_mac_get_ctx_params OSSL_FUNC_MAC_GET_CTX_PARAMS
	OSSL_FUNC_mac_set_ctx_params OSSL_FUNC_MAC_SET_CTX_PARAMS

	OSSL_FUNC_mac_gettable_params OSSL_FUNC_MAC_GETTABLE_PARAMS
	OSSL_FUNC_mac_gettable_ctx_params OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS
	OSSL_FUNC_mac_settable_ctx_params OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS

	A mac algorithm implementation may not implement all of these functions.
	In order to be a consistent set of functions, at least the following functions
	must be implemented: OSSL_FUNC_mac_newctx(), OSSL_FUNC_mac_freectx(), OSSL_FUNC_mac_init(),
	OSSL_FUNC_mac_update(), OSSL_FUNC_mac_final().
	All other functions are optional.

	=head2 Context Management Functions

	OSSL_FUNC_mac_newctx() should create and return a pointer to a provider side
	structure for holding context information during a mac operation.
	A pointer to this context will be passed back in a number of the other mac
	operation function calls.
	The parameter I<provctx> is the provider context generated during provider
	initialisation (see L<provider(7)>).

	OSSL_FUNC_mac_freectx() is passed a pointer to the provider side mac context in
	the I<mctx> parameter.
	If it receives NULL as I<mctx> value, it should not do anything other than
	return.
	This function should free any resources associated with that context.

	OSSL_FUNC_mac_dupctx() should duplicate the provider side mac context in the
	I<mctx> parameter and return the duplicate copy.

	=head2 Encryption/Decryption Functions

	OSSL_FUNC_mac_init() initialises a mac operation given a newly created provider
	side mac context in the I<mctx> parameter. The I<params> are set before setting
	the MAC I<key> of I<keylen> bytes.

	OSSL_FUNC_mac_update() is called to supply data for MAC computation of a previously
	initialised mac operation.
	The I<mctx> parameter contains a pointer to a previously initialised provider
	side context.
	OSSL_FUNC_mac_update() may be called multiple times for a single mac operation.

	OSSL_FUNC_mac_final() completes the MAC computation started through previous
	OSSL_FUNC_mac_init() and OSSL_FUNC_mac_update() calls.
	The I<mctx> parameter contains a pointer to the provider side context.
	The resulting MAC should be written to I<out> and the amount of data written
	to I<*outl>, which should not exceed I<outsize> bytes.
	The same expectations apply to I<outsize> as documented for
	L<EVP_MAC_final(3)>.

	=head2 Mac Parameters

	See L<OSSL_PARAM(3)> for further details on the parameters structure used by
	these functions.

	OSSL_FUNC_mac_get_params() gets details of parameter values associated with the
	provider algorithm and stores them in I<params>.

	OSSL_FUNC_mac_set_ctx_params() sets mac parameters associated with the given
	provider side mac context I<mctx> to I<params>.
	Any parameter settings are additional to any that were previously set.
	Passing NULL for I<params> should return true.

	OSSL_FUNC_mac_get_ctx_params() gets details of currently set parameter values
	associated with the given provider side mac context I<mctx> and stores them
	in I<params>.
	Passing NULL for I<params> should return true.

	OSSL_FUNC_mac_gettable_params(), OSSL_FUNC_mac_gettable_ctx_params(),
	and OSSL_FUNC_mac_settable_ctx_params() all return constant B<OSSL_PARAM>
	arrays as descriptors of the parameters that OSSL_FUNC_mac_get_params(),
	OSSL_FUNC_mac_get_ctx_params(), and OSSL_FUNC_mac_set_ctx_params()
	can handle, respectively. OSSL_FUNC_mac_gettable_ctx_params() and
	OSSL_FUNC_mac_settable_ctx_params() will return the parameters associated
	with the provider side context I<mctx> in its current state if it is
	not NULL. Otherwise, they return the parameters associated with the
	provider side algorithm I<provctx>.

	All MAC implementations are expected to handle the following parameters:

	=over 4

	=item with OSSL_FUNC_set_ctx_params():

	=over 4

	=item "key" (B<OSSL_MAC_PARAM_KEY>) <octet string>

	Sets the key in the associated MAC ctx. This is identical to passing a I<key>
	argument to the OSSL_FUNC_mac_init() function.

	=back

	=item with OSSL_FUNC_get_params():

	=over 4

	=item "size" (B<OSSL_MAC_PARAM_SIZE>) <integer>

	Can be used to get the default MAC size (which might be the only allowable
	MAC size for the implementation).

	Note that some implementations allow setting the size that the resulting MAC
	should have as well, see the documentation of the implementation.

	=back

	=over 4

	=item "size" (B<OSSL_MAC_PARAM_BLOCK_SIZE>) <integer>

	Can be used to get the MAC block size (if supported by the algorithm).

	=back

	=back

	=head1 NOTES

	The MAC life-cycle is described in L<life_cycle-rand(7)>. Providers should
	ensure that the various transitions listed there are supported. At some point
	the EVP layer will begin enforcing the listed transitions.

	=head1 RETURN VALUES

	OSSL_FUNC_mac_newctx() and OSSL_FUNC_mac_dupctx() should return the newly created
	provider side mac context, or NULL on failure.

	OSSL_FUNC_mac_init(), OSSL_FUNC_mac_update(), OSSL_FUNC_mac_final(), OSSL_FUNC_mac_get_params(),
	OSSL_FUNC_mac_get_ctx_params() and OSSL_FUNC_mac_set_ctx_params() should return 1 for
	success or 0 on error.

	OSSL_FUNC_mac_gettable_params(), OSSL_FUNC_mac_gettable_ctx_params() and
	OSSL_FUNC_mac_settable_ctx_params() should return a constant B<OSSL_PARAM>
	array, or NULL if none is offered.

	=head1 SEE ALSO

	L<provider(7)>,
	L<EVP_MAC-BLAKE2(7)>, L<EVP_MAC-CMAC(7)>, L<EVP_MAC-GMAC(7)>,
	L<EVP_MAC-HMAC(7)>, L<EVP_MAC-KMAC(7)>, L<EVP_MAC-Poly1305(7)>,
	L<EVP_MAC-Siphash(7)>,
	L<life_cycle-mac(7)>, L<EVP_MAC(3)>

	=head1 HISTORY

	The provider MAC interface was introduced in OpenSSL 3.0.

	=head1 COPYRIGHT

	Copyright 2019-2021 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