provider-signature - The signature library <-> provider functions
#include <openssl/core_numbers.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 *OP_signature_newctx(void *provctx); void OP_signature_freectx(void *ctx); void *OP_signature_dupctx(void *ctx);
/* Signing */
int OP_signature_sign_init(void *ctx, void *provkey);
int OP_signature_sign(void *ctx, unsigned char *sig, size_t *siglen,
size_t sigsize, const unsigned char *tbs, size_t tbslen);
/* Verifying */
int OP_signature_verify_init(void *ctx, void *provkey);
int OP_signature_verify(void *ctx, const unsigned char *sig, size_t siglen,
const unsigned char *tbs, size_t tbslen);
/* Verify Recover */
int OP_signature_verify_recover_init(void *ctx, void *provkey);
int OP_signature_verify_recover(void *ctx, unsigned char *rout,
size_t *routlen, size_t routsize,
const unsigned char *sig, size_t siglen);
/* Signature parameters */ int OP_signature_get_ctx_params(void *ctx, OSSL_PARAM params[]); const OSSL_PARAM *OP_signature_gettable_ctx_params(void); int OP_signature_set_ctx_params(void *ctx, const OSSL_PARAM params[]); const OSSL_PARAM *OP_signature_settable_ctx_params(void);
This documentation is primarily aimed at provider authors. See provider(7) for further information.
The signature (OSSL_OP_SIGNATURE) operation enables providers to implement signature algorithms and make them available to applications via the API functions EVP_PKEY_sign(3), EVP_PKEY_verify(3), and EVP_PKEY_verify_recover(3) (as well as other related functions).
All "functions" mentioned here are passed as function pointers between
libcrypto and the provider in OSSL_DISPATCH arrays via
OSSL_ALGORITHM arrays that are returned by the provider's
provider_query_operation() function
(see provider-base(7)/Provider Functions).
All these "functions" have a corresponding function type definition
named OSSL_{name}_fn, and a helper function to retrieve the
function pointer from an OSSL_DISPATCH element named
OSSL_get_{name}.
For example, the "function" OP_signature_newctx() has these:
typedef void *(OSSL_OP_signature_newctx_fn)(void *provctx);
static ossl_inline OSSL_OP_signature_newctx_fn
OSSL_get_OP_signature_newctx(const OSSL_DISPATCH *opf);
OSSL_DISPATCH arrays are indexed by numbers that are provided as macros in openssl-core_numbers.h(7), as follows:
OP_signature_newctx OSSL_FUNC_SIGNATURE_NEWCTX OP_signature_freectx OSSL_FUNC_SIGNATURE_FREECTX OP_signature_dupctx OSSL_FUNC_SIGNATURE_DUPCTX
OP_signature_sign_init OSSL_FUNC_SIGNATURE_SIGN_INIT OP_signature_sign OSSL_FUNC_SIGNATURE_SIGN
OP_signature_verify_init OSSL_FUNC_SIGNATURE_VERIFY_INIT OP_signature_verify OSSL_FUNC_SIGNATURE_VERIFY
OP_signature_verify_recover_init OSSL_FUNC_SIGNATURE_VERIFY_RECOVER_INIT OP_signature_verify_recover OSSL_FUNC_SIGNATURE_VERIFY_RECOVER
OP_signature_get_ctx_params OSSL_FUNC_SIGNATURE_GET_CTX_PARAMS OP_signature_gettable_ctx_params OSSL_FUNC_SIGNATURE_GETTABLE_CTX_PARAMS OP_signature_set_ctx_params OSSL_FUNC_SIGNATURE_SET_CTX_PARAMS OP_signature_settable_ctx_params OSSL_FUNC_SIGNATURE_SETTABLE_CTX_PARAMS
A signature algorithm implementation may not implement all of these functions. In order to be a consistent set of functions a provider must implement OP_signature_newctx and OP_signature_freectx. It must also implement both of OP_signature_sign_init and OP_signature_sign, or both of OP_signature_verify_init and OP_signature_verify, or both of OP_signature_verify_recover_init and OP_signature_verify_recover. All other functions are optional.
A signature algorithm must also implement some mechanism for generating, loading or importing keys via the key management (OSSL_OP_KEYMGMT) operation. See provider-keymgmt(7) for further details.
OP_signature_newctx() should create and return a pointer to a provider side
structure for holding context information during a signature operation.
A pointer to this context will be passed back in a number of the other signature
operation function calls.
The parameter provctx is the provider context generated during provider
initialisation (see provider(7)).
OP_signature_freectx() is passed a pointer to the provider side signature
context in the ctx parameter.
This function should free any resources associated with that context.
OP_signature_dupctx() should duplicate the provider side signature context in
the ctx parameter and return the duplicate copy.
OP_signature_sign_init() initialises a context for signing given a provider side
signature context in the ctx parameter, and a pointer to a provider key object
in the provkey parameter.
The key object should have been previously generated, loaded or imported into
the provider using the key management (OSSL_OP_KEYMGMT) operation (see
provider-keymgmt(7)>.
OP_signature_sign() performs the actual signing itself.
A previously initialised signature context is passed in the ctx
parameter.
The data to be signed is pointed to be the tbs parameter which is tbslen
bytes long.
Unless sig is NULL, the signature should be written to the location pointed
to by the sig parameter and it should not exceed sigsize bytes in length.
The length of the signature should be written to *siglen.
If sig is NULL then the maximum length of the signature should be written to
*siglen.
OP_signature_verify_init() initialises a context for verifying a signature given
a provider side signature context in the ctx parameter, and a pointer to a
provider key object in the provkey parameter.
The key object should have been previously generated, loaded or imported into
the provider using the key management (OSSL_OP_KEYMGMT) operation (see
provider-keymgmt(7)>.
OP_signature_verify() performs the actual verification itself.
A previously initialised signature context is passed in the ctx parameter.
The data that the signature covers is pointed to be the tbs parameter which
is tbslen bytes long.
The signature is pointed to by the sig parameter which is siglen bytes
long.
OP_signature_verify_recover_init() initialises a context for recovering the
signed data given a provider side signature context in the ctx parameter, and
a pointer to a provider key object in the provkey parameter.
The key object should have been previously generated, loaded or imported into
the provider using the key management (OSSL_OP_KEYMGMT) operation (see
provider-keymgmt(7)>.
OP_signature_verify_recover() performs the actual verify recover itself.
A previously initialised signature context is passed in the ctx parameter.
The signature is pointed to by the sig parameter which is siglen bytes
long.
Unless rout is NULL, the recovered data should be written to the location
pointed to by rout which should not exceed routsize bytes in length.
The length of the recovered data should be written to *routlen.
If rout is NULL then the maximum size of the output buffer is written to
the routlen parameter.
See OSSL_PARAM(3) for further details on the parameters structure used by
the OP_signature_get_ctx_params() and OP_signature_set_ctx_params() functions.
OP_signature_get_ctx_params() gets signature parameters associated with the
given provider side signature context ctx and stored them in params.
OP_signature_set_ctx_params() sets the signature parameters associated with the
given provider side signature context ctx to params.
Any parameter settings are additional to any that were previously set.
Parameters currently recognised by built-in signature algorithms are as follows. Not all parameters are relevant to, or are understood by all signature algorithms:
Get or sets the name of the digest algorithm used for the input to the signature functions.
Gets or sets the output size of the digest algorithm used for the input to the signature functions. The length of the "digest-size" parameter should not exceed that of a size_t.
OP_signature_gettable_ctx_params() and OP_signature_settable_ctx_params() get a
constant OSSL_PARAM array that describes the gettable and settable parameters,
i.e. parameters that can be used with OP_signature_get_ctx_params() and
OP_signature_set_ctx_params() respectively.
See OSSL_PARAM(3) for the use of OSSL_PARAM as parameter descriptor.
OP_signature_newctx() and OP_signature_dupctx() should return the newly created
provider side signature, or NULL on failure.
All other functions should return 1 for success or 0 on error.
provider(7)
The provider SIGNATURE interface was introduced in OpenSSL 3.0.
Copyright 2019 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 https://www.openssl.org/source/license.html.