provider-asym_cipher - The asym_cipher 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_asym_cipher_newctx(void *provctx); void OP_asym_cipher_freectx(void *ctx); void *OP_asym_cipher_dupctx(void *ctx);
/* Encryption */ int OP_asym_cipher_encrypt_init(void *ctx, void *provkey); int OP_asym_cipher_encrypt(void *ctx, unsigned char *out, size_t *outlen, size_t outsize, const unsigned char *in, size_t inlen);
/* Decryption */ int OP_asym_cipher_decrypt_init(void *ctx, void *provkey); int OP_asym_cipher_decrypt(void *ctx, unsigned char *out, size_t *outlen, size_t outsize, const unsigned char *in, size_t inlen);
/* Asymmetric Cipher parameters */ int OP_asym_cipher_get_ctx_params(void *ctx, OSSL_PARAM params[]); const OSSL_PARAM *OP_asym_cipher_gettable_ctx_params(void); int OP_asym_cipher_set_ctx_params(void *ctx, const OSSL_PARAM params[]); const OSSL_PARAM *OP_asym_cipher_settable_ctx_params(void);
This documentation is primarily aimed at provider authors. See provider(7) for further information.
The asymmetric cipher (OSSL_OP_ASYM_CIPHER) operation enables providers to implement asymmetric cipher algorithms and make them available to applications via the API functions EVP_PKEY_encrypt(3), EVP_PKEY_decrypt(3) and 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_asym_cipher_newctx()
has these:
typedef void *(OSSL_OP_asym_cipher_newctx_fn)(void *provctx); static ossl_inline OSSL_OP_asym_cipher_newctx_fn OSSL_get_OP_asym_cipher_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_asym_cipher_newctx OSSL_FUNC_ASYM_CIPHER_NEWCTX OP_asym_cipher_freectx OSSL_FUNC_ASYM_CIPHER_FREECTX OP_asym_cipher_dupctx OSSL_FUNC_ASYM_CIPHER_DUPCTX
OP_asym_cipher_encrypt_init OSSL_FUNC_ASYM_CIPHER_ENCRYPT_INIT OP_asym_cipher_encrypt OSSL_FUNC_ASYM_CIPHER_ENCRYPT
OP_asym_cipher_decrypt_init OSSL_FUNC_ASYM_CIPHER_DECRYPT_INIT OP_asym_cipher_decrypt OSSL_FUNC_ASYM_CIPHER_DECRYPT
OP_asym_cipher_get_ctx_params OSSL_FUNC_ASYM_CIPHER_GET_CTX_PARAMS OP_asym_cipher_gettable_ctx_params OSSL_FUNC_ASYM_CIPHER_GETTABLE_CTX_PARAMS OP_asym_cipher_set_ctx_params OSSL_FUNC_ASYM_CIPHER_SET_CTX_PARAMS OP_asym_cipher_settable_ctx_params OSSL_FUNC_ASYM_CIPHER_SETTABLE_CTX_PARAMS
An asymmetric cipher algorithm implementation may not implement all of these functions. In order to be a consistent set of functions a provider must implement OP_asym_cipher_newctx and OP_asym_cipher_freectx. It must also implement both of OP_asym_cipher_encrypt_init and OP_asym_cipher_encrypt, or both of OP_asym_cipher_decrypt_init and OP_asym_cipher_decrypt. OP_asym_cipher_get_ctx_params is optional but if it is present then so must OP_asym_cipher_gettable_ctx_params. Similarly, OP_asym_cipher_set_ctx_params is optional but if it is present then so must OP_asym_cipher_settable_ctx_params.
An asymmetric cipher 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_asym_cipher_newctx()
should create and return a pointer to a provider side
structure for holding context information during an asymmetric cipher operation.
A pointer to this context will be passed back in a number of the other
asymmetric cipher operation function calls.
The parameter provctx is the provider context generated during provider
initialisation (see provider(7)).
OP_asym_cipher_freectx()
is passed a pointer to the provider side asymmetric
cipher context in the ctx parameter.
This function should free any resources associated with that context.
OP_asym_cipher_dupctx()
should duplicate the provider side asymmetric cipher
context in the ctx parameter and return the duplicate copy.
OP_asym_cipher_encrypt_init()
initialises a context for an asymmetric encryption
given a provider side asymmetric cipher 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_asym_cipher_encrypt()
performs the actual encryption itself.
A previously initialised asymmetric cipher context is passed in the ctx
parameter.
The data to be encrypted is pointed to by the in parameter which is inlen
bytes long.
Unless out is NULL, the encrypted data should be written to the location
pointed to by the out parameter and it should not exceed outsize bytes in
length.
The length of the encrypted data should be written to *outlen.
If out is NULL then the maximum length of the encrypted data should be
written to *outlen.
OP_asym_cipher_decrypt_init()
initialises a context for an asymmetric decryption
given a provider side asymmetric cipher 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_asym_cipher_decrypt()
performs the actual decryption itself.
A previously initialised asymmetric cipher context is passed in the ctx
parameter.
The data to be decrypted is pointed to by the in parameter which is inlen
bytes long.
Unless out is NULL, the decrypted data should be written to the location
pointed to by the out parameter and it should not exceed outsize bytes in
length.
The length of the decrypted data should be written to *outlen.
If out is NULL then the maximum length of the decrypted data should be
written to *outlen.
See OSSL_PARAM(3) for further details on the parameters structure used by
the OP_asym_cipher_get_ctx_params()
and OP_asym_cipher_set_ctx_params()
functions.
OP_asym_cipher_get_ctx_params()
gets asymmetric cipher parameters associated
with the given provider side asymmetric cipher context ctx and stores them in
params.
OP_asym_cipher_set_ctx_params()
sets the asymmetric cipher parameters associated
with the given provider side asymmetric cipher context ctx to params.
Any parameter settings are additional to any that were previously set.
Parameters currently recognised by built-in asymmetric cipher algorithms are as follows. Not all parameters are relevant to, or are understood by all asymmetric cipher algorithms:
The type of padding to be used. The interpretation of this value will depend on the algorithm in use. The default provider understands these RSA padding modes: 1 (RSA_PKCS1_PADDING), 2 (RSA_SSLV23_PADDING), 3 (RSA_NO_PADDING), 4 (RSA_PKCS1_OAEP_PADDING), 5 (RSA_X931_PADDING), 6 (RSA_PKCS1_PSS_PADDING) and 7 (RSA_PKCS1_WITH_TLS_PADDING). See EVP_PKEY_CTX_set_rsa_padding(3) for further details.
Gets or sets the name of the OAEP digest algorithm used when OAEP padding is in use.
Gets or sets the properties to use when fetching the OAEP digest algorithm.
Gets or sets the name of the MGF1 digest algorithm used when OAEP or PSS padding is in use.
Gets or sets the properties to use when fetching the MGF1 digest algorithm.
Gets or sets the OAEP label used when OAEP padding is in use.
Gets the length of an OAEP label when OAEP padding is in use.
The TLS protocol version first requested by the client. See RSA_PKCS1_WITH_TLS_PADDING on the page EVP_PKEY_CTX_set_rsa_padding(3).
The negotiated TLS protocol version. See RSA_PKCS1_WITH_TLS_PADDING on the page EVP_PKEY_CTX_set_rsa_padding(3).
OP_asym_cipher_gettable_ctx_params()
and OP_asym_cipher_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_asym_cipherget_ctx_params()
and OP_asym_cipher_set_ctx_params()
respectively.
See OSSL_PARAM(3) for the use of OSSL_PARAM as parameter descriptor.
OP_asym_cipher_newctx()
and OP_asym_cipher_dupctx()
should return the newly
created provider side asymmetric cipher context, or NULL on failure.
All other functions should return 1 for success or 0 on error.
provider(7)
The provider ASYM_CIPHER 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.