provider-cipher(7) - man - phpMan

 


provider-cipher(7)
NAME SYNOPSIS DESCRIPTION RETURN VALUES SEE ALSO HISTORY COPYRIGHT
PROVIDER-CIPHER(7SSL)                          OpenSSL                         PROVIDER-CIPHER(7SSL)



NAME
       provider-cipher - The cipher library <-> provider functions

SYNOPSIS
        #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_cipher_newctx(void *provctx);
        void OSSL_FUNC_cipher_freectx(void *cctx);
        void *OSSL_FUNC_cipher_dupctx(void *cctx);

        /* Encryption/decryption */
        int OSSL_FUNC_cipher_encrypt_init(void *cctx, const unsigned char *key,
                                          size_t keylen, const unsigned char *iv,
                                          size_t ivlen, const OSSL_PARAM params[]);
        int OSSL_FUNC_cipher_decrypt_init(void *cctx, const unsigned char *key,
                                          size_t keylen, const unsigned char *iv,
                                          size_t ivlen, const OSSL_PARAM params[]);
        int OSSL_FUNC_cipher_update(void *cctx, unsigned char *out, size_t *outl,
                                    size_t outsize, const unsigned char *in, size_t inl);
        int OSSL_FUNC_cipher_final(void *cctx, unsigned char *out, size_t *outl,
                                   size_t outsize);
        int OSSL_FUNC_cipher_cipher(void *cctx, unsigned char *out, size_t *outl,
                                    size_t outsize, const unsigned char *in, size_t inl);

        /* Cipher parameter descriptors */
        const OSSL_PARAM *OSSL_FUNC_cipher_gettable_params(void *provctx);

        /* Cipher operation parameter descriptors */
        const OSSL_PARAM *OSSL_FUNC_cipher_gettable_ctx_params(void *cctx,
                                                               void *provctx);
        const OSSL_PARAM *OSSL_FUNC_cipher_settable_ctx_params(void *cctx,
                                                               void *provctx);

        /* Cipher parameters */
        int OSSL_FUNC_cipher_get_params(OSSL_PARAM params[]);

        /* Cipher operation parameters */
        int OSSL_FUNC_cipher_get_ctx_params(void *cctx, OSSL_PARAM params[]);
        int OSSL_FUNC_cipher_set_ctx_params(void *cctx, const OSSL_PARAM params[]);

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

       The CIPHER operation enables providers to implement cipher algorithms and make them available
       to applications via the API functions EVP_EncryptInit_ex(3), EVP_EncryptUpdate(3) and
       EVP_EncryptFinal(3) (as well as the decrypt equivalents 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 Functions" in
       provider-base(7)).

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

        typedef void *(OSSL_OSSL_FUNC_cipher_newctx_fn)(void *provctx);
        static ossl_inline OSSL_OSSL_FUNC_cipher_newctx_fn
            OSSL_FUNC_cipher_newctx(const OSSL_DISPATCH *opf);

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

        OSSL_FUNC_cipher_newctx               OSSL_FUNC_CIPHER_NEWCTX
        OSSL_FUNC_cipher_freectx              OSSL_FUNC_CIPHER_FREECTX
        OSSL_FUNC_cipher_dupctx               OSSL_FUNC_CIPHER_DUPCTX

        OSSL_FUNC_cipher_encrypt_init         OSSL_FUNC_CIPHER_ENCRYPT_INIT
        OSSL_FUNC_cipher_decrypt_init         OSSL_FUNC_CIPHER_DECRYPT_INIT
        OSSL_FUNC_cipher_update               OSSL_FUNC_CIPHER_UPDATE
        OSSL_FUNC_cipher_final                OSSL_FUNC_CIPHER_FINAL
        OSSL_FUNC_cipher_cipher               OSSL_FUNC_CIPHER_CIPHER

        OSSL_FUNC_cipher_get_params           OSSL_FUNC_CIPHER_GET_PARAMS
        OSSL_FUNC_cipher_get_ctx_params       OSSL_FUNC_CIPHER_GET_CTX_PARAMS
        OSSL_FUNC_cipher_set_ctx_params       OSSL_FUNC_CIPHER_SET_CTX_PARAMS

        OSSL_FUNC_cipher_gettable_params      OSSL_FUNC_CIPHER_GETTABLE_PARAMS
        OSSL_FUNC_cipher_gettable_ctx_params  OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS
        OSSL_FUNC_cipher_settable_ctx_params  OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS

       A cipher algorithm implementation may not implement all of these functions.  In order to be a
       consistent set of functions there must at least be a complete set of "encrypt" functions, or
       a complete set of "decrypt" functions, or a single "cipher" function.  In all cases both the
       OSSL_FUNC_cipher_newctx and OSSL_FUNC_cipher_freectx functions must be present.  All other
       functions are optional.

   Context Management Functions
       OSSL_FUNC_cipher_newctx() should create and return a pointer to a provider side structure for
       holding context information during a cipher operation.  A pointer to this context will be
       passed back in a number of the other cipher operation function calls.  The parameter provctx
       is the provider context generated during provider initialisation (see provider(7)).

       OSSL_FUNC_cipher_freectx() is passed a pointer to the provider side cipher context in the
       cctx parameter.  This function should free any resources associated with that context.

       OSSL_FUNC_cipher_dupctx() should duplicate the provider side cipher context in the cctx
       parameter and return the duplicate copy.

   Encryption/Decryption Functions
       OSSL_FUNC_cipher_encrypt_init() initialises a cipher operation for encryption given a newly
       created provider side cipher context in the cctx parameter.  The key to be used is given in
       key which is keylen bytes long.  The IV to be used is given in iv which is ivlen bytes long.
       The params, if not NULL, should be set on the context in a manner similar to using
       OSSL_FUNC_cipher_set_ctx_params().

       OSSL_FUNC_cipher_decrypt_init() is the same as OSSL_FUNC_cipher_encrypt_init() except that it
       initialises the context for a decryption operation.

       OSSL_FUNC_cipher_update() is called to supply data to be encrypted/decrypted as part of a
       previously initialised cipher operation.  The cctx parameter contains a pointer to a
       previously initialised provider side context.  OSSL_FUNC_cipher_update() should
       encrypt/decrypt inl bytes of data at the location pointed to by in.  The encrypted data
       should be stored in out and the amount of data written to *outl which should not exceed
       outsize bytes.  OSSL_FUNC_cipher_update() may be called multiple times for a single cipher
       operation.  It is the responsibility of the cipher implementation to handle input lengths
       that are not multiples of the block length.  In such cases a cipher implementation will
       typically cache partial blocks of input data until a complete block is obtained.  out may be
       the same location as in but it should not partially overlap.  The same expectations apply to
       outsize as documented for EVP_EncryptUpdate(3) and EVP_DecryptUpdate(3).

       OSSL_FUNC_cipher_final() completes an encryption or decryption started through previous
       OSSL_FUNC_cipher_encrypt_init() or OSSL_FUNC_cipher_decrypt_init(), and
       OSSL_FUNC_cipher_update() calls.  The cctx parameter contains a pointer to the provider side
       context.  Any final encryption/decryption output should be written to out and the amount of
       data written to *outl which should not exceed outsize bytes.  The same expectations apply to
       outsize as documented for EVP_EncryptFinal(3) and EVP_DecryptFinal(3).

       OSSL_FUNC_cipher_cipher() performs encryption/decryption using the provider side cipher
       context in the cctx parameter that should have been previously initialised via a call to
       OSSL_FUNC_cipher_encrypt_init() or OSSL_FUNC_cipher_decrypt_init().  This should call the raw
       underlying cipher function without any padding.  This will be invoked in the provider as a
       result of the application calling EVP_Cipher(3).  The application is responsible for ensuring
       that the input is a multiple of the block length.  The data to be encrypted/decrypted will be
       in in, and it will be inl bytes in length.  The output from the encryption/decryption should
       be stored in out and the amount of data stored should be put in *outl which should be no more
       than outsize bytes.

   Cipher Parameters
       See OSSL_PARAM(3) for further details on the parameters structure used by these functions.

       OSSL_FUNC_cipher_get_params() gets details of the algorithm implementation and stores them in
       params.

       OSSL_FUNC_cipher_set_ctx_params() sets cipher operation parameters for the provider side
       cipher context cctx to params.  Any parameter settings are additional to any that were
       previously set.  Passing NULL for params should return true.

       OSSL_FUNC_cipher_get_ctx_params() gets cipher operation details details from the given
       provider side cipher context cctx and stores them in params.  Passing NULL for params should
       return true.

       OSSL_FUNC_cipher_gettable_params(), OSSL_FUNC_cipher_gettable_ctx_params(), and
       OSSL_FUNC_cipher_settable_ctx_params() all return constant OSSL_PARAM arrays as descriptors
       of the parameters that OSSL_FUNC_cipher_get_params(), OSSL_FUNC_cipher_get_ctx_params(), and
       OSSL_FUNC_cipher_set_ctx_params() can handle, respectively.
       OSSL_FUNC_cipher_gettable_ctx_params() and OSSL_FUNC_cipher_settable_ctx_params() will return
       the parameters associated with the provider side context cctx in its current state if it is
       not NULL.  Otherwise, they return the parameters associated with the provider side algorithm
       provctx.

       Parameters currently recognised by built-in ciphers are listed in "PARAMETERS" in
       EVP_EncryptInit(3).  Not all parameters are relevant to, or are understood by all ciphers.

RETURN VALUES
       OSSL_FUNC_cipher_newctx() and OSSL_FUNC_cipher_dupctx() should return the newly created
       provider side cipher context, or NULL on failure.

       OSSL_FUNC_cipher_encrypt_init(), OSSL_FUNC_cipher_decrypt_init(), OSSL_FUNC_cipher_update(),
       OSSL_FUNC_cipher_final(), OSSL_FUNC_cipher_cipher(), OSSL_FUNC_cipher_get_params(),
       OSSL_FUNC_cipher_get_ctx_params() and OSSL_FUNC_cipher_set_ctx_params() should return 1 for
       success or 0 on error.

       OSSL_FUNC_cipher_gettable_params(), OSSL_FUNC_cipher_gettable_ctx_params() and
       OSSL_FUNC_cipher_settable_ctx_params() should return a constant OSSL_PARAM array, or NULL if
       none is offered.

SEE ALSO
       provider(7), OSSL_PROVIDER-FIPS(7), OSSL_PROVIDER-default(7), OSSL_PROVIDER-legacy(7),
       EVP_CIPHER-AES(7), EVP_CIPHER-ARIA(7), EVP_CIPHER-BLOWFISH(7), EVP_CIPHER-CAMELLIA(7),
       EVP_CIPHER-CAST(7), EVP_CIPHER-CHACHA(7), EVP_CIPHER-DES(7), EVP_CIPHER-IDEA(7),
       EVP_CIPHER-RC2(7), EVP_CIPHER-RC4(7), EVP_CIPHER-RC5(7), EVP_CIPHER-SEED(7),
       EVP_CIPHER-SM4(7), life_cycle-cipher(7), EVP_EncryptInit(3)

HISTORY
       The provider CIPHER interface was introduced in OpenSSL 3.0.

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 <https://www.openssl.org/source/license.html>.



3.0.2                                        2026-04-07                        PROVIDER-CIPHER(7SSL)

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