# PROVIDER-CIPHER(7SSL) - man - phpMan [PROVIDER-CIPHER(7SSL)](https://www.chedong.com/phpMan.php/man/PROVIDER-CIPHER/7SSL/markdown) OpenSSL [PROVIDER-CIPHER(7SSL)](https://www.chedong.com/phpMan.php/man/PROVIDER-CIPHER/7SSL/markdown) ## NAME provider-cipher - The cipher library <-> provider functions ## SYNOPSIS #include #include /* * 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)](https://www.chedong.com/phpMan.php/man/provider/7/markdown) 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)](https://www.chedong.com/phpMan.php/man/ex/3/markdown), **EVP**___**[EncryptUpdate**(3)](https://www.chedong.com/phpMan.php/man/EncryptUpdate/3/markdown) and **EVP**___**[EncryptFinal**(3)](https://www.chedong.com/phpMan.php/man/EncryptFinal/3/markdown) (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)](https://www.chedong.com/phpMan.php/man/provider-base/7/markdown)). 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)](https://www.chedong.com/phpMan.php/man/dispatch.h/7/markdown), 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)](https://www.chedong.com/phpMan.php/man/provider/7/markdown)). **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)](https://www.chedong.com/phpMan.php/man/EncryptUpdate/3/markdown) and **EVP**___**[DecryptUpdate**(3)](https://www.chedong.com/phpMan.php/man/DecryptUpdate/3/markdown). **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)](https://www.chedong.com/phpMan.php/man/EncryptFinal/3/markdown) and **EVP**___**[DecryptFinal**(3)](https://www.chedong.com/phpMan.php/man/DecryptFinal/3/markdown). **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)](https://www.chedong.com/phpMan.php/man/Cipher/3/markdown). 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)](https://www.chedong.com/phpMan.php/man/PARAM/3/markdown) 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)](https://www.chedong.com/phpMan.php/man/EncryptInit/3/markdown). 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)](https://www.chedong.com/phpMan.php/man/provider/7/markdown), **OSSL**___**[PROVIDER-FIPS**(7)](https://www.chedong.com/phpMan.php/man/PROVIDER-FIPS/7/markdown), **OSSL**___**[PROVIDER-default**(7)](https://www.chedong.com/phpMan.php/man/PROVIDER-default/7/markdown), **OSSL**___**[PROVIDER-legacy**(7)](https://www.chedong.com/phpMan.php/man/PROVIDER-legacy/7/markdown), **EVP**___**[CIPHER-AES**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-AES/7/markdown), **EVP**___**[CIPHER-ARIA**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-ARIA/7/markdown), **EVP**___**[CIPHER-BLOWFISH**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-BLOWFISH/7/markdown), **EVP**___**[CIPHER-CAMELLIA**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-CAMELLIA/7/markdown), **EVP**___**[CIPHER-CAST**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-CAST/7/markdown), **EVP**___**[CIPHER-CHACHA**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-CHACHA/7/markdown), **EVP**___**[CIPHER-DES**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-DES/7/markdown), **EVP**___**[CIPHER-IDEA**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-IDEA/7/markdown), **EVP**___**[CIPHER-RC2**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-RC2/7/markdown), **EVP**___**[CIPHER-RC4**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-RC4/7/markdown), **EVP**___**[CIPHER-RC5**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-RC5/7/markdown), **EVP**___**[CIPHER-SEED**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-SEED/7/markdown), **EVP**___**[CIPHER-SM4**(7)](https://www.chedong.com/phpMan.php/man/CIPHER-SM4/7/markdown), **life**___**[cycle-cipher**(7)](https://www.chedong.com/phpMan.php/man/cycle-cipher/7/markdown), **EVP**___**[EncryptInit**(3)](https://www.chedong.com/phpMan.php/man/EncryptInit/3/markdown) ## 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 <>. 3.0.2 2026-04-07 [PROVIDER-CIPHER(7SSL)](https://www.chedong.com/phpMan.php/man/PROVIDER-CIPHER/7SSL/markdown)