1PROVIDER-CIPHER(7ossl)              OpenSSL             PROVIDER-CIPHER(7ossl)


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


9        #include <openssl/core_dispatch.h>
10        #include <openssl/core_names.h>
12        /*
13         * None of these are actual functions, but are displayed like this for
14         * the function signatures for functions that are offered as function
15         * pointers in OSSL_DISPATCH arrays.
16         */
18        /* Context management */
19        void *OSSL_FUNC_cipher_newctx(void *provctx);
20        void OSSL_FUNC_cipher_freectx(void *cctx);
21        void *OSSL_FUNC_cipher_dupctx(void *cctx);
23        /* Encryption/decryption */
24        int OSSL_FUNC_cipher_encrypt_init(void *cctx, const unsigned char *key,
25                                          size_t keylen, const unsigned char *iv,
26                                          size_t ivlen, const OSSL_PARAM params[]);
27        int OSSL_FUNC_cipher_decrypt_init(void *cctx, const unsigned char *key,
28                                          size_t keylen, const unsigned char *iv,
29                                          size_t ivlen, const OSSL_PARAM params[]);
30        int OSSL_FUNC_cipher_update(void *cctx, unsigned char *out, size_t *outl,
31                                    size_t outsize, const unsigned char *in, size_t inl);
32        int OSSL_FUNC_cipher_final(void *cctx, unsigned char *out, size_t *outl,
33                                   size_t outsize);
34        int OSSL_FUNC_cipher_cipher(void *cctx, unsigned char *out, size_t *outl,
35                                    size_t outsize, const unsigned char *in, size_t inl);
37        /* Cipher parameter descriptors */
38        const OSSL_PARAM *OSSL_FUNC_cipher_gettable_params(void *provctx);
40        /* Cipher operation parameter descriptors */
41        const OSSL_PARAM *OSSL_FUNC_cipher_gettable_ctx_params(void *cctx,
42                                                               void *provctx);
43        const OSSL_PARAM *OSSL_FUNC_cipher_settable_ctx_params(void *cctx,
44                                                               void *provctx);
46        /* Cipher parameters */
47        int OSSL_FUNC_cipher_get_params(OSSL_PARAM params[]);
49        /* Cipher operation parameters */
50        int OSSL_FUNC_cipher_get_ctx_params(void *cctx, OSSL_PARAM params[]);
51        int OSSL_FUNC_cipher_set_ctx_params(void *cctx, const OSSL_PARAM params[]);


54       This documentation is primarily aimed at provider authors. See
55       provider(7) for further information.
57       The CIPHER operation enables providers to implement cipher algorithms
58       and make them available to applications via the API functions
59       EVP_EncryptInit_ex(3), EVP_EncryptUpdate(3) and EVP_EncryptFinal(3) (as
60       well as the decrypt equivalents and other related functions).
62       All "functions" mentioned here are passed as function pointers between
63       libcrypto and the provider in OSSL_DISPATCH arrays via OSSL_ALGORITHM
64       arrays that are returned by the provider's provider_query_operation()
65       function (see "Provider Functions" in provider-base(7)).
67       All these "functions" have a corresponding function type definition
68       named OSSL_FUNC_{name}_fn, and a helper function to retrieve the
69       function pointer from an OSSL_DISPATCH element named OSSL_FUNC_{name}.
70       For example, the "function" OSSL_FUNC_cipher_newctx() has these:
72        typedef void *(OSSL_FUNC_cipher_newctx_fn)(void *provctx);
73        static ossl_inline OSSL_FUNC_cipher_newctx_fn
74            OSSL_FUNC_cipher_newctx(const OSSL_DISPATCH *opf);
76       OSSL_DISPATCH arrays are indexed by numbers that are provided as macros
77       in openssl-core_dispatch.h(7), as follows:
79        OSSL_FUNC_cipher_newctx               OSSL_FUNC_CIPHER_NEWCTX
80        OSSL_FUNC_cipher_freectx              OSSL_FUNC_CIPHER_FREECTX
81        OSSL_FUNC_cipher_dupctx               OSSL_FUNC_CIPHER_DUPCTX
83        OSSL_FUNC_cipher_encrypt_init         OSSL_FUNC_CIPHER_ENCRYPT_INIT
84        OSSL_FUNC_cipher_decrypt_init         OSSL_FUNC_CIPHER_DECRYPT_INIT
85        OSSL_FUNC_cipher_update               OSSL_FUNC_CIPHER_UPDATE
86        OSSL_FUNC_cipher_final                OSSL_FUNC_CIPHER_FINAL
87        OSSL_FUNC_cipher_cipher               OSSL_FUNC_CIPHER_CIPHER
89        OSSL_FUNC_cipher_get_params           OSSL_FUNC_CIPHER_GET_PARAMS
90        OSSL_FUNC_cipher_get_ctx_params       OSSL_FUNC_CIPHER_GET_CTX_PARAMS
91        OSSL_FUNC_cipher_set_ctx_params       OSSL_FUNC_CIPHER_SET_CTX_PARAMS
93        OSSL_FUNC_cipher_gettable_params      OSSL_FUNC_CIPHER_GETTABLE_PARAMS
94        OSSL_FUNC_cipher_gettable_ctx_params  OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS
95        OSSL_FUNC_cipher_settable_ctx_params  OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS
97       A cipher algorithm implementation may not implement all of these
98       functions.  In order to be a consistent set of functions there must at
99       least be a complete set of "encrypt" functions, or a complete set of
100       "decrypt" functions, or a single "cipher" function.  In all cases both
101       the OSSL_FUNC_cipher_newctx and OSSL_FUNC_cipher_freectx functions must
102       be present.  All other functions are optional.
104   Context Management Functions
105       OSSL_FUNC_cipher_newctx() should create and return a pointer to a
106       provider side structure for holding context information during a cipher
107       operation.  A pointer to this context will be passed back in a number
108       of the other cipher operation function calls.  The parameter provctx is
109       the provider context generated during provider initialisation (see
110       provider(7)).
112       OSSL_FUNC_cipher_freectx() is passed a pointer to the provider side
113       cipher context in the cctx parameter.  This function should free any
114       resources associated with that context.
116       OSSL_FUNC_cipher_dupctx() should duplicate the provider side cipher
117       context in the cctx parameter and return the duplicate copy.
119   Encryption/Decryption Functions
120       OSSL_FUNC_cipher_encrypt_init() initialises a cipher operation for
121       encryption given a newly created provider side cipher context in the
122       cctx parameter.  The key to be used is given in key which is keylen
123       bytes long.  The IV to be used is given in iv which is ivlen bytes
124       long.  The params, if not NULL, should be set on the context in a
125       manner similar to using OSSL_FUNC_cipher_set_ctx_params().
127       OSSL_FUNC_cipher_decrypt_init() is the same as
128       OSSL_FUNC_cipher_encrypt_init() except that it initialises the context
129       for a decryption operation.
131       OSSL_FUNC_cipher_update() is called to supply data to be
132       encrypted/decrypted as part of a previously initialised cipher
133       operation.  The cctx parameter contains a pointer to a previously
134       initialised provider side context.  OSSL_FUNC_cipher_update() should
135       encrypt/decrypt inl bytes of data at the location pointed to by in.
136       The encrypted data should be stored in out and the amount of data
137       written to *outl which should not exceed outsize bytes.
138       OSSL_FUNC_cipher_update() may be called multiple times for a single
139       cipher operation.  It is the responsibility of the cipher
140       implementation to handle input lengths that are not multiples of the
141       block length.  In such cases a cipher implementation will typically
142       cache partial blocks of input data until a complete block is obtained.
143       out may be the same location as in but it should not partially overlap.
144       The same expectations apply to outsize as documented for
145       EVP_EncryptUpdate(3) and EVP_DecryptUpdate(3).
147       OSSL_FUNC_cipher_final() completes an encryption or decryption started
148       through previous OSSL_FUNC_cipher_encrypt_init() or
149       OSSL_FUNC_cipher_decrypt_init(), and OSSL_FUNC_cipher_update() calls.
150       The cctx parameter contains a pointer to the provider side context.
151       Any final encryption/decryption output should be written to out and the
152       amount of data written to *outl which should not exceed outsize bytes.
153       The same expectations apply to outsize as documented for
154       EVP_EncryptFinal(3) and EVP_DecryptFinal(3).
156       OSSL_FUNC_cipher_cipher() performs encryption/decryption using the
157       provider side cipher context in the cctx parameter that should have
158       been previously initialised via a call to
159       OSSL_FUNC_cipher_encrypt_init() or OSSL_FUNC_cipher_decrypt_init().
160       This should call the raw underlying cipher function without any
161       padding.  This will be invoked in the provider as a result of the
162       application calling EVP_Cipher(3).  The application is responsible for
163       ensuring that the input is a multiple of the block length.  The data to
164       be encrypted/decrypted will be in in, and it will be inl bytes in
165       length.  The output from the encryption/decryption should be stored in
166       out and the amount of data stored should be put in *outl which should
167       be no more than outsize bytes.
169   Cipher Parameters
170       See OSSL_PARAM(3) for further details on the parameters structure used
171       by these functions.
173       OSSL_FUNC_cipher_get_params() gets details of the algorithm
174       implementation and stores them in params.
176       OSSL_FUNC_cipher_set_ctx_params() sets cipher operation parameters for
177       the provider side cipher context cctx to params.  Any parameter
178       settings are additional to any that were previously set.  Passing NULL
179       for params should return true.
181       OSSL_FUNC_cipher_get_ctx_params() gets cipher operation details details
182       from the given provider side cipher context cctx and stores them in
183       params.  Passing NULL for params should return true.
185       OSSL_FUNC_cipher_gettable_params(),
186       OSSL_FUNC_cipher_gettable_ctx_params(), and
187       OSSL_FUNC_cipher_settable_ctx_params() all return constant OSSL_PARAM
188       arrays as descriptors of the parameters that
189       OSSL_FUNC_cipher_get_params(), OSSL_FUNC_cipher_get_ctx_params(), and
190       OSSL_FUNC_cipher_set_ctx_params() can handle, respectively.
191       OSSL_FUNC_cipher_gettable_ctx_params() and
192       OSSL_FUNC_cipher_settable_ctx_params() will return the parameters
193       associated with the provider side context cctx in its current state if
194       it is not NULL.  Otherwise, they return the parameters associated with
195       the provider side algorithm provctx.
197       Parameters currently recognised by built-in ciphers are listed in
198       "PARAMETERS" in EVP_EncryptInit(3).  Not all parameters are relevant
199       to, or are understood by all ciphers.


202       OSSL_FUNC_cipher_newctx() and OSSL_FUNC_cipher_dupctx() should return
203       the newly created provider side cipher context, or NULL on failure.
205       OSSL_FUNC_cipher_encrypt_init(), OSSL_FUNC_cipher_decrypt_init(),
206       OSSL_FUNC_cipher_update(), OSSL_FUNC_cipher_final(),
207       OSSL_FUNC_cipher_cipher(), OSSL_FUNC_cipher_get_params(),
208       OSSL_FUNC_cipher_get_ctx_params() and OSSL_FUNC_cipher_set_ctx_params()
209       should return 1 for success or 0 on error.
211       OSSL_FUNC_cipher_gettable_params(),
212       OSSL_FUNC_cipher_gettable_ctx_params() and
213       OSSL_FUNC_cipher_settable_ctx_params() should return a constant
214       OSSL_PARAM array, or NULL if none is offered.


217       provider(7), OSSL_PROVIDER-FIPS(7), OSSL_PROVIDER-default(7),
221       EVP_CIPHER-RC2(7), EVP_CIPHER-RC4(7), EVP_CIPHER-RC5(7),
222       EVP_CIPHER-SEED(7), EVP_CIPHER-SM4(7), life_cycle-cipher(7),
223       EVP_EncryptInit(3)


226       The provider CIPHER interface was introduced in OpenSSL 3.0.
229       Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
231       Licensed under the Apache License 2.0 (the "License").  You may not use
232       this file except in compliance with the License.  You can obtain a copy
233       in the file LICENSE in the source distribution or at
234       <https://www.openssl.org/source/license.html>.
2383.0.5                             2022-07-05            PROVIDER-CIPHER(7ossl)