1PROVIDER-CIPHER(7ossl) OpenSSL PROVIDER-CIPHER(7ossl)
2
6 provider-cipher - The cipher library <-> provider functions
7
9 #include <openssl/core_dispatch.h>
10 #include <openssl/core_names.h>
11 /*
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 */
17 /* 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);
22 /* 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);
36 /* Cipher parameter descriptors */
38 const OSSL_PARAM *OSSL_FUNC_cipher_gettable_params(void *provctx);
39 /* 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);
45 /* Cipher parameters */
47 int OSSL_FUNC_cipher_get_params(OSSL_PARAM params[]);
48 /* 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[]);
52
54 This documentation is primarily aimed at provider authors. See
55 provider(7) for further information.
56 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).
61 All "functions" mentioned here are passed as function pointers between
63 libcrypto and the provider in OSSL_DISPATCH(3) arrays via
64 OSSL_ALGORITHM(3) arrays that are returned by the provider's
65 provider_query_operation() function (see "Provider Functions" in
66 provider-base(7)).
67 All these "functions" have a corresponding function type definition
69 named OSSL_FUNC_{name}_fn, and a helper function to retrieve the
70 function pointer from an OSSL_DISPATCH(3) element named
71 OSSL_FUNC_{name}. For example, the "function"
72 OSSL_FUNC_cipher_newctx() has these:
73 typedef void *(OSSL_FUNC_cipher_newctx_fn)(void *provctx);
75 static ossl_inline OSSL_FUNC_cipher_newctx_fn
76 OSSL_FUNC_cipher_newctx(const OSSL_DISPATCH *opf);
77 OSSL_DISPATCH(3) arrays are indexed by numbers that are provided as
79 macros in openssl-core_dispatch.h(7), as follows:
80 OSSL_FUNC_cipher_newctx OSSL_FUNC_CIPHER_NEWCTX
82 OSSL_FUNC_cipher_freectx OSSL_FUNC_CIPHER_FREECTX
83 OSSL_FUNC_cipher_dupctx OSSL_FUNC_CIPHER_DUPCTX
84 OSSL_FUNC_cipher_encrypt_init OSSL_FUNC_CIPHER_ENCRYPT_INIT
86 OSSL_FUNC_cipher_decrypt_init OSSL_FUNC_CIPHER_DECRYPT_INIT
87 OSSL_FUNC_cipher_update OSSL_FUNC_CIPHER_UPDATE
88 OSSL_FUNC_cipher_final OSSL_FUNC_CIPHER_FINAL
89 OSSL_FUNC_cipher_cipher OSSL_FUNC_CIPHER_CIPHER
90 OSSL_FUNC_cipher_get_params OSSL_FUNC_CIPHER_GET_PARAMS
92 OSSL_FUNC_cipher_get_ctx_params OSSL_FUNC_CIPHER_GET_CTX_PARAMS
93 OSSL_FUNC_cipher_set_ctx_params OSSL_FUNC_CIPHER_SET_CTX_PARAMS
94 OSSL_FUNC_cipher_gettable_params OSSL_FUNC_CIPHER_GETTABLE_PARAMS
96 OSSL_FUNC_cipher_gettable_ctx_params OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS
97 OSSL_FUNC_cipher_settable_ctx_params OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS
98 A cipher algorithm implementation may not implement all of these
100 functions. In order to be a consistent set of functions there must at
101 least be a complete set of "encrypt" functions, or a complete set of
102 "decrypt" functions, or a single "cipher" function. In all cases both
103 the OSSL_FUNC_cipher_newctx and OSSL_FUNC_cipher_freectx functions must
104 be present. All other functions are optional.
105 Context Management Functions
107 OSSL_FUNC_cipher_newctx() should create and return a pointer to a
108 provider side structure for holding context information during a cipher
109 operation. A pointer to this context will be passed back in a number
110 of the other cipher operation function calls. The parameter provctx is
111 the provider context generated during provider initialisation (see
112 provider(7)).
113 OSSL_FUNC_cipher_freectx() is passed a pointer to the provider side
115 cipher context in the cctx parameter. This function should free any
116 resources associated with that context.
117 OSSL_FUNC_cipher_dupctx() should duplicate the provider side cipher
119 context in the cctx parameter and return the duplicate copy.
120 Encryption/Decryption Functions
122 OSSL_FUNC_cipher_encrypt_init() initialises a cipher operation for
123 encryption given a newly created provider side cipher context in the
124 cctx parameter. The key to be used is given in key which is keylen
125 bytes long. The IV to be used is given in iv which is ivlen bytes
126 long. The params, if not NULL, should be set on the context in a
127 manner similar to using OSSL_FUNC_cipher_set_ctx_params().
128 OSSL_FUNC_cipher_decrypt_init() is the same as
130 OSSL_FUNC_cipher_encrypt_init() except that it initialises the context
131 for a decryption operation.
132 OSSL_FUNC_cipher_update() is called to supply data to be
134 encrypted/decrypted as part of a previously initialised cipher
135 operation. The cctx parameter contains a pointer to a previously
136 initialised provider side context. OSSL_FUNC_cipher_update() should
137 encrypt/decrypt inl bytes of data at the location pointed to by in.
138 The encrypted data should be stored in out and the amount of data
139 written to *outl which should not exceed outsize bytes.
140 OSSL_FUNC_cipher_update() may be called multiple times for a single
141 cipher operation. It is the responsibility of the cipher
142 implementation to handle input lengths that are not multiples of the
143 block length. In such cases a cipher implementation will typically
144 cache partial blocks of input data until a complete block is obtained.
145 out may be the same location as in but it should not partially overlap.
146 The same expectations apply to outsize as documented for
147 EVP_EncryptUpdate(3) and EVP_DecryptUpdate(3).
148 OSSL_FUNC_cipher_final() completes an encryption or decryption started
150 through previous OSSL_FUNC_cipher_encrypt_init() or
151 OSSL_FUNC_cipher_decrypt_init(), and OSSL_FUNC_cipher_update() calls.
152 The cctx parameter contains a pointer to the provider side context.
153 Any final encryption/decryption output should be written to out and the
154 amount of data written to *outl which should not exceed outsize bytes.
155 The same expectations apply to outsize as documented for
156 EVP_EncryptFinal(3) and EVP_DecryptFinal(3).
157 OSSL_FUNC_cipher_cipher() performs encryption/decryption using the
159 provider side cipher context in the cctx parameter that should have
160 been previously initialised via a call to
161 OSSL_FUNC_cipher_encrypt_init() or OSSL_FUNC_cipher_decrypt_init().
162 This should call the raw underlying cipher function without any
163 padding. This will be invoked in the provider as a result of the
164 application calling EVP_Cipher(3). The application is responsible for
165 ensuring that the input is a multiple of the block length. The data to
166 be encrypted/decrypted will be in in, and it will be inl bytes in
167 length. The output from the encryption/decryption should be stored in
168 out and the amount of data stored should be put in *outl which should
169 be no more than outsize bytes.
170 Cipher Parameters
172 See OSSL_PARAM(3) for further details on the parameters structure used
173 by these functions.
174 OSSL_FUNC_cipher_get_params() gets details of the algorithm
176 implementation and stores them in params.
177 OSSL_FUNC_cipher_set_ctx_params() sets cipher operation parameters for
179 the provider side cipher context cctx to params. Any parameter
180 settings are additional to any that were previously set. Passing NULL
181 for params should return true.
182 OSSL_FUNC_cipher_get_ctx_params() gets cipher operation details details
184 from the given provider side cipher context cctx and stores them in
185 params. Passing NULL for params should return true.
186 OSSL_FUNC_cipher_gettable_params(),
188 OSSL_FUNC_cipher_gettable_ctx_params(), and
189 OSSL_FUNC_cipher_settable_ctx_params() all return constant
190 OSSL_PARAM(3) arrays as descriptors of the parameters that
191 OSSL_FUNC_cipher_get_params(), OSSL_FUNC_cipher_get_ctx_params(), and
192 OSSL_FUNC_cipher_set_ctx_params() can handle, respectively.
193 OSSL_FUNC_cipher_gettable_ctx_params() and
194 OSSL_FUNC_cipher_settable_ctx_params() will return the parameters
195 associated with the provider side context cctx in its current state if
196 it is not NULL. Otherwise, they return the parameters associated with
197 the provider side algorithm provctx.
198 Parameters currently recognised by built-in ciphers are listed in
200 "PARAMETERS" in EVP_EncryptInit(3). Not all parameters are relevant
201 to, or are understood by all ciphers.
202
204 OSSL_FUNC_cipher_newctx() and OSSL_FUNC_cipher_dupctx() should return
205 the newly created provider side cipher context, or NULL on failure.
206 OSSL_FUNC_cipher_encrypt_init(), OSSL_FUNC_cipher_decrypt_init(),
208 OSSL_FUNC_cipher_update(), OSSL_FUNC_cipher_final(),
209 OSSL_FUNC_cipher_cipher(), OSSL_FUNC_cipher_get_params(),
210 OSSL_FUNC_cipher_get_ctx_params() and OSSL_FUNC_cipher_set_ctx_params()
211 should return 1 for success or 0 on error.
212 OSSL_FUNC_cipher_gettable_params(),
214 OSSL_FUNC_cipher_gettable_ctx_params() and
215 OSSL_FUNC_cipher_settable_ctx_params() should return a constant
216 OSSL_PARAM(3) array, or NULL if none is offered.
217
219 provider(7), OSSL_PROVIDER-FIPS(7), OSSL_PROVIDER-default(7),
220 OSSL_PROVIDER-legacy(7), EVP_CIPHER-AES(7), EVP_CIPHER-ARIA(7),
221 EVP_CIPHER-BLOWFISH(7), EVP_CIPHER-CAMELLIA(7), EVP_CIPHER-CAST(7),
222 EVP_CIPHER-CHACHA(7), EVP_CIPHER-DES(7), EVP_CIPHER-IDEA(7),
223 EVP_CIPHER-RC2(7), EVP_CIPHER-RC4(7), EVP_CIPHER-RC5(7),
224 EVP_CIPHER-SEED(7), EVP_CIPHER-SM4(7), EVP_CIPHER-NULL(7),
225 life_cycle-cipher(7), EVP_EncryptInit(3)
226
228 The provider CIPHER interface was introduced in OpenSSL 3.0.
229
231 Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
232 Licensed under the Apache License 2.0 (the "License"). You may not use
234 this file except in compliance with the License. You can obtain a copy
235 in the file LICENSE in the source distribution or at
236 <https://www.openssl.org/source/license.html>.
2373.0.9 2023-07-27 PROVIDER-CIPHER(7ossl)