1EVP_ENCRYPTINIT(3ossl) OpenSSL EVP_ENCRYPTINIT(3ossl)
2
6 EVP_CIPHER_fetch, EVP_CIPHER_up_ref, EVP_CIPHER_free,
7 EVP_CIPHER_CTX_new, EVP_CIPHER_CTX_reset, EVP_CIPHER_CTX_free,
8 EVP_CIPHER_CTX_dup, EVP_CIPHER_CTX_copy, EVP_EncryptInit_ex,
9 EVP_EncryptInit_ex2, EVP_EncryptUpdate, EVP_EncryptFinal_ex,
10 EVP_DecryptInit_ex, EVP_DecryptInit_ex2, EVP_DecryptUpdate,
11 EVP_DecryptFinal_ex, EVP_CipherInit_ex, EVP_CipherInit_ex2,
12 EVP_CipherUpdate, EVP_CipherFinal_ex, EVP_CIPHER_CTX_set_key_length,
13 EVP_CIPHER_CTX_ctrl, EVP_EncryptInit, EVP_EncryptFinal,
14 EVP_DecryptInit, EVP_DecryptFinal, EVP_CipherInit, EVP_CipherFinal,
15 EVP_Cipher, EVP_get_cipherbyname, EVP_get_cipherbynid,
16 EVP_get_cipherbyobj, EVP_CIPHER_is_a, EVP_CIPHER_get0_name,
17 EVP_CIPHER_get0_description, EVP_CIPHER_names_do_all,
18 EVP_CIPHER_get0_provider, EVP_CIPHER_get_nid, EVP_CIPHER_get_params,
19 EVP_CIPHER_gettable_params, EVP_CIPHER_get_block_size,
20 EVP_CIPHER_get_key_length, EVP_CIPHER_get_iv_length,
21 EVP_CIPHER_get_flags, EVP_CIPHER_get_mode, EVP_CIPHER_get_type,
22 EVP_CIPHER_CTX_cipher, EVP_CIPHER_CTX_get0_cipher,
23 EVP_CIPHER_CTX_get1_cipher, EVP_CIPHER_CTX_get0_name,
24 EVP_CIPHER_CTX_get_nid, EVP_CIPHER_CTX_get_params,
25 EVP_CIPHER_gettable_ctx_params, EVP_CIPHER_CTX_gettable_params,
26 EVP_CIPHER_CTX_set_params, EVP_CIPHER_settable_ctx_params,
27 EVP_CIPHER_CTX_settable_params, EVP_CIPHER_CTX_get_block_size,
28 EVP_CIPHER_CTX_get_key_length, EVP_CIPHER_CTX_get_iv_length,
29 EVP_CIPHER_CTX_get_tag_length, EVP_CIPHER_CTX_get_app_data,
30 EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_flags,
31 EVP_CIPHER_CTX_set_flags, EVP_CIPHER_CTX_clear_flags,
32 EVP_CIPHER_CTX_test_flags, EVP_CIPHER_CTX_get_type,
33 EVP_CIPHER_CTX_get_mode, EVP_CIPHER_CTX_get_num,
34 EVP_CIPHER_CTX_set_num, EVP_CIPHER_CTX_is_encrypting,
35 EVP_CIPHER_param_to_asn1, EVP_CIPHER_asn1_to_param,
36 EVP_CIPHER_CTX_set_padding, EVP_enc_null, EVP_CIPHER_do_all_provided,
37 EVP_CIPHER_nid, EVP_CIPHER_name, EVP_CIPHER_block_size,
38 EVP_CIPHER_key_length, EVP_CIPHER_iv_length, EVP_CIPHER_flags,
39 EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_encrypting,
40 EVP_CIPHER_CTX_nid, EVP_CIPHER_CTX_block_size,
41 EVP_CIPHER_CTX_key_length, EVP_CIPHER_CTX_iv_length,
42 EVP_CIPHER_CTX_tag_length, EVP_CIPHER_CTX_num, EVP_CIPHER_CTX_type,
43 EVP_CIPHER_CTX_mode - EVP cipher routines
44
46 #include <openssl/evp.h>
47 EVP_CIPHER *EVP_CIPHER_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
49 const char *properties);
50 int EVP_CIPHER_up_ref(EVP_CIPHER *cipher);
51 void EVP_CIPHER_free(EVP_CIPHER *cipher);
52 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void);
53 int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx);
54 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx);
55 EVP_CIPHER_CTX *EVP_CIPHER_CTX_dup(const EVP_CIPHER_CTX *in);
56 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in);
57 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
59 ENGINE *impl, const unsigned char *key, const unsigned char *iv);
60 int EVP_EncryptInit_ex2(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
61 const unsigned char *key, const unsigned char *iv,
62 const OSSL_PARAM params[]);
63 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
64 int *outl, const unsigned char *in, int inl);
65 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl);
66 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
68 ENGINE *impl, const unsigned char *key, const unsigned char *iv);
69 int EVP_DecryptInit_ex2(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
70 const unsigned char *key, const unsigned char *iv,
71 const OSSL_PARAM params[]);
72 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
73 int *outl, const unsigned char *in, int inl);
74 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
75 int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
77 ENGINE *impl, const unsigned char *key, const unsigned char *iv, int enc);
78 int EVP_CipherInit_ex2(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
79 const unsigned char *key, const unsigned char *iv,
80 int enc, const OSSL_PARAM params[]);
81 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
82 int *outl, const unsigned char *in, int inl);
83 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
84 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
86 const unsigned char *key, const unsigned char *iv);
87 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl);
88 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
90 const unsigned char *key, const unsigned char *iv);
91 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
92 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
94 const unsigned char *key, const unsigned char *iv, int enc);
95 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
96 int EVP_Cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
98 const unsigned char *in, unsigned int inl);
99 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *x, int padding);
101 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *x, int keylen);
102 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int cmd, int p1, void *p2);
103 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key);
104 void EVP_CIPHER_CTX_set_flags(EVP_CIPHER_CTX *ctx, int flags);
105 void EVP_CIPHER_CTX_clear_flags(EVP_CIPHER_CTX *ctx, int flags);
106 int EVP_CIPHER_CTX_test_flags(const EVP_CIPHER_CTX *ctx, int flags);
107 const EVP_CIPHER *EVP_get_cipherbyname(const char *name);
109 const EVP_CIPHER *EVP_get_cipherbynid(int nid);
110 const EVP_CIPHER *EVP_get_cipherbyobj(const ASN1_OBJECT *a);
111 int EVP_CIPHER_get_nid(const EVP_CIPHER *e);
113 int EVP_CIPHER_is_a(const EVP_CIPHER *cipher, const char *name);
114 int EVP_CIPHER_names_do_all(const EVP_CIPHER *cipher,
115 void (*fn)(const char *name, void *data),
116 void *data);
117 const char *EVP_CIPHER_get0_name(const EVP_CIPHER *cipher);
118 const char *EVP_CIPHER_get0_description(const EVP_CIPHER *cipher);
119 const OSSL_PROVIDER *EVP_CIPHER_get0_provider(const EVP_CIPHER *cipher);
120 int EVP_CIPHER_get_block_size(const EVP_CIPHER *e);
121 int EVP_CIPHER_get_key_length(const EVP_CIPHER *e);
122 int EVP_CIPHER_get_iv_length(const EVP_CIPHER *e);
123 unsigned long EVP_CIPHER_get_flags(const EVP_CIPHER *e);
124 unsigned long EVP_CIPHER_get_mode(const EVP_CIPHER *e);
125 int EVP_CIPHER_get_type(const EVP_CIPHER *cipher);
126 const EVP_CIPHER *EVP_CIPHER_CTX_get0_cipher(const EVP_CIPHER_CTX *ctx);
128 EVP_CIPHER *EVP_CIPHER_CTX_get1_cipher(const EVP_CIPHER_CTX *ctx);
129 int EVP_CIPHER_CTX_get_nid(const EVP_CIPHER_CTX *ctx);
130 const char *EVP_CIPHER_CTX_get0_name(const EVP_CIPHER_CTX *ctx);
131 int EVP_CIPHER_get_params(EVP_CIPHER *cipher, OSSL_PARAM params[]);
133 int EVP_CIPHER_CTX_set_params(EVP_CIPHER_CTX *ctx, const OSSL_PARAM params[]);
134 int EVP_CIPHER_CTX_get_params(EVP_CIPHER_CTX *ctx, OSSL_PARAM params[]);
135 const OSSL_PARAM *EVP_CIPHER_gettable_params(const EVP_CIPHER *cipher);
136 const OSSL_PARAM *EVP_CIPHER_settable_ctx_params(const EVP_CIPHER *cipher);
137 const OSSL_PARAM *EVP_CIPHER_gettable_ctx_params(const EVP_CIPHER *cipher);
138 const OSSL_PARAM *EVP_CIPHER_CTX_settable_params(EVP_CIPHER_CTX *ctx);
139 const OSSL_PARAM *EVP_CIPHER_CTX_gettable_params(EVP_CIPHER_CTX *ctx);
140 int EVP_CIPHER_CTX_get_block_size(const EVP_CIPHER_CTX *ctx);
141 int EVP_CIPHER_CTX_get_key_length(const EVP_CIPHER_CTX *ctx);
142 int EVP_CIPHER_CTX_get_iv_length(const EVP_CIPHER_CTX *ctx);
143 int EVP_CIPHER_CTX_get_tag_length(const EVP_CIPHER_CTX *ctx);
144 void *EVP_CIPHER_CTX_get_app_data(const EVP_CIPHER_CTX *ctx);
145 void EVP_CIPHER_CTX_set_app_data(const EVP_CIPHER_CTX *ctx, void *data);
146 int EVP_CIPHER_CTX_get_type(const EVP_CIPHER_CTX *ctx);
147 int EVP_CIPHER_CTX_get_mode(const EVP_CIPHER_CTX *ctx);
148 int EVP_CIPHER_CTX_get_num(const EVP_CIPHER_CTX *ctx);
149 int EVP_CIPHER_CTX_set_num(EVP_CIPHER_CTX *ctx, int num);
150 int EVP_CIPHER_CTX_is_encrypting(const EVP_CIPHER_CTX *ctx);
151 int EVP_CIPHER_param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
153 int EVP_CIPHER_asn1_to_param(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
154 void EVP_CIPHER_do_all_provided(OSSL_LIB_CTX *libctx,
156 void (*fn)(EVP_CIPHER *cipher, void *arg),
157 void *arg);
158 #define EVP_CIPHER_nid EVP_CIPHER_get_nid
160 #define EVP_CIPHER_name EVP_CIPHER_get0_name
161 #define EVP_CIPHER_block_size EVP_CIPHER_get_block_size
162 #define EVP_CIPHER_key_length EVP_CIPHER_get_key_length
163 #define EVP_CIPHER_iv_length EVP_CIPHER_get_iv_length
164 #define EVP_CIPHER_flags EVP_CIPHER_get_flags
165 #define EVP_CIPHER_mode EVP_CIPHER_get_mode
166 #define EVP_CIPHER_type EVP_CIPHER_get_type
167 #define EVP_CIPHER_CTX_encrypting EVP_CIPHER_CTX_is_encrypting
168 #define EVP_CIPHER_CTX_nid EVP_CIPHER_CTX_get_nid
169 #define EVP_CIPHER_CTX_block_size EVP_CIPHER_CTX_get_block_size
170 #define EVP_CIPHER_CTX_key_length EVP_CIPHER_CTX_get_key_length
171 #define EVP_CIPHER_CTX_iv_length EVP_CIPHER_CTX_get_iv_length
172 #define EVP_CIPHER_CTX_tag_length EVP_CIPHER_CTX_get_tag_length
173 #define EVP_CIPHER_CTX_num EVP_CIPHER_CTX_get_num
174 #define EVP_CIPHER_CTX_type EVP_CIPHER_CTX_get_type
175 #define EVP_CIPHER_CTX_mode EVP_CIPHER_CTX_get_mode
176 The following function has been deprecated since OpenSSL 3.0, and can
178 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
179 version value, see openssl_user_macros(7):
180 const EVP_CIPHER *EVP_CIPHER_CTX_cipher(const EVP_CIPHER_CTX *ctx);
182 The following function has been deprecated since OpenSSL 1.1.0, and can
184 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
185 version value, see openssl_user_macros(7):
186 int EVP_CIPHER_CTX_flags(const EVP_CIPHER_CTX *ctx);
188
190 The EVP cipher routines are a high-level interface to certain symmetric
191 ciphers.
192 The EVP_CIPHER type is a structure for cipher method implementation.
194 EVP_CIPHER_fetch()
196 Fetches the cipher implementation for the given algorithm from any
197 provider offering it, within the criteria given by the properties.
198 See "ALGORITHM FETCHING" in crypto(7) for further information.
199 The returned value must eventually be freed with EVP_CIPHER_free().
201 Fetched EVP_CIPHER structures are reference counted.
203 EVP_CIPHER_up_ref()
205 Increments the reference count for an EVP_CIPHER structure.
206 EVP_CIPHER_free()
208 Decrements the reference count for the fetched EVP_CIPHER
209 structure. If the reference count drops to 0 then the structure is
210 freed.
211 EVP_CIPHER_CTX_new()
213 Allocates and returns a cipher context.
214 EVP_CIPHER_CTX_free()
216 Clears all information from a cipher context and frees any
217 allocated memory associated with it, including ctx itself. This
218 function should be called after all operations using a cipher are
219 complete so sensitive information does not remain in memory.
220 EVP_CIPHER_CTX_dup()
222 Can be used to duplicate the cipher state from in. This is useful
223 to avoid multiple EVP_MD_fetch() calls or if large amounts of data
224 are to be hashed which only differ in the last few bytes.
225 EVP_CIPHER_CTX_copy()
227 Can be used to copy the cipher state from in to out.
228 EVP_CIPHER_CTX_ctrl()
230 This is a legacy method. EVP_CIPHER_CTX_set_params() and
231 EVP_CIPHER_CTX_get_params() is the mechanism that should be used to
232 set and get parameters that are used by providers.
233 Performs cipher-specific control actions on context ctx. The
235 control command is indicated in cmd and any additional arguments in
236 p1 and p2. EVP_CIPHER_CTX_ctrl() must be called after
237 EVP_CipherInit_ex2(). Other restrictions may apply depending on the
238 control type and cipher implementation.
239 If this function happens to be used with a fetched EVP_CIPHER, it
241 will translate the controls that are known to OpenSSL into
242 OSSL_PARAM(3) parameters with keys defined by OpenSSL and call
243 EVP_CIPHER_CTX_get_params() or EVP_CIPHER_CTX_set_params() as is
244 appropriate for each control command.
245 See "CONTROLS" below for more information, including what
247 translations are being done.
248 EVP_CIPHER_get_params()
250 Retrieves the requested list of algorithm params from a CIPHER
251 cipher. See "PARAMETERS" below for more information.
252 EVP_CIPHER_CTX_get_params()
254 Retrieves the requested list of params from CIPHER context ctx.
255 See "PARAMETERS" below for more information.
256 EVP_CIPHER_CTX_set_params()
258 Sets the list of params into a CIPHER context ctx. See
259 "PARAMETERS" below for more information.
260 EVP_CIPHER_gettable_params()
262 Get a constant OSSL_PARAM(3) array that describes the retrievable
263 parameters that can be used with EVP_CIPHER_get_params().
264 EVP_CIPHER_gettable_ctx_params() and EVP_CIPHER_CTX_gettable_params()
266 Get a constant OSSL_PARAM(3) array that describes the retrievable
267 parameters that can be used with EVP_CIPHER_CTX_get_params().
268 EVP_CIPHER_gettable_ctx_params() returns the parameters that can be
269 retrieved from the algorithm, whereas
270 EVP_CIPHER_CTX_gettable_params() returns the parameters that can be
271 retrieved in the context's current state.
272 EVP_CIPHER_settable_ctx_params() and EVP_CIPHER_CTX_settable_params()
274 Get a constant OSSL_PARAM(3) array that describes the settable
275 parameters that can be used with EVP_CIPHER_CTX_set_params().
276 EVP_CIPHER_settable_ctx_params() returns the parameters that can be
277 set from the algorithm, whereas EVP_CIPHER_CTX_settable_params()
278 returns the parameters that can be set in the context's current
279 state.
280 EVP_EncryptInit_ex2()
282 Sets up cipher context ctx for encryption with cipher type. type is
283 typically supplied by calling EVP_CIPHER_fetch(). type may also be
284 set using legacy functions such as EVP_aes_256_cbc(), but this is
285 not recommended for new applications. key is the symmetric key to
286 use and iv is the IV to use (if necessary), the actual number of
287 bytes used for the key and IV depends on the cipher. The parameters
288 params will be set on the context after initialisation. It is
289 possible to set all parameters to NULL except type in an initial
290 call and supply the remaining parameters in subsequent calls, all
291 of which have type set to NULL. This is done when the default
292 cipher parameters are not appropriate. For EVP_CIPH_GCM_MODE the
293 IV will be generated internally if it is not specified.
294 EVP_EncryptInit_ex()
296 This legacy function is similar to EVP_EncryptInit_ex2() when impl
297 is NULL. The implementation of the type from the impl engine will
298 be used if it exists.
299 EVP_EncryptUpdate()
301 Encrypts inl bytes from the buffer in and writes the encrypted
302 version to out. This function can be called multiple times to
303 encrypt successive blocks of data. The amount of data written
304 depends on the block alignment of the encrypted data. For most
305 ciphers and modes, the amount of data written can be anything from
306 zero bytes to (inl + cipher_block_size - 1) bytes. For wrap cipher
307 modes, the amount of data written can be anything from zero bytes
308 to (inl + cipher_block_size) bytes. For stream ciphers, the amount
309 of data written can be anything from zero bytes to inl bytes.
310 Thus, out should contain sufficient room for the operation being
311 performed. The actual number of bytes written is placed in outl.
312 It also checks if in and out are partially overlapping, and if they
313 are 0 is returned to indicate failure.
314 If padding is enabled (the default) then EVP_EncryptFinal_ex()
316 encrypts the "final" data, that is any data that remains in a
317 partial block. It uses standard block padding (aka PKCS padding)
318 as described in the NOTES section, below. The encrypted final data
319 is written to out which should have sufficient space for one cipher
320 block. The number of bytes written is placed in outl. After this
321 function is called the encryption operation is finished and no
322 further calls to EVP_EncryptUpdate() should be made.
323 If padding is disabled then EVP_EncryptFinal_ex() will not encrypt
325 any more data and it will return an error if any data remains in a
326 partial block: that is if the total data length is not a multiple
327 of the block size.
328 EVP_DecryptInit_ex2(), EVP_DecryptInit_ex(), EVP_DecryptUpdate() and
330 EVP_DecryptFinal_ex()
331 These functions are the corresponding decryption operations.
332 EVP_DecryptFinal() will return an error code if padding is enabled
333 and the final block is not correctly formatted. The parameters and
334 restrictions are identical to the encryption operations except that
335 if padding is enabled the decrypted data buffer out passed to
336 EVP_DecryptUpdate() should have sufficient room for (inl +
337 cipher_block_size) bytes unless the cipher block size is 1 in which
338 case inl bytes is sufficient.
339 EVP_CipherInit_ex2(), EVP_CipherInit_ex(), EVP_CipherUpdate() and
341 EVP_CipherFinal_ex()
342 These functions can be used for decryption or encryption. The
343 operation performed depends on the value of the enc parameter. It
344 should be set to 1 for encryption, 0 for decryption and -1 to leave
345 the value unchanged (the actual value of 'enc' being supplied in a
346 previous call).
347 EVP_CIPHER_CTX_reset()
349 Clears all information from a cipher context and free up any
350 allocated memory associated with it, except the ctx itself. This
351 function should be called anytime ctx is reused by another
352 EVP_CipherInit() / EVP_CipherUpdate() / EVP_CipherFinal() series of
353 calls.
354 EVP_EncryptInit(), EVP_DecryptInit() and EVP_CipherInit()
356 Behave in a similar way to EVP_EncryptInit_ex(),
357 EVP_DecryptInit_ex() and EVP_CipherInit_ex() except if the type is
358 not a fetched cipher they use the default implementation of the
359 type.
360 EVP_EncryptFinal(), EVP_DecryptFinal() and EVP_CipherFinal()
362 Identical to EVP_EncryptFinal_ex(), EVP_DecryptFinal_ex() and
363 EVP_CipherFinal_ex(). In previous releases they also cleaned up the
364 ctx, but this is no longer done and EVP_CIPHER_CTX_cleanup() must
365 be called to free any context resources.
366 EVP_Cipher()
368 Encrypts or decrypts a maximum inl amount of bytes from in and
369 leaves the result in out.
370 For legacy ciphers - If the cipher doesn't have the flag
372 EVP_CIPH_FLAG_CUSTOM_CIPHER set, then inl must be a multiple of
373 EVP_CIPHER_get_block_size(). If it isn't, the result is undefined.
374 If the cipher has that flag set, then inl can be any size.
375 Due to the constraints of the API contract of this function it
377 shouldn't be used in applications, please consider using
378 EVP_CipherUpdate() and EVP_CipherFinal_ex() instead.
379 EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj()
381 Returns an EVP_CIPHER structure when passed a cipher name, a cipher
382 NID or an ASN1_OBJECT structure respectively.
383 EVP_get_cipherbyname() will return NULL for algorithms such as
385 "AES-128-SIV", "AES-128-CBC-CTS" and "CAMELLIA-128-CBC-CTS" which
386 were previously only accessible via low level interfaces.
387 The EVP_get_cipherbyname() function is present for backwards
389 compatibility with OpenSSL prior to version 3 and is different to
390 the EVP_CIPHER_fetch() function since it does not attempt to
391 "fetch" an implementation of the cipher. Additionally, it only
392 knows about ciphers that are built-in to OpenSSL and have an
393 associated NID. Similarly EVP_get_cipherbynid() and
394 EVP_get_cipherbyobj() also return objects without an associated
395 implementation.
396 When the cipher objects returned by these functions are used (such
398 as in a call to EVP_EncryptInit_ex()) an implementation of the
399 cipher will be implicitly fetched from the loaded providers. This
400 fetch could fail if no suitable implementation is available. Use
401 EVP_CIPHER_fetch() instead to explicitly fetch the algorithm and an
402 associated implementation from a provider.
403 See "ALGORITHM FETCHING" in crypto(7) for more information about
405 fetching.
406 The cipher objects returned from these functions do not need to be
408 freed with EVP_CIPHER_free().
409 EVP_CIPHER_get_nid() and EVP_CIPHER_CTX_get_nid()
411 Return the NID of a cipher when passed an EVP_CIPHER or
412 EVP_CIPHER_CTX structure. The actual NID value is an internal
413 value which may not have a corresponding OBJECT IDENTIFIER.
414 EVP_CIPHER_CTX_set_flags(), EVP_CIPHER_CTX_clear_flags() and
416 EVP_CIPHER_CTX_test_flags()
417 Sets, clears and tests ctx flags. See "FLAGS" below for more
418 information.
419 For provided ciphers EVP_CIPHER_CTX_set_flags() should be called
421 only after the fetched cipher has been assigned to the ctx. It is
422 recommended to use "PARAMETERS" instead.
423 EVP_CIPHER_CTX_set_padding()
425 Enables or disables padding. This function should be called after
426 the context is set up for encryption or decryption with
427 EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or
428 EVP_CipherInit_ex2(). By default encryption operations are padded
429 using standard block padding and the padding is checked and removed
430 when decrypting. If the pad parameter is zero then no padding is
431 performed, the total amount of data encrypted or decrypted must
432 then be a multiple of the block size or an error will occur.
433 EVP_CIPHER_get_key_length() and EVP_CIPHER_CTX_get_key_length()
435 Return the key length of a cipher when passed an EVP_CIPHER or
436 EVP_CIPHER_CTX structure. The constant EVP_MAX_KEY_LENGTH is the
437 maximum key length for all ciphers. Note: although
438 EVP_CIPHER_get_key_length() is fixed for a given cipher, the value
439 of EVP_CIPHER_CTX_get_key_length() may be different for variable
440 key length ciphers.
441 EVP_CIPHER_CTX_set_key_length()
443 Sets the key length of the cipher context. If the cipher is a
444 fixed length cipher then attempting to set the key length to any
445 value other than the fixed value is an error.
446 EVP_CIPHER_get_iv_length() and EVP_CIPHER_CTX_get_iv_length()
448 Return the IV length of a cipher when passed an EVP_CIPHER or
449 EVP_CIPHER_CTX. It will return zero if the cipher does not use an
450 IV. The constant EVP_MAX_IV_LENGTH is the maximum IV length for
451 all ciphers.
452 EVP_CIPHER_CTX_get_tag_length()
454 Returns the tag length of an AEAD cipher when passed a
455 EVP_CIPHER_CTX. It will return zero if the cipher does not support
456 a tag. It returns a default value if the tag length has not been
457 set.
458 EVP_CIPHER_get_block_size() and EVP_CIPHER_CTX_get_block_size()
460 Return the block size of a cipher when passed an EVP_CIPHER or
461 EVP_CIPHER_CTX structure. The constant EVP_MAX_BLOCK_LENGTH is also
462 the maximum block length for all ciphers.
463 EVP_CIPHER_get_type() and EVP_CIPHER_CTX_get_type()
465 Return the type of the passed cipher or context. This "type" is the
466 actual NID of the cipher OBJECT IDENTIFIER and as such it ignores
467 the cipher parameters (40 bit RC2 and 128 bit RC2 have the same
468 NID). If the cipher does not have an object identifier or does not
469 have ASN1 support this function will return NID_undef.
470 EVP_CIPHER_is_a()
472 Returns 1 if cipher is an implementation of an algorithm that's
473 identifiable with name, otherwise 0. If cipher is a legacy cipher
474 (it's the return value from the likes of EVP_aes128() rather than
475 the result of an EVP_CIPHER_fetch()), only cipher names registered
476 with the default library context (see OSSL_LIB_CTX(3)) will be
477 considered.
478 EVP_CIPHER_get0_name() and EVP_CIPHER_CTX_get0_name()
480 Return the name of the passed cipher or context. For fetched
481 ciphers with multiple names, only one of them is returned. See also
482 EVP_CIPHER_names_do_all().
483 EVP_CIPHER_names_do_all()
485 Traverses all names for the cipher, and calls fn with each name and
486 data. This is only useful with fetched EVP_CIPHERs.
487 EVP_CIPHER_get0_description()
489 Returns a description of the cipher, meant for display and human
490 consumption. The description is at the discretion of the cipher
491 implementation.
492 EVP_CIPHER_get0_provider()
494 Returns an OSSL_PROVIDER pointer to the provider that implements
495 the given EVP_CIPHER.
496 EVP_CIPHER_CTX_get0_cipher()
498 Returns the EVP_CIPHER structure when passed an EVP_CIPHER_CTX
499 structure. EVP_CIPHER_CTX_get1_cipher() is the same except the
500 ownership is passed to the caller.
501 EVP_CIPHER_get_mode() and EVP_CIPHER_CTX_get_mode()
503 Return the block cipher mode: EVP_CIPH_ECB_MODE, EVP_CIPH_CBC_MODE,
504 EVP_CIPH_CFB_MODE, EVP_CIPH_OFB_MODE, EVP_CIPH_CTR_MODE,
505 EVP_CIPH_GCM_MODE, EVP_CIPH_CCM_MODE, EVP_CIPH_XTS_MODE,
506 EVP_CIPH_WRAP_MODE, EVP_CIPH_OCB_MODE or EVP_CIPH_SIV_MODE. If the
507 cipher is a stream cipher then EVP_CIPH_STREAM_CIPHER is returned.
508 EVP_CIPHER_get_flags()
510 Returns any flags associated with the cipher. See "FLAGS" for a
511 list of currently defined flags.
512 EVP_CIPHER_CTX_get_num() and EVP_CIPHER_CTX_set_num()
514 Gets or sets the cipher specific "num" parameter for the associated
515 ctx. Built-in ciphers typically use this to track how much of the
516 current underlying block has been "used" already.
517 EVP_CIPHER_CTX_is_encrypting()
519 Reports whether the ctx is being used for encryption or decryption.
520 EVP_CIPHER_CTX_flags()
522 A deprecated macro calling
523 "EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ctx))". Do not
524 use.
525 EVP_CIPHER_param_to_asn1()
527 Sets the AlgorithmIdentifier "parameter" based on the passed
528 cipher. This will typically include any parameters and an IV. The
529 cipher IV (if any) must be set when this call is made. This call
530 should be made before the cipher is actually "used" (before any
531 EVP_EncryptUpdate(), EVP_DecryptUpdate() calls for example). This
532 function may fail if the cipher does not have any ASN1 support.
533 EVP_CIPHER_asn1_to_param()
535 Sets the cipher parameters based on an ASN1 AlgorithmIdentifier
536 "parameter". The precise effect depends on the cipher. In the case
537 of RC2, for example, it will set the IV and effective key length.
538 This function should be called after the base cipher type is set
539 but before the key is set. For example EVP_CipherInit() will be
540 called with the IV and key set to NULL, EVP_CIPHER_asn1_to_param()
541 will be called and finally EVP_CipherInit() again with all
542 parameters except the key set to NULL. It is possible for this
543 function to fail if the cipher does not have any ASN1 support or
544 the parameters cannot be set (for example the RC2 effective key
545 length is not supported.
546 EVP_CIPHER_CTX_rand_key()
548 Generates a random key of the appropriate length based on the
549 cipher context. The EVP_CIPHER can provide its own random key
550 generation routine to support keys of a specific form. key must
551 point to a buffer at least as big as the value returned by
552 EVP_CIPHER_CTX_get_key_length().
553 EVP_CIPHER_do_all_provided()
555 Traverses all ciphers implemented by all activated providers in the
556 given library context libctx, and for each of the implementations,
557 calls the given function fn with the implementation method and the
558 given arg as argument.
559
561 See OSSL_PARAM(3) for information about passing parameters.
562 Gettable EVP_CIPHER parameters
564 When EVP_CIPHER_fetch() is called it internally calls
565 EVP_CIPHER_get_params() and caches the results.
566 EVP_CIPHER_get_params() can be used with the following OSSL_PARAM(3)
568 keys:
569 "mode" (OSSL_CIPHER_PARAM_MODE) <unsigned integer>
571 Gets the mode for the associated cipher algorithm cipher. See
572 "EVP_CIPHER_get_mode() and EVP_CIPHER_CTX_get_mode()" for a list of
573 valid modes. Use EVP_CIPHER_get_mode() to retrieve the cached
574 value.
575 "keylen" (OSSL_CIPHER_PARAM_KEYLEN) <unsigned integer>
577 Gets the key length for the associated cipher algorithm cipher.
578 Use EVP_CIPHER_get_key_length() to retrieve the cached value.
579 "ivlen" (OSSL_CIPHER_PARAM_IVLEN) <unsigned integer>
581 Gets the IV length for the associated cipher algorithm cipher. Use
582 EVP_CIPHER_get_iv_length() to retrieve the cached value.
583 "blocksize" (OSSL_CIPHER_PARAM_BLOCK_SIZE) <unsigned integer>
585 Gets the block size for the associated cipher algorithm cipher.
586 The block size should be 1 for stream ciphers. Note that the block
587 size for a cipher may be different to the block size for the
588 underlying encryption/decryption primitive. For example AES in CTR
589 mode has a block size of 1 (because it operates like a stream
590 cipher), even though AES has a block size of 16. Use
591 EVP_CIPHER_get_block_size() to retrieve the cached value.
592 "aead" (OSSL_CIPHER_PARAM_AEAD) <integer>
594 Gets 1 if this is an AEAD cipher algorithm, otherwise it gets 0.
595 Use (EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) to
596 retrieve the cached value.
597 "custom-iv" (OSSL_CIPHER_PARAM_CUSTOM_IV) <integer>
599 Gets 1 if the cipher algorithm cipher has a custom IV, otherwise it
600 gets 0. Storing and initializing the IV is left entirely to the
601 implementation, if a custom IV is used. Use
602 (EVP_CIPHER_get_flags(cipher) & EVP_CIPH_CUSTOM_IV) to retrieve the
603 cached value.
604 "cts" (OSSL_CIPHER_PARAM_CTS) <integer>
606 Gets 1 if the cipher algorithm cipher uses ciphertext stealing,
607 otherwise it gets 0. This is currently used to indicate that the
608 cipher is a one shot that only allows a single call to
609 EVP_CipherUpdate(). Use (EVP_CIPHER_get_flags(cipher) &
610 EVP_CIPH_FLAG_CTS) to retrieve the cached value.
611 "tls-multi" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK) <integer>
613 Gets 1 if the cipher algorithm cipher supports interleaving of
614 crypto blocks, otherwise it gets 0. The interleaving is an
615 optimization only applicable to certain TLS ciphers. Use
616 (EVP_CIPHER_get_flags(cipher) & EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK) to
617 retrieve the cached value.
618 "has-randkey" (OSSL_CIPHER_PARAM_HAS_RANDKEY) <integer>
620 Gets 1 if the cipher algorithm cipher supports the gettable
621 EVP_CIPHER_CTX parameter OSSL_CIPHER_PARAM_RANDOM_KEY. Only DES and
622 3DES set this to 1, all other OpenSSL ciphers return 0.
623 Gettable and Settable EVP_CIPHER_CTX parameters
625 The following OSSL_PARAM(3) keys can be used with both
626 EVP_CIPHER_CTX_get_params() and EVP_CIPHER_CTX_set_params().
627 "padding" (OSSL_CIPHER_PARAM_PADDING) <unsigned integer>
629 Gets or sets the padding mode for the cipher context ctx. Padding
630 is enabled if the value is 1, and disabled if the value is 0. See
631 also EVP_CIPHER_CTX_set_padding().
632 "num" (OSSL_CIPHER_PARAM_NUM) <unsigned integer>
634 Gets or sets the cipher specific "num" parameter for the cipher
635 context ctx. Built-in ciphers typically use this to track how much
636 of the current underlying block has been "used" already. See also
637 EVP_CIPHER_CTX_get_num() and EVP_CIPHER_CTX_set_num().
638 "keylen" (OSSL_CIPHER_PARAM_KEYLEN) <unsigned integer>
640 Gets or sets the key length for the cipher context ctx. The length
641 of the "keylen" parameter should not exceed that of a size_t. See
642 also EVP_CIPHER_CTX_get_key_length() and
643 EVP_CIPHER_CTX_set_key_length().
644 "tag" (OSSL_CIPHER_PARAM_AEAD_TAG) <octet string>
646 Gets or sets the AEAD tag for the associated cipher context ctx.
647 See "AEAD Interface" in EVP_EncryptInit(3).
648 "keybits" (OSSL_CIPHER_PARAM_RC2_KEYBITS) <unsigned integer>
650 Gets or sets the effective keybits used for a RC2 cipher. The
651 length of the "keybits" parameter should not exceed that of a
652 size_t.
653 "rounds" (OSSL_CIPHER_PARAM_ROUNDS) <unsigned integer>
655 Gets or sets the number of rounds to be used for a cipher. This is
656 used by the RC5 cipher.
657 "alg_id_param" (OSSL_CIPHER_PARAM_ALGORITHM_ID_PARAMS) <octet string>
659 Used to pass the DER encoded AlgorithmIdentifier parameter to or
660 from the cipher implementation. Functions like
661 EVP_CIPHER_param_to_asn1(3) and EVP_CIPHER_asn1_to_param(3) use
662 this parameter for any implementation that has the flag
663 EVP_CIPH_FLAG_CUSTOM_ASN1 set.
664 "cts_mode" (OSSL_CIPHER_PARAM_CTS_MODE) <UTF8 string>
666 Gets or sets the cipher text stealing mode. For all modes the
667 output size is the same as the input size. The input length must be
668 greater than or equal to the block size. (The block size for AES
669 and CAMELLIA is 16 bytes).
670 Valid values for the mode are:
672 "CS1"
674 The NIST variant of cipher text stealing. For input lengths
675 that are multiples of the block size it is equivalent to using
676 a "AES-XXX-CBC" or "CAMELLIA-XXX-CBC" cipher otherwise the
677 second last cipher text block is a partial block.
678 "CS2"
680 For input lengths that are multiples of the block size it is
681 equivalent to using a "AES-XXX-CBC" or "CAMELLIA-XXX-CBC"
682 cipher, otherwise it is the same as "CS3" mode.
683 "CS3"
685 The Kerberos5 variant of cipher text stealing which always
686 swaps the last cipher text block with the previous block (which
687 may be a partial or full block depending on the input length).
688 If the input length is exactly one full block then this is
689 equivalent to using a "AES-XXX-CBC" or "CAMELLIA-XXX-CBC"
690 cipher.
691 The default is "CS1". This is only supported for
693 "AES-128-CBC-CTS", "AES-192-CBC-CTS", "AES-256-CBC-CTS",
694 "CAMELLIA-128-CBC-CTS", "CAMELLIA-192-CBC-CTS" and
695 "CAMELLIA-256-CBC-CTS".
696 "tls1multi_interleave" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE)
698 <unsigned integer>
699 Sets or gets the number of records being sent in one go for a tls1
700 multiblock cipher operation (either 4 or 8 records).
701 Gettable EVP_CIPHER_CTX parameters
703 The following OSSL_PARAM(3) keys can be used with
704 EVP_CIPHER_CTX_get_params():
705 "ivlen" (OSSL_CIPHER_PARAM_IVLEN and <OSSL_CIPHER_PARAM_AEAD_IVLEN)
707 <unsigned integer>
708 Gets the IV length for the cipher context ctx. The length of the
709 "ivlen" parameter should not exceed that of a size_t. See also
710 EVP_CIPHER_CTX_get_iv_length().
711 "iv" (OSSL_CIPHER_PARAM_IV) <octet string OR octet ptr>
713 Gets the IV used to initialize the associated cipher context ctx.
714 See also EVP_CIPHER_CTX_get_original_iv().
715 "updated-iv" (OSSL_CIPHER_PARAM_UPDATED_IV) <octet string OR octet ptr>
717 Gets the updated pseudo-IV state for the associated cipher context,
718 e.g., the previous ciphertext block for CBC mode or the iteratively
719 encrypted IV value for OFB mode. Note that octet pointer access is
720 deprecated and is provided only for backwards compatibility with
721 historical libcrypto APIs. See also
722 EVP_CIPHER_CTX_get_updated_iv().
723 "randkey" (OSSL_CIPHER_PARAM_RANDOM_KEY) <octet string>
725 Gets an implementation specific randomly generated key for the
726 associated cipher context ctx. This is currently only supported by
727 DES and 3DES (which set the key to odd parity).
728 "taglen" (OSSL_CIPHER_PARAM_AEAD_TAGLEN) <unsigned integer>
730 Gets the tag length to be used for an AEAD cipher for the
731 associated cipher context ctx. It gets a default value if it has
732 not been set. The length of the "taglen" parameter should not
733 exceed that of a size_t. See also EVP_CIPHER_CTX_get_tag_length().
734 "tlsaadpad" (OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD) <unsigned integer>
736 Gets the length of the tag that will be added to a TLS record for
737 the AEAD tag for the associated cipher context ctx. The length of
738 the "tlsaadpad" parameter should not exceed that of a size_t.
739 "tlsivgen" (OSSL_CIPHER_PARAM_AEAD_TLS1_GET_IV_GEN) <octet string>
741 Gets the invocation field generated for encryption. Can only be
742 called after "tlsivfixed" is set. This is only used for GCM mode.
743 "tls1multi_enclen" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_LEN)
745 <unsigned integer>
746 Get the total length of the record returned from the
747 "tls1multi_enc" operation.
748 "tls1multi_maxbufsz" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_BUFSIZE)
750 <unsigned integer>
751 Gets the maximum record length for a TLS1 multiblock cipher
752 operation. The length of the "tls1multi_maxbufsz" parameter should
753 not exceed that of a size_t.
754 "tls1multi_aadpacklen" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD_PACKLEN)
756 <unsigned integer>
757 Gets the result of running the "tls1multi_aad" operation.
758 "tls-mac" (OSSL_CIPHER_PARAM_TLS_MAC) <octet ptr>
760 Used to pass the TLS MAC data.
761 Settable EVP_CIPHER_CTX parameters
763 The following OSSL_PARAM(3) keys can be used with
764 EVP_CIPHER_CTX_set_params():
765 "mackey" (OSSL_CIPHER_PARAM_AEAD_MAC_KEY) <octet string>
767 Sets the MAC key used by composite AEAD ciphers such as
768 AES-CBC-HMAC-SHA256.
769 "speed" (OSSL_CIPHER_PARAM_SPEED) <unsigned integer>
771 Sets the speed option for the associated cipher context. This is
772 only supported by AES SIV ciphers which disallow multiple
773 operations by default. Setting "speed" to 1 allows another encrypt
774 or decrypt operation to be performed. This is used for performance
775 testing.
776 "use-bits" (OSSL_CIPHER_PARAM_USE_BITS) <unsigned integer>
778 Determines if the input length inl passed to EVP_EncryptUpdate(),
779 EVP_DecryptUpdate() and EVP_CipherUpdate() is the number of bits or
780 number of bytes. Setting "use-bits" to 1 uses bits. The default is
781 in bytes. This is only used for CFB1 ciphers.
782 This can be set using EVP_CIPHER_CTX_set_flags(ctx,
784 EVP_CIPH_FLAG_LENGTH_BITS).
785 "tls-version" (OSSL_CIPHER_PARAM_TLS_VERSION) <integer>
787 Sets the TLS version.
788 "tls-mac-size" (OSSL_CIPHER_PARAM_TLS_MAC_SIZE) <unsigned integer>
790 Set the TLS MAC size.
791 "tlsaad" (OSSL_CIPHER_PARAM_AEAD_TLS1_AAD) <octet string>
793 Sets TLSv1.2 AAD information for the associated cipher context ctx.
794 TLSv1.2 AAD information is always 13 bytes in length and is as
795 defined for the "additional_data" field described in section
796 6.2.3.3 of RFC5246.
797 "tlsivfixed" (OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED) <octet string>
799 Sets the fixed portion of an IV for an AEAD cipher used in a TLS
800 record encryption/ decryption for the associated cipher context.
801 TLS record encryption/decryption always occurs "in place" so that
802 the input and output buffers are always the same memory location.
803 AEAD IVs in TLSv1.2 consist of an implicit "fixed" part and an
804 explicit part that varies with every record. Setting a TLS fixed
805 IV changes a cipher to encrypt/decrypt TLS records. TLS records
806 are encrypted/decrypted using a single OSSL_FUNC_cipher_cipher call
807 per record. For a record decryption the first bytes of the input
808 buffer will be the explicit part of the IV and the final bytes of
809 the input buffer will be the AEAD tag. The length of the explicit
810 part of the IV and the tag length will depend on the cipher in use
811 and will be defined in the RFC for the relevant ciphersuite. In
812 order to allow for "in place" decryption the plaintext output
813 should be written to the same location in the output buffer that
814 the ciphertext payload was read from, i.e. immediately after the
815 explicit IV.
816 When encrypting a record the first bytes of the input buffer should
818 be empty to allow space for the explicit IV, as will the final
819 bytes where the tag will be written. The length of the input
820 buffer will include the length of the explicit IV, the payload, and
821 the tag bytes. The cipher implementation should generate the
822 explicit IV and write it to the beginning of the output buffer, do
823 "in place" encryption of the payload and write that to the output
824 buffer, and finally add the tag onto the end of the output buffer.
825 Whether encrypting or decrypting the value written to *outl in the
827 OSSL_FUNC_cipher_cipher call should be the length of the payload
828 excluding the explicit IV length and the tag length.
829 "tlsivinv" (OSSL_CIPHER_PARAM_AEAD_TLS1_SET_IV_INV) <octet string>
831 Sets the invocation field used for decryption. Can only be called
832 after "tlsivfixed" is set. This is only used for GCM mode.
833 "tls1multi_enc" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC) <octet string>
835 Triggers a multiblock TLS1 encrypt operation for a TLS1 aware
836 cipher that supports sending 4 or 8 records in one go. The cipher
837 performs both the MAC and encrypt stages and constructs the record
838 headers itself. "tls1multi_enc" supplies the output buffer for the
839 encrypt operation, "tls1multi_encin" & "tls1multi_interleave" must
840 also be set in order to supply values to the encrypt operation.
841 "tls1multi_encin" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_IN) <octet
843 string>
844 Supplies the data to encrypt for a TLS1 multiblock cipher
845 operation.
846 "tls1multi_maxsndfrag"
848 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_SEND_FRAGMENT) <unsigned
849 integer>
850 Sets the maximum send fragment size for a TLS1 multiblock cipher
851 operation. It must be set before using "tls1multi_maxbufsz". The
852 length of the "tls1multi_maxsndfrag" parameter should not exceed
853 that of a size_t.
854 "tls1multi_aad" (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD) <octet string>
856 Sets the authenticated additional data used by a TLS1 multiblock
857 cipher operation. The supplied data consists of 13 bytes of record
858 data containing: Bytes 0-7: The sequence number of the first record
859 Byte 8: The record type Byte 9-10: The protocol version Byte 11-12:
860 Input length (Always 0)
861 "tls1multi_interleave" must also be set for this operation.
863
865 The Mappings from EVP_CIPHER_CTX_ctrl() identifiers to PARAMETERS are
866 listed in the following section. See the "PARAMETERS" section for more
867 details.
868 EVP_CIPHER_CTX_ctrl() can be used to send the following standard
870 controls:
871 EVP_CTRL_AEAD_SET_IVLEN and EVP_CTRL_GET_IVLEN
873 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
874 and EVP_CIPHER_CTX_get_params() get called with an OSSL_PARAM(3)
875 item with the key "ivlen" (OSSL_CIPHER_PARAM_IVLEN).
876 EVP_CTRL_AEAD_SET_IV_FIXED
878 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
879 gets called with an OSSL_PARAM(3) item with the key "tlsivfixed"
880 (OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED).
881 EVP_CTRL_AEAD_SET_MAC_KEY
883 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
884 gets called with an OSSL_PARAM(3) item with the key "mackey"
885 (OSSL_CIPHER_PARAM_AEAD_MAC_KEY).
886 EVP_CTRL_AEAD_SET_TAG and EVP_CTRL_AEAD_GET_TAG
888 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
889 and EVP_CIPHER_CTX_get_params() get called with an OSSL_PARAM(3)
890 item with the key "tag" (OSSL_CIPHER_PARAM_AEAD_TAG).
891 EVP_CTRL_CCM_SET_L
893 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
894 gets called with an OSSL_PARAM(3) item with the key "ivlen"
895 (OSSL_CIPHER_PARAM_IVLEN) with a value of (15 - L)
896 EVP_CTRL_COPY
898 There is no OSSL_PARAM mapping for this. Use EVP_CIPHER_CTX_copy()
899 instead.
900 EVP_CTRL_GCM_SET_IV_INV
902 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
903 gets called with an OSSL_PARAM(3) item with the key "tlsivinv"
904 (OSSL_CIPHER_PARAM_AEAD_TLS1_SET_IV_INV).
905 EVP_CTRL_RAND_KEY
907 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
908 gets called with an OSSL_PARAM(3) item with the key "randkey"
909 (OSSL_CIPHER_PARAM_RANDOM_KEY).
910 EVP_CTRL_SET_KEY_LENGTH
912 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
913 gets called with an OSSL_PARAM(3) item with the key "keylen"
914 (OSSL_CIPHER_PARAM_KEYLEN).
915 EVP_CTRL_SET_RC2_KEY_BITS and EVP_CTRL_GET_RC2_KEY_BITS
917 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
918 and EVP_CIPHER_CTX_get_params() get called with an OSSL_PARAM(3)
919 item with the key "keybits" (OSSL_CIPHER_PARAM_RC2_KEYBITS).
920 EVP_CTRL_SET_RC5_ROUNDS and EVP_CTRL_GET_RC5_ROUNDS
922 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
923 and EVP_CIPHER_CTX_get_params() get called with an OSSL_PARAM(3)
924 item with the key "rounds" (OSSL_CIPHER_PARAM_ROUNDS).
925 EVP_CTRL_SET_SPEED
927 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
928 gets called with an OSSL_PARAM(3) item with the key "speed"
929 (OSSL_CIPHER_PARAM_SPEED).
930 EVP_CTRL_GCM_IV_GEN
932 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_get_params()
933 gets called with an OSSL_PARAM(3) item with the key "tlsivgen"
934 (OSSL_CIPHER_PARAM_AEAD_TLS1_GET_IV_GEN).
935 EVP_CTRL_AEAD_TLS1_AAD
937 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
938 get called with an OSSL_PARAM(3) item with the key "tlsaad"
939 (OSSL_CIPHER_PARAM_AEAD_TLS1_AAD) followed by
940 EVP_CIPHER_CTX_get_params() with a key of "tlsaadpad"
941 (OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD).
942 EVP_CTRL_TLS1_1_MULTIBLOCK_MAX_BUFSIZE
944 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
945 gets called with an OSSL_PARAM(3) item with the key
946 OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_SEND_FRAGMENT followed by
947 EVP_CIPHER_CTX_get_params() with a key of "tls1multi_maxbufsz"
948 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_MAX_BUFSIZE).
949 EVP_CTRL_TLS1_1_MULTIBLOCK_AAD
951 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
952 gets called with OSSL_PARAM(3) items with the keys "tls1multi_aad"
953 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD) and "tls1multi_interleave"
954 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE) followed by
955 EVP_CIPHER_CTX_get_params() with keys of "tls1multi_aadpacklen"
956 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_AAD_PACKLEN) and
957 "tls1multi_interleave"
958 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE).
959 EVP_CTRL_TLS1_1_MULTIBLOCK_ENCRYPT
961 When used with a fetched EVP_CIPHER, EVP_CIPHER_CTX_set_params()
962 gets called with OSSL_PARAM(3) items with the keys "tls1multi_enc"
963 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC), "tls1multi_encin"
964 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_IN) and
965 "tls1multi_interleave"
966 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_INTERLEAVE), followed by
967 EVP_CIPHER_CTX_get_params() with a key of "tls1multi_enclen"
968 (OSSL_CIPHER_PARAM_TLS1_MULTIBLOCK_ENC_LEN).
969
971 EVP_CIPHER_CTX_set_flags(), EVP_CIPHER_CTX_clear_flags() and
972 EVP_CIPHER_CTX_test_flags(). can be used to manipulate and test these
973 EVP_CIPHER_CTX flags:
974 EVP_CIPH_NO_PADDING
976 Used by EVP_CIPHER_CTX_set_padding().
977 See also "Gettable and Settable EVP_CIPHER_CTX parameters"
979 "padding"
980 EVP_CIPH_FLAG_LENGTH_BITS
982 See "Settable EVP_CIPHER_CTX parameters" "use-bits".
983 EVP_CIPHER_CTX_FLAG_WRAP_ALLOW
985 Used for Legacy purposes only. This flag needed to be set to
986 indicate the cipher handled wrapping.
987 EVP_CIPHER_flags() uses the following flags that have mappings to
989 "Gettable EVP_CIPHER parameters":
990 EVP_CIPH_FLAG_AEAD_CIPHER
992 See "Gettable EVP_CIPHER parameters" "aead".
993 EVP_CIPH_CUSTOM_IV
995 See "Gettable EVP_CIPHER parameters" "custom-iv".
996 EVP_CIPH_FLAG_CTS
998 See "Gettable EVP_CIPHER parameters" "cts".
999 EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK;
1001 See "Gettable EVP_CIPHER parameters" "tls-multi".
1002 EVP_CIPH_RAND_KEY
1004 See "Gettable EVP_CIPHER parameters" "has-randkey".
1005 EVP_CIPHER_flags() uses the following flags for legacy purposes only:
1007 EVP_CIPH_VARIABLE_LENGTH
1009 EVP_CIPH_FLAG_CUSTOM_CIPHER
1010 EVP_CIPH_ALWAYS_CALL_INIT
1011 EVP_CIPH_CTRL_INIT
1012 EVP_CIPH_CUSTOM_KEY_LENGTH
1013 EVP_CIPH_CUSTOM_COPY
1014 EVP_CIPH_FLAG_DEFAULT_ASN1
1015 See EVP_CIPHER_meth_set_flags(3) for further information related to
1016 the above flags.
1017
1019 EVP_CIPHER_fetch() returns a pointer to a EVP_CIPHER for success and
1020 NULL for failure.
1021 EVP_CIPHER_up_ref() returns 1 for success or 0 otherwise.
1023 EVP_CIPHER_CTX_new() returns a pointer to a newly created
1025 EVP_CIPHER_CTX for success and NULL for failure.
1026 EVP_CIPHER_CTX_dup() returns a new EVP_MD_CTX if successful or NULL on
1028 failure.
1029 EVP_CIPHER_CTX_copy() returns 1 if successful or 0 for failure.
1031 EVP_EncryptInit_ex2(), EVP_EncryptUpdate() and EVP_EncryptFinal_ex()
1033 return 1 for success and 0 for failure.
1034 EVP_DecryptInit_ex2() and EVP_DecryptUpdate() return 1 for success and
1036 0 for failure. EVP_DecryptFinal_ex() returns 0 if the decrypt failed
1037 or 1 for success.
1038 EVP_CipherInit_ex2() and EVP_CipherUpdate() return 1 for success and 0
1040 for failure. EVP_CipherFinal_ex() returns 0 for a decryption failure
1041 or 1 for success.
1042 EVP_Cipher() returns the amount of encrypted / decrypted bytes, or -1
1044 on failure if the flag EVP_CIPH_FLAG_CUSTOM_CIPHER is set for the
1045 cipher. EVP_Cipher() returns 1 on success or 0 on failure, if the flag
1046 EVP_CIPH_FLAG_CUSTOM_CIPHER is not set for the cipher.
1047 EVP_CIPHER_CTX_reset() returns 1 for success and 0 for failure.
1049 EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj()
1051 return an EVP_CIPHER structure or NULL on error.
1052 EVP_CIPHER_get_nid() and EVP_CIPHER_CTX_get_nid() return a NID.
1054 EVP_CIPHER_get_block_size() and EVP_CIPHER_CTX_get_block_size() return
1056 the block size.
1057 EVP_CIPHER_get_key_length() and EVP_CIPHER_CTX_get_key_length() return
1059 the key length.
1060 EVP_CIPHER_CTX_set_padding() always returns 1.
1062 EVP_CIPHER_get_iv_length() and EVP_CIPHER_CTX_get_iv_length() return
1064 the IV length or zero if the cipher does not use an IV.
1065 EVP_CIPHER_CTX_get_tag_length() return the tag length or zero if the
1067 cipher does not use a tag.
1068 EVP_CIPHER_get_type() and EVP_CIPHER_CTX_get_type() return the NID of
1070 the cipher's OBJECT IDENTIFIER or NID_undef if it has no defined OBJECT
1071 IDENTIFIER.
1072 EVP_CIPHER_CTX_cipher() returns an EVP_CIPHER structure.
1074 EVP_CIPHER_CTX_get_num() returns a nonnegative num value or
1076 EVP_CTRL_RET_UNSUPPORTED if the implementation does not support the
1077 call or on any other error.
1078 EVP_CIPHER_CTX_set_num() returns 1 on success and 0 if the
1080 implementation does not support the call or on any other error.
1081 EVP_CIPHER_CTX_is_encrypting() returns 1 if the ctx is set up for
1083 encryption 0 otherwise.
1084 EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return
1086 greater than zero for success and zero or a negative number on failure.
1087 EVP_CIPHER_CTX_rand_key() returns 1 for success and zero or a negative
1089 number for failure.
1090 EVP_CIPHER_names_do_all() returns 1 if the callback was called for all
1092 names. A return value of 0 means that the callback was not called for
1093 any names.
1094
1096 All algorithms have a fixed key length unless otherwise stated.
1097 Refer to "SEE ALSO" for the full list of ciphers available through the
1099 EVP interface.
1100 EVP_enc_null()
1102 Null cipher: does nothing.
1103
1105 The EVP interface for Authenticated Encryption with Associated Data
1106 (AEAD) modes are subtly altered and several additional ctrl operations
1107 are supported depending on the mode specified.
1108 To specify additional authenticated data (AAD), a call to
1110 EVP_CipherUpdate(), EVP_EncryptUpdate() or EVP_DecryptUpdate() should
1111 be made with the output parameter out set to NULL.
1112 When decrypting, the return value of EVP_DecryptFinal() or
1114 EVP_CipherFinal() indicates whether the operation was successful. If it
1115 does not indicate success, the authentication operation has failed and
1116 any output data MUST NOT be used as it is corrupted.
1117 GCM and OCB Modes
1119 The following ctrls are supported in GCM and OCB modes.
1120 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
1122 Sets the IV length. This call can only be made before specifying an
1123 IV. If not called a default IV length is used.
1124 For GCM AES and OCB AES the default is 12 (i.e. 96 bits). For OCB
1126 mode the maximum is 15.
1127 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag)
1129 Writes "taglen" bytes of the tag value to the buffer indicated by
1130 "tag". This call can only be made when encrypting data and after
1131 all data has been processed (e.g. after an EVP_EncryptFinal()
1132 call).
1133 For OCB, "taglen" must either be 16 or the value previously set via
1135 EVP_CTRL_AEAD_SET_TAG.
1136 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag)
1138 When decrypting, this call sets the expected tag to "taglen" bytes
1139 from "tag". "taglen" must be between 1 and 16 inclusive. The tag
1140 must be set prior to any call to EVP_DecryptFinal() or
1141 EVP_DecryptFinal_ex().
1142 For GCM, this call is only valid when decrypting data.
1144 For OCB, this call is valid when decrypting data to set the
1146 expected tag, and when encrypting to set the desired tag length.
1147 In OCB mode, calling this when encrypting with "tag" set to "NULL"
1149 sets the tag length. The tag length can only be set before
1150 specifying an IV. If this is not called prior to setting the IV
1151 during encryption, then a default tag length is used.
1152 For OCB AES, the default tag length is 16 (i.e. 128 bits). It is
1154 also the maximum tag length for OCB.
1155 CCM Mode
1157 The EVP interface for CCM mode is similar to that of the GCM mode but
1158 with a few additional requirements and different ctrl values.
1159 For CCM mode, the total plaintext or ciphertext length MUST be passed
1161 to EVP_CipherUpdate(), EVP_EncryptUpdate() or EVP_DecryptUpdate() with
1162 the output and input parameters (in and out) set to NULL and the length
1163 passed in the inl parameter.
1164 The following ctrls are supported in CCM mode.
1166 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag)
1168 This call is made to set the expected CCM tag value when decrypting
1169 or the length of the tag (with the "tag" parameter set to NULL)
1170 when encrypting. The tag length is often referred to as M. If not
1171 set a default value is used (12 for AES). When decrypting, the tag
1172 needs to be set before passing in data to be decrypted, but as in
1173 GCM and OCB mode, it can be set after passing additional
1174 authenticated data (see "AEAD INTERFACE").
1175 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_L, ivlen, NULL)
1177 Sets the CCM L value. If not set a default is used (8 for AES).
1178 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
1180 Sets the CCM nonce (IV) length. This call can only be made before
1181 specifying a nonce value. The nonce length is given by 15 - L so it
1182 is 7 by default for AES.
1183 SIV Mode
1185 For SIV mode ciphers the behaviour of the EVP interface is subtly
1186 altered and several additional ctrl operations are supported.
1187 To specify any additional authenticated data (AAD) and/or a Nonce, a
1189 call to EVP_CipherUpdate(), EVP_EncryptUpdate() or EVP_DecryptUpdate()
1190 should be made with the output parameter out set to NULL.
1191 RFC5297 states that the Nonce is the last piece of AAD before the
1193 actual encrypt/decrypt takes place. The API does not differentiate the
1194 Nonce from other AAD.
1195 When decrypting the return value of EVP_DecryptFinal() or
1197 EVP_CipherFinal() indicates if the operation was successful. If it does
1198 not indicate success the authentication operation has failed and any
1199 output data MUST NOT be used as it is corrupted.
1200 The API does not store the the SIV (Synthetic Initialization Vector) in
1202 the cipher text. Instead, it is stored as the tag within the
1203 EVP_CIPHER_CTX. The SIV must be retrieved from the context after
1204 encryption, and set into the context before decryption.
1205 This differs from RFC5297 in that the cipher output from encryption,
1207 and the cipher input to decryption, does not contain the SIV. This also
1208 means that the plain text and cipher text lengths are identical.
1209 The following ctrls are supported in SIV mode, and are used to get and
1211 set the Synthetic Initialization Vector:
1212 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag);
1214 Writes taglen bytes of the tag value (the Synthetic Initialization
1215 Vector) to the buffer indicated by tag. This call can only be made
1216 when encrypting data and after all data has been processed (e.g.
1217 after an EVP_EncryptFinal() call). For SIV mode the taglen must be
1218 16.
1219 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag);
1221 Sets the expected tag (the Synthetic Initialization Vector) to
1222 taglen bytes from tag. This call is only legal when decrypting data
1223 and must be made before any data is processed (e.g. before any
1224 EVP_DecryptUpdate() calls). For SIV mode the taglen must be 16.
1225 SIV mode makes two passes over the input data, thus, only one call to
1227 EVP_CipherUpdate(), EVP_EncryptUpdate() or EVP_DecryptUpdate() should
1228 be made with out set to a non-NULL value. A call to EVP_DecryptFinal()
1229 or EVP_CipherFinal() is not required, but will indicate if the update
1230 operation succeeded.
1231 ChaCha20-Poly1305
1233 The following ctrls are supported for the ChaCha20-Poly1305 AEAD
1234 algorithm.
1235 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
1237 Sets the nonce length. This call is now redundant since the only
1238 valid value is the default length of 12 (i.e. 96 bits). Prior to
1239 OpenSSL 3.0 a nonce of less than 12 bytes could be used to
1240 automatically pad the iv with leading 0 bytes to make it 12 bytes
1241 in length.
1242 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag)
1244 Writes "taglen" bytes of the tag value to the buffer indicated by
1245 "tag". This call can only be made when encrypting data and after
1246 all data has been processed (e.g. after an EVP_EncryptFinal()
1247 call).
1248 "taglen" specified here must be 16 (POLY1305_BLOCK_SIZE, i.e.
1250 128-bits) or less.
1251 EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag)
1253 Sets the expected tag to "taglen" bytes from "tag". The tag length
1254 can only be set before specifying an IV. "taglen" must be between
1255 1 and 16 (POLY1305_BLOCK_SIZE) inclusive. This call is only valid
1256 when decrypting data.
1257
1259 Where possible the EVP interface to symmetric ciphers should be used in
1260 preference to the low-level interfaces. This is because the code then
1261 becomes transparent to the cipher used and much more flexible.
1262 Additionally, the EVP interface will ensure the use of platform
1263 specific cryptographic acceleration such as AES-NI (the low-level
1264 interfaces do not provide the guarantee).
1265 PKCS padding works by adding n padding bytes of value n to make the
1267 total length of the encrypted data a multiple of the block size.
1268 Padding is always added so if the data is already a multiple of the
1269 block size n will equal the block size. For example if the block size
1270 is 8 and 11 bytes are to be encrypted then 5 padding bytes of value 5
1271 will be added.
1272 When decrypting the final block is checked to see if it has the correct
1274 form.
1275 Although the decryption operation can produce an error if padding is
1277 enabled, it is not a strong test that the input data or key is correct.
1278 A random block has better than 1 in 256 chance of being of the correct
1279 format and problems with the input data earlier on will not produce a
1280 final decrypt error.
1281 If padding is disabled then the decryption operation will always
1283 succeed if the total amount of data decrypted is a multiple of the
1284 block size.
1285 The functions EVP_EncryptInit(), EVP_EncryptInit_ex(),
1287 EVP_EncryptFinal(), EVP_DecryptInit(), EVP_DecryptInit_ex(),
1288 EVP_CipherInit(), EVP_CipherInit_ex() and EVP_CipherFinal() are
1289 obsolete but are retained for compatibility with existing code. New
1290 code should use EVP_EncryptInit_ex2(), EVP_EncryptFinal_ex(),
1291 EVP_DecryptInit_ex2(), EVP_DecryptFinal_ex(), EVP_CipherInit_ex2() and
1292 EVP_CipherFinal_ex() because they can reuse an existing context without
1293 allocating and freeing it up on each call.
1294 There are some differences between functions EVP_CipherInit() and
1296 EVP_CipherInit_ex(), significant in some circumstances.
1297 EVP_CipherInit() fills the passed context object with zeros. As a
1298 consequence, EVP_CipherInit() does not allow step-by-step
1299 initialization of the ctx when the key and iv are passed in separate
1300 calls. It also means that the flags set for the CTX are removed, and it
1301 is especially important for the EVP_CIPHER_CTX_FLAG_WRAP_ALLOW flag
1302 treated specially in EVP_CipherInit_ex().
1303 Ignoring failure returns of the EVP_CIPHER_CTX initialization functions
1305 can lead to subsequent undefined behavior when calling the functions
1306 that update or finalize the context. The only valid calls on the
1307 EVP_CIPHER_CTX when initialization fails are calls that attempt another
1308 initialization of the context or release the context.
1309 EVP_get_cipherbynid(), and EVP_get_cipherbyobj() are implemented as
1311 macros.
1312
1314 EVP_MAX_KEY_LENGTH and EVP_MAX_IV_LENGTH only refer to the internal
1315 ciphers with default key lengths. If custom ciphers exceed these values
1316 the results are unpredictable. This is because it has become standard
1317 practice to define a generic key as a fixed unsigned char array
1318 containing EVP_MAX_KEY_LENGTH bytes.
1319 The ASN1 code is incomplete (and sometimes inaccurate) it has only been
1321 tested for certain common S/MIME ciphers (RC2, DES, triple DES) in CBC
1322 mode.
1323
1325 Encrypt a string using IDEA:
1326 int do_crypt(char *outfile)
1328 {
1329 unsigned char outbuf[1024];
1330 int outlen, tmplen;
1331 /*
1332 * Bogus key and IV: we'd normally set these from
1333 * another source.
1334 */
1335 unsigned char key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1336 unsigned char iv[] = {1,2,3,4,5,6,7,8};
1337 char intext[] = "Some Crypto Text";
1338 EVP_CIPHER_CTX *ctx;
1339 FILE *out;
1340 ctx = EVP_CIPHER_CTX_new();
1342 if (!EVP_EncryptInit_ex2(ctx, EVP_idea_cbc(), key, iv, NULL)) {
1343 /* Error */
1344 EVP_CIPHER_CTX_free(ctx);
1345 return 0;
1346 }
1347 if (!EVP_EncryptUpdate(ctx, outbuf, &outlen, intext, strlen(intext))) {
1349 /* Error */
1350 EVP_CIPHER_CTX_free(ctx);
1351 return 0;
1352 }
1353 /*
1354 * Buffer passed to EVP_EncryptFinal() must be after data just
1355 * encrypted to avoid overwriting it.
1356 */
1357 if (!EVP_EncryptFinal_ex(ctx, outbuf + outlen, &tmplen)) {
1358 /* Error */
1359 EVP_CIPHER_CTX_free(ctx);
1360 return 0;
1361 }
1362 outlen += tmplen;
1363 EVP_CIPHER_CTX_free(ctx);
1364 /*
1365 * Need binary mode for fopen because encrypted data is
1366 * binary data. Also cannot use strlen() on it because
1367 * it won't be NUL terminated and may contain embedded
1368 * NULs.
1369 */
1370 out = fopen(outfile, "wb");
1371 if (out == NULL) {
1372 /* Error */
1373 return 0;
1374 }
1375 fwrite(outbuf, 1, outlen, out);
1376 fclose(out);
1377 return 1;
1378 }
1379 The ciphertext from the above example can be decrypted using the
1381 openssl utility with the command line (shown on two lines for clarity):
1382 openssl idea -d \
1384 -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708 <filename
1385 General encryption and decryption function example using FILE I/O and
1387 AES128 with a 128-bit key:
1388 int do_crypt(FILE *in, FILE *out, int do_encrypt)
1390 {
1391 /* Allow enough space in output buffer for additional block */
1392 unsigned char inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];
1393 int inlen, outlen;
1394 EVP_CIPHER_CTX *ctx;
1395 /*
1396 * Bogus key and IV: we'd normally set these from
1397 * another source.
1398 */
1399 unsigned char key[] = "0123456789abcdeF";
1400 unsigned char iv[] = "1234567887654321";
1401 /* Don't set key or IV right away; we want to check lengths */
1403 ctx = EVP_CIPHER_CTX_new();
1404 if (!EVP_CipherInit_ex2(ctx, EVP_aes_128_cbc(), NULL, NULL,
1405 do_encrypt, NULL)) {
1406 /* Error */
1407 EVP_CIPHER_CTX_free(ctx);
1408 return 0;
1409 }
1410 OPENSSL_assert(EVP_CIPHER_CTX_get_key_length(ctx) == 16);
1411 OPENSSL_assert(EVP_CIPHER_CTX_get_iv_length(ctx) == 16);
1412 /* Now we can set key and IV */
1414 if (!EVP_CipherInit_ex2(ctx, NULL, key, iv, do_encrypt, NULL)) {
1415 /* Error */
1416 EVP_CIPHER_CTX_free(ctx);
1417 return 0;
1418 }
1419 for (;;) {
1421 inlen = fread(inbuf, 1, 1024, in);
1422 if (inlen <= 0)
1423 break;
1424 if (!EVP_CipherUpdate(ctx, outbuf, &outlen, inbuf, inlen)) {
1425 /* Error */
1426 EVP_CIPHER_CTX_free(ctx);
1427 return 0;
1428 }
1429 fwrite(outbuf, 1, outlen, out);
1430 }
1431 if (!EVP_CipherFinal_ex(ctx, outbuf, &outlen)) {
1432 /* Error */
1433 EVP_CIPHER_CTX_free(ctx);
1434 return 0;
1435 }
1436 fwrite(outbuf, 1, outlen, out);
1437 EVP_CIPHER_CTX_free(ctx);
1439 return 1;
1440 }
1441 Encryption using AES-CBC with a 256-bit key with "CS1" ciphertext
1443 stealing.
1444 int encrypt(const unsigned char *key, const unsigned char *iv,
1446 const unsigned char *msg, size_t msg_len, unsigned char *out)
1447 {
1448 /*
1449 * This assumes that key size is 32 bytes and the iv is 16 bytes.
1450 * For ciphertext stealing mode the length of the ciphertext "out" will be
1451 * the same size as the plaintext size "msg_len".
1452 * The "msg_len" can be any size >= 16.
1453 */
1454 int ret = 0, encrypt = 1, outlen, len;
1455 EVP_CIPHER_CTX *ctx = NULL;
1456 EVP_CIPHER *cipher = NULL;
1457 OSSL_PARAM params[2];
1458 ctx = EVP_CIPHER_CTX_new();
1460 cipher = EVP_CIPHER_fetch(NULL, "AES-256-CBC-CTS", NULL);
1461 if (ctx == NULL || cipher == NULL)
1462 goto err;
1463 /*
1465 * The default is "CS1" so this is not really needed,
1466 * but would be needed to set either "CS2" or "CS3".
1467 */
1468 params[0] = OSSL_PARAM_construct_utf8_string(OSSL_CIPHER_PARAM_CTS_MODE,
1469 "CS1", 0);
1470 params[1] = OSSL_PARAM_construct_end();
1471 if (!EVP_CipherInit_ex2(ctx, cipher, key, iv, encrypt, params))
1473 goto err;
1474 /* NOTE: CTS mode does not support multiple calls to EVP_CipherUpdate() */
1476 if (!EVP_CipherUpdate(ctx, out, &outlen, msg, msg_len))
1477 goto err;
1478 if (!EVP_CipherFinal_ex(ctx, out + outlen, &len))
1479 goto err;
1480 ret = 1;
1481 err:
1482 EVP_CIPHER_free(cipher);
1483 EVP_CIPHER_CTX_free(ctx);
1484 return ret;
1485 }
1486
1488 evp(7), property(7), "ALGORITHM FETCHING" in crypto(7),
1489 provider-cipher(7), life_cycle-cipher(7)
1490 Supported ciphers are listed in:
1492 EVP_aes_128_gcm(3), EVP_aria_128_gcm(3), EVP_bf_cbc(3),
1494 EVP_camellia_128_ecb(3), EVP_cast5_cbc(3), EVP_chacha20(3),
1495 EVP_des_cbc(3), EVP_desx_cbc(3), EVP_idea_cbc(3), EVP_rc2_cbc(3),
1496 EVP_rc4(3), EVP_rc5_32_12_16_cbc(3), EVP_seed_cbc(3), EVP_sm4_cbc(3),
1497
1499 Support for OCB mode was added in OpenSSL 1.1.0.
1500 EVP_CIPHER_CTX was made opaque in OpenSSL 1.1.0. As a result,
1502 EVP_CIPHER_CTX_reset() appeared and EVP_CIPHER_CTX_cleanup()
1503 disappeared. EVP_CIPHER_CTX_init() remains as an alias for
1504 EVP_CIPHER_CTX_reset().
1505 The EVP_CIPHER_CTX_cipher() function was deprecated in OpenSSL 3.0; use
1507 EVP_CIPHER_CTX_get0_cipher() instead.
1508 The EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2(), EVP_CipherInit_ex2(),
1510 EVP_CIPHER_fetch(), EVP_CIPHER_free(), EVP_CIPHER_up_ref(),
1511 EVP_CIPHER_CTX_get0_cipher(), EVP_CIPHER_CTX_get1_cipher(),
1512 EVP_CIPHER_get_params(), EVP_CIPHER_CTX_set_params(),
1513 EVP_CIPHER_CTX_get_params(), EVP_CIPHER_gettable_params(),
1514 EVP_CIPHER_settable_ctx_params(), EVP_CIPHER_gettable_ctx_params(),
1515 EVP_CIPHER_CTX_settable_params() and EVP_CIPHER_CTX_gettable_params()
1516 functions were added in 3.0.
1517 The EVP_CIPHER_nid(), EVP_CIPHER_name(), EVP_CIPHER_block_size(),
1519 EVP_CIPHER_key_length(), EVP_CIPHER_iv_length(), EVP_CIPHER_flags(),
1520 EVP_CIPHER_mode(), EVP_CIPHER_type(), EVP_CIPHER_CTX_nid(),
1521 EVP_CIPHER_CTX_block_size(), EVP_CIPHER_CTX_key_length(),
1522 EVP_CIPHER_CTX_iv_length(), EVP_CIPHER_CTX_tag_length(),
1523 EVP_CIPHER_CTX_num(), EVP_CIPHER_CTX_type(), and EVP_CIPHER_CTX_mode()
1524 functions were renamed to include "get" or "get0" in their names in
1525 OpenSSL 3.0, respectively. The old names are kept as non-deprecated
1526 alias macros.
1527 The EVP_CIPHER_CTX_encrypting() function was renamed to
1529 EVP_CIPHER_CTX_is_encrypting() in OpenSSL 3.0. The old name is kept as
1530 non-deprecated alias macro.
1531 The EVP_CIPHER_CTX_flags() macro was deprecated in OpenSSL 1.1.0.
1533 EVP_CIPHER_CTX_dup() was added in OpenSSL 3.1.
1535
1537 Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.
1538 Licensed under the Apache License 2.0 (the "License"). You may not use
1540 this file except in compliance with the License. You can obtain a copy
1541 in the file LICENSE in the source distribution or at
1542 <https://www.openssl.org/source/license.html>.
15433.1.1 2023-08-31 EVP_ENCRYPTINIT(3ossl)