5 EVP_MD_fetch, EVP_MD_up_ref, EVP_MD_free,
6 EVP_MD_get_params, EVP_MD_gettable_params,
7 EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy,
8 EVP_MD_CTX_copy_ex, EVP_MD_CTX_ctrl,
9 EVP_MD_CTX_set_params, EVP_MD_CTX_get_params,
10 EVP_MD_settable_ctx_params, EVP_MD_gettable_ctx_params,
11 EVP_MD_CTX_settable_params, EVP_MD_CTX_gettable_params,
12 EVP_MD_CTX_set_flags, EVP_MD_CTX_clear_flags, EVP_MD_CTX_test_flags,
13 EVP_Digest, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate,
14 EVP_DigestFinal_ex, EVP_DigestFinalXOF, EVP_DigestFinal,
15 EVP_MD_is_a, EVP_MD_name, EVP_MD_number, EVP_MD_names_do_all, EVP_MD_provider,
16 EVP_MD_type, EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_flags,
18 EVP_MD_CTX_md, EVP_MD_CTX_type, EVP_MD_CTX_size, EVP_MD_CTX_block_size,
19 EVP_MD_CTX_md_data, EVP_MD_CTX_update_fn, EVP_MD_CTX_set_update_fn,
21 EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj,
22 EVP_MD_CTX_pkey_ctx, EVP_MD_CTX_set_pkey_ctx,
23 EVP_MD_do_all_provided
28 #include <openssl/evp.h>
30 EVP_MD *EVP_MD_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
31 const char *properties);
32 int EVP_MD_up_ref(EVP_MD *md);
33 void EVP_MD_free(EVP_MD *md);
34 int EVP_MD_get_params(const EVP_MD *digest, OSSL_PARAM params[]);
35 const OSSL_PARAM *EVP_MD_gettable_params(const EVP_MD *digest);
36 EVP_MD_CTX *EVP_MD_CTX_new(void);
37 int EVP_MD_CTX_reset(EVP_MD_CTX *ctx);
38 void EVP_MD_CTX_free(EVP_MD_CTX *ctx);
39 void EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void* p2);
40 int EVP_MD_CTX_get_params(EVP_MD_CTX *ctx, OSSL_PARAM params[]);
41 int EVP_MD_CTX_set_params(EVP_MD_CTX *ctx, const OSSL_PARAM params[]);
42 const OSSL_PARAM *EVP_MD_settable_ctx_params(const EVP_MD *md);
43 const OSSL_PARAM *EVP_MD_gettable_ctx_params(const EVP_MD *md);
44 const OSSL_PARAM *EVP_MD_CTX_settable_params(EVP_MD_CTX *ctx);
45 const OSSL_PARAM *EVP_MD_CTX_gettable_params(EVP_MD_CTX *ctx);
46 void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, int flags);
47 void EVP_MD_CTX_clear_flags(EVP_MD_CTX *ctx, int flags);
48 int EVP_MD_CTX_test_flags(const EVP_MD_CTX *ctx, int flags);
50 int EVP_Digest(const void *data, size_t count, unsigned char *md,
51 unsigned int *size, const EVP_MD *type, ENGINE *impl);
52 int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl);
53 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);
54 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s);
55 int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t len);
57 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in);
59 int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type);
60 int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s);
62 int EVP_MD_CTX_copy(EVP_MD_CTX *out, EVP_MD_CTX *in);
64 const char *EVP_MD_name(const EVP_MD *md);
65 int EVP_MD_number(const EVP_MD *md);
66 int EVP_MD_is_a(const EVP_MD *md, const char *name);
67 int EVP_MD_names_do_all(const EVP_MD *md,
68 void (*fn)(const char *name, void *data),
70 const OSSL_PROVIDER *EVP_MD_provider(const EVP_MD *md);
71 int EVP_MD_type(const EVP_MD *md);
72 int EVP_MD_pkey_type(const EVP_MD *md);
73 int EVP_MD_size(const EVP_MD *md);
74 int EVP_MD_block_size(const EVP_MD *md);
75 unsigned long EVP_MD_flags(const EVP_MD *md);
77 const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx);
78 const char *EVP_MD_CTX_name(const EVP_MD_CTX *ctx);
79 int EVP_MD_CTX_size(const EVP_MD_CTX *ctx);
80 int EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx);
81 int EVP_MD_CTX_type(const EVP_MD_CTX *ctx);
82 void *EVP_MD_CTX_md_data(const EVP_MD_CTX *ctx);
84 const EVP_MD *EVP_md_null(void);
86 const EVP_MD *EVP_get_digestbyname(const char *name);
87 const EVP_MD *EVP_get_digestbynid(int type);
88 const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *o);
90 EVP_PKEY_CTX *EVP_MD_CTX_pkey_ctx(const EVP_MD_CTX *ctx);
91 void EVP_MD_CTX_set_pkey_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pctx);
93 void EVP_MD_do_all_provided(OSSL_LIB_CTX *libctx,
94 void (*fn)(EVP_MD *mac, void *arg),
97 Deprecated since OpenSSL 3.0, can be hidden entirely by defining
98 B<OPENSSL_API_COMPAT> with a suitable version value, see
99 L<openssl_user_macros(7)>:
101 int (*EVP_MD_CTX_update_fn(EVP_MD_CTX *ctx))(EVP_MD_CTX *ctx,
102 const void *data, size_t count);
104 void EVP_MD_CTX_set_update_fn(EVP_MD_CTX *ctx,
105 int (*update)(EVP_MD_CTX *ctx,
106 const void *data, size_t count));
110 The EVP digest routines are a high-level interface to message digests,
111 and should be used instead of the digest-specific functions.
113 The B<EVP_MD> type is a structure for digest method implementation.
119 Fetches the digest implementation for the given I<algorithm> from any
120 provider offering it, within the criteria given by the I<properties>.
121 See L<provider(7)/Fetching algorithms> for further information.
123 The returned value must eventually be freed with EVP_MD_free().
125 Fetched B<EVP_MD> structures are reference counted.
127 =item EVP_MD_up_ref()
129 Increments the reference count for an B<EVP_MD> structure.
133 Decrements the reference count for the fetched B<EVP_MD> structure.
134 If the reference count drops to 0 then the structure is freed.
136 =item EVP_MD_CTX_new()
138 Allocates and returns a digest context.
140 =item EVP_MD_CTX_reset()
142 Resets the digest context I<ctx>. This can be used to reuse an already
145 =item EVP_MD_CTX_free()
147 Cleans up digest context I<ctx> and frees up the space allocated to it.
149 =item EVP_MD_CTX_ctrl()
151 I<This is a legacy method. EVP_MD_CTX_set_params() and EVP_MD_CTX_get_params()
152 is the mechanism that should be used to set and get parameters that are used by
155 Performs digest-specific control actions on context I<ctx>. The control command
156 is indicated in I<cmd> and any additional arguments in I<p1> and I<p2>.
157 EVP_MD_CTX_ctrl() must be called after EVP_DigestInit_ex(). Other restrictions
158 may apply depending on the control type and digest implementation.
160 If this function happens to be used with a fetched B<EVP_MD>, it will
161 translate the controls that are known to OpenSSL into L<OSSL_PARAM(3)>
162 parameters with keys defined by OpenSSL and call EVP_MD_CTX_get_params() or
163 EVP_MD_CTX_set_params() as is appropriate for each control command.
165 See L</CONTROLS> below for more information, including what translations are
168 =item EVP_MD_get_params()
170 Retrieves the requested list of I<params> from a MD I<md>.
171 See L</PARAMETERS> below for more information.
173 =item EVP_MD_CTX_get_params()
175 Retrieves the requested list of I<params> from a MD context I<ctx>.
176 See L</PARAMETERS> below for more information.
178 =item EVP_MD_CTX_set_params()
180 Sets the list of I<params> into a MD context I<ctx>.
181 See L</PARAMETERS> below for more information.
183 =item EVP_MD_gettable_params(), EVP_MD_gettable_ctx_params(),
184 EVP_MD_settable_ctx_params(), EVP_MD_CTX_gettable_params(),
185 EVP_MD_CTX_settable_params()
187 Get a B<OSSL_PARAM> array that describes the retrievable and settable
188 parameters. EVP_MD_gettable_params() returns parameters that can be used with
189 EVP_MD_get_params(). EVP_MD_gettable_ctx_params() and
190 EVP_MD_CTX_gettable_params() return parameters that can be used with
191 EVP_MD_CTX_get_params(). EVP_MD_settable_ctx_params() and
192 EVP_MD_CTX_settable_params() return parameters that can be used with
193 EVP_MD_CTX_set_params().
194 See L<OSSL_PARAM(3)> for the use of B<OSSL_PARAM> as parameter descriptor.
196 =item EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags(), EVP_MD_CTX_test_flags()
198 Sets, clears and tests I<ctx> flags. See L</FLAGS> below for more information.
202 A wrapper around the Digest Init_ex, Update and Final_ex functions.
203 Hashes I<count> bytes of data at I<data> using a digest I<type> from ENGINE
204 I<impl>. The digest value is placed in I<md> and its length is written at I<size>
205 if the pointer is not NULL. At most B<EVP_MAX_MD_SIZE> bytes will be written.
206 If I<impl> is NULL the default implementation of digest I<type> is used.
208 =item EVP_DigestInit_ex()
210 Sets up digest context I<ctx> to use a digest I<type>.
211 I<type> is typically supplied by a function such as EVP_sha1(), or a
212 value explicitly fetched with EVP_MD_fetch().
214 If I<impl> is non-NULL, its implementation of the digest I<type> is used if
215 there is one, and if not, the default implementation is used.
217 The I<type> parameter can be NULL if I<ctx> has been already initialized
218 with another EVP_DigestInit_ex() call and has not been reset with
221 =item EVP_DigestUpdate()
223 Hashes I<cnt> bytes of data at I<d> into the digest context I<ctx>. This
224 function can be called several times on the same I<ctx> to hash additional
227 =item EVP_DigestFinal_ex()
229 Retrieves the digest value from I<ctx> and places it in I<md>. If the I<s>
230 parameter is not NULL then the number of bytes of data written (i.e. the
231 length of the digest) will be written to the integer at I<s>, at most
232 B<EVP_MAX_MD_SIZE> bytes will be written. After calling EVP_DigestFinal_ex()
233 no additional calls to EVP_DigestUpdate() can be made, but
234 EVP_DigestInit_ex() can be called to initialize a new digest operation.
236 =item EVP_DigestFinalXOF()
238 Interfaces to extendable-output functions, XOFs, such as SHAKE128 and SHAKE256.
239 It retrieves the digest value from I<ctx> and places it in I<len>-sized I<md>.
240 After calling this function no additional calls to EVP_DigestUpdate() can be
241 made, but EVP_DigestInit_ex() can be called to initialize a new operation.
243 =item EVP_MD_CTX_copy_ex()
245 Can be used to copy the message digest state from I<in> to I<out>. This is
246 useful if large amounts of data are to be hashed which only differ in the last
249 =item EVP_DigestInit()
251 Behaves in the same way as EVP_DigestInit_ex() except it always uses the
252 default digest implementation and calls EVP_MD_CTX_reset() so it cannot
253 be used with an I<type> of NULL.
255 =item EVP_DigestFinal()
257 Similar to EVP_DigestFinal_ex() except after computing the digest
258 the digest context I<ctx> is automatically cleaned up with EVP_MD_CTX_reset().
260 =item EVP_MD_CTX_copy()
262 Similar to EVP_MD_CTX_copy_ex() except the destination I<out> does not have to
267 Returns 1 if I<md> is an implementation of an algorithm that's
268 identifiable with I<name>, otherwise 0.
270 If I<md> is a legacy digest (it's the return value from the likes of
271 EVP_sha256() rather than the result of an EVP_MD_fetch()), only cipher
272 names registered with the default library context (see
273 L<OSSL_LIB_CTX(3)>) will be considered.
275 =item EVP_MD_number()
277 Returns the internal dynamic number assigned to the I<md>. This is
278 only useful with fetched B<EVP_MD>s.
283 Return the name of the given message digest. For fetched message
284 digests with multiple names, only one of them is returned; it's
285 recommended to use EVP_MD_names_do_all() instead.
287 =item EVP_MD_names_do_all()
289 Traverses all names for the I<md>, and calls I<fn> with each name and
290 I<data>. This is only useful with fetched B<EVP_MD>s.
292 =item EVP_MD_provider()
294 Returns an B<OSSL_PROVIDER> pointer to the provider that implements the given
300 Return the size of the message digest when passed an B<EVP_MD> or an
301 B<EVP_MD_CTX> structure, i.e. the size of the hash.
303 =item EVP_MD_block_size(),
304 EVP_MD_CTX_block_size()
306 Return the block size of the message digest when passed an B<EVP_MD> or an
307 B<EVP_MD_CTX> structure.
312 Return the NID of the OBJECT IDENTIFIER representing the given message digest
313 when passed an B<EVP_MD> structure. For example, C<EVP_MD_type(EVP_sha1())>
314 returns B<NID_sha1>. This function is normally used when setting ASN1 OIDs.
316 =item EVP_MD_CTX_md_data()
318 Return the digest method private data for the passed B<EVP_MD_CTX>.
319 The space is allocated by OpenSSL and has the size originally set with
320 EVP_MD_meth_set_app_datasize().
322 =item EVP_MD_CTX_md()
324 Returns the B<EVP_MD> structure corresponding to the passed B<EVP_MD_CTX>. This
325 will be the same B<EVP_MD> object originally passed to EVP_DigestInit_ex() (or
326 other similar function) when the EVP_MD_CTX was first initialised. Note that
327 where explicit fetch is in use (see L<EVP_MD_fetch(3)>) the value returned from
328 this function will not have its reference count incremented and therefore it
329 should not be used after the EVP_MD_CTX is freed.
331 =item EVP_MD_CTX_set_update_fn()
333 Sets the update function for I<ctx> to I<update>.
334 This is the function that is called by EVP_DigestUpdate(). If not set, the
335 update function from the B<EVP_MD> type specified at initialization is used.
337 =item EVP_MD_CTX_update_fn()
339 Returns the update function for I<ctx>.
343 Returns the I<md> flags. Note that these are different from the B<EVP_MD_CTX>
344 ones. See L<EVP_MD_meth_set_flags(3)> for more information.
346 =item EVP_MD_pkey_type()
348 Returns the NID of the public key signing algorithm associated with this
349 digest. For example EVP_sha1() is associated with RSA so this will return
350 B<NID_sha1WithRSAEncryption>. Since digests and signature algorithms are no
351 longer linked this function is only retained for compatibility reasons.
355 A "null" message digest that does nothing: i.e. the hash it returns is of zero
358 =item EVP_get_digestbyname(),
359 EVP_get_digestbynid(),
360 EVP_get_digestbyobj()
362 Returns an B<EVP_MD> structure when passed a digest name, a digest B<NID> or an
363 B<ASN1_OBJECT> structure respectively.
365 =item EVP_MD_CTX_pkey_ctx()
367 Returns the B<EVP_PKEY_CTX> assigned to I<ctx>. The returned pointer should not
368 be freed by the caller.
370 =item EVP_MD_CTX_set_pkey_ctx()
372 Assigns an B<EVP_PKEY_CTX> to B<EVP_MD_CTX>. This is usually used to provide
373 a customized B<EVP_PKEY_CTX> to L<EVP_DigestSignInit(3)> or
374 L<EVP_DigestVerifyInit(3)>. The I<pctx> passed to this function should be freed
375 by the caller. A NULL I<pctx> pointer is also allowed to clear the B<EVP_PKEY_CTX>
376 assigned to I<ctx>. In such case, freeing the cleared B<EVP_PKEY_CTX> or not
377 depends on how the B<EVP_PKEY_CTX> is created.
379 =item EVP_MD_do_all_provided()
381 Traverses all messages digests implemented by all activated providers
382 in the given library context I<libctx>, and for each of the implementations,
383 calls the given function I<fn> with the implementation method and the given
390 See L<OSSL_PARAM(3)> for information about passing parameters.
392 EVP_MD_CTX_set_params() can be used with the following OSSL_PARAM keys:
396 =item "xoflen" (B<OSSL_DIGEST_PARAM_XOFLEN>) <unsigned integer>
398 Sets the digest length for extendable output functions.
399 It is used by the SHAKE algorithm and should not exceed what can be given
402 =item "pad-type" (B<OSSL_DIGEST_PARAM_PAD_TYPE>) <unsigned integer>
404 Sets the padding type.
405 It is used by the MDC2 algorithm.
409 EVP_MD_CTX_get_params() can be used with the following OSSL_PARAM keys:
413 =item "micalg" (B<OSSL_PARAM_DIGEST_KEY_MICALG>) <UTF8 string>.
415 Gets the digest Message Integrity Check algorithm string. This is used when
416 creating S/MIME multipart/signed messages, as specified in RFC 3851.
417 It may be used by external engines or providers.
423 EVP_MD_CTX_ctrl() can be used to send the following standard controls:
427 =item EVP_MD_CTRL_MICALG
429 Gets the digest Message Integrity Check algorithm string. This is used when
430 creating S/MIME multipart/signed messages, as specified in RFC 3851.
431 The string value is written to I<p2>.
433 When used with a fetched B<EVP_MD>, EVP_MD_CTX_get_params() gets called with
434 an L<OSSL_PARAM(3)> item with the key "micalg" (B<OSSL_DIGEST_PARAM_MICALG>).
436 =item EVP_MD_CTRL_XOF_LEN
438 This control sets the digest length for extendable output functions to I<p1>.
439 Sending this control directly should not be necessary, the use of
440 EVP_DigestFinalXOF() is preferred.
441 Currently used by SHAKE.
443 When used with a fetched B<EVP_MD>, EVP_MD_CTX_get_params() gets called with
444 an L<OSSL_PARAM(3)> item with the key "xoflen" (B<OSSL_DIGEST_PARAM_XOFLEN>).
450 EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags() and EVP_MD_CTX_test_flags()
451 can be used the manipulate and test these B<EVP_MD_CTX> flags:
455 =item EVP_MD_CTX_FLAG_ONESHOT
457 This flag instructs the digest to optimize for one update only, if possible.
459 =for comment EVP_MD_CTX_FLAG_CLEANED is internal, don't mention it
461 =for comment EVP_MD_CTX_FLAG_REUSE is internal, don't mention it
463 =for comment We currently avoid documenting flags that are only bit holder:
464 EVP_MD_CTX_FLAG_NON_FIPS_ALLOW, EVP_MD_CTX_FLAGS_PAD_*
466 =item EVP_MD_CTX_FLAG_NO_INIT
468 This flag instructs EVP_DigestInit() and similar not to initialise the
469 implementation specific data.
471 =item EVP_MD_CTX_FLAG_FINALISE
473 Some functions such as EVP_DigestSign only finalise copies of internal
474 contexts so additional data can be included after the finalisation call.
475 This is inefficient if this functionality is not required, and can be
476 disabled with this flag.
486 Returns a pointer to a B<EVP_MD> for success or NULL for failure.
488 =item EVP_MD_up_ref()
490 Returns 1 for success or 0 for failure.
492 =item EVP_DigestInit_ex(),
497 success and 0 for failure.
499 =item EVP_MD_CTX_ctrl()
501 Returns 1 if successful or 0 for failure.
503 =item EVP_MD_CTX_set_params(),
504 EVP_MD_CTX_get_params()
506 Returns 1 if successful or 0 for failure.
508 =item EVP_MD_CTX_settable_params(),
509 EVP_MD_CTX_gettable_params()
511 Return an array of constant B<OSSL_PARAM>s, or NULL if there is none
514 =item EVP_MD_CTX_copy_ex()
516 Returns 1 if successful or 0 for failure.
521 Returns the NID of the corresponding OBJECT IDENTIFIER or NID_undef if none
527 EVP_MD_CTX_block_size()
529 Returns the digest or block size in bytes.
533 Returns a pointer to the B<EVP_MD> structure of the "null" message digest.
535 =item EVP_get_digestbyname(),
536 EVP_get_digestbynid(),
537 EVP_get_digestbyobj()
539 Returns either an B<EVP_MD> structure or NULL if an error occurs.
541 =item EVP_MD_CTX_set_pkey_ctx()
543 This function has no return value.
545 =item EVP_MD_names_do_all()
547 Returns 1 if the callback was called for all names. A return value of 0 means
548 that the callback was not called for any names.
554 The B<EVP> interface to message digests should almost always be used in
555 preference to the low-level interfaces. This is because the code then becomes
556 transparent to the digest used and much more flexible.
558 New applications should use the SHA-2 (such as L<EVP_sha256(3)>) or the SHA-3
559 digest algorithms (such as L<EVP_sha3_512(3)>). The other digest algorithms
560 are still in common use.
562 For most applications the I<impl> parameter to EVP_DigestInit_ex() will be
563 set to NULL to use the default digest implementation.
565 The functions EVP_DigestInit(), EVP_DigestFinal() and EVP_MD_CTX_copy() are
566 obsolete but are retained to maintain compatibility with existing code. New
567 applications should use EVP_DigestInit_ex(), EVP_DigestFinal_ex() and
568 EVP_MD_CTX_copy_ex() because they can efficiently reuse a digest context
569 instead of initializing and cleaning it up on each call and allow non default
570 implementations of digests to be specified.
572 If digest contexts are not cleaned up after use,
573 memory leaks will occur.
575 EVP_MD_CTX_name(), EVP_MD_CTX_size(), EVP_MD_CTX_block_size(),
576 EVP_MD_CTX_type(), EVP_get_digestbynid() and EVP_get_digestbyobj() are defined
579 EVP_MD_CTX_ctrl() sends commands to message digests for additional configuration
584 This example digests the data "Test Message\n" and "Hello World\n", using the
585 digest name passed on the command line.
589 #include <openssl/evp.h>
591 int main(int argc, char *argv[])
595 char mess1[] = "Test Message\n";
596 char mess2[] = "Hello World\n";
597 unsigned char md_value[EVP_MAX_MD_SIZE];
598 unsigned int md_len, i;
600 if (argv[1] == NULL) {
601 printf("Usage: mdtest digestname\n");
605 md = EVP_get_digestbyname(argv[1]);
607 printf("Unknown message digest %s\n", argv[1]);
611 mdctx = EVP_MD_CTX_new();
612 EVP_DigestInit_ex(mdctx, md, NULL);
613 EVP_DigestUpdate(mdctx, mess1, strlen(mess1));
614 EVP_DigestUpdate(mdctx, mess2, strlen(mess2));
615 EVP_DigestFinal_ex(mdctx, md_value, &md_len);
616 EVP_MD_CTX_free(mdctx);
618 printf("Digest is: ");
619 for (i = 0; i < md_len; i++)
620 printf("%02x", md_value[i]);
628 L<EVP_MD_meth_new(3)>,
634 The full list of digest algorithms are provided below.
636 L<EVP_blake2b512(3)>,
647 L<provider(7)/Fetching algorithms>
651 The EVP_MD_CTX_create() and EVP_MD_CTX_destroy() functions were renamed to
652 EVP_MD_CTX_new() and EVP_MD_CTX_free() in OpenSSL 1.1.0, respectively.
654 The link between digests and signing algorithms was fixed in OpenSSL 1.0 and
655 later, so now EVP_sha1() can be used with RSA and DSA.
657 The EVP_dss1() function was removed in OpenSSL 1.1.0.
659 The EVP_MD_CTX_set_pkey_ctx() function was added in OpenSSL 1.1.1.
661 The EVP_MD_fetch(), EVP_MD_free(), EVP_MD_up_ref(), EVP_MD_CTX_set_params()
662 and EVP_MD_CTX_get_params() functions were added in OpenSSL 3.0.
663 The EVP_MD_CTX_update_fn() and EVP_MD_CTX_set_update_fn() were deprecated
668 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
670 Licensed under the Apache License 2.0 (the "License"). You may not use
671 this file except in compliance with the License. You can obtain a copy
672 in the file LICENSE in the source distribution or at
673 L<https://www.openssl.org/source/license.html>.