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Commit | Line | Data |
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3cbe1980 DSH |
1 | =pod |
2 | ||
3 | =head1 NAME | |
4 | ||
2cafb1df | 5 | EVP_MD_fetch, |
ae3ff60e | 6 | EVP_MD_get_params, EVP_MD_gettable_params, |
37842dfa | 7 | EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy, |
ae3ff60e RL |
8 | EVP_MD_CTX_copy_ex, EVP_MD_CTX_ctrl, |
9 | EVP_MD_CTX_set_params, EVP_MD_CTX_get_params, | |
10 | EVP_MD_CTX_settable_params, EVP_MD_CTX_gettable_params, | |
d5e5e2ff | 11 | EVP_MD_CTX_set_flags, EVP_MD_CTX_clear_flags, EVP_MD_CTX_test_flags, |
37842dfa | 12 | EVP_Digest, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate, |
cd8d1456 | 13 | EVP_DigestFinal_ex, EVP_DigestFinalXOF, EVP_DigestFinal, |
1d2622d4 | 14 | EVP_MD_name, EVP_MD_provider, |
37842dfa | 15 | EVP_MD_type, EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_flags, |
c750bc08 | 16 | EVP_MD_CTX_name, |
37842dfa AS |
17 | EVP_MD_CTX_md, EVP_MD_CTX_type, EVP_MD_CTX_size, EVP_MD_CTX_block_size, |
18 | EVP_MD_CTX_md_data, EVP_MD_CTX_update_fn, EVP_MD_CTX_set_update_fn, | |
a9cf71a3 | 19 | EVP_md_null, |
37842dfa | 20 | EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj, |
c540f00f RL |
21 | EVP_MD_CTX_pkey_ctx, EVP_MD_CTX_set_pkey_ctx, |
22 | EVP_MD_do_all_ex | |
23 | - EVP digest routines | |
3cbe1980 DSH |
24 | |
25 | =head1 SYNOPSIS | |
26 | ||
27 | #include <openssl/evp.h> | |
28 | ||
2cafb1df RL |
29 | EVP_MD *EVP_MD_fetch(OPENSSL_CTX *ctx, const char *algorithm, |
30 | const char *properties); | |
ae3ff60e RL |
31 | int EVP_MD_get_params(const EVP_MD *digest, OSSL_PARAM params[]); |
32 | const OSSL_PARAM *EVP_MD_gettable_params(const EVP_MD *digest); | |
25191fff RL |
33 | EVP_MD_CTX *EVP_MD_CTX_new(void); |
34 | int EVP_MD_CTX_reset(EVP_MD_CTX *ctx); | |
35 | void EVP_MD_CTX_free(EVP_MD_CTX *ctx); | |
52ad5b60 | 36 | void EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void* p2); |
4e7991b4 | 37 | int EVP_MD_CTX_get_params(EVP_MD_CTX *ctx, OSSL_PARAM params[]); |
d5e5e2ff | 38 | int EVP_MD_CTX_set_params(EVP_MD_CTX *ctx, const OSSL_PARAM params[]); |
ae3ff60e RL |
39 | const OSSL_PARAM *EVP_MD_CTX_settable_params(const EVP_MD *digest); |
40 | const OSSL_PARAM *EVP_MD_CTX_gettable_params(const EVP_MD *digest); | |
a9cf71a3 RL |
41 | void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, int flags); |
42 | void EVP_MD_CTX_clear_flags(EVP_MD_CTX *ctx, int flags); | |
43 | int EVP_MD_CTX_test_flags(const EVP_MD_CTX *ctx, int flags); | |
e72d734d | 44 | |
37842dfa AS |
45 | int EVP_Digest(const void *data, size_t count, unsigned char *md, |
46 | unsigned int *size, const EVP_MD *type, ENGINE *impl); | |
e72d734d | 47 | int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); |
109d3123 | 48 | int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); |
e9b77246 | 49 | int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s); |
cd8d1456 | 50 | int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t len); |
e72d734d | 51 | |
aebb9aac | 52 | int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in); |
e72d734d DSH |
53 | |
54 | int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type); | |
e9b77246 | 55 | int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s); |
3cbe1980 | 56 | |
aebb9aac | 57 | int EVP_MD_CTX_copy(EVP_MD_CTX *out, EVP_MD_CTX *in); |
e72d734d | 58 | |
c750bc08 | 59 | const char *EVP_MD_name(const EVP_MD *md); |
1d2622d4 | 60 | const OSSL_PROVIDER *EVP_MD_provider(const EVP_MD *md); |
5a34fcd7 | 61 | int EVP_MD_type(const EVP_MD *md); |
05ea606a | 62 | int EVP_MD_pkey_type(const EVP_MD *md); |
5a34fcd7 DSH |
63 | int EVP_MD_size(const EVP_MD *md); |
64 | int EVP_MD_block_size(const EVP_MD *md); | |
37842dfa | 65 | unsigned long EVP_MD_flags(const EVP_MD *md); |
3cbe1980 | 66 | |
5a34fcd7 | 67 | const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx); |
c750bc08 | 68 | const char *EVP_MD_CTX_name(const EVP_MD_CTX *ctx); |
25191fff RL |
69 | int EVP_MD_CTX_size(const EVP_MD *ctx); |
70 | int EVP_MD_CTX_block_size(const EVP_MD *ctx); | |
71 | int EVP_MD_CTX_type(const EVP_MD *ctx); | |
a9cf71a3 | 72 | void *EVP_MD_CTX_md_data(const EVP_MD_CTX *ctx); |
37842dfa AS |
73 | int (*EVP_MD_CTX_update_fn(EVP_MD_CTX *ctx))(EVP_MD_CTX *ctx, |
74 | const void *data, size_t count); | |
75 | void EVP_MD_CTX_set_update_fn(EVP_MD_CTX *ctx, | |
76 | int (*update)(EVP_MD_CTX *ctx, | |
77 | const void *data, size_t count)); | |
3cbe1980 | 78 | |
13588350 | 79 | const EVP_MD *EVP_md_null(void); |
e4adad92 | 80 | |
3cbe1980 | 81 | const EVP_MD *EVP_get_digestbyname(const char *name); |
25191fff RL |
82 | const EVP_MD *EVP_get_digestbynid(int type); |
83 | const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *o); | |
3cbe1980 | 84 | |
37842dfa | 85 | EVP_PKEY_CTX *EVP_MD_CTX_pkey_ctx(const EVP_MD_CTX *ctx); |
675f4cee PY |
86 | void EVP_MD_CTX_set_pkey_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pctx); |
87 | ||
c540f00f RL |
88 | void EVP_MD_do_all_ex(OPENSSL_CTX *libctx, |
89 | void (*fn)(EVP_MD *mac, void *arg), | |
90 | void *arg); | |
91 | ||
3cbe1980 DSH |
92 | =head1 DESCRIPTION |
93 | ||
c7497f34 RS |
94 | The EVP digest routines are a high level interface to message digests, |
95 | and should be used instead of the cipher-specific functions. | |
3cbe1980 | 96 | |
bbda8ce9 | 97 | =over 4 |
25191fff | 98 | |
2cafb1df RL |
99 | =item EVP_MD_fetch() |
100 | ||
101 | Fetches the digest implementation for the given B<algorithm> from any | |
102 | provider offering it, within the criteria given by the B<properties>. | |
103 | See L<provider(7)/Fetching algorithms> for further information. | |
104 | ||
105 | The returned value must eventually be freed with L<EVP_MD_meth_free(3)>. | |
106 | ||
bbda8ce9 | 107 | =item EVP_MD_CTX_new() |
e72d734d | 108 | |
b45497c3 | 109 | Allocates and returns a digest context. |
e72d734d | 110 | |
bbda8ce9 | 111 | =item EVP_MD_CTX_reset() |
52ad5b60 | 112 | |
bbda8ce9 RT |
113 | Resets the digest context B<ctx>. This can be used to reuse an already |
114 | existing context. | |
3cbe1980 | 115 | |
bbda8ce9 | 116 | =item EVP_MD_CTX_free() |
3cbe1980 | 117 | |
bbda8ce9 | 118 | Cleans up digest context B<ctx> and frees up the space allocated to it. |
3cbe1980 | 119 | |
bbda8ce9 RT |
120 | =item EVP_MD_CTX_ctrl() |
121 | ||
83b4a243 | 122 | This is a legacy method. EVP_MD_CTX_set_params() and EVP_MD_CTX_get_params() |
d5e5e2ff SL |
123 | is the mechanism that should be used to set and get parameters that are used by |
124 | providers. | |
37842dfa AS |
125 | Performs digest-specific control actions on context B<ctx>. The control command |
126 | is indicated in B<cmd> and any additional arguments in B<p1> and B<p2>. | |
127 | EVP_MD_CTX_ctrl() must be called after EVP_DigestInit_ex(). Other restrictions | |
128 | may apply depending on the control type and digest implementation. | |
129 | See L</CONTROLS> below for more information. | |
bbda8ce9 | 130 | |
ae3ff60e RL |
131 | =item EVP_MD_get_params() |
132 | ||
133 | Retrieves the requested list of B<params> from a MD B<md>. | |
134 | See L</PARAMS> below for more information. | |
135 | ||
136 | =item EVP_MD_CTX_get_params() | |
d5e5e2ff SL |
137 | |
138 | Retrieves the requested list of B<params> from a MD context B<ctx>. | |
139 | See L</PARAMS> below for more information. | |
140 | ||
ae3ff60e | 141 | =item EVP_MD_CTX_set_params() |
d5e5e2ff | 142 | |
ae3ff60e | 143 | Sets the list of B<params> into a MD context B<ctx>. |
d5e5e2ff SL |
144 | See L</PARAMS> below for more information. |
145 | ||
ae3ff60e RL |
146 | =item EVP_MD_gettable_params(), EVP_MD_CTX_gettable_params(), |
147 | EVP_MD_CTX_settable_params() | |
148 | ||
149 | Get a B<OSSL_PARAM> array that describes the retrievable and settable | |
150 | parameters, i.e. parameters that can be used with EVP_MD_get_params(), | |
151 | EVP_MD_CTX_get_params() and EVP_MD_CTX_set_params(), respectively. | |
152 | See L<OSSL_PARAM(3)> for the use of B<OSSL_PARAM> as parameter descriptor. | |
153 | ||
a9cf71a3 RL |
154 | =item EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags(), EVP_MD_CTX_test_flags() |
155 | ||
156 | Sets, clears and tests B<ctx> flags. See L</FLAGS> below for more information. | |
157 | ||
37842dfa AS |
158 | =item EVP_Digest() |
159 | ||
160 | A wrapper around the Digest Init_ex, Update and Final_ex functions. | |
161 | Hashes B<count> bytes of data at B<data> using a digest B<type> from ENGINE | |
162 | B<impl>. The digest value is placed in B<md> and its length is written at B<size> | |
163 | if the pointer is not NULL. At most B<EVP_MAX_MD_SIZE> bytes will be written. | |
164 | If B<impl> is NULL the default implementation of digest B<type> is used. | |
165 | ||
bbda8ce9 RT |
166 | =item EVP_DigestInit_ex() |
167 | ||
2cafb1df RL |
168 | Sets up digest context B<ctx> to use a digest B<type>. |
169 | B<type> is typically supplied by a function such as EVP_sha1(), or a | |
170 | value explicitly fetched with EVP_MD_fetch(). | |
171 | ||
172 | If B<impl> is non-NULL, its implementation of the digest B<type> is used if | |
173 | there is one, and if not, the default implementation is used. | |
bbda8ce9 RT |
174 | |
175 | =item EVP_DigestUpdate() | |
176 | ||
177 | Hashes B<cnt> bytes of data at B<d> into the digest context B<ctx>. This | |
178 | function can be called several times on the same B<ctx> to hash additional | |
179 | data. | |
180 | ||
181 | =item EVP_DigestFinal_ex() | |
182 | ||
183 | Retrieves the digest value from B<ctx> and places it in B<md>. If the B<s> | |
184 | parameter is not NULL then the number of bytes of data written (i.e. the | |
185 | length of the digest) will be written to the integer at B<s>, at most | |
186 | B<EVP_MAX_MD_SIZE> bytes will be written. After calling EVP_DigestFinal_ex() | |
cd8d1456 | 187 | no additional calls to EVP_DigestUpdate() can be made, but |
bbda8ce9 RT |
188 | EVP_DigestInit_ex() can be called to initialize a new digest operation. |
189 | ||
190 | =item EVP_DigestFinalXOF() | |
191 | ||
192 | Interfaces to extendable-output functions, XOFs, such as SHAKE128 and SHAKE256. | |
193 | It retrieves the digest value from B<ctx> and places it in B<len>-sized <B>md. | |
194 | After calling this function no additional calls to EVP_DigestUpdate() can be | |
195 | made, but EVP_DigestInit_ex() can be called to initialize a new operation. | |
196 | ||
197 | =item EVP_MD_CTX_copy_ex() | |
198 | ||
199 | Can be used to copy the message digest state from B<in> to B<out>. This is | |
200 | useful if large amounts of data are to be hashed which only differ in the last | |
b45497c3 | 201 | few bytes. |
bbda8ce9 RT |
202 | |
203 | =item EVP_DigestInit() | |
204 | ||
b45497c3 P |
205 | Behaves in the same way as EVP_DigestInit_ex() except it always uses the |
206 | default digest implementation. | |
bbda8ce9 RT |
207 | |
208 | =item EVP_DigestFinal() | |
209 | ||
210 | Similar to EVP_DigestFinal_ex() except the digest context B<ctx> is | |
211 | automatically cleaned up. | |
212 | ||
213 | =item EVP_MD_CTX_copy() | |
cd8d1456 | 214 | |
bbda8ce9 RT |
215 | Similar to EVP_MD_CTX_copy_ex() except the destination B<out> does not have to |
216 | be initialized. | |
e72d734d | 217 | |
c750bc08 RL |
218 | =item EVP_MD_name(), |
219 | EVP_MD_CTX_name() | |
220 | ||
221 | Return the name of the given message digest. | |
222 | ||
1d2622d4 RL |
223 | =item EVP_MD_provider() |
224 | ||
225 | Returns an B<OSSL_PROVIDER> pointer to the provider that implements the given | |
226 | B<EVP_MD>. | |
227 | ||
bbda8ce9 RT |
228 | =item EVP_MD_size(), |
229 | EVP_MD_CTX_size() | |
e72d734d | 230 | |
bbda8ce9 RT |
231 | Return the size of the message digest when passed an B<EVP_MD> or an |
232 | B<EVP_MD_CTX> structure, i.e. the size of the hash. | |
e72d734d | 233 | |
bbda8ce9 RT |
234 | =item EVP_MD_block_size(), |
235 | EVP_MD_CTX_block_size() | |
3cbe1980 | 236 | |
bbda8ce9 RT |
237 | Return the block size of the message digest when passed an B<EVP_MD> or an |
238 | B<EVP_MD_CTX> structure. | |
3cbe1980 | 239 | |
bbda8ce9 RT |
240 | =item EVP_MD_type(), |
241 | EVP_MD_CTX_type() | |
3cbe1980 | 242 | |
bbda8ce9 RT |
243 | Return the NID of the OBJECT IDENTIFIER representing the given message digest |
244 | when passed an B<EVP_MD> structure. For example, C<EVP_MD_type(EVP_sha1())> | |
245 | returns B<NID_sha1>. This function is normally used when setting ASN1 OIDs. | |
3cbe1980 | 246 | |
a9cf71a3 RL |
247 | =item EVP_MD_CTX_md_data() |
248 | ||
249 | Return the digest method private data for the passed B<EVP_MD_CTX>. | |
250 | The space is allocated by OpenSSL and has the size originally set with | |
251 | EVP_MD_meth_set_app_datasize(). | |
252 | ||
bbda8ce9 | 253 | =item EVP_MD_CTX_md() |
3cbe1980 | 254 | |
b7c913c8 MC |
255 | Returns the B<EVP_MD> structure corresponding to the passed B<EVP_MD_CTX>. This |
256 | will be the same B<EVP_MD> object originally passed to EVP_DigestInit_ex() (or | |
257 | other similar function) when the EVP_MD_CTX was first initialised. Note that | |
258 | where explicit fetch is in use (see L<EVP_MD_fetch(3)>) the value returned from | |
259 | this function will not have its reference count incremented and therefore it | |
260 | should not be used after the EVP_MD_CTX is freed. | |
3cbe1980 | 261 | |
37842dfa AS |
262 | =item EVP_MD_CTX_set_update_fn() |
263 | ||
264 | Sets the update function for B<ctx> to B<update>. | |
265 | This is the function that is called by EVP_DigestUpdate. If not set, the | |
266 | update function from the B<EVP_MD> type specified at initialization is used. | |
267 | ||
268 | =item EVP_MD_CTX_update_fn() | |
269 | ||
270 | Returns the update function for B<ctx>. | |
271 | ||
272 | =item EVP_MD_flags() | |
273 | ||
274 | Returns the B<md> flags. Note that these are different from the B<EVP_MD_CTX> | |
275 | ones. See L<EVP_MD_meth_set_flags(3)> for more information. | |
276 | ||
bbda8ce9 | 277 | =item EVP_MD_pkey_type() |
3cbe1980 | 278 | |
bbda8ce9 RT |
279 | Returns the NID of the public key signing algorithm associated with this |
280 | digest. For example EVP_sha1() is associated with RSA so this will return | |
281 | B<NID_sha1WithRSAEncryption>. Since digests and signature algorithms are no | |
282 | longer linked this function is only retained for compatibility reasons. | |
3cbe1980 | 283 | |
bbda8ce9 RT |
284 | =item EVP_md_null() |
285 | ||
286 | A "null" message digest that does nothing: i.e. the hash it returns is of zero | |
287 | length. | |
288 | ||
289 | =item EVP_get_digestbyname(), | |
290 | EVP_get_digestbynid(), | |
291 | EVP_get_digestbyobj() | |
292 | ||
293 | Returns an B<EVP_MD> structure when passed a digest name, a digest B<NID> or an | |
294 | B<ASN1_OBJECT> structure respectively. | |
295 | ||
37842dfa AS |
296 | =item EVP_MD_CTX_pkey_ctx() |
297 | ||
298 | Returns the B<EVP_PKEY_CTX> assigned to B<ctx>. The returned pointer should not | |
299 | be freed by the caller. | |
300 | ||
675f4cee PY |
301 | =item EVP_MD_CTX_set_pkey_ctx() |
302 | ||
303 | Assigns an B<EVP_PKEY_CTX> to B<EVP_MD_CTX>. This is usually used to provide | |
37842dfa | 304 | a customized B<EVP_PKEY_CTX> to L<EVP_DigestSignInit(3)> or |
81c79453 | 305 | L<EVP_DigestVerifyInit(3)>. The B<pctx> passed to this function should be freed |
f922dac8 | 306 | by the caller. A NULL B<pctx> pointer is also allowed to clear the B<EVP_PKEY_CTX> |
81c79453 PY |
307 | assigned to B<ctx>. In such case, freeing the cleared B<EVP_PKEY_CTX> or not |
308 | depends on how the B<EVP_PKEY_CTX> is created. | |
675f4cee | 309 | |
c540f00f RL |
310 | =item EVP_MD_do_all_ex() |
311 | ||
312 | Traverses all messages digests implemented by all activated providers | |
313 | in the given library context I<libctx>, and for each of the implementations, | |
314 | calls the given function I<fn> with the implementation method and the given | |
315 | I<arg> as argument. | |
316 | ||
bbda8ce9 | 317 | =back |
3cbe1980 | 318 | |
d5e5e2ff SL |
319 | =head1 PARAMS |
320 | ||
321 | See L<OSSL_PARAM(3)> for information about passing parameters. | |
322 | ||
323 | EVP_MD_CTX_set_params() can be used with the following OSSL_PARAM keys: | |
324 | ||
325 | =over 4 | |
326 | ||
327 | =item OSSL_PARAM_DIGEST_KEY_XOFLEN <size_t> | |
328 | ||
329 | Sets the digest length for extendable output functions. | |
330 | It is used by the SHAKE algorithm. | |
331 | ||
332 | =item OSSL_PARAM_DIGEST_KEY_PAD_TYPE <int> | |
333 | ||
334 | Sets the pad type. | |
335 | It is used by the MDC2 algorithm. | |
336 | ||
337 | =back | |
338 | ||
339 | EVP_MD_CTX_get_params() can be used with the following OSSL_PARAM keys: | |
340 | ||
341 | =over 4 | |
342 | ||
343 | =item OSSL_PARAM_DIGEST_KEY_MICALG <utf8string>. | |
344 | ||
345 | Gets the digest Message Integrity Check algorithm string. This is used when | |
346 | creating S/MIME multipart/signed messages, as specified in RFC 3851. | |
347 | It may be used by external engines or providers. | |
348 | ||
349 | =back | |
350 | ||
37842dfa AS |
351 | =head1 CONTROLS |
352 | ||
353 | EVP_MD_CTX_ctrl() can be used to send the following standard controls: | |
354 | ||
355 | =over 4 | |
356 | ||
357 | =item EVP_MD_CTRL_MICALG | |
358 | ||
359 | Gets the digest Message Integrity Check algorithm string. This is used when | |
360 | creating S/MIME multipart/signed messages, as specified in RFC 3851. | |
361 | The string value is written to B<p2>. | |
362 | ||
363 | =item EVP_MD_CTRL_XOF_LEN | |
364 | ||
365 | This control sets the digest length for extendable output functions to B<p1>. | |
366 | Sending this control directly should not be necessary, the use of | |
367 | C<EVP_DigestFinalXOF()> is preferred. | |
368 | Currently used by SHAKE. | |
369 | ||
370 | =back | |
371 | ||
a9cf71a3 RL |
372 | =head1 FLAGS |
373 | ||
374 | EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags() and EVP_MD_CTX_test_flags() | |
375 | can be used the manipulate and test these B<EVP_MD_CTX> flags: | |
376 | ||
377 | =over 4 | |
378 | ||
379 | =item EVP_MD_CTX_FLAG_ONESHOT | |
380 | ||
381 | This flag instructs the digest to optimize for one update only, if possible. | |
382 | ||
383 | =for comment EVP_MD_CTX_FLAG_CLEANED is internal, don't mention it | |
384 | ||
385 | =for comment EVP_MD_CTX_FLAG_REUSE is internal, don't mention it | |
386 | ||
387 | =for comment We currently avoid documenting flags that are only bit holder: | |
388 | EVP_MD_CTX_FLAG_NON_FIPS_ALLOW, EVP_MD_CTX_FLAGS_PAD_* | |
389 | ||
390 | =item EVP_MD_CTX_FLAG_NO_INIT | |
391 | ||
392 | This flag instructs EVP_DigestInit() and similar not to initialise the | |
393 | implementation specific data. | |
394 | ||
395 | =item EVP_MD_CTX_FLAG_FINALISE | |
396 | ||
397 | Some functions such as EVP_DigestSign only finalise copies of internal | |
398 | contexts so additional data can be included after the finalisation call. | |
399 | This is inefficient if this functionality is not required, and can be | |
400 | disabled with this flag. | |
401 | ||
402 | =back | |
403 | ||
3cbe1980 DSH |
404 | =head1 RETURN VALUES |
405 | ||
bbda8ce9 RT |
406 | =over 4 |
407 | ||
2cafb1df RL |
408 | =item EVP_MD_fetch() |
409 | ||
410 | Returns a pointer to a B<EVP_MD> for success or NULL for failure. | |
411 | ||
bbda8ce9 RT |
412 | =item EVP_DigestInit_ex(), |
413 | EVP_DigestUpdate(), | |
414 | EVP_DigestFinal_ex() | |
415 | ||
416 | Returns 1 for | |
13588350 | 417 | success and 0 for failure. |
3cbe1980 | 418 | |
bbda8ce9 RT |
419 | =item EVP_MD_CTX_ctrl() |
420 | ||
421 | Returns 1 if successful or 0 for failure. | |
422 | ||
d5e5e2ff SL |
423 | =item EVP_MD_CTX_set_params(), |
424 | EVP_MD_CTX_get_params() | |
425 | ||
426 | Returns 1 if successful or 0 for failure. | |
427 | ||
ae3ff60e RL |
428 | =item EVP_MD_CTX_settable_params(), |
429 | EVP_MD_CTX_gettable_params() | |
430 | ||
431 | Return an array of constant B<OSSL_PARAM>s, or NULL if there is none | |
432 | to get. | |
433 | ||
bbda8ce9 | 434 | =item EVP_MD_CTX_copy_ex() |
52ad5b60 | 435 | |
bbda8ce9 | 436 | Returns 1 if successful or 0 for failure. |
3cbe1980 | 437 | |
bbda8ce9 | 438 | =item EVP_MD_type(), |
37842dfa | 439 | EVP_MD_pkey_type() |
3cbe1980 | 440 | |
bbda8ce9 RT |
441 | Returns the NID of the corresponding OBJECT IDENTIFIER or NID_undef if none |
442 | exists. | |
3cbe1980 | 443 | |
bbda8ce9 RT |
444 | =item EVP_MD_size(), |
445 | EVP_MD_block_size(), | |
446 | EVP_MD_CTX_size(), | |
447 | EVP_MD_CTX_block_size() | |
3cbe1980 | 448 | |
bbda8ce9 RT |
449 | Returns the digest or block size in bytes. |
450 | ||
451 | =item EVP_md_null() | |
452 | ||
453 | Returns a pointer to the B<EVP_MD> structure of the "null" message digest. | |
454 | ||
455 | =item EVP_get_digestbyname(), | |
456 | EVP_get_digestbynid(), | |
457 | EVP_get_digestbyobj() | |
458 | ||
459 | Returns either an B<EVP_MD> structure or NULL if an error occurs. | |
460 | ||
675f4cee PY |
461 | =item EVP_MD_CTX_set_pkey_ctx() |
462 | ||
463 | This function has no return value. | |
464 | ||
bbda8ce9 | 465 | =back |
3cbe1980 DSH |
466 | |
467 | =head1 NOTES | |
468 | ||
469 | The B<EVP> interface to message digests should almost always be used in | |
470 | preference to the low level interfaces. This is because the code then becomes | |
471 | transparent to the digest used and much more flexible. | |
472 | ||
bbda8ce9 | 473 | New applications should use the SHA-2 (such as L<EVP_sha256(3)>) or the SHA-3 |
89f66fe2 | 474 | digest algorithms (such as L<EVP_sha3_512(3)>). The other digest algorithms |
475 | are still in common use. | |
3cbe1980 | 476 | |
e72d734d DSH |
477 | For most applications the B<impl> parameter to EVP_DigestInit_ex() will be |
478 | set to NULL to use the default digest implementation. | |
479 | ||
7b3e11c5 | 480 | The functions EVP_DigestInit(), EVP_DigestFinal() and EVP_MD_CTX_copy() are |
e72d734d | 481 | obsolete but are retained to maintain compatibility with existing code. New |
7b3e11c5 | 482 | applications should use EVP_DigestInit_ex(), EVP_DigestFinal_ex() and |
e72d734d DSH |
483 | EVP_MD_CTX_copy_ex() because they can efficiently reuse a digest context |
484 | instead of initializing and cleaning it up on each call and allow non default | |
485 | implementations of digests to be specified. | |
486 | ||
fa332bba | 487 | If digest contexts are not cleaned up after use, |
7b3e11c5 | 488 | memory leaks will occur. |
13588350 | 489 | |
c750bc08 RL |
490 | EVP_MD_CTX_name(), EVP_MD_CTX_size(), EVP_MD_CTX_block_size(), |
491 | EVP_MD_CTX_type(), EVP_get_digestbynid() and EVP_get_digestbyobj() are defined | |
492 | as macros. | |
5a34fcd7 | 493 | |
52ad5b60 TS |
494 | EVP_MD_CTX_ctrl() sends commands to message digests for additional configuration |
495 | or control. | |
5a34fcd7 | 496 | |
3cbe1980 DSH |
497 | =head1 EXAMPLE |
498 | ||
499 | This example digests the data "Test Message\n" and "Hello World\n", using the | |
500 | digest name passed on the command line. | |
501 | ||
502 | #include <stdio.h> | |
19ac1bf2 | 503 | #include <string.h> |
3cbe1980 DSH |
504 | #include <openssl/evp.h> |
505 | ||
19ac1bf2 | 506 | int main(int argc, char *argv[]) |
3cbe1980 | 507 | { |
2947af32 BB |
508 | EVP_MD_CTX *mdctx; |
509 | const EVP_MD *md; | |
510 | char mess1[] = "Test Message\n"; | |
511 | char mess2[] = "Hello World\n"; | |
512 | unsigned char md_value[EVP_MAX_MD_SIZE]; | |
19ac1bf2 | 513 | unsigned int md_len, i; |
2947af32 BB |
514 | |
515 | if (argv[1] == NULL) { | |
516 | printf("Usage: mdtest digestname\n"); | |
517 | exit(1); | |
518 | } | |
519 | ||
520 | md = EVP_get_digestbyname(argv[1]); | |
521 | if (md == NULL) { | |
522 | printf("Unknown message digest %s\n", argv[1]); | |
523 | exit(1); | |
524 | } | |
525 | ||
526 | mdctx = EVP_MD_CTX_new(); | |
527 | EVP_DigestInit_ex(mdctx, md, NULL); | |
528 | EVP_DigestUpdate(mdctx, mess1, strlen(mess1)); | |
529 | EVP_DigestUpdate(mdctx, mess2, strlen(mess2)); | |
530 | EVP_DigestFinal_ex(mdctx, md_value, &md_len); | |
531 | EVP_MD_CTX_free(mdctx); | |
532 | ||
533 | printf("Digest is: "); | |
534 | for (i = 0; i < md_len; i++) | |
535 | printf("%02x", md_value[i]); | |
536 | printf("\n"); | |
537 | ||
538 | exit(0); | |
3cbe1980 DSH |
539 | } |
540 | ||
3cbe1980 DSH |
541 | =head1 SEE ALSO |
542 | ||
37842dfa | 543 | L<EVP_MD_meth_new(3)>, |
9b86974e | 544 | L<dgst(1)>, |
d5e5e2ff SL |
545 | L<evp(7)>, |
546 | L<OSSL_PROVIDER(3)>, | |
547 | L<OSSL_PARAM(3)> | |
4facdbb5 | 548 | |
bbda8ce9 RT |
549 | The full list of digest algorithms are provided below. |
550 | ||
551 | L<EVP_blake2b512(3)>, | |
552 | L<EVP_md2(3)>, | |
553 | L<EVP_md4(3)>, | |
554 | L<EVP_md5(3)>, | |
555 | L<EVP_mdc2(3)>, | |
556 | L<EVP_ripemd160(3)>, | |
557 | L<EVP_sha1(3)>, | |
558 | L<EVP_sha224(3)>, | |
559 | L<EVP_sha3_224(3)>, | |
67e247fa | 560 | L<EVP_sm3(3)>, |
bbda8ce9 | 561 | L<EVP_whirlpool(3)> |
2cafb1df | 562 | L<provider(7)/Fetching algorithms> |
bbda8ce9 | 563 | |
3cbe1980 DSH |
564 | =head1 HISTORY |
565 | ||
fc5ecadd DMSP |
566 | The EVP_MD_CTX_create() and EVP_MD_CTX_destroy() functions were renamed to |
567 | EVP_MD_CTX_new() and EVP_MD_CTX_free() in OpenSSL 1.1.0, respectively. | |
25191fff | 568 | |
3fa39ed7 | 569 | The link between digests and signing algorithms was fixed in OpenSSL 1.0 and |
a95d7574 RS |
570 | later, so now EVP_sha1() can be used with RSA and DSA. |
571 | ||
fc5ecadd | 572 | The EVP_dss1() function was removed in OpenSSL 1.1.0. |
3fa39ed7 | 573 | |
fc5ecadd | 574 | The EVP_MD_CTX_set_pkey_ctx() function was added in 1.1.1. |
675f4cee | 575 | |
d5e5e2ff SL |
576 | The EVP_MD_CTX_set_params() and EVP_MD_CTX_get_params() functions were |
577 | added in 3.0. | |
578 | ||
e2f92610 RS |
579 | =head1 COPYRIGHT |
580 | ||
d5e5e2ff | 581 | Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved. |
e2f92610 | 582 | |
4746f25a | 583 | Licensed under the Apache License 2.0 (the "License"). You may not use |
e2f92610 RS |
584 | this file except in compliance with the License. You can obtain a copy |
585 | in the file LICENSE in the source distribution or at | |
586 | L<https://www.openssl.org/source/license.html>. | |
587 | ||
588 | =cut |