7 EVP_PKEY_CTX_ctrl_uint64,
9 EVP_PKEY_CTX_set_signature_md,
10 EVP_PKEY_CTX_get_signature_md,
11 EVP_PKEY_CTX_set_mac_key,
12 EVP_PKEY_CTX_set_group_name,
13 EVP_PKEY_CTX_get_group_name,
14 EVP_PKEY_CTX_set_rsa_padding,
15 EVP_PKEY_CTX_get_rsa_padding,
16 EVP_PKEY_CTX_set_rsa_pss_saltlen,
17 EVP_PKEY_CTX_get_rsa_pss_saltlen,
18 EVP_PKEY_CTX_set_rsa_keygen_bits,
19 EVP_PKEY_CTX_set_rsa_keygen_pubexp,
20 EVP_PKEY_CTX_set_rsa_keygen_primes,
21 EVP_PKEY_CTX_set_rsa_mgf1_md_name,
22 EVP_PKEY_CTX_set_rsa_mgf1_md,
23 EVP_PKEY_CTX_get_rsa_mgf1_md,
24 EVP_PKEY_CTX_get_rsa_mgf1_md_name,
25 EVP_PKEY_CTX_set_rsa_oaep_md_name,
26 EVP_PKEY_CTX_set_rsa_oaep_md,
27 EVP_PKEY_CTX_get_rsa_oaep_md,
28 EVP_PKEY_CTX_get_rsa_oaep_md_name,
29 EVP_PKEY_CTX_set0_rsa_oaep_label,
30 EVP_PKEY_CTX_get0_rsa_oaep_label,
31 EVP_PKEY_CTX_set_dsa_paramgen_bits,
32 EVP_PKEY_CTX_set_dsa_paramgen_q_bits,
33 EVP_PKEY_CTX_set_dsa_paramgen_md,
34 EVP_PKEY_CTX_set_dsa_paramgen_md_props,
35 EVP_PKEY_CTX_set_dsa_paramgen_gindex,
36 EVP_PKEY_CTX_set_dsa_paramgen_type,
37 EVP_PKEY_CTX_set_dsa_paramgen_seed,
38 EVP_PKEY_CTX_set_dh_paramgen_prime_len,
39 EVP_PKEY_CTX_set_dh_paramgen_subprime_len,
40 EVP_PKEY_CTX_set_dh_paramgen_generator,
41 EVP_PKEY_CTX_set_dh_paramgen_type,
42 EVP_PKEY_CTX_set_dh_paramgen_gindex,
43 EVP_PKEY_CTX_set_dh_paramgen_seed,
44 EVP_PKEY_CTX_set_dh_rfc5114,
45 EVP_PKEY_CTX_set_dhx_rfc5114,
46 EVP_PKEY_CTX_set_dh_pad,
47 EVP_PKEY_CTX_set_dh_nid,
48 EVP_PKEY_CTX_set_dh_kdf_type,
49 EVP_PKEY_CTX_get_dh_kdf_type,
50 EVP_PKEY_CTX_set0_dh_kdf_oid,
51 EVP_PKEY_CTX_get0_dh_kdf_oid,
52 EVP_PKEY_CTX_set_dh_kdf_md,
53 EVP_PKEY_CTX_get_dh_kdf_md,
54 EVP_PKEY_CTX_set_dh_kdf_outlen,
55 EVP_PKEY_CTX_get_dh_kdf_outlen,
56 EVP_PKEY_CTX_set0_dh_kdf_ukm,
57 EVP_PKEY_CTX_get0_dh_kdf_ukm,
58 EVP_PKEY_CTX_set_ec_paramgen_curve_nid,
59 EVP_PKEY_CTX_set_ec_param_enc,
60 EVP_PKEY_CTX_set_ecdh_cofactor_mode,
61 EVP_PKEY_CTX_get_ecdh_cofactor_mode,
62 EVP_PKEY_CTX_set_ecdh_kdf_type,
63 EVP_PKEY_CTX_get_ecdh_kdf_type,
64 EVP_PKEY_CTX_set_ecdh_kdf_md,
65 EVP_PKEY_CTX_get_ecdh_kdf_md,
66 EVP_PKEY_CTX_set_ecdh_kdf_outlen,
67 EVP_PKEY_CTX_get_ecdh_kdf_outlen,
68 EVP_PKEY_CTX_set0_ecdh_kdf_ukm,
69 EVP_PKEY_CTX_get0_ecdh_kdf_ukm,
70 EVP_PKEY_CTX_set1_id, EVP_PKEY_CTX_get1_id, EVP_PKEY_CTX_get1_id_len
71 - algorithm specific control operations
75 #include <openssl/evp.h>
77 int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
78 int cmd, int p1, void *p2);
79 int EVP_PKEY_CTX_ctrl_uint64(EVP_PKEY_CTX *ctx, int keytype, int optype,
80 int cmd, uint64_t value);
81 int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
84 int EVP_PKEY_CTX_md(EVP_PKEY_CTX *ctx, int optype, int cmd, const char *md);
86 int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
87 int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd);
89 int EVP_PKEY_CTX_set_mac_key(EVP_PKEY_CTX *ctx, const unsigned char *key,
91 int EVP_PKEY_CTX_set_group_name(EVP_PKEY_CTX *ctx, const char *name);
92 int EVP_PKEY_CTX_get_group_name(EVP_PKEY_CTX *ctx, char *name, size_t namelen);
94 #include <openssl/rsa.h>
96 int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int pad);
97 int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx, int *pad);
98 int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int saltlen);
99 int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int *saltlen);
100 int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx, int mbits);
101 int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
102 int EVP_PKEY_CTX_set_rsa_keygen_primes(EVP_PKEY_CTX *ctx, int primes);
103 int EVP_PKEY_CTX_set_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
104 const char *mdprops);
105 int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
106 int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
107 int EVP_PKEY_CTX_get_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, char *name,
109 int EVP_PKEY_CTX_set_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
110 const char *mdprops);
111 int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
112 int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
113 int EVP_PKEY_CTX_get_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, char *name,
115 int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char *label,
117 int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char **label);
119 #include <openssl/dsa.h>
121 int EVP_PKEY_CTX_set_dsa_paramgen_bits(EVP_PKEY_CTX *ctx, int nbits);
122 int EVP_PKEY_CTX_set_dsa_paramgen_q_bits(EVP_PKEY_CTX *ctx, int qbits);
123 int EVP_PKEY_CTX_set_dsa_paramgen_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
124 int EVP_PKEY_CTX_set_dsa_paramgen_md_props(EVP_PKEY_CTX *ctx,
126 const char *md_properties);
127 int EVP_PKEY_CTX_set_dsa_paramgen_type(EVP_PKEY_CTX *ctx, const char *name);
128 int EVP_PKEY_CTX_set_dsa_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
129 int EVP_PKEY_CTX_set_dsa_paramgen_seed(EVP_PKEY_CTX *ctx,
130 const unsigned char *seed,
133 #include <openssl/dh.h>
135 int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int len);
136 int EVP_PKEY_CTX_set_dh_paramgen_subprime_len(EVP_PKEY_CTX *ctx, int len);
137 int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);
138 int EVP_PKEY_CTX_set_dh_paramgen_type(EVP_PKEY_CTX *ctx, int type);
139 int EVP_PKEY_CTX_set_dh_pad(EVP_PKEY_CTX *ctx, int pad);
140 int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid);
141 int EVP_PKEY_CTX_set_dh_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
142 int EVP_PKEY_CTX_set_dhx_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
143 int EVP_PKEY_CTX_set_dh_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
144 int EVP_PKEY_CTX_set_dh_paramgen_seed(EVP_PKEY_CTX *ctx,
145 const unsigned char *seed,
147 int EVP_PKEY_CTX_set_dh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
148 int EVP_PKEY_CTX_get_dh_kdf_type(EVP_PKEY_CTX *ctx);
149 int EVP_PKEY_CTX_set0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT *oid);
150 int EVP_PKEY_CTX_get0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT **oid);
151 int EVP_PKEY_CTX_set_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
152 int EVP_PKEY_CTX_get_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
153 int EVP_PKEY_CTX_set_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
154 int EVP_PKEY_CTX_get_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
155 int EVP_PKEY_CTX_set0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
156 int EVP_PKEY_CTX_get0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
158 #include <openssl/ec.h>
160 int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid);
161 int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc);
162 int EVP_PKEY_CTX_set_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx, int cofactor_mode);
163 int EVP_PKEY_CTX_get_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx);
164 int EVP_PKEY_CTX_set_ecdh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
165 int EVP_PKEY_CTX_get_ecdh_kdf_type(EVP_PKEY_CTX *ctx);
166 int EVP_PKEY_CTX_set_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
167 int EVP_PKEY_CTX_get_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
168 int EVP_PKEY_CTX_set_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
169 int EVP_PKEY_CTX_get_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
170 int EVP_PKEY_CTX_set0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
171 int EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
173 int EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len);
174 int EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id);
175 int EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *id_len);
179 EVP_PKEY_CTX_ctrl() sends a control operation to the context I<ctx>. The key
180 type used must match I<keytype> if it is not -1. The parameter I<optype> is a
181 mask indicating which operations the control can be applied to.
182 The control command is indicated in I<cmd> and any additional arguments in
185 For I<cmd> = B<EVP_PKEY_CTRL_SET_MAC_KEY>, I<p1> is the length of the MAC key,
186 and I<p2> is the MAC key. This is used by Poly1305, SipHash, HMAC and CMAC.
188 Applications will not normally call EVP_PKEY_CTX_ctrl() directly but will
189 instead call one of the algorithm specific functions below.
191 EVP_PKEY_CTX_ctrl_uint64() is a wrapper that directly passes a
192 uint64 value as I<p2> to EVP_PKEY_CTX_ctrl().
194 EVP_PKEY_CTX_ctrl_str() allows an application to send an algorithm
195 specific control operation to a context I<ctx> in string form. This is
196 intended to be used for options specified on the command line or in text
197 files. The commands supported are documented in the openssl utility
198 command line pages for the option I<-pkeyopt> which is supported by the
199 I<pkeyutl>, I<genpkey> and I<req> commands.
201 EVP_PKEY_CTX_md() sends a message digest control operation to the context
202 I<ctx>. The message digest is specified by its name I<md>.
204 EVP_PKEY_CTX_set_signature_md() sets the message digest type used
205 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
207 EVP_PKEY_CTX_get_signature_md()gets the message digest type used
208 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
210 Key generation typically involves setting up parameters to be used and
211 generating the private and public key data. Some algorithm implementations
212 allow private key data to be set explicitly using EVP_PKEY_CTX_set_mac_key().
213 In this case key generation is simply the process of setting up the
214 parameters for the key and then setting the raw key data to the value explicitly.
215 Normally applications would call L<EVP_PKEY_new_raw_private_key(3)> or similar
218 EVP_PKEY_CTX_set_mac_key() can be used with any of the algorithms supported by
219 the L<EVP_PKEY_new_raw_private_key(3)> function.
221 EVP_PKEY_CTX_set_group_name() sets the group name to I<name> for parameter and
222 key generation. For example for EC keys this will set the curve name and for
223 DH keys it will set the name of the finite field group.
225 EVP_PKEY_CTX_get_group_name() finds the group name that's currently
226 set with I<ctx>, and writes it to the location that I<name> points at, as long
227 as its size I<namelen> is large enough to store that name, including a
228 terminating NUL byte.
230 =head2 RSA parameters
232 EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding mode for I<ctx>.
233 The I<pad> parameter can take the value B<RSA_PKCS1_PADDING> for PKCS#1
234 padding, B<RSA_SSLV23_PADDING> for SSLv23 padding, B<RSA_NO_PADDING> for
235 no padding, B<RSA_PKCS1_OAEP_PADDING> for OAEP padding (encrypt and
236 decrypt only), B<RSA_X931_PADDING> for X9.31 padding (signature operations
237 only), B<RSA_PKCS1_PSS_PADDING> (sign and verify only) and
238 B<RSA_PKCS1_WITH_TLS_PADDING> for TLS RSA ClientKeyExchange message padding
241 Two RSA padding modes behave differently if EVP_PKEY_CTX_set_signature_md()
242 is used. If this function is called for PKCS#1 padding the plaintext buffer is
243 an actual digest value and is encapsulated in a DigestInfo structure according
244 to PKCS#1 when signing and this structure is expected (and stripped off) when
245 verifying. If this control is not used with RSA and PKCS#1 padding then the
246 supplied data is used directly and not encapsulated. In the case of X9.31
247 padding for RSA the algorithm identifier byte is added or checked and removed
248 if this control is called. If it is not called then the first byte of the plaintext
249 buffer is expected to be the algorithm identifier byte.
251 EVP_PKEY_CTX_get_rsa_padding() gets the RSA padding mode for I<ctx>.
253 EVP_PKEY_CTX_set_rsa_pss_saltlen() sets the RSA PSS salt length to I<saltlen>.
254 As its name implies it is only supported for PSS padding. If this function is
255 not called then the maximum salt length is used when signing and auto detection
256 when verifying. Three special values are supported:
260 =item B<RSA_PSS_SALTLEN_DIGEST>
262 sets the salt length to the digest length.
264 =item B<RSA_PSS_SALTLEN_MAX>
266 sets the salt length to the maximum permissible value.
268 =item B<RSA_PSS_SALTLEN_AUTO>
270 causes the salt length to be automatically determined based on the
271 B<PSS> block structure when verifying. When signing, it has the same
272 meaning as B<RSA_PSS_SALTLEN_MAX>.
276 EVP_PKEY_CTX_get_rsa_pss_saltlen() gets the RSA PSS salt length for I<ctx>.
277 The padding mode must already have been set to B<RSA_PKCS1_PSS_PADDING>.
279 EVP_PKEY_CTX_set_rsa_keygen_bits() sets the RSA key length for
280 RSA key generation to I<bits>. If not specified 2048 bits is used.
282 EVP_PKEY_CTX_set_rsa_keygen_pubexp() sets the public exponent value for RSA key
283 generation to I<pubexp>. Currently it should be an odd integer. The
284 I<pubexp> pointer is used internally by this function so it should not be
285 modified or freed after the call. If not specified 65537 is used.
287 EVP_PKEY_CTX_set_rsa_keygen_primes() sets the number of primes for
288 RSA key generation to I<primes>. If not specified 2 is used.
290 EVP_PKEY_CTX_set_rsa_mgf1_md_name() sets the MGF1 digest for RSA
291 padding schemes to the digest named I<mdname>. If the RSA algorithm
292 implementation for the selected provider supports it then the digest will be
293 fetched using the properties I<mdprops>. If not explicitly set the signing
294 digest is used. The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>
295 or B<RSA_PKCS1_PSS_PADDING>.
297 EVP_PKEY_CTX_set_rsa_mgf1_md() does the same as
298 EVP_PKEY_CTX_set_rsa_mgf1_md_name() except that the name of the digest is
299 inferred from the supplied I<md> and it is not possible to specify any
302 EVP_PKEY_CTX_get_rsa_mgf1_md_name() gets the name of the MGF1
303 digest algorithm for I<ctx>. If not explicitly set the signing digest is used.
304 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING> or
305 B<RSA_PKCS1_PSS_PADDING>.
307 EVP_PKEY_CTX_get_rsa_mgf1_md() does the same as
308 EVP_PKEY_CTX_get_rsa_mgf1_md_name() except that it returns a pointer to an
309 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
310 returned. The EVP_MD object may be NULL if the digest is not one of these (such
311 as a digest only implemented in a third party provider).
313 EVP_PKEY_CTX_set_rsa_oaep_md_name() sets the message digest type
314 used in RSA OAEP to the digest named I<mdname>. If the RSA algorithm
315 implementation for the selected provider supports it then the digest will be
316 fetched using the properties I<mdprops>. The padding mode must have been set to
317 B<RSA_PKCS1_OAEP_PADDING>.
319 EVP_PKEY_CTX_set_rsa_oaep_md() does the same as
320 EVP_PKEY_CTX_set_rsa_oaep_md_name() except that the name of the digest is
321 inferred from the supplied I<md> and it is not possible to specify any
324 EVP_PKEY_CTX_get_rsa_oaep_md_name() gets the message digest
325 algorithm name used in RSA OAEP and stores it in the buffer I<name> which is of
326 size I<namelen>. The padding mode must have been set to
327 B<RSA_PKCS1_OAEP_PADDING>. The buffer should be sufficiently large for any
328 expected digest algorithm names or the function will fail.
330 EVP_PKEY_CTX_get_rsa_oaep_md() does the same as
331 EVP_PKEY_CTX_get_rsa_oaep_md_name() except that it returns a pointer to an
332 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
333 returned. The EVP_MD object may be NULL if the digest is not one of these (such
334 as a digest only implemented in a third party provider).
336 EVP_PKEY_CTX_set0_rsa_oaep_label() sets the RSA OAEP label to
337 I<label> and its length to I<len>. If I<label> is NULL or I<len> is 0,
338 the label is cleared. The library takes ownership of the label so the
339 caller should not free the original memory pointed to by I<label>.
340 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>.
342 EVP_PKEY_CTX_get0_rsa_oaep_label() gets the RSA OAEP label to
343 I<label>. The return value is the label length. The padding mode
344 must have been set to B<RSA_PKCS1_OAEP_PADDING>. The resulting pointer is owned
345 by the library and should not be freed by the caller.
347 B<RSA_PKCS1_WITH_TLS_PADDING> is used when decrypting an RSA encrypted TLS
348 pre-master secret in a TLS ClientKeyExchange message. It is the same as
349 RSA_PKCS1_PADDING except that it additionally verifies that the result is the
350 correct length and the first two bytes are the protocol version initially
351 requested by the client. If the encrypted content is publicly invalid then the
352 decryption will fail. However, if the padding checks fail then decryption will
353 still appear to succeed but a random TLS premaster secret will be returned
354 instead. This padding mode accepts two parameters which can be set using the
355 L<EVP_PKEY_CTX_set_params(3)> function. These are
356 OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION and
357 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, both of which are expected to be
358 unsigned integers. Normally only the first of these will be set and represents
359 the TLS protocol version that was first requested by the client (e.g. 0x0303 for
360 TLSv1.2, 0x0302 for TLSv1.1 etc). Historically some buggy clients would use the
361 negotiated protocol version instead of the protocol version first requested. If
362 this behaviour should be tolerated then
363 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION should be set to the actual
364 negotiated protocol version. Otherwise it should be left unset.
366 =head2 DSA parameters
368 EVP_PKEY_CTX_set_dsa_paramgen_bits() sets the number of bits used for DSA
369 parameter generation to B<nbits>. If not specified, 2048 is used.
371 EVP_PKEY_CTX_set_dsa_paramgen_q_bits() sets the number of bits in the subprime
372 parameter I<q> for DSA parameter generation to I<qbits>. If not specified, 224
373 is used. If a digest function is specified below, this parameter is ignored and
374 instead, the number of bits in I<q> matches the size of the digest.
376 EVP_PKEY_CTX_set_dsa_paramgen_md() sets the digest function used for DSA
377 parameter generation to I<md>. If not specified, one of SHA-1, SHA-224, or
378 SHA-256 is selected to match the bit length of I<q> above.
380 EVP_PKEY_CTX_set_dsa_paramgen_md_props() sets the digest function used for DSA
381 parameter generation using I<md_name> and I<md_properties> to retrieve the
382 digest from a provider.
383 If not specified, I<md_name> will be set to one of SHA-1, SHA-224, or
384 SHA-256 depending on the bit length of I<q> above. I<md_properties> is a
385 property query string that has a default value of '' if not specified.
387 EVP_PKEY_CTX_set_dsa_paramgen_gindex() sets the I<gindex> used by the generator
388 G. The default value is -1 which uses unverifiable g, otherwise a positive value
389 uses verifiable g. This value must be saved if key validation of g is required,
390 since it is not part of a persisted key.
392 EVP_PKEY_CTX_set_dsa_paramgen_seed() sets the I<seed> to use for generation
393 rather than using a randomly generated value for the seed. This is useful for
394 testing purposes only and can fail if the seed does not produce primes for both
395 p & q on its first iteration. This value must be saved if key validation of
396 p, q, and verifiable g are required, since it is not part of a persisted key.
398 EVP_PKEY_CTX_set_dsa_paramgen_type() sets the generation type to use FIPS186-4
399 generation if I<name> is "fips186_4", or FIPS186-2 generation if I<name> is
400 "fips186_2". The default value is "fips186_4".
404 EVP_PKEY_CTX_set_dh_paramgen_prime_len() sets the length of the DH prime
405 parameter I<p> for DH parameter generation. If this function is not called then
406 2048 is used. Only accepts lengths greater than or equal to 256.
408 EVP_PKEY_CTX_set_dh_paramgen_subprime_len() sets the length of the DH
409 optional subprime parameter I<q> for DH parameter generation. The default is
410 256 if the prime is at least 2048 bits long or 160 otherwise. The DH paramgen
411 type must have been set to "fips186_4".
413 EVP_PKEY_CTX_set_dh_paramgen_generator() sets DH generator to I<gen> for DH
414 parameter generation. If not specified 2 is used.
416 EVP_PKEY_CTX_set_dh_paramgen_type() sets the key type for DH parameter
417 generation. The supported parameters are:
421 =item B<DH_PARAMGEN_TYPE_GROUP>
423 Use a named group. If only the safe prime parameter I<p> is set this can be
424 used to select a ffdhe safe prime group of the correct size.
426 =item B<DH_PARAMGEN_TYPE_FIPS_186_4>
428 FIPS186-4 FFC parameter generator.
430 =item B<DH_PARAMGEN_TYPE_FIPS_186_2>
432 FIPS186-2 FFC parameter generator (X9.42 DH).
434 =item B<DH_PARAMGEN_TYPE_GENERATOR>
436 Uses a safe prime generator g (PKCS#3 format).
440 The default is B<DH_PARAMGEN_TYPE_GENERATOR>.
442 EVP_PKEY_CTX_set_dh_paramgen_gindex() sets the I<gindex> used by the generator G.
443 The default value is -1 which uses unverifiable g, otherwise a positive value
444 uses verifiable g. This value must be saved if key validation of g is required,
445 since it is not part of a persisted key.
447 EVP_PKEY_CTX_set_dh_paramgen_seed() sets the I<seed> to use for generation
448 rather than using a randomly generated value for the seed. This is useful for
449 testing purposes only and can fail if the seed does not produce primes for both
450 p & q on its first iteration. This value must be saved if key validation of p, q,
451 and verifiable g are required, since it is not part of a persisted key.
453 EVP_PKEY_CTX_set_dh_pad() sets the DH padding mode.
454 If I<pad> is 1 the shared secret is padded with zeros up to the size of the DH
456 If I<pad> is zero (the default) then no padding is performed.
458 EVP_PKEY_CTX_set_dh_nid() sets the DH parameters to values corresponding to
459 I<nid> as defined in RFC7919 or RFC3526. The I<nid> parameter must be
460 B<NID_ffdhe2048>, B<NID_ffdhe3072>, B<NID_ffdhe4096>, B<NID_ffdhe6144>,
461 B<NID_ffdhe8192>, B<NID_modp_1536>, B<NID_modp_2048>, B<NID_modp_3072>,
462 B<NID_modp_4096>, B<NID_modp_6144>, B<NID_modp_8192> or B<NID_undef> to clear
463 the stored value. This function can be called during parameter or key generation.
464 The nid parameter and the rfc5114 parameter are mutually exclusive.
466 EVP_PKEY_CTX_set_dh_rfc5114() and EVP_PKEY_CTX_set_dhx_rfc5114() both set the
467 DH parameters to the values defined in RFC5114. The I<rfc5114> parameter must
468 be 1, 2 or 3 corresponding to RFC5114 sections 2.1, 2.2 and 2.3. or 0 to clear
469 the stored value. This macro can be called during parameter generation. The
470 I<ctx> must have a key type of B<EVP_PKEY_DHX>.
471 The rfc5114 parameter and the nid parameter are mutually exclusive.
473 =head2 DH key derivation function parameters
475 Note that all of the following functions require that the I<ctx> parameter has
476 a private key type of B<EVP_PKEY_DHX>. When using key derivation, the output of
477 EVP_PKEY_derive() is the output of the KDF instead of the DH shared secret.
478 The KDF output is typically used as a Key Encryption Key (KEK) that in turn
479 encrypts a Content Encryption Key (CEK).
481 EVP_PKEY_CTX_set_dh_kdf_type() sets the key derivation function type to I<kdf>
482 for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
483 B<EVP_PKEY_DH_KDF_X9_42> which uses the key derivation specified in RFC2631
484 (based on the keying algorithm described in X9.42). When using key derivation,
485 the I<kdf_oid>, I<kdf_md> and I<kdf_outlen> parameters must also be specified.
487 EVP_PKEY_CTX_get_dh_kdf_type() gets the key derivation function type for I<ctx>
488 used for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
489 B<EVP_PKEY_DH_KDF_X9_42>.
491 EVP_PKEY_CTX_set0_dh_kdf_oid() sets the key derivation function object
492 identifier to I<oid> for DH key derivation. This OID should identify the
493 algorithm to be used with the Content Encryption Key.
494 The library takes ownership of the object identifier so the caller should not
495 free the original memory pointed to by I<oid>.
497 EVP_PKEY_CTX_get0_dh_kdf_oid() gets the key derivation function oid for I<ctx>
498 used for DH key derivation. The resulting pointer is owned by the library and
499 should not be freed by the caller.
501 EVP_PKEY_CTX_set_dh_kdf_md() sets the key derivation function message digest to
502 I<md> for DH key derivation. Note that RFC2631 specifies that this digest should
503 be SHA1 but OpenSSL tolerates other digests.
505 EVP_PKEY_CTX_get_dh_kdf_md() gets the key derivation function message digest for
506 I<ctx> used for DH key derivation.
508 EVP_PKEY_CTX_set_dh_kdf_outlen() sets the key derivation function output length
509 to I<len> for DH key derivation.
511 EVP_PKEY_CTX_get_dh_kdf_outlen() gets the key derivation function output length
512 for I<ctx> used for DH key derivation.
514 EVP_PKEY_CTX_set0_dh_kdf_ukm() sets the user key material to I<ukm> and its
515 length to I<len> for DH key derivation. This parameter is optional and
516 corresponds to the partyAInfo field in RFC2631 terms. The specification
517 requires that it is 512 bits long but this is not enforced by OpenSSL.
518 The library takes ownership of the user key material so the caller should not
519 free the original memory pointed to by I<ukm>.
521 EVP_PKEY_CTX_get0_dh_kdf_ukm() gets the user key material for I<ctx>.
522 The return value is the user key material length. The resulting pointer is owned
523 by the library and should not be freed by the caller.
527 Use EVP_PKEY_CTX_set_group_name() (described above) to set the curve name to
528 I<name> for parameter and key generation.
530 EVP_PKEY_CTX_set_ec_paramgen_curve_nid() does the same as
531 EVP_PKEY_CTX_set_group_name(), but is specific to EC and uses a I<nid> rather
534 For EC parameter generation, one of EVP_PKEY_CTX_set_group_name()
535 or EVP_PKEY_CTX_set_ec_paramgen_curve_nid() must be called or an error occurs
536 because there is no default curve.
537 These function can also be called to set the curve explicitly when
538 generating an EC key.
540 EVP_PKEY_CTX_get_group_name() (described above) can be used to obtain the curve
541 name that's currently set with I<ctx>.
543 EVP_PKEY_CTX_set_ec_param_enc() sets the EC parameter encoding to I<param_enc>
544 when generating EC parameters or an EC key. The encoding can be
545 B<OPENSSL_EC_EXPLICIT_CURVE> for explicit parameters (the default in versions
546 of OpenSSL before 1.1.0) or B<OPENSSL_EC_NAMED_CURVE> to use named curve form.
547 For maximum compatibility the named curve form should be used. Note: the
548 B<OPENSSL_EC_NAMED_CURVE> value was added in OpenSSL 1.1.0; previous
549 versions should use 0 instead.
551 =head2 ECDH parameters
553 EVP_PKEY_CTX_set_ecdh_cofactor_mode() sets the cofactor mode to I<cofactor_mode>
554 for ECDH key derivation. Possible values are 1 to enable cofactor
555 key derivation, 0 to disable it and -1 to clear the stored cofactor mode and
556 fallback to the private key cofactor mode.
558 EVP_PKEY_CTX_get_ecdh_cofactor_mode() returns the cofactor mode for I<ctx> used
559 for ECDH key derivation. Possible values are 1 when cofactor key derivation is
560 enabled and 0 otherwise.
562 =head2 ECDH key derivation function parameters
564 EVP_PKEY_CTX_set_ecdh_kdf_type() sets the key derivation function type to
565 I<kdf> for ECDH key derivation. Possible values are B<EVP_PKEY_ECDH_KDF_NONE>
566 and B<EVP_PKEY_ECDH_KDF_X9_63> which uses the key derivation specified in X9.63.
567 When using key derivation, the I<kdf_md> and I<kdf_outlen> parameters must
570 EVP_PKEY_CTX_get_ecdh_kdf_type() returns the key derivation function type for
571 I<ctx> used for ECDH key derivation. Possible values are
572 B<EVP_PKEY_ECDH_KDF_NONE> and B<EVP_PKEY_ECDH_KDF_X9_63>.
574 EVP_PKEY_CTX_set_ecdh_kdf_md() sets the key derivation function message digest
575 to I<md> for ECDH key derivation. Note that X9.63 specifies that this digest
576 should be SHA1 but OpenSSL tolerates other digests.
578 EVP_PKEY_CTX_get_ecdh_kdf_md() gets the key derivation function message digest
579 for I<ctx> used for ECDH key derivation.
581 EVP_PKEY_CTX_set_ecdh_kdf_outlen() sets the key derivation function output
582 length to I<len> for ECDH key derivation.
584 EVP_PKEY_CTX_get_ecdh_kdf_outlen() gets the key derivation function output
585 length for I<ctx> used for ECDH key derivation.
587 EVP_PKEY_CTX_set0_ecdh_kdf_ukm() sets the user key material to I<ukm> for ECDH
588 key derivation. This parameter is optional and corresponds to the shared info in
589 X9.63 terms. The library takes ownership of the user key material so the caller
590 should not free the original memory pointed to by I<ukm>.
592 EVP_PKEY_CTX_get0_ecdh_kdf_ukm() gets the user key material for I<ctx>.
593 The return value is the user key material length. The resulting pointer is owned
594 by the library and should not be freed by the caller.
596 =head2 Other parameters
598 EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and EVP_PKEY_CTX_get1_id_len()
599 are used to manipulate the special identifier field for specific signature
600 algorithms such as SM2. The EVP_PKEY_CTX_set1_id() sets an ID pointed by I<id> with
601 the length I<id_len> to the library. The library takes a copy of the id so that
602 the caller can safely free the original memory pointed to by I<id>.
603 EVP_PKEY_CTX_get1_id_len() returns the length of the ID set via a previous call
604 to EVP_PKEY_CTX_set1_id(). The length is usually used to allocate adequate
605 memory for further calls to EVP_PKEY_CTX_get1_id(). EVP_PKEY_CTX_get1_id()
606 returns the previously set ID value to caller in I<id>. The caller should
607 allocate adequate memory space for the I<id> before calling EVP_PKEY_CTX_get1_id().
611 All other functions described on this page return a positive value for success
612 and 0 or a negative value for failure. In particular a return value of -2
613 indicates the operation is not supported by the public key algorithm.
617 L<EVP_PKEY_CTX_set_params(3)>,
618 L<EVP_PKEY_CTX_new(3)>,
619 L<EVP_PKEY_encrypt(3)>,
620 L<EVP_PKEY_decrypt(3)>,
622 L<EVP_PKEY_verify(3)>,
623 L<EVP_PKEY_verify_recover(3)>,
624 L<EVP_PKEY_derive(3)>,
625 L<EVP_PKEY_keygen(3)>
629 EVP_PKEY_CTX_get_rsa_oaep_md_name(), EVP_PKEY_CTX_get_rsa_mgf1_md_name(),
630 EVP_PKEY_CTX_set_rsa_mgf1_md_name(), EVP_PKEY_CTX_set_rsa_oaep_md_name(),
631 EVP_PKEY_CTX_set_dsa_paramgen_md_props(), EVP_PKEY_CTX_set_dsa_paramgen_gindex(),
632 EVP_PKEY_CTX_set_dsa_paramgen_type(), EVP_PKEY_CTX_set_dsa_paramgen_seed(),
633 EVP_PKEY_CTX_set_group_name() and EVP_PKEY_CTX_get_group_name()
634 were added in OpenSSL 3.0.
636 The EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and
637 EVP_PKEY_CTX_get1_id_len() macros were added in 1.1.1, other functions were
638 added in OpenSSL 1.0.0.
640 In OpenSSL 1.1.1 and below the functions were mostly macros.
641 From OpenSSL 3.0 they are all functions.
645 Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
647 Licensed under the Apache License 2.0 (the "License"). You may not use
648 this file except in compliance with the License. You can obtain a copy
649 in the file LICENSE in the source distribution or at
650 L<https://www.openssl.org/source/license.html>.