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_set1_rsa_keygen_pubexp,
21 EVP_PKEY_CTX_set_rsa_keygen_primes,
22 EVP_PKEY_CTX_set_rsa_mgf1_md_name,
23 EVP_PKEY_CTX_set_rsa_mgf1_md,
24 EVP_PKEY_CTX_get_rsa_mgf1_md,
25 EVP_PKEY_CTX_get_rsa_mgf1_md_name,
26 EVP_PKEY_CTX_set_rsa_oaep_md_name,
27 EVP_PKEY_CTX_set_rsa_oaep_md,
28 EVP_PKEY_CTX_get_rsa_oaep_md,
29 EVP_PKEY_CTX_get_rsa_oaep_md_name,
30 EVP_PKEY_CTX_set0_rsa_oaep_label,
31 EVP_PKEY_CTX_get0_rsa_oaep_label,
32 EVP_PKEY_CTX_set_dsa_paramgen_bits,
33 EVP_PKEY_CTX_set_dsa_paramgen_q_bits,
34 EVP_PKEY_CTX_set_dsa_paramgen_md,
35 EVP_PKEY_CTX_set_dsa_paramgen_md_props,
36 EVP_PKEY_CTX_set_dsa_paramgen_gindex,
37 EVP_PKEY_CTX_set_dsa_paramgen_type,
38 EVP_PKEY_CTX_set_dsa_paramgen_seed,
39 EVP_PKEY_CTX_set_dh_paramgen_prime_len,
40 EVP_PKEY_CTX_set_dh_paramgen_subprime_len,
41 EVP_PKEY_CTX_set_dh_paramgen_generator,
42 EVP_PKEY_CTX_set_dh_paramgen_type,
43 EVP_PKEY_CTX_set_dh_paramgen_gindex,
44 EVP_PKEY_CTX_set_dh_paramgen_seed,
45 EVP_PKEY_CTX_set_dh_rfc5114,
46 EVP_PKEY_CTX_set_dhx_rfc5114,
47 EVP_PKEY_CTX_set_dh_pad,
48 EVP_PKEY_CTX_set_dh_nid,
49 EVP_PKEY_CTX_set_dh_kdf_type,
50 EVP_PKEY_CTX_get_dh_kdf_type,
51 EVP_PKEY_CTX_set0_dh_kdf_oid,
52 EVP_PKEY_CTX_get0_dh_kdf_oid,
53 EVP_PKEY_CTX_set_dh_kdf_md,
54 EVP_PKEY_CTX_get_dh_kdf_md,
55 EVP_PKEY_CTX_set_dh_kdf_outlen,
56 EVP_PKEY_CTX_get_dh_kdf_outlen,
57 EVP_PKEY_CTX_set0_dh_kdf_ukm,
58 EVP_PKEY_CTX_get0_dh_kdf_ukm,
59 EVP_PKEY_CTX_set_ec_paramgen_curve_nid,
60 EVP_PKEY_CTX_set_ec_param_enc,
61 EVP_PKEY_CTX_set_ecdh_cofactor_mode,
62 EVP_PKEY_CTX_get_ecdh_cofactor_mode,
63 EVP_PKEY_CTX_set_ecdh_kdf_type,
64 EVP_PKEY_CTX_get_ecdh_kdf_type,
65 EVP_PKEY_CTX_set_ecdh_kdf_md,
66 EVP_PKEY_CTX_get_ecdh_kdf_md,
67 EVP_PKEY_CTX_set_ecdh_kdf_outlen,
68 EVP_PKEY_CTX_get_ecdh_kdf_outlen,
69 EVP_PKEY_CTX_set0_ecdh_kdf_ukm,
70 EVP_PKEY_CTX_get0_ecdh_kdf_ukm,
71 EVP_PKEY_CTX_set1_id, EVP_PKEY_CTX_get1_id, EVP_PKEY_CTX_get1_id_len,
72 EVP_PKEY_CTX_set_kem_op
73 - algorithm specific control operations
77 #include <openssl/evp.h>
79 int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
80 int cmd, int p1, void *p2);
81 int EVP_PKEY_CTX_ctrl_uint64(EVP_PKEY_CTX *ctx, int keytype, int optype,
82 int cmd, uint64_t value);
83 int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
86 int EVP_PKEY_CTX_md(EVP_PKEY_CTX *ctx, int optype, int cmd, const char *md);
88 int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
89 int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd);
91 int EVP_PKEY_CTX_set_mac_key(EVP_PKEY_CTX *ctx, const unsigned char *key,
93 int EVP_PKEY_CTX_set_group_name(EVP_PKEY_CTX *ctx, const char *name);
94 int EVP_PKEY_CTX_get_group_name(EVP_PKEY_CTX *ctx, char *name, size_t namelen);
96 int EVP_PKEY_CTX_set_kem_op(EVP_PKEY_CTX *ctx, const char *op);
98 #include <openssl/rsa.h>
100 int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int pad);
101 int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx, int *pad);
102 int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int saltlen);
103 int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int *saltlen);
104 int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx, int mbits);
105 int EVP_PKEY_CTX_set1_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
106 int EVP_PKEY_CTX_set_rsa_keygen_primes(EVP_PKEY_CTX *ctx, int primes);
107 int EVP_PKEY_CTX_set_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
108 const char *mdprops);
109 int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
110 int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
111 int EVP_PKEY_CTX_get_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, char *name,
113 int EVP_PKEY_CTX_set_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
114 const char *mdprops);
115 int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
116 int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
117 int EVP_PKEY_CTX_get_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, char *name,
119 int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char *label,
121 int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char **label);
123 #include <openssl/dsa.h>
125 int EVP_PKEY_CTX_set_dsa_paramgen_bits(EVP_PKEY_CTX *ctx, int nbits);
126 int EVP_PKEY_CTX_set_dsa_paramgen_q_bits(EVP_PKEY_CTX *ctx, int qbits);
127 int EVP_PKEY_CTX_set_dsa_paramgen_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
128 int EVP_PKEY_CTX_set_dsa_paramgen_md_props(EVP_PKEY_CTX *ctx,
130 const char *md_properties);
131 int EVP_PKEY_CTX_set_dsa_paramgen_type(EVP_PKEY_CTX *ctx, const char *name);
132 int EVP_PKEY_CTX_set_dsa_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
133 int EVP_PKEY_CTX_set_dsa_paramgen_seed(EVP_PKEY_CTX *ctx,
134 const unsigned char *seed,
137 #include <openssl/dh.h>
139 int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int len);
140 int EVP_PKEY_CTX_set_dh_paramgen_subprime_len(EVP_PKEY_CTX *ctx, int len);
141 int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);
142 int EVP_PKEY_CTX_set_dh_paramgen_type(EVP_PKEY_CTX *ctx, int type);
143 int EVP_PKEY_CTX_set_dh_pad(EVP_PKEY_CTX *ctx, int pad);
144 int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid);
145 int EVP_PKEY_CTX_set_dh_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
146 int EVP_PKEY_CTX_set_dhx_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
147 int EVP_PKEY_CTX_set_dh_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
148 int EVP_PKEY_CTX_set_dh_paramgen_seed(EVP_PKEY_CTX *ctx,
149 const unsigned char *seed,
151 int EVP_PKEY_CTX_set_dh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
152 int EVP_PKEY_CTX_get_dh_kdf_type(EVP_PKEY_CTX *ctx);
153 int EVP_PKEY_CTX_set0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT *oid);
154 int EVP_PKEY_CTX_get0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT **oid);
155 int EVP_PKEY_CTX_set_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
156 int EVP_PKEY_CTX_get_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
157 int EVP_PKEY_CTX_set_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
158 int EVP_PKEY_CTX_get_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
159 int EVP_PKEY_CTX_set0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
160 int EVP_PKEY_CTX_get0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
162 #include <openssl/ec.h>
164 int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid);
165 int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc);
166 int EVP_PKEY_CTX_set_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx, int cofactor_mode);
167 int EVP_PKEY_CTX_get_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx);
168 int EVP_PKEY_CTX_set_ecdh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
169 int EVP_PKEY_CTX_get_ecdh_kdf_type(EVP_PKEY_CTX *ctx);
170 int EVP_PKEY_CTX_set_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
171 int EVP_PKEY_CTX_get_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
172 int EVP_PKEY_CTX_set_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
173 int EVP_PKEY_CTX_get_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
174 int EVP_PKEY_CTX_set0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
175 int EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
177 int EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len);
178 int EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id);
179 int EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *id_len);
181 Deprecated since OpenSSL 3.0, can be hidden entirely by defining
182 B<OPENSSL_API_COMPAT> with a suitable version value, see
183 L<openssl_user_macros(7)>:
185 #include <openssl/rsa.h>
187 int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
191 EVP_PKEY_CTX_ctrl() sends a control operation to the context I<ctx>. The key
192 type used must match I<keytype> if it is not -1. The parameter I<optype> is a
193 mask indicating which operations the control can be applied to.
194 The control command is indicated in I<cmd> and any additional arguments in
197 For I<cmd> = B<EVP_PKEY_CTRL_SET_MAC_KEY>, I<p1> is the length of the MAC key,
198 and I<p2> is the MAC key. This is used by Poly1305, SipHash, HMAC and CMAC.
200 Applications will not normally call EVP_PKEY_CTX_ctrl() directly but will
201 instead call one of the algorithm specific functions below.
203 EVP_PKEY_CTX_ctrl_uint64() is a wrapper that directly passes a
204 uint64 value as I<p2> to EVP_PKEY_CTX_ctrl().
206 EVP_PKEY_CTX_ctrl_str() allows an application to send an algorithm
207 specific control operation to a context I<ctx> in string form. This is
208 intended to be used for options specified on the command line or in text
209 files. The commands supported are documented in the openssl utility
210 command line pages for the option I<-pkeyopt> which is supported by the
211 I<pkeyutl>, I<genpkey> and I<req> commands.
213 EVP_PKEY_CTX_md() sends a message digest control operation to the context
214 I<ctx>. The message digest is specified by its name I<md>.
216 EVP_PKEY_CTX_set_signature_md() sets the message digest type used
217 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
219 EVP_PKEY_CTX_get_signature_md()gets the message digest type used
220 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
222 Key generation typically involves setting up parameters to be used and
223 generating the private and public key data. Some algorithm implementations
224 allow private key data to be set explicitly using EVP_PKEY_CTX_set_mac_key().
225 In this case key generation is simply the process of setting up the
226 parameters for the key and then setting the raw key data to the value explicitly.
227 Normally applications would call L<EVP_PKEY_new_raw_private_key(3)> or similar
230 EVP_PKEY_CTX_set_mac_key() can be used with any of the algorithms supported by
231 the L<EVP_PKEY_new_raw_private_key(3)> function.
233 EVP_PKEY_CTX_set_group_name() sets the group name to I<name> for parameter and
234 key generation. For example for EC keys this will set the curve name and for
235 DH keys it will set the name of the finite field group.
237 EVP_PKEY_CTX_get_group_name() finds the group name that's currently
238 set with I<ctx>, and writes it to the location that I<name> points at, as long
239 as its size I<namelen> is large enough to store that name, including a
240 terminating NUL byte.
242 =head2 RSA parameters
244 EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding mode for I<ctx>.
245 The I<pad> parameter can take the value B<RSA_PKCS1_PADDING> for PKCS#1
246 padding, B<RSA_SSLV23_PADDING> for SSLv23 padding, B<RSA_NO_PADDING> for
247 no padding, B<RSA_PKCS1_OAEP_PADDING> for OAEP padding (encrypt and
248 decrypt only), B<RSA_X931_PADDING> for X9.31 padding (signature operations
249 only), B<RSA_PKCS1_PSS_PADDING> (sign and verify only) and
250 B<RSA_PKCS1_WITH_TLS_PADDING> for TLS RSA ClientKeyExchange message padding
253 Two RSA padding modes behave differently if EVP_PKEY_CTX_set_signature_md()
254 is used. If this function is called for PKCS#1 padding the plaintext buffer is
255 an actual digest value and is encapsulated in a DigestInfo structure according
256 to PKCS#1 when signing and this structure is expected (and stripped off) when
257 verifying. If this control is not used with RSA and PKCS#1 padding then the
258 supplied data is used directly and not encapsulated. In the case of X9.31
259 padding for RSA the algorithm identifier byte is added or checked and removed
260 if this control is called. If it is not called then the first byte of the plaintext
261 buffer is expected to be the algorithm identifier byte.
263 EVP_PKEY_CTX_get_rsa_padding() gets the RSA padding mode for I<ctx>.
265 EVP_PKEY_CTX_set_rsa_pss_saltlen() sets the RSA PSS salt length to I<saltlen>.
266 As its name implies it is only supported for PSS padding. If this function is
267 not called then the maximum salt length is used when signing and auto detection
268 when verifying. Three special values are supported:
272 =item B<RSA_PSS_SALTLEN_DIGEST>
274 sets the salt length to the digest length.
276 =item B<RSA_PSS_SALTLEN_MAX>
278 sets the salt length to the maximum permissible value.
280 =item B<RSA_PSS_SALTLEN_AUTO>
282 causes the salt length to be automatically determined based on the
283 B<PSS> block structure when verifying. When signing, it has the same
284 meaning as B<RSA_PSS_SALTLEN_MAX>.
288 EVP_PKEY_CTX_get_rsa_pss_saltlen() gets the RSA PSS salt length for I<ctx>.
289 The padding mode must already have been set to B<RSA_PKCS1_PSS_PADDING>.
291 EVP_PKEY_CTX_set_rsa_keygen_bits() sets the RSA key length for
292 RSA key generation to I<bits>. If not specified 2048 bits is used.
294 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() sets the public exponent value for RSA key
295 generation to the value stored in I<pubexp>. Currently it should be an odd
296 integer. In accordance with the OpenSSL naming convention, the I<pubexp> pointer
297 must be freed independently of the EVP_PKEY_CTX (ie, it is internally copied).
298 If not specified 65537 is used.
300 EVP_PKEY_CTX_set_rsa_keygen_pubexp() does the same as
301 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() except that there is no internal copy and
302 therefore I<pubexp> should not be modified or freed after the call.
304 EVP_PKEY_CTX_set_rsa_keygen_primes() sets the number of primes for
305 RSA key generation to I<primes>. If not specified 2 is used.
307 EVP_PKEY_CTX_set_rsa_mgf1_md_name() sets the MGF1 digest for RSA
308 padding schemes to the digest named I<mdname>. If the RSA algorithm
309 implementation for the selected provider supports it then the digest will be
310 fetched using the properties I<mdprops>. If not explicitly set the signing
311 digest is used. The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>
312 or B<RSA_PKCS1_PSS_PADDING>.
314 EVP_PKEY_CTX_set_rsa_mgf1_md() does the same as
315 EVP_PKEY_CTX_set_rsa_mgf1_md_name() except that the name of the digest is
316 inferred from the supplied I<md> and it is not possible to specify any
319 EVP_PKEY_CTX_get_rsa_mgf1_md_name() gets the name of the MGF1
320 digest algorithm for I<ctx>. If not explicitly set the signing digest is used.
321 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING> or
322 B<RSA_PKCS1_PSS_PADDING>.
324 EVP_PKEY_CTX_get_rsa_mgf1_md() does the same as
325 EVP_PKEY_CTX_get_rsa_mgf1_md_name() except that it returns a pointer to an
326 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
327 returned. The EVP_MD object may be NULL if the digest is not one of these (such
328 as a digest only implemented in a third party provider).
330 EVP_PKEY_CTX_set_rsa_oaep_md_name() sets the message digest type
331 used in RSA OAEP to the digest named I<mdname>. If the RSA algorithm
332 implementation for the selected provider supports it then the digest will be
333 fetched using the properties I<mdprops>. The padding mode must have been set to
334 B<RSA_PKCS1_OAEP_PADDING>.
336 EVP_PKEY_CTX_set_rsa_oaep_md() does the same as
337 EVP_PKEY_CTX_set_rsa_oaep_md_name() except that the name of the digest is
338 inferred from the supplied I<md> and it is not possible to specify any
341 EVP_PKEY_CTX_get_rsa_oaep_md_name() gets the message digest
342 algorithm name used in RSA OAEP and stores it in the buffer I<name> which is of
343 size I<namelen>. The padding mode must have been set to
344 B<RSA_PKCS1_OAEP_PADDING>. The buffer should be sufficiently large for any
345 expected digest algorithm names or the function will fail.
347 EVP_PKEY_CTX_get_rsa_oaep_md() does the same as
348 EVP_PKEY_CTX_get_rsa_oaep_md_name() except that it returns a pointer to an
349 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
350 returned. The EVP_MD object may be NULL if the digest is not one of these (such
351 as a digest only implemented in a third party provider).
353 EVP_PKEY_CTX_set0_rsa_oaep_label() sets the RSA OAEP label to
354 I<label> and its length to I<len>. If I<label> is NULL or I<len> is 0,
355 the label is cleared. The library takes ownership of the label so the
356 caller should not free the original memory pointed to by I<label>.
357 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>.
359 EVP_PKEY_CTX_get0_rsa_oaep_label() gets the RSA OAEP label to
360 I<label>. The return value is the label length. The padding mode
361 must have been set to B<RSA_PKCS1_OAEP_PADDING>. The resulting pointer is owned
362 by the library and should not be freed by the caller.
364 B<RSA_PKCS1_WITH_TLS_PADDING> is used when decrypting an RSA encrypted TLS
365 pre-master secret in a TLS ClientKeyExchange message. It is the same as
366 RSA_PKCS1_PADDING except that it additionally verifies that the result is the
367 correct length and the first two bytes are the protocol version initially
368 requested by the client. If the encrypted content is publicly invalid then the
369 decryption will fail. However, if the padding checks fail then decryption will
370 still appear to succeed but a random TLS premaster secret will be returned
371 instead. This padding mode accepts two parameters which can be set using the
372 L<EVP_PKEY_CTX_set_params(3)> function. These are
373 OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION and
374 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, both of which are expected to be
375 unsigned integers. Normally only the first of these will be set and represents
376 the TLS protocol version that was first requested by the client (e.g. 0x0303 for
377 TLSv1.2, 0x0302 for TLSv1.1 etc). Historically some buggy clients would use the
378 negotiated protocol version instead of the protocol version first requested. If
379 this behaviour should be tolerated then
380 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION should be set to the actual
381 negotiated protocol version. Otherwise it should be left unset.
383 =head2 DSA parameters
385 EVP_PKEY_CTX_set_dsa_paramgen_bits() sets the number of bits used for DSA
386 parameter generation to B<nbits>. If not specified, 2048 is used.
388 EVP_PKEY_CTX_set_dsa_paramgen_q_bits() sets the number of bits in the subprime
389 parameter I<q> for DSA parameter generation to I<qbits>. If not specified, 224
390 is used. If a digest function is specified below, this parameter is ignored and
391 instead, the number of bits in I<q> matches the size of the digest.
393 EVP_PKEY_CTX_set_dsa_paramgen_md() sets the digest function used for DSA
394 parameter generation to I<md>. If not specified, one of SHA-1, SHA-224, or
395 SHA-256 is selected to match the bit length of I<q> above.
397 EVP_PKEY_CTX_set_dsa_paramgen_md_props() sets the digest function used for DSA
398 parameter generation using I<md_name> and I<md_properties> to retrieve the
399 digest from a provider.
400 If not specified, I<md_name> will be set to one of SHA-1, SHA-224, or
401 SHA-256 depending on the bit length of I<q> above. I<md_properties> is a
402 property query string that has a default value of '' if not specified.
404 EVP_PKEY_CTX_set_dsa_paramgen_gindex() sets the I<gindex> used by the generator
405 G. The default value is -1 which uses unverifiable g, otherwise a positive value
406 uses verifiable g. This value must be saved if key validation of g is required,
407 since it is not part of a persisted key.
409 EVP_PKEY_CTX_set_dsa_paramgen_seed() sets the I<seed> to use for generation
410 rather than using a randomly generated value for the seed. This is useful for
411 testing purposes only and can fail if the seed does not produce primes for both
412 p & q on its first iteration. This value must be saved if key validation of
413 p, q, and verifiable g are required, since it is not part of a persisted key.
415 EVP_PKEY_CTX_set_dsa_paramgen_type() sets the generation type to use FIPS186-4
416 generation if I<name> is "fips186_4", or FIPS186-2 generation if I<name> is
417 "fips186_2". The default value for the default provider is "fips186_2". The
418 default value for the FIPS provider is "fips186_4".
422 EVP_PKEY_CTX_set_dh_paramgen_prime_len() sets the length of the DH prime
423 parameter I<p> for DH parameter generation. If this function is not called then
424 2048 is used. Only accepts lengths greater than or equal to 256.
426 EVP_PKEY_CTX_set_dh_paramgen_subprime_len() sets the length of the DH
427 optional subprime parameter I<q> for DH parameter generation. The default is
428 256 if the prime is at least 2048 bits long or 160 otherwise. The DH paramgen
429 type must have been set to "fips186_4".
431 EVP_PKEY_CTX_set_dh_paramgen_generator() sets DH generator to I<gen> for DH
432 parameter generation. If not specified 2 is used.
434 EVP_PKEY_CTX_set_dh_paramgen_type() sets the key type for DH parameter
435 generation. The supported parameters are:
439 =item B<DH_PARAMGEN_TYPE_GROUP>
441 Use a named group. If only the safe prime parameter I<p> is set this can be
442 used to select a ffdhe safe prime group of the correct size.
444 =item B<DH_PARAMGEN_TYPE_FIPS_186_4>
446 FIPS186-4 FFC parameter generator.
448 =item B<DH_PARAMGEN_TYPE_FIPS_186_2>
450 FIPS186-2 FFC parameter generator (X9.42 DH).
452 =item B<DH_PARAMGEN_TYPE_GENERATOR>
454 Uses a safe prime generator g (PKCS#3 format).
458 The default is B<DH_PARAMGEN_TYPE_GENERATOR> in the default provider for the
459 "DH" keytype, and B<DH_PARAMGEN_TYPE_FIPS_186_4> in the FIPS provider and for
460 the "DHX" keytype in the default provider.
462 EVP_PKEY_CTX_set_dh_paramgen_gindex() sets the I<gindex> used by the generator G.
463 The default value is -1 which uses unverifiable g, otherwise a positive value
464 uses verifiable g. This value must be saved if key validation of g is required,
465 since it is not part of a persisted key.
467 EVP_PKEY_CTX_set_dh_paramgen_seed() sets the I<seed> to use for generation
468 rather than using a randomly generated value for the seed. This is useful for
469 testing purposes only and can fail if the seed does not produce primes for both
470 p & q on its first iteration. This value must be saved if key validation of p, q,
471 and verifiable g are required, since it is not part of a persisted key.
473 EVP_PKEY_CTX_set_dh_pad() sets the DH padding mode.
474 If I<pad> is 1 the shared secret is padded with zeros up to the size of the DH
476 If I<pad> is zero (the default) then no padding is performed.
478 EVP_PKEY_CTX_set_dh_nid() sets the DH parameters to values corresponding to
479 I<nid> as defined in RFC7919 or RFC3526. The I<nid> parameter must be
480 B<NID_ffdhe2048>, B<NID_ffdhe3072>, B<NID_ffdhe4096>, B<NID_ffdhe6144>,
481 B<NID_ffdhe8192>, B<NID_modp_1536>, B<NID_modp_2048>, B<NID_modp_3072>,
482 B<NID_modp_4096>, B<NID_modp_6144>, B<NID_modp_8192> or B<NID_undef> to clear
483 the stored value. This function can be called during parameter or key generation.
484 The nid parameter and the rfc5114 parameter are mutually exclusive.
486 EVP_PKEY_CTX_set_dh_rfc5114() and EVP_PKEY_CTX_set_dhx_rfc5114() both set the
487 DH parameters to the values defined in RFC5114. The I<rfc5114> parameter must
488 be 1, 2 or 3 corresponding to RFC5114 sections 2.1, 2.2 and 2.3. or 0 to clear
489 the stored value. This macro can be called during parameter generation. The
490 I<ctx> must have a key type of B<EVP_PKEY_DHX>.
491 The rfc5114 parameter and the nid parameter are mutually exclusive.
493 =head2 DH key derivation function parameters
495 Note that all of the following functions require that the I<ctx> parameter has
496 a private key type of B<EVP_PKEY_DHX>. When using key derivation, the output of
497 EVP_PKEY_derive() is the output of the KDF instead of the DH shared secret.
498 The KDF output is typically used as a Key Encryption Key (KEK) that in turn
499 encrypts a Content Encryption Key (CEK).
501 EVP_PKEY_CTX_set_dh_kdf_type() sets the key derivation function type to I<kdf>
502 for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
503 B<EVP_PKEY_DH_KDF_X9_42> which uses the key derivation specified in RFC2631
504 (based on the keying algorithm described in X9.42). When using key derivation,
505 the I<kdf_oid>, I<kdf_md> and I<kdf_outlen> parameters must also be specified.
507 EVP_PKEY_CTX_get_dh_kdf_type() gets the key derivation function type for I<ctx>
508 used for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
509 B<EVP_PKEY_DH_KDF_X9_42>.
511 EVP_PKEY_CTX_set0_dh_kdf_oid() sets the key derivation function object
512 identifier to I<oid> for DH key derivation. This OID should identify the
513 algorithm to be used with the Content Encryption Key.
514 The library takes ownership of the object identifier so the caller should not
515 free the original memory pointed to by I<oid>.
517 EVP_PKEY_CTX_get0_dh_kdf_oid() gets the key derivation function oid for I<ctx>
518 used for DH key derivation. The resulting pointer is owned by the library and
519 should not be freed by the caller.
521 EVP_PKEY_CTX_set_dh_kdf_md() sets the key derivation function message digest to
522 I<md> for DH key derivation. Note that RFC2631 specifies that this digest should
523 be SHA1 but OpenSSL tolerates other digests.
525 EVP_PKEY_CTX_get_dh_kdf_md() gets the key derivation function message digest for
526 I<ctx> used for DH key derivation.
528 EVP_PKEY_CTX_set_dh_kdf_outlen() sets the key derivation function output length
529 to I<len> for DH key derivation.
531 EVP_PKEY_CTX_get_dh_kdf_outlen() gets the key derivation function output length
532 for I<ctx> used for DH key derivation.
534 EVP_PKEY_CTX_set0_dh_kdf_ukm() sets the user key material to I<ukm> and its
535 length to I<len> for DH key derivation. This parameter is optional and
536 corresponds to the partyAInfo field in RFC2631 terms. The specification
537 requires that it is 512 bits long but this is not enforced by OpenSSL.
538 The library takes ownership of the user key material so the caller should not
539 free the original memory pointed to by I<ukm>.
541 EVP_PKEY_CTX_get0_dh_kdf_ukm() gets the user key material for I<ctx>.
542 The return value is the user key material length. The resulting pointer is owned
543 by the library and should not be freed by the caller.
547 Use EVP_PKEY_CTX_set_group_name() (described above) to set the curve name to
548 I<name> for parameter and key generation.
550 EVP_PKEY_CTX_set_ec_paramgen_curve_nid() does the same as
551 EVP_PKEY_CTX_set_group_name(), but is specific to EC and uses a I<nid> rather
554 For EC parameter generation, one of EVP_PKEY_CTX_set_group_name()
555 or EVP_PKEY_CTX_set_ec_paramgen_curve_nid() must be called or an error occurs
556 because there is no default curve.
557 These function can also be called to set the curve explicitly when
558 generating an EC key.
560 EVP_PKEY_CTX_get_group_name() (described above) can be used to obtain the curve
561 name that's currently set with I<ctx>.
563 EVP_PKEY_CTX_set_ec_param_enc() sets the EC parameter encoding to I<param_enc>
564 when generating EC parameters or an EC key. The encoding can be
565 B<OPENSSL_EC_EXPLICIT_CURVE> for explicit parameters (the default in versions
566 of OpenSSL before 1.1.0) or B<OPENSSL_EC_NAMED_CURVE> to use named curve form.
567 For maximum compatibility the named curve form should be used. Note: the
568 B<OPENSSL_EC_NAMED_CURVE> value was added in OpenSSL 1.1.0; previous
569 versions should use 0 instead.
571 =head2 ECDH parameters
573 EVP_PKEY_CTX_set_ecdh_cofactor_mode() sets the cofactor mode to I<cofactor_mode>
574 for ECDH key derivation. Possible values are 1 to enable cofactor
575 key derivation, 0 to disable it and -1 to clear the stored cofactor mode and
576 fallback to the private key cofactor mode.
578 EVP_PKEY_CTX_get_ecdh_cofactor_mode() returns the cofactor mode for I<ctx> used
579 for ECDH key derivation. Possible values are 1 when cofactor key derivation is
580 enabled and 0 otherwise.
582 =head2 ECDH key derivation function parameters
584 EVP_PKEY_CTX_set_ecdh_kdf_type() sets the key derivation function type to
585 I<kdf> for ECDH key derivation. Possible values are B<EVP_PKEY_ECDH_KDF_NONE>
586 and B<EVP_PKEY_ECDH_KDF_X9_63> which uses the key derivation specified in X9.63.
587 When using key derivation, the I<kdf_md> and I<kdf_outlen> parameters must
590 EVP_PKEY_CTX_get_ecdh_kdf_type() returns the key derivation function type for
591 I<ctx> used for ECDH key derivation. Possible values are
592 B<EVP_PKEY_ECDH_KDF_NONE> and B<EVP_PKEY_ECDH_KDF_X9_63>.
594 EVP_PKEY_CTX_set_ecdh_kdf_md() sets the key derivation function message digest
595 to I<md> for ECDH key derivation. Note that X9.63 specifies that this digest
596 should be SHA1 but OpenSSL tolerates other digests.
598 EVP_PKEY_CTX_get_ecdh_kdf_md() gets the key derivation function message digest
599 for I<ctx> used for ECDH key derivation.
601 EVP_PKEY_CTX_set_ecdh_kdf_outlen() sets the key derivation function output
602 length to I<len> for ECDH key derivation.
604 EVP_PKEY_CTX_get_ecdh_kdf_outlen() gets the key derivation function output
605 length for I<ctx> used for ECDH key derivation.
607 EVP_PKEY_CTX_set0_ecdh_kdf_ukm() sets the user key material to I<ukm> for ECDH
608 key derivation. This parameter is optional and corresponds to the shared info in
609 X9.63 terms. The library takes ownership of the user key material so the caller
610 should not free the original memory pointed to by I<ukm>.
612 EVP_PKEY_CTX_get0_ecdh_kdf_ukm() gets the user key material for I<ctx>.
613 The return value is the user key material length. The resulting pointer is owned
614 by the library and should not be freed by the caller.
616 =head2 Other parameters
618 EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and EVP_PKEY_CTX_get1_id_len()
619 are used to manipulate the special identifier field for specific signature
620 algorithms such as SM2. The EVP_PKEY_CTX_set1_id() sets an ID pointed by I<id> with
621 the length I<id_len> to the library. The library takes a copy of the id so that
622 the caller can safely free the original memory pointed to by I<id>.
623 EVP_PKEY_CTX_get1_id_len() returns the length of the ID set via a previous call
624 to EVP_PKEY_CTX_set1_id(). The length is usually used to allocate adequate
625 memory for further calls to EVP_PKEY_CTX_get1_id(). EVP_PKEY_CTX_get1_id()
626 returns the previously set ID value to caller in I<id>. The caller should
627 allocate adequate memory space for the I<id> before calling EVP_PKEY_CTX_get1_id().
629 EVP_PKEY_CTX_set_kem_op() sets the KEM operation to run. This can be set after
630 EVP_PKEY_encapsulate_init() or EVP_PKEY_decapsulate_init() to select the
631 kem operation. RSA is the only key type that supports encapsulation currently,
632 and as there is no default operation for the RSA type, this function must be
633 called before EVP_PKEY_encapsulate() or EVP_PKEY_decapsulate().
637 All other functions described on this page return a positive value for success
638 and 0 or a negative value for failure. In particular a return value of -2
639 indicates the operation is not supported by the public key algorithm.
643 L<EVP_PKEY_CTX_set_params(3)>,
644 L<EVP_PKEY_CTX_new(3)>,
645 L<EVP_PKEY_encrypt(3)>,
646 L<EVP_PKEY_decrypt(3)>,
648 L<EVP_PKEY_verify(3)>,
649 L<EVP_PKEY_verify_recover(3)>,
650 L<EVP_PKEY_derive(3)>,
651 L<EVP_PKEY_keygen(3)>
652 L<EVP_PKEY_encapsulate(3)>
653 L<EVP_PKEY_decapsulate(3)>
657 EVP_PKEY_CTX_get_rsa_oaep_md_name(), EVP_PKEY_CTX_get_rsa_mgf1_md_name(),
658 EVP_PKEY_CTX_set_rsa_mgf1_md_name(), EVP_PKEY_CTX_set_rsa_oaep_md_name(),
659 EVP_PKEY_CTX_set_dsa_paramgen_md_props(), EVP_PKEY_CTX_set_dsa_paramgen_gindex(),
660 EVP_PKEY_CTX_set_dsa_paramgen_type(), EVP_PKEY_CTX_set_dsa_paramgen_seed(),
661 EVP_PKEY_CTX_set_group_name() and EVP_PKEY_CTX_get_group_name()
662 were added in OpenSSL 3.0.
664 The EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and
665 EVP_PKEY_CTX_get1_id_len() macros were added in 1.1.1, other functions were
666 added in OpenSSL 1.0.0.
668 In OpenSSL 1.1.1 and below the functions were mostly macros.
669 From OpenSSL 3.0 they are all functions.
673 Copyright 2006-2020 The OpenSSL Project Authors. All Rights Reserved.
675 Licensed under the Apache License 2.0 (the "License"). You may not use
676 this file except in compliance with the License. You can obtain a copy
677 in the file LICENSE in the source distribution or at
678 L<https://www.openssl.org/source/license.html>.