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, void *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);
161 #include <openssl/ec.h>
163 int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid);
164 int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc);
165 int EVP_PKEY_CTX_set_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx, int cofactor_mode);
166 int EVP_PKEY_CTX_get_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx);
167 int EVP_PKEY_CTX_set_ecdh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
168 int EVP_PKEY_CTX_get_ecdh_kdf_type(EVP_PKEY_CTX *ctx);
169 int EVP_PKEY_CTX_set_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
170 int EVP_PKEY_CTX_get_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
171 int EVP_PKEY_CTX_set_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
172 int EVP_PKEY_CTX_get_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
173 int EVP_PKEY_CTX_set0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
175 int EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len);
176 int EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id);
177 int EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *id_len);
179 The following functions have been deprecated since OpenSSL 3.0, and can be
180 hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
181 see L<openssl_user_macros(7)>:
183 #include <openssl/rsa.h>
185 int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
187 #include <openssl/dh.h>
189 int EVP_PKEY_CTX_get0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
191 #include <openssl/ec.h>
193 int EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
197 EVP_PKEY_CTX_ctrl() sends a control operation to the context I<ctx>. The key
198 type used must match I<keytype> if it is not -1. The parameter I<optype> is a
199 mask indicating which operations the control can be applied to.
200 The control command is indicated in I<cmd> and any additional arguments in
203 For I<cmd> = B<EVP_PKEY_CTRL_SET_MAC_KEY>, I<p1> is the length of the MAC key,
204 and I<p2> is the MAC key. This is used by Poly1305, SipHash, HMAC and CMAC.
206 Applications will not normally call EVP_PKEY_CTX_ctrl() directly but will
207 instead call one of the algorithm specific functions below.
209 EVP_PKEY_CTX_ctrl_uint64() is a wrapper that directly passes a
210 uint64 value as I<p2> to EVP_PKEY_CTX_ctrl().
212 EVP_PKEY_CTX_ctrl_str() allows an application to send an algorithm
213 specific control operation to a context I<ctx> in string form. This is
214 intended to be used for options specified on the command line or in text
215 files. The commands supported are documented in the openssl utility
216 command line pages for the option I<-pkeyopt> which is supported by the
217 I<pkeyutl>, I<genpkey> and I<req> commands.
219 EVP_PKEY_CTX_md() sends a message digest control operation to the context
220 I<ctx>. The message digest is specified by its name I<md>.
222 EVP_PKEY_CTX_set_signature_md() sets the message digest type used
223 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
225 EVP_PKEY_CTX_get_signature_md()gets the message digest type used
226 in a signature. It can be used in the RSA, DSA and ECDSA algorithms.
228 Key generation typically involves setting up parameters to be used and
229 generating the private and public key data. Some algorithm implementations
230 allow private key data to be set explicitly using EVP_PKEY_CTX_set_mac_key().
231 In this case key generation is simply the process of setting up the
232 parameters for the key and then setting the raw key data to the value explicitly.
233 Normally applications would call L<EVP_PKEY_new_raw_private_key(3)> or similar
236 EVP_PKEY_CTX_set_mac_key() can be used with any of the algorithms supported by
237 the L<EVP_PKEY_new_raw_private_key(3)> function.
239 EVP_PKEY_CTX_set_group_name() sets the group name to I<name> for parameter and
240 key generation. For example for EC keys this will set the curve name and for
241 DH keys it will set the name of the finite field group.
243 EVP_PKEY_CTX_get_group_name() finds the group name that's currently
244 set with I<ctx>, and writes it to the location that I<name> points at, as long
245 as its size I<namelen> is large enough to store that name, including a
246 terminating NUL byte.
248 =head2 RSA parameters
250 EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding mode for I<ctx>.
251 The I<pad> parameter can take the value B<RSA_PKCS1_PADDING> for PKCS#1
252 padding, B<RSA_NO_PADDING> for
253 no padding, B<RSA_PKCS1_OAEP_PADDING> for OAEP padding (encrypt and
254 decrypt only), B<RSA_X931_PADDING> for X9.31 padding (signature operations
255 only), B<RSA_PKCS1_PSS_PADDING> (sign and verify only) and
256 B<RSA_PKCS1_WITH_TLS_PADDING> for TLS RSA ClientKeyExchange message padding
259 Two RSA padding modes behave differently if EVP_PKEY_CTX_set_signature_md()
260 is used. If this function is called for PKCS#1 padding the plaintext buffer is
261 an actual digest value and is encapsulated in a DigestInfo structure according
262 to PKCS#1 when signing and this structure is expected (and stripped off) when
263 verifying. If this control is not used with RSA and PKCS#1 padding then the
264 supplied data is used directly and not encapsulated. In the case of X9.31
265 padding for RSA the algorithm identifier byte is added or checked and removed
266 if this control is called. If it is not called then the first byte of the plaintext
267 buffer is expected to be the algorithm identifier byte.
269 EVP_PKEY_CTX_get_rsa_padding() gets the RSA padding mode for I<ctx>.
271 EVP_PKEY_CTX_set_rsa_pss_saltlen() sets the RSA PSS salt length to I<saltlen>.
272 As its name implies it is only supported for PSS padding. If this function is
273 not called then the salt length is maximized up to the digest length when
274 signing and auto detection when verifying. Four special values are supported:
278 =item B<RSA_PSS_SALTLEN_DIGEST>
280 sets the salt length to the digest length.
282 =item B<RSA_PSS_SALTLEN_MAX>
284 sets the salt length to the maximum permissible value.
286 =item B<RSA_PSS_SALTLEN_AUTO>
288 causes the salt length to be automatically determined based on the
289 B<PSS> block structure when verifying. When signing, it has the same
290 meaning as B<RSA_PSS_SALTLEN_MAX>.
292 =item B<RSA_PSS_SALTLEN_AUTO_DIGEST_MAX>
294 causes the salt length to be automatically determined based on the B<PSS> block
295 structure when verifying, like B<RSA_PSS_SALTLEN_AUTO>. When signing, the salt
296 length is maximized up to a maximum of the digest length to comply with FIPS
301 EVP_PKEY_CTX_get_rsa_pss_saltlen() gets the RSA PSS salt length for I<ctx>.
302 The padding mode must already have been set to B<RSA_PKCS1_PSS_PADDING>.
304 EVP_PKEY_CTX_set_rsa_keygen_bits() sets the RSA key length for
305 RSA key generation to I<bits>. If not specified 2048 bits is used.
307 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() sets the public exponent value for RSA key
308 generation to the value stored in I<pubexp>. Currently it should be an odd
309 integer. In accordance with the OpenSSL naming convention, the I<pubexp> pointer
310 must be freed independently of the EVP_PKEY_CTX (ie, it is internally copied).
311 If not specified 65537 is used.
313 EVP_PKEY_CTX_set_rsa_keygen_pubexp() does the same as
314 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() except that there is no internal copy and
315 therefore I<pubexp> should not be modified or freed after the call.
317 EVP_PKEY_CTX_set_rsa_keygen_primes() sets the number of primes for
318 RSA key generation to I<primes>. If not specified 2 is used.
320 EVP_PKEY_CTX_set_rsa_mgf1_md_name() sets the MGF1 digest for RSA
321 padding schemes to the digest named I<mdname>. If the RSA algorithm
322 implementation for the selected provider supports it then the digest will be
323 fetched using the properties I<mdprops>. If not explicitly set the signing
324 digest is used. The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>
325 or B<RSA_PKCS1_PSS_PADDING>.
327 EVP_PKEY_CTX_set_rsa_mgf1_md() does the same as
328 EVP_PKEY_CTX_set_rsa_mgf1_md_name() except that the name of the digest is
329 inferred from the supplied I<md> and it is not possible to specify any
332 EVP_PKEY_CTX_get_rsa_mgf1_md_name() gets the name of the MGF1
333 digest algorithm for I<ctx>. If not explicitly set the signing digest is used.
334 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING> or
335 B<RSA_PKCS1_PSS_PADDING>.
337 EVP_PKEY_CTX_get_rsa_mgf1_md() does the same as
338 EVP_PKEY_CTX_get_rsa_mgf1_md_name() except that it returns a pointer to an
339 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
340 returned. The EVP_MD object may be NULL if the digest is not one of these (such
341 as a digest only implemented in a third party provider).
343 EVP_PKEY_CTX_set_rsa_oaep_md_name() sets the message digest type
344 used in RSA OAEP to the digest named I<mdname>. If the RSA algorithm
345 implementation for the selected provider supports it then the digest will be
346 fetched using the properties I<mdprops>. The padding mode must have been set to
347 B<RSA_PKCS1_OAEP_PADDING>.
349 EVP_PKEY_CTX_set_rsa_oaep_md() does the same as
350 EVP_PKEY_CTX_set_rsa_oaep_md_name() except that the name of the digest is
351 inferred from the supplied I<md> and it is not possible to specify any
354 EVP_PKEY_CTX_get_rsa_oaep_md_name() gets the message digest
355 algorithm name used in RSA OAEP and stores it in the buffer I<name> which is of
356 size I<namelen>. The padding mode must have been set to
357 B<RSA_PKCS1_OAEP_PADDING>. The buffer should be sufficiently large for any
358 expected digest algorithm names or the function will fail.
360 EVP_PKEY_CTX_get_rsa_oaep_md() does the same as
361 EVP_PKEY_CTX_get_rsa_oaep_md_name() except that it returns a pointer to an
362 EVP_MD object instead. Note that only known, built-in EVP_MD objects will be
363 returned. The EVP_MD object may be NULL if the digest is not one of these (such
364 as a digest only implemented in a third party provider).
366 EVP_PKEY_CTX_set0_rsa_oaep_label() sets the RSA OAEP label to binary data
367 I<label> and its length in bytes to I<len>. If I<label> is NULL or I<len> is 0,
368 the label is cleared. The library takes ownership of the label so the
369 caller should not free the original memory pointed to by I<label>.
370 The padding mode must have been set to B<RSA_PKCS1_OAEP_PADDING>.
372 EVP_PKEY_CTX_get0_rsa_oaep_label() gets the RSA OAEP label to
373 I<label>. The return value is the label length. The padding mode
374 must have been set to B<RSA_PKCS1_OAEP_PADDING>. The resulting pointer is owned
375 by the library and should not be freed by the caller.
377 B<RSA_PKCS1_WITH_TLS_PADDING> is used when decrypting an RSA encrypted TLS
378 pre-master secret in a TLS ClientKeyExchange message. It is the same as
379 RSA_PKCS1_PADDING except that it additionally verifies that the result is the
380 correct length and the first two bytes are the protocol version initially
381 requested by the client. If the encrypted content is publicly invalid then the
382 decryption will fail. However, if the padding checks fail then decryption will
383 still appear to succeed but a random TLS premaster secret will be returned
384 instead. This padding mode accepts two parameters which can be set using the
385 L<EVP_PKEY_CTX_set_params(3)> function. These are
386 OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION and
387 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, both of which are expected to be
388 unsigned integers. Normally only the first of these will be set and represents
389 the TLS protocol version that was first requested by the client (e.g. 0x0303 for
390 TLSv1.2, 0x0302 for TLSv1.1 etc). Historically some buggy clients would use the
391 negotiated protocol version instead of the protocol version first requested. If
392 this behaviour should be tolerated then
393 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION should be set to the actual
394 negotiated protocol version. Otherwise it should be left unset.
396 =head2 DSA parameters
398 EVP_PKEY_CTX_set_dsa_paramgen_bits() sets the number of bits used for DSA
399 parameter generation to B<nbits>. If not specified, 2048 is used.
401 EVP_PKEY_CTX_set_dsa_paramgen_q_bits() sets the number of bits in the subprime
402 parameter I<q> for DSA parameter generation to I<qbits>. If not specified, 224
403 is used. If a digest function is specified below, this parameter is ignored and
404 instead, the number of bits in I<q> matches the size of the digest.
406 EVP_PKEY_CTX_set_dsa_paramgen_md() sets the digest function used for DSA
407 parameter generation to I<md>. If not specified, one of SHA-1, SHA-224, or
408 SHA-256 is selected to match the bit length of I<q> above.
410 EVP_PKEY_CTX_set_dsa_paramgen_md_props() sets the digest function used for DSA
411 parameter generation using I<md_name> and I<md_properties> to retrieve the
412 digest from a provider.
413 If not specified, I<md_name> will be set to one of SHA-1, SHA-224, or
414 SHA-256 depending on the bit length of I<q> above. I<md_properties> is a
415 property query string that has a default value of '' if not specified.
417 EVP_PKEY_CTX_set_dsa_paramgen_gindex() sets the I<gindex> used by the generator
418 G. The default value is -1 which uses unverifiable g, otherwise a positive value
419 uses verifiable g. This value must be saved if key validation of g is required,
420 since it is not part of a persisted key.
422 EVP_PKEY_CTX_set_dsa_paramgen_seed() sets the I<seed> to use for generation
423 rather than using a randomly generated value for the seed. This is useful for
424 testing purposes only and can fail if the seed does not produce primes for both
425 p & q on its first iteration. This value must be saved if key validation of
426 p, q, and verifiable g are required, since it is not part of a persisted key.
428 EVP_PKEY_CTX_set_dsa_paramgen_type() sets the generation type to use FIPS186-4
429 generation if I<name> is "fips186_4", or FIPS186-2 generation if I<name> is
430 "fips186_2". The default value for the default provider is "fips186_2". The
431 default value for the FIPS provider is "fips186_4".
435 EVP_PKEY_CTX_set_dh_paramgen_prime_len() sets the length of the DH prime
436 parameter I<p> for DH parameter generation. If this function is not called then
437 2048 is used. Only accepts lengths greater than or equal to 256.
439 EVP_PKEY_CTX_set_dh_paramgen_subprime_len() sets the length of the DH
440 optional subprime parameter I<q> for DH parameter generation. The default is
441 256 if the prime is at least 2048 bits long or 160 otherwise. The DH paramgen
442 type must have been set to "fips186_4".
444 EVP_PKEY_CTX_set_dh_paramgen_generator() sets DH generator to I<gen> for DH
445 parameter generation. If not specified 2 is used.
447 EVP_PKEY_CTX_set_dh_paramgen_type() sets the key type for DH parameter
448 generation. The supported parameters are:
452 =item B<DH_PARAMGEN_TYPE_GROUP>
454 Use a named group. If only the safe prime parameter I<p> is set this can be
455 used to select a ffdhe safe prime group of the correct size.
457 =item B<DH_PARAMGEN_TYPE_FIPS_186_4>
459 FIPS186-4 FFC parameter generator.
461 =item B<DH_PARAMGEN_TYPE_FIPS_186_2>
463 FIPS186-2 FFC parameter generator (X9.42 DH).
465 =item B<DH_PARAMGEN_TYPE_GENERATOR>
467 Uses a safe prime generator g (PKCS#3 format).
471 The default in the default provider is B<DH_PARAMGEN_TYPE_GENERATOR> for the
472 "DH" keytype, and B<DH_PARAMGEN_TYPE_FIPS_186_2> for the "DHX" keytype. In the
473 FIPS provider the default value is B<DH_PARAMGEN_TYPE_GROUP> for the "DH"
474 keytype and <B<DH_PARAMGEN_TYPE_FIPS_186_4> for the "DHX" keytype.
476 EVP_PKEY_CTX_set_dh_paramgen_gindex() sets the I<gindex> used by the generator G.
477 The default value is -1 which uses unverifiable g, otherwise a positive value
478 uses verifiable g. This value must be saved if key validation of g is required,
479 since it is not part of a persisted key.
481 EVP_PKEY_CTX_set_dh_paramgen_seed() sets the I<seed> to use for generation
482 rather than using a randomly generated value for the seed. This is useful for
483 testing purposes only and can fail if the seed does not produce primes for both
484 p & q on its first iteration. This value must be saved if key validation of p, q,
485 and verifiable g are required, since it is not part of a persisted key.
487 EVP_PKEY_CTX_set_dh_pad() sets the DH padding mode.
488 If I<pad> is 1 the shared secret is padded with zeros up to the size of the DH
490 If I<pad> is zero (the default) then no padding is performed.
492 EVP_PKEY_CTX_set_dh_nid() sets the DH parameters to values corresponding to
493 I<nid> as defined in RFC7919 or RFC3526. The I<nid> parameter must be
494 B<NID_ffdhe2048>, B<NID_ffdhe3072>, B<NID_ffdhe4096>, B<NID_ffdhe6144>,
495 B<NID_ffdhe8192>, B<NID_modp_1536>, B<NID_modp_2048>, B<NID_modp_3072>,
496 B<NID_modp_4096>, B<NID_modp_6144>, B<NID_modp_8192> or B<NID_undef> to clear
497 the stored value. This function can be called during parameter or key generation.
498 The nid parameter and the rfc5114 parameter are mutually exclusive.
500 EVP_PKEY_CTX_set_dh_rfc5114() and EVP_PKEY_CTX_set_dhx_rfc5114() both set the
501 DH parameters to the values defined in RFC5114. The I<rfc5114> parameter must
502 be 1, 2 or 3 corresponding to RFC5114 sections 2.1, 2.2 and 2.3. or 0 to clear
503 the stored value. This macro can be called during parameter generation. The
504 I<ctx> must have a key type of B<EVP_PKEY_DHX>.
505 The rfc5114 parameter and the nid parameter are mutually exclusive.
507 =head2 DH key derivation function parameters
509 Note that all of the following functions require that the I<ctx> parameter has
510 a private key type of B<EVP_PKEY_DHX>. When using key derivation, the output of
511 EVP_PKEY_derive() is the output of the KDF instead of the DH shared secret.
512 The KDF output is typically used as a Key Encryption Key (KEK) that in turn
513 encrypts a Content Encryption Key (CEK).
515 EVP_PKEY_CTX_set_dh_kdf_type() sets the key derivation function type to I<kdf>
516 for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
517 B<EVP_PKEY_DH_KDF_X9_42> which uses the key derivation specified in RFC2631
518 (based on the keying algorithm described in X9.42). When using key derivation,
519 the I<kdf_oid>, I<kdf_md> and I<kdf_outlen> parameters must also be specified.
521 EVP_PKEY_CTX_get_dh_kdf_type() gets the key derivation function type for I<ctx>
522 used for DH key derivation. Possible values are B<EVP_PKEY_DH_KDF_NONE> and
523 B<EVP_PKEY_DH_KDF_X9_42>.
525 EVP_PKEY_CTX_set0_dh_kdf_oid() sets the key derivation function object
526 identifier to I<oid> for DH key derivation. This OID should identify the
527 algorithm to be used with the Content Encryption Key.
528 The library takes ownership of the object identifier so the caller should not
529 free the original memory pointed to by I<oid>.
531 EVP_PKEY_CTX_get0_dh_kdf_oid() gets the key derivation function oid for I<ctx>
532 used for DH key derivation. The resulting pointer is owned by the library and
533 should not be freed by the caller.
535 EVP_PKEY_CTX_set_dh_kdf_md() sets the key derivation function message digest to
536 I<md> for DH key derivation. Note that RFC2631 specifies that this digest should
537 be SHA1 but OpenSSL tolerates other digests.
539 EVP_PKEY_CTX_get_dh_kdf_md() gets the key derivation function message digest for
540 I<ctx> used for DH key derivation.
542 EVP_PKEY_CTX_set_dh_kdf_outlen() sets the key derivation function output length
543 to I<len> for DH key derivation.
545 EVP_PKEY_CTX_get_dh_kdf_outlen() gets the key derivation function output length
546 for I<ctx> used for DH key derivation.
548 EVP_PKEY_CTX_set0_dh_kdf_ukm() sets the user key material to I<ukm> and its
549 length to I<len> for DH key derivation. This parameter is optional and
550 corresponds to the partyAInfo field in RFC2631 terms. The specification
551 requires that it is 512 bits long but this is not enforced by OpenSSL.
552 The library takes ownership of the user key material so the caller should not
553 free the original memory pointed to by I<ukm>.
555 EVP_PKEY_CTX_get0_dh_kdf_ukm() gets the user key material for I<ctx>.
556 The return value is the user key material length. The resulting pointer is owned
557 by the library and should not be freed by the caller.
561 Use EVP_PKEY_CTX_set_group_name() (described above) to set the curve name to
562 I<name> for parameter and key generation.
564 EVP_PKEY_CTX_set_ec_paramgen_curve_nid() does the same as
565 EVP_PKEY_CTX_set_group_name(), but is specific to EC and uses a I<nid> rather
568 For EC parameter generation, one of EVP_PKEY_CTX_set_group_name()
569 or EVP_PKEY_CTX_set_ec_paramgen_curve_nid() must be called or an error occurs
570 because there is no default curve.
571 These function can also be called to set the curve explicitly when
572 generating an EC key.
574 EVP_PKEY_CTX_get_group_name() (described above) can be used to obtain the curve
575 name that's currently set with I<ctx>.
577 EVP_PKEY_CTX_set_ec_param_enc() sets the EC parameter encoding to I<param_enc>
578 when generating EC parameters or an EC key. The encoding can be
579 B<OPENSSL_EC_EXPLICIT_CURVE> for explicit parameters (the default in versions
580 of OpenSSL before 1.1.0) or B<OPENSSL_EC_NAMED_CURVE> to use named curve form.
581 For maximum compatibility the named curve form should be used. Note: the
582 B<OPENSSL_EC_NAMED_CURVE> value was added in OpenSSL 1.1.0; previous
583 versions should use 0 instead.
585 =head2 ECDH parameters
587 EVP_PKEY_CTX_set_ecdh_cofactor_mode() sets the cofactor mode to I<cofactor_mode>
588 for ECDH key derivation. Possible values are 1 to enable cofactor
589 key derivation, 0 to disable it and -1 to clear the stored cofactor mode and
590 fallback to the private key cofactor mode.
592 EVP_PKEY_CTX_get_ecdh_cofactor_mode() returns the cofactor mode for I<ctx> used
593 for ECDH key derivation. Possible values are 1 when cofactor key derivation is
594 enabled and 0 otherwise.
596 =head2 ECDH key derivation function parameters
598 EVP_PKEY_CTX_set_ecdh_kdf_type() sets the key derivation function type to
599 I<kdf> for ECDH key derivation. Possible values are B<EVP_PKEY_ECDH_KDF_NONE>
600 and B<EVP_PKEY_ECDH_KDF_X9_63> which uses the key derivation specified in X9.63.
601 When using key derivation, the I<kdf_md> and I<kdf_outlen> parameters must
604 EVP_PKEY_CTX_get_ecdh_kdf_type() returns the key derivation function type for
605 I<ctx> used for ECDH key derivation. Possible values are
606 B<EVP_PKEY_ECDH_KDF_NONE> and B<EVP_PKEY_ECDH_KDF_X9_63>.
608 EVP_PKEY_CTX_set_ecdh_kdf_md() sets the key derivation function message digest
609 to I<md> for ECDH key derivation. Note that X9.63 specifies that this digest
610 should be SHA1 but OpenSSL tolerates other digests.
612 EVP_PKEY_CTX_get_ecdh_kdf_md() gets the key derivation function message digest
613 for I<ctx> used for ECDH key derivation.
615 EVP_PKEY_CTX_set_ecdh_kdf_outlen() sets the key derivation function output
616 length to I<len> for ECDH key derivation.
618 EVP_PKEY_CTX_get_ecdh_kdf_outlen() gets the key derivation function output
619 length for I<ctx> used for ECDH key derivation.
621 EVP_PKEY_CTX_set0_ecdh_kdf_ukm() sets the user key material to I<ukm> for ECDH
622 key derivation. This parameter is optional and corresponds to the shared info in
623 X9.63 terms. The library takes ownership of the user key material so the caller
624 should not free the original memory pointed to by I<ukm>.
626 EVP_PKEY_CTX_get0_ecdh_kdf_ukm() gets the user key material for I<ctx>.
627 The return value is the user key material length. The resulting pointer is owned
628 by the library and should not be freed by the caller.
630 =head2 Other parameters
632 EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and EVP_PKEY_CTX_get1_id_len()
633 are used to manipulate the special identifier field for specific signature
634 algorithms such as SM2. The EVP_PKEY_CTX_set1_id() sets an ID pointed by I<id> with
635 the length I<id_len> to the library. The library takes a copy of the id so that
636 the caller can safely free the original memory pointed to by I<id>.
637 EVP_PKEY_CTX_get1_id_len() returns the length of the ID set via a previous call
638 to EVP_PKEY_CTX_set1_id(). The length is usually used to allocate adequate
639 memory for further calls to EVP_PKEY_CTX_get1_id(). EVP_PKEY_CTX_get1_id()
640 returns the previously set ID value to caller in I<id>. The caller should
641 allocate adequate memory space for the I<id> before calling EVP_PKEY_CTX_get1_id().
643 EVP_PKEY_CTX_set_kem_op() sets the KEM operation to run. This can be set after
644 EVP_PKEY_encapsulate_init() or EVP_PKEY_decapsulate_init() to select the
645 kem operation. RSA is the only key type that supports encapsulation currently,
646 and as there is no default operation for the RSA type, this function must be
647 called before EVP_PKEY_encapsulate() or EVP_PKEY_decapsulate().
651 All other functions described on this page return a positive value for success
652 and 0 or a negative value for failure. In particular a return value of -2
653 indicates the operation is not supported by the public key algorithm.
657 L<EVP_PKEY_CTX_set_params(3)>,
658 L<EVP_PKEY_CTX_new(3)>,
659 L<EVP_PKEY_encrypt(3)>,
660 L<EVP_PKEY_decrypt(3)>,
662 L<EVP_PKEY_verify(3)>,
663 L<EVP_PKEY_verify_recover(3)>,
664 L<EVP_PKEY_derive(3)>,
665 L<EVP_PKEY_keygen(3)>
666 L<EVP_PKEY_encapsulate(3)>
667 L<EVP_PKEY_decapsulate(3)>
671 EVP_PKEY_CTX_get_rsa_oaep_md_name(), EVP_PKEY_CTX_get_rsa_mgf1_md_name(),
672 EVP_PKEY_CTX_set_rsa_mgf1_md_name(), EVP_PKEY_CTX_set_rsa_oaep_md_name(),
673 EVP_PKEY_CTX_set_dsa_paramgen_md_props(), EVP_PKEY_CTX_set_dsa_paramgen_gindex(),
674 EVP_PKEY_CTX_set_dsa_paramgen_type(), EVP_PKEY_CTX_set_dsa_paramgen_seed(),
675 EVP_PKEY_CTX_set_group_name() and EVP_PKEY_CTX_get_group_name()
676 were added in OpenSSL 3.0.
678 The EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and
679 EVP_PKEY_CTX_get1_id_len() macros were added in 1.1.1, other functions were
680 added in OpenSSL 1.0.0.
682 In OpenSSL 1.1.1 and below the functions were mostly macros.
683 From OpenSSL 3.0 they are all functions.
685 EVP_PKEY_CTX_set_rsa_keygen_pubexp(), EVP_PKEY_CTX_get0_dh_kdf_ukm(),
686 and EVP_PKEY_CTX_get0_ecdh_kdf_ukm() were deprecated in OpenSSL 3.0.
690 Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
692 Licensed under the Apache License 2.0 (the "License"). You may not use
693 this file except in compliance with the License. You can obtain a copy
694 in the file LICENSE in the source distribution or at
695 L<https://www.openssl.org/source/license.html>.