1EVP_PKEY_CTX_CTRL(3ossl) OpenSSL EVP_PKEY_CTX_CTRL(3ossl)
2
6 EVP_PKEY_CTX_ctrl, EVP_PKEY_CTX_ctrl_str, EVP_PKEY_CTX_ctrl_uint64,
7 EVP_PKEY_CTX_md, EVP_PKEY_CTX_set_signature_md,
8 EVP_PKEY_CTX_get_signature_md, EVP_PKEY_CTX_set_mac_key,
9 EVP_PKEY_CTX_set_group_name, EVP_PKEY_CTX_get_group_name,
10 EVP_PKEY_CTX_set_rsa_padding, EVP_PKEY_CTX_get_rsa_padding,
11 EVP_PKEY_CTX_set_rsa_pss_saltlen, EVP_PKEY_CTX_get_rsa_pss_saltlen,
12 EVP_PKEY_CTX_set_rsa_keygen_bits, EVP_PKEY_CTX_set_rsa_keygen_pubexp,
13 EVP_PKEY_CTX_set1_rsa_keygen_pubexp,
14 EVP_PKEY_CTX_set_rsa_keygen_primes, EVP_PKEY_CTX_set_rsa_mgf1_md_name,
15 EVP_PKEY_CTX_set_rsa_mgf1_md, EVP_PKEY_CTX_get_rsa_mgf1_md,
16 EVP_PKEY_CTX_get_rsa_mgf1_md_name, EVP_PKEY_CTX_set_rsa_oaep_md_name,
17 EVP_PKEY_CTX_set_rsa_oaep_md, EVP_PKEY_CTX_get_rsa_oaep_md,
18 EVP_PKEY_CTX_get_rsa_oaep_md_name, EVP_PKEY_CTX_set0_rsa_oaep_label,
19 EVP_PKEY_CTX_get0_rsa_oaep_label, EVP_PKEY_CTX_set_dsa_paramgen_bits,
20 EVP_PKEY_CTX_set_dsa_paramgen_q_bits, EVP_PKEY_CTX_set_dsa_paramgen_md,
21 EVP_PKEY_CTX_set_dsa_paramgen_md_props,
22 EVP_PKEY_CTX_set_dsa_paramgen_gindex,
23 EVP_PKEY_CTX_set_dsa_paramgen_type, EVP_PKEY_CTX_set_dsa_paramgen_seed,
24 EVP_PKEY_CTX_set_dh_paramgen_prime_len,
25 EVP_PKEY_CTX_set_dh_paramgen_subprime_len,
26 EVP_PKEY_CTX_set_dh_paramgen_generator,
27 EVP_PKEY_CTX_set_dh_paramgen_type, EVP_PKEY_CTX_set_dh_paramgen_gindex,
28 EVP_PKEY_CTX_set_dh_paramgen_seed, EVP_PKEY_CTX_set_dh_rfc5114,
29 EVP_PKEY_CTX_set_dhx_rfc5114, EVP_PKEY_CTX_set_dh_pad,
30 EVP_PKEY_CTX_set_dh_nid, EVP_PKEY_CTX_set_dh_kdf_type,
31 EVP_PKEY_CTX_get_dh_kdf_type, EVP_PKEY_CTX_set0_dh_kdf_oid,
32 EVP_PKEY_CTX_get0_dh_kdf_oid, EVP_PKEY_CTX_set_dh_kdf_md,
33 EVP_PKEY_CTX_get_dh_kdf_md, EVP_PKEY_CTX_set_dh_kdf_outlen,
34 EVP_PKEY_CTX_get_dh_kdf_outlen, EVP_PKEY_CTX_set0_dh_kdf_ukm,
35 EVP_PKEY_CTX_get0_dh_kdf_ukm, EVP_PKEY_CTX_set_ec_paramgen_curve_nid,
36 EVP_PKEY_CTX_set_ec_param_enc, EVP_PKEY_CTX_set_ecdh_cofactor_mode,
37 EVP_PKEY_CTX_get_ecdh_cofactor_mode, EVP_PKEY_CTX_set_ecdh_kdf_type,
38 EVP_PKEY_CTX_get_ecdh_kdf_type, EVP_PKEY_CTX_set_ecdh_kdf_md,
39 EVP_PKEY_CTX_get_ecdh_kdf_md, EVP_PKEY_CTX_set_ecdh_kdf_outlen,
40 EVP_PKEY_CTX_get_ecdh_kdf_outlen, EVP_PKEY_CTX_set0_ecdh_kdf_ukm,
41 EVP_PKEY_CTX_get0_ecdh_kdf_ukm, EVP_PKEY_CTX_set1_id,
42 EVP_PKEY_CTX_get1_id, EVP_PKEY_CTX_get1_id_len, EVP_PKEY_CTX_set_kem_op
43 - algorithm specific control operations
44
46 #include <openssl/evp.h>
47 int EVP_PKEY_CTX_ctrl(EVP_PKEY_CTX *ctx, int keytype, int optype,
49 int cmd, int p1, void *p2);
50 int EVP_PKEY_CTX_ctrl_uint64(EVP_PKEY_CTX *ctx, int keytype, int optype,
51 int cmd, uint64_t value);
52 int EVP_PKEY_CTX_ctrl_str(EVP_PKEY_CTX *ctx, const char *type,
53 const char *value);
54 int EVP_PKEY_CTX_md(EVP_PKEY_CTX *ctx, int optype, int cmd, const char *md);
56 int EVP_PKEY_CTX_set_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
58 int EVP_PKEY_CTX_get_signature_md(EVP_PKEY_CTX *ctx, const EVP_MD **pmd);
59 int EVP_PKEY_CTX_set_mac_key(EVP_PKEY_CTX *ctx, const unsigned char *key,
61 int len);
62 int EVP_PKEY_CTX_set_group_name(EVP_PKEY_CTX *ctx, const char *name);
63 int EVP_PKEY_CTX_get_group_name(EVP_PKEY_CTX *ctx, char *name, size_t namelen);
64 int EVP_PKEY_CTX_set_kem_op(EVP_PKEY_CTX *ctx, const char *op);
66 #include <openssl/rsa.h>
68 int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int pad);
70 int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx, int *pad);
71 int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int saltlen);
72 int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int *saltlen);
73 int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx, int mbits);
74 int EVP_PKEY_CTX_set1_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
75 int EVP_PKEY_CTX_set_rsa_keygen_primes(EVP_PKEY_CTX *ctx, int primes);
76 int EVP_PKEY_CTX_set_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
77 const char *mdprops);
78 int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
79 int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
80 int EVP_PKEY_CTX_get_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, char *name,
81 size_t namelen);
82 int EVP_PKEY_CTX_set_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
83 const char *mdprops);
84 int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
85 int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
86 int EVP_PKEY_CTX_get_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, char *name,
87 size_t namelen);
88 int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx, void *label,
89 int len);
90 int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char **label);
91 #include <openssl/dsa.h>
93 int EVP_PKEY_CTX_set_dsa_paramgen_bits(EVP_PKEY_CTX *ctx, int nbits);
95 int EVP_PKEY_CTX_set_dsa_paramgen_q_bits(EVP_PKEY_CTX *ctx, int qbits);
96 int EVP_PKEY_CTX_set_dsa_paramgen_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
97 int EVP_PKEY_CTX_set_dsa_paramgen_md_props(EVP_PKEY_CTX *ctx,
98 const char *md_name,
99 const char *md_properties);
100 int EVP_PKEY_CTX_set_dsa_paramgen_type(EVP_PKEY_CTX *ctx, const char *name);
101 int EVP_PKEY_CTX_set_dsa_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
102 int EVP_PKEY_CTX_set_dsa_paramgen_seed(EVP_PKEY_CTX *ctx,
103 const unsigned char *seed,
104 size_t seedlen);
105 #include <openssl/dh.h>
107 int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int len);
109 int EVP_PKEY_CTX_set_dh_paramgen_subprime_len(EVP_PKEY_CTX *ctx, int len);
110 int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);
111 int EVP_PKEY_CTX_set_dh_paramgen_type(EVP_PKEY_CTX *ctx, int type);
112 int EVP_PKEY_CTX_set_dh_pad(EVP_PKEY_CTX *ctx, int pad);
113 int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid);
114 int EVP_PKEY_CTX_set_dh_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
115 int EVP_PKEY_CTX_set_dhx_rfc5114(EVP_PKEY_CTX *ctx, int rfc5114);
116 int EVP_PKEY_CTX_set_dh_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
117 int EVP_PKEY_CTX_set_dh_paramgen_seed(EVP_PKEY_CTX *ctx,
118 const unsigned char *seed,
119 size_t seedlen);
120 int EVP_PKEY_CTX_set_dh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
121 int EVP_PKEY_CTX_get_dh_kdf_type(EVP_PKEY_CTX *ctx);
122 int EVP_PKEY_CTX_set0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT *oid);
123 int EVP_PKEY_CTX_get0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT **oid);
124 int EVP_PKEY_CTX_set_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
125 int EVP_PKEY_CTX_get_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
126 int EVP_PKEY_CTX_set_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
127 int EVP_PKEY_CTX_get_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
128 int EVP_PKEY_CTX_set0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
129 #include <openssl/ec.h>
131 int EVP_PKEY_CTX_set_ec_paramgen_curve_nid(EVP_PKEY_CTX *ctx, int nid);
133 int EVP_PKEY_CTX_set_ec_param_enc(EVP_PKEY_CTX *ctx, int param_enc);
134 int EVP_PKEY_CTX_set_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx, int cofactor_mode);
135 int EVP_PKEY_CTX_get_ecdh_cofactor_mode(EVP_PKEY_CTX *ctx);
136 int EVP_PKEY_CTX_set_ecdh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
137 int EVP_PKEY_CTX_get_ecdh_kdf_type(EVP_PKEY_CTX *ctx);
138 int EVP_PKEY_CTX_set_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
139 int EVP_PKEY_CTX_get_ecdh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
140 int EVP_PKEY_CTX_set_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
141 int EVP_PKEY_CTX_get_ecdh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
142 int EVP_PKEY_CTX_set0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
143 int EVP_PKEY_CTX_set1_id(EVP_PKEY_CTX *ctx, void *id, size_t id_len);
145 int EVP_PKEY_CTX_get1_id(EVP_PKEY_CTX *ctx, void *id);
146 int EVP_PKEY_CTX_get1_id_len(EVP_PKEY_CTX *ctx, size_t *id_len);
147 The following functions have been deprecated since OpenSSL 3.0, and can
149 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
150 version value, see openssl_user_macros(7):
151 #include <openssl/rsa.h>
153 int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp);
155 #include <openssl/dh.h>
157 int EVP_PKEY_CTX_get0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
159 #include <openssl/ec.h>
161 int EVP_PKEY_CTX_get0_ecdh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
163
165 EVP_PKEY_CTX_ctrl() sends a control operation to the context ctx. The
166 key type used must match keytype if it is not -1. The parameter optype
167 is a mask indicating which operations the control can be applied to.
168 The control command is indicated in cmd and any additional arguments in
169 p1 and p2.
170 For cmd = EVP_PKEY_CTRL_SET_MAC_KEY, p1 is the length of the MAC key,
172 and p2 is the MAC key. This is used by Poly1305, SipHash, HMAC and
173 CMAC.
174 Applications will not normally call EVP_PKEY_CTX_ctrl() directly but
176 will instead call one of the algorithm specific functions below.
177 EVP_PKEY_CTX_ctrl_uint64() is a wrapper that directly passes a uint64
179 value as p2 to EVP_PKEY_CTX_ctrl().
180 EVP_PKEY_CTX_ctrl_str() allows an application to send an algorithm
182 specific control operation to a context ctx in string form. This is
183 intended to be used for options specified on the command line or in
184 text files. The commands supported are documented in the openssl
185 utility command line pages for the option -pkeyopt which is supported
186 by the pkeyutl, genpkey and req commands.
187 EVP_PKEY_CTX_md() sends a message digest control operation to the
189 context ctx. The message digest is specified by its name md.
190 EVP_PKEY_CTX_set_signature_md() sets the message digest type used in a
192 signature. It can be used in the RSA, DSA and ECDSA algorithms.
193 EVP_PKEY_CTX_get_signature_md()gets the message digest type used in a
195 signature. It can be used in the RSA, DSA and ECDSA algorithms.
196 Key generation typically involves setting up parameters to be used and
198 generating the private and public key data. Some algorithm
199 implementations allow private key data to be set explicitly using
200 EVP_PKEY_CTX_set_mac_key(). In this case key generation is simply the
201 process of setting up the parameters for the key and then setting the
202 raw key data to the value explicitly. Normally applications would call
203 EVP_PKEY_new_raw_private_key(3) or similar functions instead.
204 EVP_PKEY_CTX_set_mac_key() can be used with any of the algorithms
206 supported by the EVP_PKEY_new_raw_private_key(3) function.
207 EVP_PKEY_CTX_set_group_name() sets the group name to name for parameter
209 and key generation. For example for EC keys this will set the curve
210 name and for DH keys it will set the name of the finite field group.
211 EVP_PKEY_CTX_get_group_name() finds the group name that's currently set
213 with ctx, and writes it to the location that name points at, as long as
214 its size namelen is large enough to store that name, including a
215 terminating NUL byte.
216 RSA parameters
218 EVP_PKEY_CTX_set_rsa_padding() sets the RSA padding mode for ctx. The
219 pad parameter can take the value RSA_PKCS1_PADDING for PKCS#1 padding,
220 RSA_NO_PADDING for no padding, RSA_PKCS1_OAEP_PADDING for OAEP padding
221 (encrypt and decrypt only), RSA_X931_PADDING for X9.31 padding
222 (signature operations only), RSA_PKCS1_PSS_PADDING (sign and verify
223 only) and RSA_PKCS1_WITH_TLS_PADDING for TLS RSA ClientKeyExchange
224 message padding (decryption only).
225 Two RSA padding modes behave differently if
227 EVP_PKEY_CTX_set_signature_md() is used. If this function is called for
228 PKCS#1 padding the plaintext buffer is an actual digest value and is
229 encapsulated in a DigestInfo structure according to PKCS#1 when signing
230 and this structure is expected (and stripped off) when verifying. If
231 this control is not used with RSA and PKCS#1 padding then the supplied
232 data is used directly and not encapsulated. In the case of X9.31
233 padding for RSA the algorithm identifier byte is added or checked and
234 removed if this control is called. If it is not called then the first
235 byte of the plaintext buffer is expected to be the algorithm identifier
236 byte.
237 EVP_PKEY_CTX_get_rsa_padding() gets the RSA padding mode for ctx.
239 EVP_PKEY_CTX_set_rsa_pss_saltlen() sets the RSA PSS salt length to
241 saltlen. As its name implies it is only supported for PSS padding. If
242 this function is not called then the maximum salt length is used when
243 signing and auto detection when verifying. Three special values are
244 supported:
245 RSA_PSS_SALTLEN_DIGEST
247 sets the salt length to the digest length.
248 RSA_PSS_SALTLEN_MAX
250 sets the salt length to the maximum permissible value.
251 RSA_PSS_SALTLEN_AUTO
253 causes the salt length to be automatically determined based on the
254 PSS block structure when verifying. When signing, it has the same
255 meaning as RSA_PSS_SALTLEN_MAX.
256 EVP_PKEY_CTX_get_rsa_pss_saltlen() gets the RSA PSS salt length for
258 ctx. The padding mode must already have been set to
259 RSA_PKCS1_PSS_PADDING.
260 EVP_PKEY_CTX_set_rsa_keygen_bits() sets the RSA key length for RSA key
262 generation to bits. If not specified 2048 bits is used.
263 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() sets the public exponent value
265 for RSA key generation to the value stored in pubexp. Currently it
266 should be an odd integer. In accordance with the OpenSSL naming
267 convention, the pubexp pointer must be freed independently of the
268 EVP_PKEY_CTX (ie, it is internally copied). If not specified 65537 is
269 used.
270 EVP_PKEY_CTX_set_rsa_keygen_pubexp() does the same as
272 EVP_PKEY_CTX_set1_rsa_keygen_pubexp() except that there is no internal
273 copy and therefore pubexp should not be modified or freed after the
274 call.
275 EVP_PKEY_CTX_set_rsa_keygen_primes() sets the number of primes for RSA
277 key generation to primes. If not specified 2 is used.
278 EVP_PKEY_CTX_set_rsa_mgf1_md_name() sets the MGF1 digest for RSA
280 padding schemes to the digest named mdname. If the RSA algorithm
281 implementation for the selected provider supports it then the digest
282 will be fetched using the properties mdprops. If not explicitly set the
283 signing digest is used. The padding mode must have been set to
284 RSA_PKCS1_OAEP_PADDING or RSA_PKCS1_PSS_PADDING.
285 EVP_PKEY_CTX_set_rsa_mgf1_md() does the same as
287 EVP_PKEY_CTX_set_rsa_mgf1_md_name() except that the name of the digest
288 is inferred from the supplied md and it is not possible to specify any
289 properties.
290 EVP_PKEY_CTX_get_rsa_mgf1_md_name() gets the name of the MGF1 digest
292 algorithm for ctx. If not explicitly set the signing digest is used.
293 The padding mode must have been set to RSA_PKCS1_OAEP_PADDING or
294 RSA_PKCS1_PSS_PADDING.
295 EVP_PKEY_CTX_get_rsa_mgf1_md() does the same as
297 EVP_PKEY_CTX_get_rsa_mgf1_md_name() except that it returns a pointer to
298 an EVP_MD object instead. Note that only known, built-in EVP_MD objects
299 will be returned. The EVP_MD object may be NULL if the digest is not
300 one of these (such as a digest only implemented in a third party
301 provider).
302 EVP_PKEY_CTX_set_rsa_oaep_md_name() sets the message digest type used
304 in RSA OAEP to the digest named mdname. If the RSA algorithm
305 implementation for the selected provider supports it then the digest
306 will be fetched using the properties mdprops. The padding mode must
307 have been set to RSA_PKCS1_OAEP_PADDING.
308 EVP_PKEY_CTX_set_rsa_oaep_md() does the same as
310 EVP_PKEY_CTX_set_rsa_oaep_md_name() except that the name of the digest
311 is inferred from the supplied md and it is not possible to specify any
312 properties.
313 EVP_PKEY_CTX_get_rsa_oaep_md_name() gets the message digest algorithm
315 name used in RSA OAEP and stores it in the buffer name which is of size
316 namelen. The padding mode must have been set to RSA_PKCS1_OAEP_PADDING.
317 The buffer should be sufficiently large for any expected digest
318 algorithm names or the function will fail.
319 EVP_PKEY_CTX_get_rsa_oaep_md() does the same as
321 EVP_PKEY_CTX_get_rsa_oaep_md_name() except that it returns a pointer to
322 an EVP_MD object instead. Note that only known, built-in EVP_MD objects
323 will be returned. The EVP_MD object may be NULL if the digest is not
324 one of these (such as a digest only implemented in a third party
325 provider).
326 EVP_PKEY_CTX_set0_rsa_oaep_label() sets the RSA OAEP label to binary
328 data label and its length in bytes to len. If label is NULL or len is
329 0, the label is cleared. The library takes ownership of the label so
330 the caller should not free the original memory pointed to by label.
331 The padding mode must have been set to RSA_PKCS1_OAEP_PADDING.
332 EVP_PKEY_CTX_get0_rsa_oaep_label() gets the RSA OAEP label to label.
334 The return value is the label length. The padding mode must have been
335 set to RSA_PKCS1_OAEP_PADDING. The resulting pointer is owned by the
336 library and should not be freed by the caller.
337 RSA_PKCS1_WITH_TLS_PADDING is used when decrypting an RSA encrypted TLS
339 pre-master secret in a TLS ClientKeyExchange message. It is the same as
340 RSA_PKCS1_PADDING except that it additionally verifies that the result
341 is the correct length and the first two bytes are the protocol version
342 initially requested by the client. If the encrypted content is publicly
343 invalid then the decryption will fail. However, if the padding checks
344 fail then decryption will still appear to succeed but a random TLS
345 premaster secret will be returned instead. This padding mode accepts
346 two parameters which can be set using the EVP_PKEY_CTX_set_params(3)
347 function. These are OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION and
348 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, both of which are
349 expected to be unsigned integers. Normally only the first of these will
350 be set and represents the TLS protocol version that was first requested
351 by the client (e.g. 0x0303 for TLSv1.2, 0x0302 for TLSv1.1 etc).
352 Historically some buggy clients would use the negotiated protocol
353 version instead of the protocol version first requested. If this
354 behaviour should be tolerated then
355 OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION should be set to the
356 actual negotiated protocol version. Otherwise it should be left unset.
357 Similarly to the RSA_PKCS1_WITH_TLS_PADDING above, since OpenSSL
359 version 3.1.0, the use of RSA_PKCS1_PADDING will return a randomly
360 generated message instead of padding errors in case padding checks
361 fail. Applications that want to remain secure while using earlier
362 versions of OpenSSL, still need to handle both the error code from the
363 RSA decryption operation and the returned message in a side channel
364 secure manner. This protection against Bleichenbacher attacks can be
365 disabled by setting the OSSL_ASYM_CIPHER_PARAM_IMPLICIT_REJECTION (an
366 unsigned integer) to 0.
367 DSA parameters
369 EVP_PKEY_CTX_set_dsa_paramgen_bits() sets the number of bits used for
370 DSA parameter generation to nbits. If not specified, 2048 is used.
371 EVP_PKEY_CTX_set_dsa_paramgen_q_bits() sets the number of bits in the
373 subprime parameter q for DSA parameter generation to qbits. If not
374 specified, 224 is used. If a digest function is specified below, this
375 parameter is ignored and instead, the number of bits in q matches the
376 size of the digest.
377 EVP_PKEY_CTX_set_dsa_paramgen_md() sets the digest function used for
379 DSA parameter generation to md. If not specified, one of SHA-1,
380 SHA-224, or SHA-256 is selected to match the bit length of q above.
381 EVP_PKEY_CTX_set_dsa_paramgen_md_props() sets the digest function used
383 for DSA parameter generation using md_name and md_properties to
384 retrieve the digest from a provider. If not specified, md_name will be
385 set to one of SHA-1, SHA-224, or SHA-256 depending on the bit length of
386 q above. md_properties is a property query string that has a default
387 value of '' if not specified.
388 EVP_PKEY_CTX_set_dsa_paramgen_gindex() sets the gindex used by the
390 generator G. The default value is -1 which uses unverifiable g,
391 otherwise a positive value uses verifiable g. This value must be saved
392 if key validation of g is required, since it is not part of a persisted
393 key.
394 EVP_PKEY_CTX_set_dsa_paramgen_seed() sets the seed to use for
396 generation rather than using a randomly generated value for the seed.
397 This is useful for testing purposes only and can fail if the seed does
398 not produce primes for both p & q on its first iteration. This value
399 must be saved if key validation of p, q, and verifiable g are required,
400 since it is not part of a persisted key.
401 EVP_PKEY_CTX_set_dsa_paramgen_type() sets the generation type to use
403 FIPS186-4 generation if name is "fips186_4", or FIPS186-2 generation if
404 name is "fips186_2". The default value for the default provider is
405 "fips186_2". The default value for the FIPS provider is "fips186_4".
406 DH parameters
408 EVP_PKEY_CTX_set_dh_paramgen_prime_len() sets the length of the DH
409 prime parameter p for DH parameter generation. If this function is not
410 called then 2048 is used. Only accepts lengths greater than or equal to
411 256.
412 EVP_PKEY_CTX_set_dh_paramgen_subprime_len() sets the length of the DH
414 optional subprime parameter q for DH parameter generation. The default
415 is 256 if the prime is at least 2048 bits long or 160 otherwise. The DH
416 paramgen type must have been set to "fips186_4".
417 EVP_PKEY_CTX_set_dh_paramgen_generator() sets DH generator to gen for
419 DH parameter generation. If not specified 2 is used.
420 EVP_PKEY_CTX_set_dh_paramgen_type() sets the key type for DH parameter
422 generation. The supported parameters are:
423 DH_PARAMGEN_TYPE_GROUP
425 Use a named group. If only the safe prime parameter p is set this
426 can be used to select a ffdhe safe prime group of the correct size.
427 DH_PARAMGEN_TYPE_FIPS_186_4
429 FIPS186-4 FFC parameter generator.
430 DH_PARAMGEN_TYPE_FIPS_186_2
432 FIPS186-2 FFC parameter generator (X9.42 DH).
433 DH_PARAMGEN_TYPE_GENERATOR
435 Uses a safe prime generator g (PKCS#3 format).
436 The default in the default provider is DH_PARAMGEN_TYPE_GENERATOR for
438 the "DH" keytype, and DH_PARAMGEN_TYPE_FIPS_186_2 for the "DHX"
439 keytype. In the FIPS provider the default value is
440 DH_PARAMGEN_TYPE_GROUP for the "DH" keytype and
441 <DH_PARAMGEN_TYPE_FIPS_186_4 for the "DHX" keytype.
442 EVP_PKEY_CTX_set_dh_paramgen_gindex() sets the gindex used by the
444 generator G. The default value is -1 which uses unverifiable g,
445 otherwise a positive value uses verifiable g. This value must be saved
446 if key validation of g is required, since it is not part of a persisted
447 key.
448 EVP_PKEY_CTX_set_dh_paramgen_seed() sets the seed to use for generation
450 rather than using a randomly generated value for the seed. This is
451 useful for testing purposes only and can fail if the seed does not
452 produce primes for both p & q on its first iteration. This value must
453 be saved if key validation of p, q, and verifiable g are required,
454 since it is not part of a persisted key.
455 EVP_PKEY_CTX_set_dh_pad() sets the DH padding mode. If pad is 1 the
457 shared secret is padded with zeros up to the size of the DH prime p.
458 If pad is zero (the default) then no padding is performed.
459 EVP_PKEY_CTX_set_dh_nid() sets the DH parameters to values
461 corresponding to nid as defined in RFC7919 or RFC3526. The nid
462 parameter must be NID_ffdhe2048, NID_ffdhe3072, NID_ffdhe4096,
463 NID_ffdhe6144, NID_ffdhe8192, NID_modp_1536, NID_modp_2048,
464 NID_modp_3072, NID_modp_4096, NID_modp_6144, NID_modp_8192 or NID_undef
465 to clear the stored value. This function can be called during parameter
466 or key generation. The nid parameter and the rfc5114 parameter are
467 mutually exclusive.
468 EVP_PKEY_CTX_set_dh_rfc5114() and EVP_PKEY_CTX_set_dhx_rfc5114() both
470 set the DH parameters to the values defined in RFC5114. The rfc5114
471 parameter must be 1, 2 or 3 corresponding to RFC5114 sections 2.1, 2.2
472 and 2.3. or 0 to clear the stored value. This macro can be called
473 during parameter generation. The ctx must have a key type of
474 EVP_PKEY_DHX. The rfc5114 parameter and the nid parameter are mutually
475 exclusive.
476 DH key derivation function parameters
478 Note that all of the following functions require that the ctx parameter
479 has a private key type of EVP_PKEY_DHX. When using key derivation, the
480 output of EVP_PKEY_derive() is the output of the KDF instead of the DH
481 shared secret. The KDF output is typically used as a Key Encryption
482 Key (KEK) that in turn encrypts a Content Encryption Key (CEK).
483 EVP_PKEY_CTX_set_dh_kdf_type() sets the key derivation function type to
485 kdf for DH key derivation. Possible values are EVP_PKEY_DH_KDF_NONE and
486 EVP_PKEY_DH_KDF_X9_42 which uses the key derivation specified in
487 RFC2631 (based on the keying algorithm described in X9.42). When using
488 key derivation, the kdf_oid, kdf_md and kdf_outlen parameters must also
489 be specified.
490 EVP_PKEY_CTX_get_dh_kdf_type() gets the key derivation function type
492 for ctx used for DH key derivation. Possible values are
493 EVP_PKEY_DH_KDF_NONE and EVP_PKEY_DH_KDF_X9_42.
494 EVP_PKEY_CTX_set0_dh_kdf_oid() sets the key derivation function object
496 identifier to oid for DH key derivation. This OID should identify the
497 algorithm to be used with the Content Encryption Key. The library
498 takes ownership of the object identifier so the caller should not free
499 the original memory pointed to by oid.
500 EVP_PKEY_CTX_get0_dh_kdf_oid() gets the key derivation function oid for
502 ctx used for DH key derivation. The resulting pointer is owned by the
503 library and should not be freed by the caller.
504 EVP_PKEY_CTX_set_dh_kdf_md() sets the key derivation function message
506 digest to md for DH key derivation. Note that RFC2631 specifies that
507 this digest should be SHA1 but OpenSSL tolerates other digests.
508 EVP_PKEY_CTX_get_dh_kdf_md() gets the key derivation function message
510 digest for ctx used for DH key derivation.
511 EVP_PKEY_CTX_set_dh_kdf_outlen() sets the key derivation function
513 output length to len for DH key derivation.
514 EVP_PKEY_CTX_get_dh_kdf_outlen() gets the key derivation function
516 output length for ctx used for DH key derivation.
517 EVP_PKEY_CTX_set0_dh_kdf_ukm() sets the user key material to ukm and
519 its length to len for DH key derivation. This parameter is optional and
520 corresponds to the partyAInfo field in RFC2631 terms. The specification
521 requires that it is 512 bits long but this is not enforced by OpenSSL.
522 The library takes ownership of the user key material so the caller
523 should not free the original memory pointed to by ukm.
524 EVP_PKEY_CTX_get0_dh_kdf_ukm() gets the user key material for ctx. The
526 return value is the user key material length. The resulting pointer is
527 owned by the library and should not be freed by the caller.
528 EC parameters
530 Use EVP_PKEY_CTX_set_group_name() (described above) to set the curve
531 name to name for parameter and key generation.
532 EVP_PKEY_CTX_set_ec_paramgen_curve_nid() does the same as
534 EVP_PKEY_CTX_set_group_name(), but is specific to EC and uses a nid
535 rather than a name string.
536 For EC parameter generation, one of EVP_PKEY_CTX_set_group_name() or
538 EVP_PKEY_CTX_set_ec_paramgen_curve_nid() must be called or an error
539 occurs because there is no default curve. These function can also be
540 called to set the curve explicitly when generating an EC key.
541 EVP_PKEY_CTX_get_group_name() (described above) can be used to obtain
543 the curve name that's currently set with ctx.
544 EVP_PKEY_CTX_set_ec_param_enc() sets the EC parameter encoding to
546 param_enc when generating EC parameters or an EC key. The encoding can
547 be OPENSSL_EC_EXPLICIT_CURVE for explicit parameters (the default in
548 versions of OpenSSL before 1.1.0) or OPENSSL_EC_NAMED_CURVE to use
549 named curve form. For maximum compatibility the named curve form
550 should be used. Note: the OPENSSL_EC_NAMED_CURVE value was added in
551 OpenSSL 1.1.0; previous versions should use 0 instead.
552 ECDH parameters
554 EVP_PKEY_CTX_set_ecdh_cofactor_mode() sets the cofactor mode to
555 cofactor_mode for ECDH key derivation. Possible values are 1 to enable
556 cofactor key derivation, 0 to disable it and -1 to clear the stored
557 cofactor mode and fallback to the private key cofactor mode.
558 EVP_PKEY_CTX_get_ecdh_cofactor_mode() returns the cofactor mode for ctx
560 used for ECDH key derivation. Possible values are 1 when cofactor key
561 derivation is enabled and 0 otherwise.
562 ECDH key derivation function parameters
564 EVP_PKEY_CTX_set_ecdh_kdf_type() sets the key derivation function type
565 to kdf for ECDH key derivation. Possible values are
566 EVP_PKEY_ECDH_KDF_NONE and EVP_PKEY_ECDH_KDF_X9_63 which uses the key
567 derivation specified in X9.63. When using key derivation, the kdf_md
568 and kdf_outlen parameters must also be specified.
569 EVP_PKEY_CTX_get_ecdh_kdf_type() returns the key derivation function
571 type for ctx used for ECDH key derivation. Possible values are
572 EVP_PKEY_ECDH_KDF_NONE and EVP_PKEY_ECDH_KDF_X9_63.
573 EVP_PKEY_CTX_set_ecdh_kdf_md() sets the key derivation function message
575 digest to md for ECDH key derivation. Note that X9.63 specifies that
576 this digest should be SHA1 but OpenSSL tolerates other digests.
577 EVP_PKEY_CTX_get_ecdh_kdf_md() gets the key derivation function message
579 digest for ctx used for ECDH key derivation.
580 EVP_PKEY_CTX_set_ecdh_kdf_outlen() sets the key derivation function
582 output length to len for ECDH key derivation.
583 EVP_PKEY_CTX_get_ecdh_kdf_outlen() gets the key derivation function
585 output length for ctx used for ECDH key derivation.
586 EVP_PKEY_CTX_set0_ecdh_kdf_ukm() sets the user key material to ukm for
588 ECDH key derivation. This parameter is optional and corresponds to the
589 shared info in X9.63 terms. The library takes ownership of the user key
590 material so the caller should not free the original memory pointed to
591 by ukm.
592 EVP_PKEY_CTX_get0_ecdh_kdf_ukm() gets the user key material for ctx.
594 The return value is the user key material length. The resulting pointer
595 is owned by the library and should not be freed by the caller.
596 Other parameters
598 EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and
599 EVP_PKEY_CTX_get1_id_len() are used to manipulate the special
600 identifier field for specific signature algorithms such as SM2. The
601 EVP_PKEY_CTX_set1_id() sets an ID pointed by id with the length id_len
602 to the library. The library takes a copy of the id so that the caller
603 can safely free the original memory pointed to by id.
604 EVP_PKEY_CTX_get1_id_len() returns the length of the ID set via a
605 previous call to EVP_PKEY_CTX_set1_id(). The length is usually used to
606 allocate adequate memory for further calls to EVP_PKEY_CTX_get1_id().
607 EVP_PKEY_CTX_get1_id() returns the previously set ID value to caller in
608 id. The caller should allocate adequate memory space for the id before
609 calling EVP_PKEY_CTX_get1_id().
610 EVP_PKEY_CTX_set_kem_op() sets the KEM operation to run. This can be
612 set after EVP_PKEY_encapsulate_init() or EVP_PKEY_decapsulate_init() to
613 select the kem operation. RSA is the only key type that supports
614 encapsulation currently, and as there is no default operation for the
615 RSA type, this function must be called before EVP_PKEY_encapsulate() or
616 EVP_PKEY_decapsulate().
617
619 All other functions described on this page return a positive value for
620 success and 0 or a negative value for failure. In particular a return
621 value of -2 indicates the operation is not supported by the public key
622 algorithm.
623
625 EVP_PKEY_CTX_set_params(3), EVP_PKEY_CTX_new(3), EVP_PKEY_encrypt(3),
626 EVP_PKEY_decrypt(3), EVP_PKEY_sign(3), EVP_PKEY_verify(3),
627 EVP_PKEY_verify_recover(3), EVP_PKEY_derive(3), EVP_PKEY_keygen(3)
628 EVP_PKEY_encapsulate(3) EVP_PKEY_decapsulate(3)
629
631 EVP_PKEY_CTX_get_rsa_oaep_md_name(),
632 EVP_PKEY_CTX_get_rsa_mgf1_md_name(),
633 EVP_PKEY_CTX_set_rsa_mgf1_md_name(),
634 EVP_PKEY_CTX_set_rsa_oaep_md_name(),
635 EVP_PKEY_CTX_set_dsa_paramgen_md_props(),
636 EVP_PKEY_CTX_set_dsa_paramgen_gindex(),
637 EVP_PKEY_CTX_set_dsa_paramgen_type(),
638 EVP_PKEY_CTX_set_dsa_paramgen_seed(), EVP_PKEY_CTX_set_group_name() and
639 EVP_PKEY_CTX_get_group_name() were added in OpenSSL 3.0.
640 The EVP_PKEY_CTX_set1_id(), EVP_PKEY_CTX_get1_id() and
642 EVP_PKEY_CTX_get1_id_len() macros were added in 1.1.1, other functions
643 were added in OpenSSL 1.0.0.
644 In OpenSSL 1.1.1 and below the functions were mostly macros. From
646 OpenSSL 3.0 they are all functions.
647 EVP_PKEY_CTX_set_rsa_keygen_pubexp(), EVP_PKEY_CTX_get0_dh_kdf_ukm(),
649 and EVP_PKEY_CTX_get0_ecdh_kdf_ukm() were deprecated in OpenSSL 3.0.
650
652 Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
653 Licensed under the Apache License 2.0 (the "License"). You may not use
655 this file except in compliance with the License. You can obtain a copy
656 in the file LICENSE in the source distribution or at
657 <https://www.openssl.org/source/license.html>.
6583.0.9 2023-07-27 EVP_PKEY_CTX_CTRL(3ossl)