5 EC_KEY_get_method, EC_KEY_set_method, EC_KEY_new_ex,
6 EC_KEY_new, EC_KEY_get_flags, EC_KEY_set_flags, EC_KEY_clear_flags,
7 EC_KEY_new_by_curve_name_ex, EC_KEY_new_by_curve_name, EC_KEY_free,
8 EC_KEY_copy, EC_KEY_dup, EC_KEY_up_ref, EC_KEY_get0_engine,
9 EC_KEY_get0_group, EC_KEY_set_group, EC_KEY_get0_private_key,
10 EC_KEY_set_private_key, EC_KEY_get0_public_key, EC_KEY_set_public_key,
12 EC_KEY_set_conv_form, EC_KEY_set_asn1_flag,
13 EC_KEY_decoded_from_explicit_params, EC_KEY_precompute_mult,
14 EC_KEY_generate_key, EC_KEY_check_key, EC_KEY_set_public_key_affine_coordinates,
15 EC_KEY_oct2key, EC_KEY_key2buf, EC_KEY_oct2priv, EC_KEY_priv2oct,
16 EC_KEY_priv2buf - Functions for creating, destroying and manipulating
21 #include <openssl/ec.h>
23 EC_KEY *EC_KEY_new_ex(OPENSSL_CTX *ctx, const char *propq);
24 EC_KEY *EC_KEY_new(void);
25 int EC_KEY_get_flags(const EC_KEY *key);
26 void EC_KEY_set_flags(EC_KEY *key, int flags);
27 void EC_KEY_clear_flags(EC_KEY *key, int flags);
28 EC_KEY *EC_KEY_new_by_curve_name_ex(OPENSSL_CTX *ctx, const char *propq,
30 EC_KEY *EC_KEY_new_by_curve_name(int nid);
31 void EC_KEY_free(EC_KEY *key);
32 EC_KEY *EC_KEY_copy(EC_KEY *dst, const EC_KEY *src);
33 EC_KEY *EC_KEY_dup(const EC_KEY *src);
34 int EC_KEY_up_ref(EC_KEY *key);
35 ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey);
36 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key);
37 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group);
38 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key);
39 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *prv);
40 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key);
41 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub);
42 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key);
43 void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform);
44 void EC_KEY_set_asn1_flag(EC_KEY *eckey, int asn1_flag);
45 int EC_KEY_decoded_from_explicit_params(const EC_KEY *key);
46 int EC_KEY_generate_key(EC_KEY *key);
47 int EC_KEY_check_key(const EC_KEY *key);
48 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y);
49 const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key);
50 int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth);
52 int EC_KEY_oct2key(EC_KEY *eckey, const unsigned char *buf, size_t len, BN_CTX *ctx);
53 size_t EC_KEY_key2buf(const EC_KEY *eckey, point_conversion_form_t form,
54 unsigned char **pbuf, BN_CTX *ctx);
56 int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
57 size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len);
59 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf);
61 Deprecated since OpenSSL 3.0:
63 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx);
67 An EC_KEY represents a public key and, optionally, the associated private
69 A new EC_KEY with no associated curve can be constructed by calling
70 EC_KEY_new_ex() and specifying the associated library context in I<ctx>
71 (see L<OPENSSL_CTX(3)>) and property query string I<propq>.
72 The I<ctx> parameter may be NULL in which case the default library context is
74 The reference count for the newly created EC_KEY is initially
76 A curve can be associated with the EC_KEY by calling
79 EC_KEY_new() is the same as EC_KEY_new_ex() except that the default library
80 context is always used.
82 Alternatively a new EC_KEY can be constructed by calling
83 EC_KEY_new_by_curve_name_ex() and supplying the nid of the associated
84 curve, the library context to be used I<ctx> (see L<OPENSSL_CTX(3)>) and any
85 property query string I<propq>.
86 The I<ctx> parameter may be NULL in which case the default library context is
87 used. The I<propq> value may also be NULL.
88 See L<EC_GROUP_new(3)> for a description of curve names.
89 This function simply wraps calls to EC_KEY_new_ex() and
90 EC_GROUP_new_by_curve_name_ex().
92 EC_KEY_new_by_curve_name() is the same as EC_KEY_new_by_curve_name_ex()
93 except that the default library context is always used and a NULL property query
96 Calling EC_KEY_free() decrements the reference count for the EC_KEY object,
97 and if it has dropped to zero then frees the memory associated with it. If
98 I<key> is NULL nothing is done.
100 EC_KEY_copy() copies the contents of the EC_KEY in I<src> into I<dest>.
102 EC_KEY_dup() creates a new EC_KEY object and copies I<ec_key> into it.
104 EC_KEY_up_ref() increments the reference count associated with the EC_KEY
107 EC_KEY_get0_engine() returns a handle to the ENGINE that has been set for
110 EC_KEY_generate_key() generates a new public and private key for the supplied
111 I<eckey> object. I<eckey> must have an EC_GROUP object associated with it
112 before calling this function. The private key is a random integer (0 < priv_key
113 < order, where I<order> is the order of the EC_GROUP object). The public key is
114 an EC_POINT on the curve calculated by multiplying the generator for the
115 curve by the private key.
117 EC_KEY_check_key() performs various sanity checks on the EC_KEY object to
118 confirm that it is valid.
120 EC_KEY_set_public_key_affine_coordinates() sets the public key for I<key> based
121 on its affine co-ordinates; i.e., it constructs an EC_POINT object based on
122 the supplied I<x> and I<y> values and sets the public key to be this
123 EC_POINT. It also performs certain sanity checks on the key to confirm
126 The functions EC_KEY_get0_group(), EC_KEY_set_group(),
127 EC_KEY_get0_private_key(), EC_KEY_set_private_key(), EC_KEY_get0_public_key(),
128 and EC_KEY_set_public_key() get and set the EC_GROUP object, the private key,
129 and the EC_POINT public key for the I<key> respectively.
131 The functions EC_KEY_get_conv_form() and EC_KEY_set_conv_form() get and set the
132 point_conversion_form for the I<key>. For a description of
133 point_conversion_forms please see L<EC_POINT_new(3)>.
135 EC_KEY_set_flags() sets the flags in the I<flags> parameter on the EC_KEY
136 object. Any flags that are already set are left set. The flags currently
137 defined are EC_FLAG_NON_FIPS_ALLOW and EC_FLAG_FIPS_CHECKED. In
138 addition there is the flag EC_FLAG_COFACTOR_ECDH which is specific to ECDH.
139 EC_KEY_get_flags() returns the current flags that are set for this EC_KEY.
140 EC_KEY_clear_flags() clears the flags indicated by the I<flags> parameter; all
141 other flags are left in their existing state.
143 EC_KEY_set_asn1_flag() sets the asn1_flag on the underlying EC_GROUP object
144 (if set). Refer to L<EC_GROUP_copy(3)> for further information on the
147 EC_KEY_decoded_from_explicit_params() returns 1 if the group of the I<key> was
148 decoded from data with explicitly encoded group parameters, -1 if the I<key>
149 is NULL or the group parameters are missing, and 0 otherwise.
151 Although deprecated in OpenSSL 3.0 and should no longer be used,
152 EC_KEY_precompute_mult() stores multiples of the underlying EC_GROUP generator
153 for faster point multiplication. See also L<EC_POINT_add(3)>.
154 Modern versions should instead switch to named curves which OpenSSL has
155 hardcoded lookup tables for.
157 EC_KEY_oct2key() and EC_KEY_key2buf() are identical to the functions
158 EC_POINT_oct2point() and EC_POINT_point2buf() except they use the public key
159 EC_POINT in I<eckey>.
161 EC_KEY_oct2priv() and EC_KEY_priv2oct() convert between the private key
162 component of I<eckey> and octet form. The octet form consists of the content
163 octets of the I<privateKey> OCTET STRING in an I<ECPrivateKey> ASN.1 structure.
165 The function EC_KEY_priv2oct() must be supplied with a buffer long enough to
166 store the octet form. The return value provides the number of octets stored.
167 Calling the function with a NULL buffer will not perform the conversion but
168 will just return the required buffer length.
170 The function EC_KEY_priv2buf() allocates a buffer of suitable length and writes
171 an EC_KEY to it in octet format. The allocated buffer is written to I<*pbuf>
172 and its length is returned. The caller must free up the allocated buffer with a
173 call to OPENSSL_free(). Since the allocated buffer value is written to I<*pbuf>
174 the I<pbuf> parameter B<MUST NOT> be B<NULL>.
176 EC_KEY_priv2buf() converts an EC_KEY private key into an allocated buffer.
180 EC_KEY_new_with_libctx(), EC_KEY_new(), EC_KEY_new_by_curve_name_ex(),
181 EC_KEY_new_by_curve_name() and EC_KEY_dup() return a pointer to the newly
182 created EC_KEY object, or NULL on error.
184 EC_KEY_get_flags() returns the flags associated with the EC_KEY object as an
187 EC_KEY_copy() returns a pointer to the destination key, or NULL on error.
189 EC_KEY_get0_engine() returns a pointer to an ENGINE, or NULL if it wasn't set.
191 EC_KEY_up_ref(), EC_KEY_set_group(), EC_KEY_set_private_key(),
192 EC_KEY_set_public_key(), EC_KEY_precompute_mult(), EC_KEY_generate_key(),
193 EC_KEY_check_key(), EC_KEY_set_public_key_affine_coordinates(),
194 EC_KEY_oct2key() and EC_KEY_oct2priv() return 1 on success or 0 on error.
196 EC_KEY_get0_group() returns the EC_GROUP associated with the EC_KEY.
198 EC_KEY_get0_private_key() returns the private key associated with the EC_KEY.
200 EC_KEY_get_conv_form() return the point_conversion_form for the EC_KEY.
202 EC_KEY_key2buf(), EC_KEY_priv2oct() and EC_KEY_priv2buf() return the length
203 of the buffer or 0 on error.
207 L<crypto(7)>, L<EC_GROUP_new(3)>,
208 L<EC_GROUP_copy(3)>, L<EC_POINT_new(3)>,
210 L<EC_GFp_simple_method(3)>,
211 L<d2i_ECPKParameters(3)>,
216 EC_KEY_precompute_mult() was deprecated in OpenSSL 3.0.
220 Copyright 2013-2020 The OpenSSL Project Authors. All Rights Reserved.
222 Licensed under the Apache License 2.0 (the "License"). You may not use
223 this file except in compliance with the License. You can obtain a copy
224 in the file LICENSE in the source distribution or at
225 L<https://www.openssl.org/source/license.html>.