34 The B<ec> command processes EC keys. They can be converted between various
35 forms and their components printed out. B<Note> OpenSSL uses the
36 private key format specified in 'SEC 1: Elliptic Curve Cryptography'
37 (http://www.secg.org/). To convert an OpenSSL EC private key into the
38 PKCS#8 private key format use the B<pkcs8> command.
46 Print out a usage message.
48 =item B<-inform DER|PEM>
50 This specifies the input format. The B<DER> option with a private key uses
51 an ASN.1 DER encoded SEC1 private key. When used with a public key it
52 uses the SubjectPublicKeyInfo structure as specified in RFC 3280.
53 The B<PEM> form is the default format: it consists of the B<DER> format base64
54 encoded with additional header and footer lines. In the case of a private key
55 PKCS#8 format is also accepted.
57 =item B<-outform DER|PEM>
59 This specifies the output format, the options have the same meaning and default
60 as the B<-inform> option.
64 This specifies the input filename to read a key from or standard input if this
65 option is not specified. If the key is encrypted a pass phrase will be
70 The input file password source. For more information about the format of B<arg>
71 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
73 =item B<-out filename>
75 This specifies the output filename to write a key to or standard output by
76 is not specified. If any encryption options are set then a pass phrase will be
77 prompted for. The output filename should B<not> be the same as the input
82 The output file password source. For more information about the format of B<arg>
83 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
85 =item B<-des|-des3|-idea>
87 These options encrypt the private key with the DES, triple DES, IDEA or
88 any other cipher supported by OpenSSL before outputting it. A pass phrase is
90 If none of these options is specified the key is written in plain text. This
91 means that using the B<ec> utility to read in an encrypted key with no
92 encryption option can be used to remove the pass phrase from a key, or by
93 setting the encryption options it can be use to add or change the pass phrase.
94 These options can only be used with PEM format output files.
98 Prints out the public, private key components and parameters.
102 This option prevents output of the encoded version of the key.
106 By default, a private key is read from the input file. With this option a
107 public key is read instead.
111 By default a private key is output. With this option a public
112 key will be output instead. This option is automatically set if the input is
117 This specifies how the points on the elliptic curve are converted
118 into octet strings. Possible values are: B<compressed> (the default
119 value), B<uncompressed> and B<hybrid>. For more information regarding
120 the point conversion forms please read the X9.62 standard.
121 B<Note> Due to patent issues the B<compressed> option is disabled
122 by default for binary curves and can be enabled by defining
123 the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
125 =item B<-param_enc arg>
127 This specifies how the elliptic curve parameters are encoded.
128 Possible value are: B<named_curve>, i.e. the ec parameters are
129 specified by an OID, or B<explicit> where the ec parameters are
130 explicitly given (see RFC 3279 for the definition of the
131 EC parameters structures). The default value is B<named_curve>.
132 B<Note> the B<implicitlyCA> alternative, as specified in RFC 3279,
133 is currently not implemented in OpenSSL.
137 This option omits the public key components from the private key output.
141 This option checks the consistency of an EC private or public key.
145 Specifying an engine (by its unique B<id> string) will cause B<ec>
146 to attempt to obtain a functional reference to the specified engine,
147 thus initialising it if needed. The engine will then be set as the default
148 for all available algorithms.
154 The PEM private key format uses the header and footer lines:
156 -----BEGIN EC PRIVATE KEY-----
157 -----END EC PRIVATE KEY-----
159 The PEM public key format uses the header and footer lines:
161 -----BEGIN PUBLIC KEY-----
162 -----END PUBLIC KEY-----
166 To encrypt a private key using triple DES:
168 openssl ec -in key.pem -des3 -out keyout.pem
170 To convert a private key from PEM to DER format:
172 openssl ec -in key.pem -outform DER -out keyout.der
174 To print out the components of a private key to standard output:
176 openssl ec -in key.pem -text -noout
178 To just output the public part of a private key:
180 openssl ec -in key.pem -pubout -out pubkey.pem
182 To change the parameters encoding to B<explicit>:
184 openssl ec -in key.pem -param_enc explicit -out keyout.pem
186 To change the point conversion form to B<compressed>:
188 openssl ec -in key.pem -conv_form compressed -out keyout.pem
192 L<ecparam(1)>, L<dsa(1)>, L<rsa(1)>
196 Copyright 2003-2017 The OpenSSL Project Authors. All Rights Reserved.
198 Licensed under the Apache License 2.0 (the "License"). You may not use
199 this file except in compliance with the License. You can obtain a copy
200 in the file LICENSE in the source distribution or at
201 L<https://www.openssl.org/source/license.html>.