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 This option prints out the value of the public key component of the key.
110 By default, a private key is read from the input file. With this option a
111 public key is read instead.
115 By default a private key is output. With this option a public
116 key will be output instead. This option is automatically set if the input is
121 This specifies how the points on the elliptic curve are converted
122 into octet strings. Possible values are: B<compressed> (the default
123 value), B<uncompressed> and B<hybrid>. For more information regarding
124 the point conversion forms please read the X9.62 standard.
125 B<Note> Due to patent issues the B<compressed> option is disabled
126 by default for binary curves and can be enabled by defining
127 the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
129 =item B<-param_enc arg>
131 This specifies how the elliptic curve parameters are encoded.
132 Possible value are: B<named_curve>, i.e. the ec parameters are
133 specified by an OID, or B<explicit> where the ec parameters are
134 explicitly given (see RFC 3279 for the definition of the
135 EC parameters structures). The default value is B<named_curve>.
136 B<Note> the B<implicitlyCA> alternative, as specified in RFC 3279,
137 is currently not implemented in OpenSSL.
141 This option omits the public key components from the private key output.
145 This option checks the consistency of an EC private or public key.
149 Specifying an engine (by its unique B<id> string) will cause B<ec>
150 to attempt to obtain a functional reference to the specified engine,
151 thus initialising it if needed. The engine will then be set as the default
152 for all available algorithms.
158 The PEM private key format uses the header and footer lines:
160 -----BEGIN EC PRIVATE KEY-----
161 -----END EC PRIVATE KEY-----
163 The PEM public key format uses the header and footer lines:
165 -----BEGIN PUBLIC KEY-----
166 -----END PUBLIC KEY-----
170 To encrypt a private key using triple DES:
172 openssl ec -in key.pem -des3 -out keyout.pem
174 To convert a private key from PEM to DER format:
176 openssl ec -in key.pem -outform DER -out keyout.der
178 To print out the components of a private key to standard output:
180 openssl ec -in key.pem -text -noout
182 To just output the public part of a private key:
184 openssl ec -in key.pem -pubout -out pubkey.pem
186 To change the parameters encoding to B<explicit>:
188 openssl ec -in key.pem -param_enc explicit -out keyout.pem
190 To change the point conversion form to B<compressed>:
192 openssl ec -in key.pem -conv_form compressed -out keyout.pem
196 L<ecparam(1)>, L<dsa(1)>, L<rsa(1)>
200 Copyright 2003-2017 The OpenSSL Project Authors. All Rights Reserved.
202 Licensed under the OpenSSL license (the "License"). You may not use
203 this file except in compliance with the License. You can obtain a copy
204 in the file LICENSE in the source distribution or at
205 L<https://www.openssl.org/source/license.html>.