4 {- join("\n", @autowarntext) -}
10 openssl-ec - EC key processing
16 [B<-inform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
17 [B<-outform> B<DER>|B<PEM>]
18 [B<-in> I<filename>|I<uri>]
30 [B<-conv_form> I<arg>]
31 [B<-param_enc> I<arg>]
34 {- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_provider_synopsis -}
38 The L<openssl-ec(1)> command processes EC keys. They can be converted between
39 various forms and their components printed out. B<Note> OpenSSL uses the
40 private key format specified in 'SEC 1: Elliptic Curve Cryptography'
41 (http://www.secg.org/). To convert an OpenSSL EC private key into the
42 PKCS#8 private key format use the L<openssl-pkcs8(1)> command.
50 Print out a usage message.
52 =item B<-inform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
54 The key input format; unspecified by default.
55 See L<openssl-format-options(1)> for details.
57 =item B<-outform> B<DER>|B<PEM>
59 The key output format; the default is B<PEM>.
60 See L<openssl-format-options(1)> for details.
62 Private keys are an SEC1 private key or PKCS#8 format.
63 Public keys are a B<SubjectPublicKeyInfo> as specified in IETF RFC 3280.
65 =item B<-in> I<filename>|I<uri>
67 This specifies the input to read a key from or standard input if this
68 option is not specified. If the key is encrypted a pass phrase will be
71 =item B<-out> I<filename>
73 This specifies the output filename to write a key to or standard output by
74 is not specified. If any encryption options are set then a pass phrase will be
75 prompted for. The output filename should B<not> be the same as the input
78 =item B<-passin> I<arg>, B<-passout> I<arg>
80 The password source for the input and output file.
81 For more information about the format of B<arg>
82 see L<openssl-passphrase-options(1)>.
84 =item B<-des>|B<-des3>|B<-idea>
86 These options encrypt the private key with the DES, triple DES, IDEA or
87 any other cipher supported by OpenSSL before outputting it. A pass phrase is
89 If none of these options is specified the key is written in plain text. This
90 means that using this command to read in an encrypted key with no
91 encryption option can be used to remove the pass phrase from a key, or by
92 setting the encryption options it can be use to add or change the pass phrase.
93 These options can only be used with PEM format output files.
97 Prints out the public, private key components and parameters.
101 This option prevents output of the encoded version of the key.
105 Print the elliptic curve parameters.
109 By default a private key is read from the input.
110 With this option a public key is read instead.
111 If the input contains no public key but a private key, its public part is used.
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
119 =item B<-conv_form> I<arg>
121 This specifies how the points on the elliptic curve are converted
122 into octet strings. Possible values are: B<compressed>, B<uncompressed> (the
123 default value) 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> I<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.
147 {- $OpenSSL::safe::opt_engine_item -}
149 {- $OpenSSL::safe::opt_provider_item -}
153 The L<openssl-pkey(1)> command is capable of performing all the operations
154 this command can, as well as supporting other public key types.
158 The documentation for the L<openssl-pkey(1)> command contains examples
159 equivalent to the ones listed here.
161 To encrypt a private key using triple DES:
163 openssl ec -in key.pem -des3 -out keyout.pem
165 To convert a private key from PEM to DER format:
167 openssl ec -in key.pem -outform DER -out keyout.der
169 To print out the components of a private key to standard output:
171 openssl ec -in key.pem -text -noout
173 To just output the public part of a private key:
175 openssl ec -in key.pem -pubout -out pubkey.pem
177 To change the parameters encoding to B<explicit>:
179 openssl ec -in key.pem -param_enc explicit -out keyout.pem
181 To change the point conversion form to B<compressed>:
183 openssl ec -in key.pem -conv_form compressed -out keyout.pem
189 L<openssl-ecparam(1)>,
195 The B<-engine> option was deprecated in OpenSSL 3.0.
197 The B<-conv_form> and B<-no_public> options are no longer supported
198 with keys loaded from an engine in OpenSSL 3.0.
202 Copyright 2003-2021 The OpenSSL Project Authors. All Rights Reserved.
204 Licensed under the Apache License 2.0 (the "License"). You may not use
205 this file except in compliance with the License. You can obtain a copy
206 in the file LICENSE in the source distribution or at
207 L<https://www.openssl.org/source/license.html>.