4 {- join("\n", @autowarntext) -}
10 openssl-ec - EC key processing
16 [B<-inform> B<DER>|B<PEM>]
17 [B<-outform> B<DER>|B<PEM>]
30 [B<-conv_form> I<arg>]
31 [B<-param_enc> I<arg>]
34 {- $OpenSSL::safe::opt_engine_synopsis -}
35 {- $OpenSSL::safe::opt_provider_synopsis -}
37 =for openssl ifdef engine
41 This command has been deprecated.
42 The L<openssl-pkey(1)> command should be used instead.
44 The L<openssl-ec(1)> command processes EC keys. They can be converted between
45 various forms and their components printed out. B<Note> OpenSSL uses the
46 private key format specified in 'SEC 1: Elliptic Curve Cryptography'
47 (http://www.secg.org/). To convert an OpenSSL EC private key into the
48 PKCS#8 private key format use the L<openssl-pkcs8(1)> command.
56 Print out a usage message.
58 =item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM>
60 The input and formats; the default is B<PEM>.
61 See L<openssl(1)/Format Options> for details.
63 Private keys are an SEC1 private key or PKCS#8 format.
64 Public keys are a B<SubjectPublicKeyInfo> as specified in IETF RFC 3280.
66 =item B<-in> I<filename>
68 This specifies the input filename to read a key from or standard input if this
69 option is not specified. If the key is encrypted a pass phrase will be
72 =item B<-out> I<filename>
74 This specifies the output filename to write a key to or standard output by
75 is not specified. If any encryption options are set then a pass phrase will be
76 prompted for. The output filename should B<not> be the same as the input
79 =item B<-passin> I<arg>, B<-passout> I<arg>
81 The password source for the input and output file.
82 For more information about the format of B<arg>
83 see L<openssl(1)/Pass Phrase Options>.
85 =item B<-des>|B<-des3>|B<-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 this command 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
115 =item B<-conv_form> I<arg>
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> I<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.
143 {- $OpenSSL::safe::opt_engine_item -}
145 {- $OpenSSL::safe::opt_provider_item -}
151 Examples equivalent to these can be found in the documentation for the
152 non-deprecated L<openssl-pkey(1)> command.
154 To encrypt a private key using triple DES:
156 openssl ec -in key.pem -des3 -out keyout.pem
158 To convert a private key from PEM to DER format:
160 openssl ec -in key.pem -outform DER -out keyout.der
162 To print out the components of a private key to standard output:
164 openssl ec -in key.pem -text -noout
166 To just output the public part of a private key:
168 openssl ec -in key.pem -pubout -out pubkey.pem
170 To change the parameters encoding to B<explicit>:
172 openssl ec -in key.pem -param_enc explicit -out keyout.pem
174 To change the point conversion form to B<compressed>:
176 openssl ec -in key.pem -conv_form compressed -out keyout.pem
182 L<openssl-ecparam(1)>,
188 This command was deprecated in OpenSSL 3.0.
192 Copyright 2003-2020 The OpenSSL Project Authors. All Rights Reserved.
194 Licensed under the Apache License 2.0 (the "License"). You may not use
195 this file except in compliance with the License. You can obtain a copy
196 in the file LICENSE in the source distribution or at
197 L<https://www.openssl.org/source/license.html>.