1EC(1)                               OpenSSL                              EC(1)
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3
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NAME

6       openssl-ec, ec - EC key processing
7

SYNOPSIS

9       openssl ec [-help] [-inform PEM|DER] [-outform PEM|DER] [-in filename]
10       [-passin arg] [-out filename] [-passout arg] [-des] [-des3] [-idea]
11       [-text] [-noout] [-param_out] [-pubin] [-pubout] [-conv_form arg]
12       [-param_enc arg] [-no_public] [-check] [-engine id]
13

DESCRIPTION

15       The ec command processes EC keys. They can be converted between various
16       forms and their components printed out. Note OpenSSL uses the private
17       key format specified in 'SEC 1: Elliptic Curve Cryptography'
18       (http://www.secg.org/). To convert an OpenSSL EC private key into the
19       PKCS#8 private key format use the pkcs8 command.
20

OPTIONS

22       -help
23           Print out a usage message.
24
25       -inform DER|PEM
26           This specifies the input format. The DER option with a private key
27           uses an ASN.1 DER encoded SEC1 private key. When used with a public
28           key it uses the SubjectPublicKeyInfo structure as specified in RFC
29           3280.  The PEM form is the default format: it consists of the DER
30           format base64 encoded with additional header and footer lines. In
31           the case of a private key PKCS#8 format is also accepted.
32
33       -outform DER|PEM
34           This specifies the output format, the options have the same meaning
35           and default as the -inform option.
36
37       -in filename
38           This specifies the input filename to read a key from or standard
39           input if this option is not specified. If the key is encrypted a
40           pass phrase will be prompted for.
41
42       -passin arg
43           The input file password source. For more information about the
44           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
45
46       -out filename
47           This specifies the output filename to write a key to or standard
48           output by is not specified. If any encryption options are set then
49           a pass phrase will be prompted for. The output filename should not
50           be the same as the input filename.
51
52       -passout arg
53           The output file password source. For more information about the
54           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
55
56       -des|-des3|-idea
57           These options encrypt the private key with the DES, triple DES,
58           IDEA or any other cipher supported by OpenSSL before outputting it.
59           A pass phrase is prompted for.  If none of these options is
60           specified the key is written in plain text. This means that using
61           the ec utility to read in an encrypted key with no encryption
62           option can be used to remove the pass phrase from a key, or by
63           setting the encryption options it can be use to add or change the
64           pass phrase.  These options can only be used with PEM format output
65           files.
66
67       -text
68           Prints out the public, private key components and parameters.
69
70       -noout
71           This option prevents output of the encoded version of the key.
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73       -pubin
74           By default, a private key is read from the input file. With this
75           option a public key is read instead.
76
77       -pubout
78           By default a private key is output. With this option a public key
79           will be output instead. This option is automatically set if the
80           input is a public key.
81
82       -conv_form
83           This specifies how the points on the elliptic curve are converted
84           into octet strings. Possible values are: compressed (the default
85           value), uncompressed and hybrid. For more information regarding the
86           point conversion forms please read the X9.62 standard.  Note Due to
87           patent issues the compressed option is disabled by default for
88           binary curves and can be enabled by defining the preprocessor macro
89           OPENSSL_EC_BIN_PT_COMP at compile time.
90
91       -param_enc arg
92           This specifies how the elliptic curve parameters are encoded.
93           Possible value are: named_curve, i.e. the ec parameters are
94           specified by an OID, or explicit where the ec parameters are
95           explicitly given (see RFC 3279 for the definition of the EC
96           parameters structures). The default value is named_curve.  Note the
97           implicitlyCA alternative, as specified in RFC 3279, is currently
98           not implemented in OpenSSL.
99
100       -no_public
101           This option omits the public key components from the private key
102           output.
103
104       -check
105           This option checks the consistency of an EC private or public key.
106
107       -engine id
108           Specifying an engine (by its unique id string) will cause ec to
109           attempt to obtain a functional reference to the specified engine,
110           thus initialising it if needed. The engine will then be set as the
111           default for all available algorithms.
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NOTES

114       The PEM private key format uses the header and footer lines:
115
116        -----BEGIN EC PRIVATE KEY-----
117        -----END EC PRIVATE KEY-----
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119       The PEM public key format uses the header and footer lines:
120
121        -----BEGIN PUBLIC KEY-----
122        -----END PUBLIC KEY-----
123

EXAMPLES

125       To encrypt a private key using triple DES:
126
127        openssl ec -in key.pem -des3 -out keyout.pem
128
129       To convert a private key from PEM to DER format:
130
131        openssl ec -in key.pem -outform DER -out keyout.der
132
133       To print out the components of a private key to standard output:
134
135        openssl ec -in key.pem -text -noout
136
137       To just output the public part of a private key:
138
139        openssl ec -in key.pem -pubout -out pubkey.pem
140
141       To change the parameters encoding to explicit:
142
143        openssl ec -in key.pem -param_enc explicit -out keyout.pem
144
145       To change the point conversion form to compressed:
146
147        openssl ec -in key.pem -conv_form compressed -out keyout.pem
148

SEE ALSO

150       ecparam(1), dsa(1), rsa(1)
151
153       Copyright 2003-2019 The OpenSSL Project Authors. All Rights Reserved.
154
155       Licensed under the OpenSSL license (the "License").  You may not use
156       this file except in compliance with the License.  You can obtain a copy
157       in the file LICENSE in the source distribution or at
158       <https://www.openssl.org/source/license.html>.
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1621.1.1c                            2019-05-28                             EC(1)
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