1OPENSSL-EC(1ossl) OpenSSL OPENSSL-EC(1ossl)
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6 openssl-ec - EC key processing
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9 openssl ec [-help] [-inform DER|PEM|P12|ENGINE] [-outform DER|PEM] [-in
10 filename|uri] [-passin arg] [-out filename] [-passout arg] [-des]
11 [-des3] [-idea] [-text] [-noout] [-param_out] [-pubin] [-pubout]
12 [-conv_form arg] [-param_enc arg] [-no_public] [-check] [-engine id]
13 [-provider name] [-provider-path path] [-propquery propq]
14
16 The openssl-ec(1) command processes EC keys. They can be converted
17 between various forms and their components printed out. Note OpenSSL
18 uses the private key format specified in 'SEC 1: Elliptic Curve
19 Cryptography' (http://www.secg.org/). To convert an OpenSSL EC private
20 key into the PKCS#8 private key format use the openssl-pkcs8(1)
21 command.
22
24 -help
25 Print out a usage message.
26 -inform DER|PEM|P12|ENGINE
28 The key input format; unspecified by default. See
29 openssl-format-options(1) for details.
30 -outform DER|PEM
32 The key output format; the default is PEM. See
33 openssl-format-options(1) for details.
34 Private keys are an SEC1 private key or PKCS#8 format. Public keys
36 are a SubjectPublicKeyInfo as specified in IETF RFC 3280.
37 -in filename|uri
39 This specifies the input to read a key from or standard input if
40 this option is not specified. If the key is encrypted a pass phrase
41 will be prompted for.
42 -out filename
44 This specifies the output filename to write a key to or standard
45 output by is not specified. If any encryption options are set then
46 a pass phrase will be prompted for. The output filename should not
47 be the same as the input filename.
48 -passin arg, -passout arg
50 The password source for the input and output file. For more
51 information about the format of arg see
52 openssl-passphrase-options(1).
53 -des|-des3|-idea
55 These options encrypt the private key with the DES, triple DES,
56 IDEA or any other cipher supported by OpenSSL before outputting it.
57 A pass phrase is prompted for. If none of these options is
58 specified the key is written in plain text. This means that using
59 this command to read in an encrypted key with no encryption option
60 can be used to remove the pass phrase from a key, or by setting the
61 encryption options it can be use to add or change the pass phrase.
62 These options can only be used with PEM format output files.
63 -text
65 Prints out the public, private key components and parameters.
66 -noout
68 This option prevents output of the encoded version of the key.
69 -param_out
71 Print the elliptic curve parameters.
72 -pubin
74 By default, a private key is read from the input file. With this
75 option a public key is read instead.
76 -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 -conv_form arg
83 This specifies how the points on the elliptic curve are converted
84 into octet strings. Possible values are: compressed, uncompressed
85 (the default value) 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 -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 -no_public
101 This option omits the public key components from the private key
102 output.
103 -check
105 This option checks the consistency of an EC private or public key.
106 -engine id
108 See "Engine Options" in openssl(1). This option is deprecated.
109 -provider name
111 -provider-path path
112 -propquery propq
113 See "Provider Options" in openssl(1), provider(7), and property(7).
114 The openssl-pkey(1) command is capable of performing all the operations
116 this command can, as well as supporting other public key types.
117
119 The documentation for the openssl-pkey(1) command contains examples
120 equivalent to the ones listed here.
121 To encrypt a private key using triple DES:
123 openssl ec -in key.pem -des3 -out keyout.pem
125 To convert a private key from PEM to DER format:
127 openssl ec -in key.pem -outform DER -out keyout.der
129 To print out the components of a private key to standard output:
131 openssl ec -in key.pem -text -noout
133 To just output the public part of a private key:
135 openssl ec -in key.pem -pubout -out pubkey.pem
137 To change the parameters encoding to explicit:
139 openssl ec -in key.pem -param_enc explicit -out keyout.pem
141 To change the point conversion form to compressed:
143 openssl ec -in key.pem -conv_form compressed -out keyout.pem
145
147 openssl(1), openssl-pkey(1), openssl-ecparam(1), openssl-dsa(1),
148 openssl-rsa(1)
149
151 The -engine option was deprecated in OpenSSL 3.0.
152 The -conv_form and -no_public options are no longer supported with keys
154 loaded from an engine in OpenSSL 3.0.
155
157 Copyright 2003-2022 The OpenSSL Project Authors. All Rights Reserved.
158 Licensed under the Apache License 2.0 (the "License"). You may not use
160 this file except in compliance with the License. You can obtain a copy
161 in the file LICENSE in the source distribution or at
162 <https://www.openssl.org/source/license.html>.
1633.1.1 2023-08-31 OPENSSL-EC(1ossl)