openssl-ec - EC key processing
openssl ec [
-help] [
-inform
DER|
PEM|
P12|
ENGINE] [
-outform
DER|
PEM] [
-in filename|
uri] [
-passin arg] [
-out filename] [
-passout
arg] [
-des] [
-des3] [
-idea] [
-text] [
-noout] [
-param_out] [
-pubin] [
-pubout] [
-conv_form arg] [
-param_enc arg] [
-no_public] [
-check] [
-engine id] [
-provider name] [
-provider-path path] [
-propquery propq]
The command processes EC keys. They can be converted
between various forms and their components printed out.
Note OpenSSL
uses the private key format specified in 'SEC 1: Elliptic Curve Cryptography'
(
http://www.secg.org/). To convert an OpenSSL EC private key into the PKCS#8
private key format use the
openssl-pkcs8(1) command.
- -help
- Print out a usage message.
-
-inform
DER|PEM|P12|ENGINE
- The key input format; unspecified by default. See
openssl-format-options(1) for details.
-
-outform DER|PEM
- The key output format; the default is PEM. See
openssl-format-options(1) for details.
Private keys are an SEC1 private key or PKCS#8 format. Public keys are a
SubjectPublicKeyInfo as specified in IETF RFC 3280.
-
-in filename|uri
- This specifies the input to read a key from or standard
input if this option is not specified. If the key is encrypted a pass
phrase will be prompted for.
-
-out filename
- This specifies the output filename to write a key to or
standard output by is not specified. If any encryption options are set
then a pass phrase will be prompted for. The output filename should
not be the same as the input filename.
-
-passin arg, -passout arg
- The password source for the input and output file. For more
information about the format of arg see
openssl-passphrase-options(1).
-
-des|-des3|-idea
- These options encrypt the private key with the DES, triple
DES, IDEA or any other cipher supported by OpenSSL before outputting it. A
pass phrase is prompted for. If none of these options is specified the key
is written in plain text. This means that using this command to read in an
encrypted key with no encryption option can be used to remove the pass
phrase from a key, or by setting the encryption options it can be use to
add or change the pass phrase. These options can only be used with PEM
format output files.
- -text
- Prints out the public, private key components and
parameters.
- -noout
- This option prevents output of the encoded version of the
key.
- -param_out
- Print the elliptic curve parameters.
- -pubin
- By default, a private key is read from the input file. With
this option a public key is read instead.
- -pubout
- By default a private key is output. With this option a
public key will be output instead. This option is automatically set if the
input is a public key.
-
-conv_form arg
- This specifies how the points on the elliptic curve are
converted into octet strings. Possible values are: compressed,
uncompressed (the default value) and hybrid. For more
information regarding the point conversion forms please read the X9.62
standard. Note Due to patent issues the compressed option is
disabled by default for binary curves and can be enabled by defining the
preprocessor macro OPENSSL_EC_BIN_PT_COMP at compile time.
-
-param_enc arg
- This specifies how the elliptic curve parameters are
encoded. Possible value are: named_curve, i.e. the ec parameters
are specified by an OID, or explicit where the ec parameters are
explicitly given (see RFC 3279 for the definition of the EC parameters
structures). The default value is named_curve. Note the
implicitlyCA alternative, as specified in RFC 3279, is currently
not implemented in OpenSSL.
- -no_public
- This option omits the public key components from the
private key output.
- -check
- This option checks the consistency of an EC private or
public key.
-
-engine id
- See "Engine Options" in openssl(1). This
option is deprecated.
-
-provider name
-
-provider-path path
-
-propquery propq
- See "Provider Options" in openssl(1),
provider(7), and property(7).
The
openssl-pkey(1) command is capable of performing all the operations
this command can, as well as supporting other public key types.
The documentation for the
openssl-pkey(1) command contains examples
equivalent to the ones listed here.
To encrypt a private key using triple DES:
openssl ec -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
openssl ec -in key.pem -outform DER -out keyout.der
To print out the components of a private key to standard output:
openssl ec -in key.pem -text -noout
To just output the public part of a private key:
openssl ec -in key.pem -pubout -out pubkey.pem
To change the parameters encoding to
explicit:
openssl ec -in key.pem -param_enc explicit -out keyout.pem
To change the point conversion form to
compressed:
openssl ec -in key.pem -conv_form compressed -out keyout.pem
openssl(1),
openssl-pkey(1),
openssl-ecparam(1),
openssl-dsa(1),
openssl-rsa(1)
The
-engine option was deprecated in OpenSSL 3.0.
The
-conv_form and
-no_public options are no longer supported with
keys loaded from an engine in OpenSSL 3.0.
Copyright 2003-2022 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at
<
https://www.openssl.org/source/license.html>.