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OPENSSL-EC(1ossl)		     OpenSSL		       OPENSSL-EC(1ossl)

NAME
     openssl-ec - EC key processing

SYNOPSIS
     openssl ec [-help] [-inform DER|PEM|P12] [-outform DER|PEM] [-in file-
     name|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] [-provider name] [-provider-path
     path] [-provparam [name:]key=value] [-propquery propq]

DESCRIPTION
     The openssl-ec(1) command processes EC keys. They can be converted between
     various forms and their components printed out. Note OpenSSL uses the pri-
     vate 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.

OPTIONS
     -help
	 Print out a usage message.

     -inform DER|PEM|P12
	 The key input format; unspecified by default.	See openssl-format-op-
	 tions(1) for details.

     -outform DER|PEM
	 The key output format; the default is PEM.  See openssl-format-op-
	 tions(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 informa-
	 tion 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.  With this option a
	 public key is read instead.  If the input contains no public key but a
	 private key, its public part is used.

     -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 de-
	 fault value) and hybrid. For more information regarding the point con-
	 version forms please read the X9.62 standard.	Note Due to patent is-
	 sues 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 out-
	 put.

     -check
	 This option checks the consistency of an EC private or public key.

     -provider name
     -provider-path path
     -provparam [name:]key=value
     -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.

EXAMPLES
     The documentation for the openssl-pkey(1) command contains examples equiva-
     lent 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

SEE ALSO
     openssl(1), openssl-pkey(1), openssl-ecparam(1), openssl-dsa(1),
     openssl-rsa(1)

HISTORY
     The -conv_form and -no_public options are no longer supported with keys
     loaded from an engine in OpenSSL 3.0.

     The -engine option was removed in OpenSSL 4.0.

COPYRIGHT
     Copyright 2003-2023 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>.

4.0.2				   2026-08-25		       OPENSSL-EC(1ossl)

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