man > openssl-ec(1)

OPENSSL-EC(1SSL)                               OpenSSL                              OPENSSL-EC(1SSL)

NAME
       openssl-ec - EC key processing

SYNOPSIS
       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]

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 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.

OPTIONS
       -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.

EXAMPLES
       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

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

HISTORY
       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
       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>.

3.0.13                                       2026-07-29                             OPENSSL-EC(1SSL)