text: =pod
  
  =head1 NAME
  
  openssl-ec,
  ec - EC key processing
  
  =head1 SYNOPSIS
  
  B<openssl> B<ec>
  [B<-help>]
  [B<-inform PEM|DER>]
  [B<-outform PEM|DER>]
  [B<-in filename>]
  [B<-passin arg>]
  [B<-out filename>]
  [B<-passout arg>]
  [B<-des>]
  [B<-des3>]
  [B<-idea>]
  [B<-text>]
  [B<-noout>]
  [B<-param_out>]
  [B<-pubin>]
  [B<-pubout>]
  [B<-conv_form arg>]
  [B<-param_enc arg>]
  [B<-no_public>]
  [B<-check>]
  [B<-engine id>]
  
  =head1 DESCRIPTION
  
  The B<ec> command processes EC keys. They can be converted between various
  forms and their components printed out. B<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 B<pkcs8> command.
  
  =head1 OPTIONS
  
  =over 4
  
  =item B<-help>
  
  Print out a usage message.
  
  =item B<-inform DER|PEM>
  
  This specifies the input format. The B<DER> option with a private key uses
  an ASN.1 DER encoded SEC1 private key. When used with a public key it
  uses the SubjectPublicKeyInfo structure as specified in RFC 3280.
  The B<PEM> form is the default format: it consists of the B<DER> format base64
  encoded with additional header and footer lines. In the case of a private key
  PKCS#8 format is also accepted.
  
  =item B<-outform DER|PEM>
  
  This specifies the output format, the options have the same meaning as the
  B<-inform> option.
  
  =item B<-in filename>
  
  This specifies the input filename 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.
  
  =item B<-passin arg>
  
  the input file password source. For more information about the format of B<arg>
  see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
  
  =item B<-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 B<not> be the same as the input
  filename.
  
  =item B<-passout arg>
  
  the output file password source. For more information about the format of B<arg>
  see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
  
  =item B<-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 the B<ec> utility 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.
  
  =item B<-text>
  
  prints out the public, private key components and parameters.
  
  =item B<-noout>
  
  this option prevents output of the encoded version of the key.
  
  =item B<-modulus>
  
  this option prints out the value of the public key component of the key.
  
  =item B<-pubin>
  
  by default a private key is read from the input file: with this option a
  public key is read instead.
  
  =item B<-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.
  
  =item B<-conv_form>
  
  This specifies how the points on the elliptic curve are converted
  into octet strings. Possible values are: B<compressed> (the default
  value), B<uncompressed> and B<hybrid>. For more information regarding
  the point conversion forms please read the X9.62 standard.
  B<Note> Due to patent issues the B<compressed> option is disabled
  by default for binary curves and can be enabled by defining
  the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
  
  =item B<-param_enc arg>
  
  This specifies how the elliptic curve parameters are encoded.
  Possible value are: B<named_curve>, i.e. the ec parameters are
  specified by an OID, or B<explicit> where the ec parameters are
  explicitly given (see RFC 3279 for the definition of the
  EC parameters structures). The default value is B<named_curve>.
  B<Note> the B<implicitlyCA> alternative, as specified in RFC 3279,
  is currently not implemented in OpenSSL.
  
  =item B<-no_public>
  
  This option omits the public key components from the private key output.
  
  =item B<-check>
  
  this option checks the consistency of an EC private or public key.
  
  =item B<-engine id>
  
  specifying an engine (by its unique B<id> string) will cause B<ec>
  to attempt to obtain a functional reference to the specified engine,
  thus initialising it if needed. The engine will then be set as the default
  for all available algorithms.
  
  =back
  
  =head1 NOTES
  
  The PEM private key format uses the header and footer lines:
  
   -----BEGIN EC PRIVATE KEY-----
   -----END EC PRIVATE KEY-----
  
  The PEM public key format uses the header and footer lines:
  
   -----BEGIN PUBLIC KEY-----
   -----END PUBLIC KEY-----
  
  =head1 EXAMPLES
  
  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 B<explicit>:
  
   openssl ec -in key.pem -param_enc explicit -out keyout.pem
  
  To change the point conversion form to B<compressed>:
  
   openssl ec -in key.pem -conv_form compressed -out keyout.pem
  
  =head1 SEE ALSO
  
  L<ecparam(1)>, L<dsa(1)>, L<rsa(1)>
  
  =head1 COPYRIGHT
  
  Copyright 2003-2016 The OpenSSL Project Authors. All Rights Reserved.
  
  Licensed under the OpenSSL license (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
  L<https://www.openssl.org/source/license.html>.
  
  =cut
  