doc/man1/openssl-ec.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 openssl-ec - EC key processing
   6
   7 =head1 SYNOPSIS
   8
   9 B<openssl> B<ec>
  10 [B<-help>]
  11 [B<-inform> B<DER>|B<PEM>]
  12 [B<-outform> B<DER>|B<PEM>]
  13 [B<-in> I<filename>]
  14 [B<-passin> I<arg>]
  15 [B<-out> I<filename>]
  16 [B<-passout> I<arg>]
  17 [B<-des>]
  18 [B<-des3>]
  19 [B<-idea>]
  20 [B<-text>]
  21 [B<-noout>]
  22 [B<-param_out>]
  23 [B<-pubin>]
  24 [B<-pubout>]
  25 [B<-conv_form> I<arg>]
  26 [B<-param_enc> I<arg>]
  27 [B<-no_public>]
  28 [B<-check>]
  29 [B<-engine> I<id>]
  30
  31 =for openssl ifdef engine
  32
  33 =head1 DESCRIPTION
  34
  35 The L<openssl-ec(1)> command processes EC keys. They can be converted between
  36 various forms and their components printed out. B<Note> OpenSSL uses the
  37 private key format specified in 'SEC 1: Elliptic Curve Cryptography'
  38 (http://www.secg.org/). To convert an OpenSSL EC private key into the
  39 PKCS#8 private key format use the L<openssl-pkcs8(1)> command.
  40
  41 =head1 OPTIONS
  42
  43 =over 4
  44
  45 =item B<-help>
  46
  47 Print out a usage message.
  48
  49 =item B<-inform> B<DER>|B<PEM>
  50
  51 This specifies the input format. The B<DER> option with a private key uses
  52 an ASN.1 DER encoded SEC1 private key. When used with a public key it
  53 uses the SubjectPublicKeyInfo structure as specified in RFC 3280.
  54 The B<PEM> form is the default format: it consists of the B<DER> format base64
  55 encoded with additional header and footer lines. In the case of a private key
  56 PKCS#8 format is also accepted.
  57
  58 =item B<-outform> B<DER>|B<PEM>
  59
  60 This specifies the output format, the options have the same meaning and default
  61 as the B<-inform> option.
  62
  63 =item B<-in> I<filename>
  64
  65 This specifies the input filename to read a key from or standard input if this
  66 option is not specified. If the key is encrypted a pass phrase will be
  67 prompted for.
  68
  69 =item B<-out> I<filename>
  70
  71 This specifies the output filename to write a key to or standard output by
  72 is not specified. If any encryption options are set then a pass phrase will be
  73 prompted for. The output filename should B<not> be the same as the input
  74 filename.
  75
  76 =item B<-passin> I<arg>, B<-passout> I<arg>
  77
  78 The password source for the input and output file.
  79 For more information about the format of B<arg>
  80 see L<openssl(1)/Pass Phrase Options>.
  81
  82 =item B<-des>|B<-des3>|B<-idea>
  83
  84 These options encrypt the private key with the DES, triple DES, IDEA or
  85 any other cipher supported by OpenSSL before outputting it. A pass phrase is
  86 prompted for.
  87 If none of these options is specified the key is written in plain text. This
  88 means that using this command to read in an encrypted key with no
  89 encryption option can be used to remove the pass phrase from a key, or by
  90 setting the encryption options it can be use to add or change the pass phrase.
  91 These options can only be used with PEM format output files.
  92
  93 =item B<-text>
  94
  95 Prints out the public, private key components and parameters.
  96
  97 =item B<-noout>
  98
  99 This option prevents output of the encoded version of the key.
 100
 101 =item B<-pubin>
 102
 103 By default, a private key is read from the input file. With this option a
 104 public key is read instead.
 105
 106 =item B<-pubout>
 107
 108 By default a private key is output. With this option a public
 109 key will be output instead. This option is automatically set if the input is
 110 a public key.
 111
 112 =item B<-conv_form> I<arg>
 113
 114 This specifies how the points on the elliptic curve are converted
 115 into octet strings. Possible values are: B<compressed> (the default
 116 value), B<uncompressed> and B<hybrid>. For more information regarding
 117 the point conversion forms please read the X9.62 standard.
 118 B<Note> Due to patent issues the B<compressed> option is disabled
 119 by default for binary curves and can be enabled by defining
 120 the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
 121
 122 =item B<-param_enc> I<arg>
 123
 124 This specifies how the elliptic curve parameters are encoded.
 125 Possible value are: B<named_curve>, i.e. the ec parameters are
 126 specified by an OID, or B<explicit> where the ec parameters are
 127 explicitly given (see RFC 3279 for the definition of the
 128 EC parameters structures). The default value is B<named_curve>.
 129 B<Note> the B<implicitlyCA> alternative, as specified in RFC 3279,
 130 is currently not implemented in OpenSSL.
 131
 132 =item B<-no_public>
 133
 134 This option omits the public key components from the private key output.
 135
 136 =item B<-check>
 137
 138 This option checks the consistency of an EC private or public key.
 139
 140 =item B<-engine> I<id>
 141
 142 Specifying an engine (by its unique I<id> string) will cause this command
 143 to attempt to obtain a functional reference to the specified engine,
 144 thus initialising it if needed. The engine will then be set as the default
 145 for all available algorithms.
 146
 147 =back
 148
 149 =head1 NOTES
 150
 151 The PEM private key format uses the header and footer lines:
 152
 153  -----BEGIN EC PRIVATE KEY-----
 154  -----END EC PRIVATE KEY-----
 155
 156 The PEM public key format uses the header and footer lines:
 157
 158  -----BEGIN PUBLIC KEY-----
 159  -----END PUBLIC KEY-----
 160
 161 =head1 EXAMPLES
 162
 163 To encrypt a private key using triple DES:
 164
 165  openssl ec -in key.pem -des3 -out keyout.pem
 166
 167 To convert a private key from PEM to DER format:
 168
 169  openssl ec -in key.pem -outform DER -out keyout.der
 170
 171 To print out the components of a private key to standard output:
 172
 173  openssl ec -in key.pem -text -noout
 174
 175 To just output the public part of a private key:
 176
 177  openssl ec -in key.pem -pubout -out pubkey.pem
 178
 179 To change the parameters encoding to B<explicit>:
 180
 181  openssl ec -in key.pem -param_enc explicit -out keyout.pem
 182
 183 To change the point conversion form to B<compressed>:
 184
 185  openssl ec -in key.pem -conv_form compressed -out keyout.pem
 186
 187 =head1 SEE ALSO
 188
 189 L<openssl(1)>,
 190 L<openssl-ecparam(1)>,
 191 L<openssl-dsa(1)>,
 192 L<openssl-rsa(1)>
 193
 194 =head1 COPYRIGHT
 195
 196 Copyright 2003-2019 The OpenSSL Project Authors. All Rights Reserved.
 197
 198 Licensed under the Apache License 2.0 (the "License").  You may not use
 199 this file except in compliance with the License.  You can obtain a copy
 200 in the file LICENSE in the source distribution or at
 201 L<https://www.openssl.org/source/license.html>.
 202
 203 =cut