doc/man1/openssl-ecparam.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 openssl-ecparam - EC parameter manipulation and generation
   6
   7 =head1 SYNOPSIS
   8
   9 B<openssl ecparam>
  10 [B<-help>]
  11 [B<-inform DER|PEM>]
  12 [B<-outform DER|PEM>]
  13 [B<-in filename>]
  14 [B<-out filename>]
  15 [B<-noout>]
  16 [B<-text>]
  17 [B<-C>]
  18 [B<-check>]
  19 [B<-check_named>]
  20 [B<-name arg>]
  21 [B<-list_curves>]
  22 [B<-conv_form arg>]
  23 [B<-param_enc arg>]
  24 [B<-no_seed>]
  25 [B<-rand file...>]
  26 [B<-writerand file>]
  27 [B<-genkey>]
  28 [B<-engine id>]
  29
  30 =head1 DESCRIPTION
  31
  32 This command is used to manipulate or generate EC parameter files.
  33
  34 =head1 OPTIONS
  35
  36 =over 4
  37
  38 =item B<-help>
  39
  40 Print out a usage message.
  41
  42 =item B<-inform DER|PEM>
  43
  44 This specifies the input format. The B<DER> option uses an ASN.1 DER encoded
  45 form compatible with RFC 3279 EcpkParameters. The PEM form is the default
  46 format: it consists of the B<DER> format base64 encoded with additional
  47 header and footer lines.
  48
  49 =item B<-outform DER|PEM>
  50
  51 This specifies the output format, the options have the same meaning and default
  52 as the B<-inform> option.
  53
  54 =item B<-in filename>
  55
  56 This specifies the input filename to read parameters from or standard input if
  57 this option is not specified.
  58
  59 =item B<-out filename>
  60
  61 This specifies the output filename parameters to. Standard output is used
  62 if this option is not present. The output filename should B<not> be the same
  63 as the input filename.
  64
  65 =item B<-noout>
  66
  67 This option inhibits the output of the encoded version of the parameters.
  68
  69 =item B<-text>
  70
  71 This option prints out the EC parameters in human readable form.
  72
  73 =item B<-C>
  74
  75 This option converts the EC parameters into C code. The parameters can then
  76 be loaded by calling the get_ec_group_XXX() function.
  77
  78 =item B<-check>
  79
  80 Validate the elliptic curve parameters.
  81
  82 =item B<-check_named>
  83
  84 Validate the elliptic name curve parameters by checking if the curve parameters
  85 match any built-in curves.
  86
  87 =item B<-name arg>
  88
  89 Use the EC parameters with the specified 'short' name. Use B<-list_curves>
  90 to get a list of all currently implemented EC parameters.
  91
  92 =item B<-list_curves>
  93
  94 If this options is specified B<ecparam> will print out a list of all
  95 currently implemented EC parameters names and exit.
  96
  97 =item B<-conv_form>
  98
  99 This specifies how the points on the elliptic curve are converted
 100 into octet strings. Possible values are: B<compressed>, B<uncompressed> (the
 101 default value) and B<hybrid>. For more information regarding
 102 the point conversion forms please read the X9.62 standard.
 103 B<Note> Due to patent issues the B<compressed> option is disabled
 104 by default for binary curves and can be enabled by defining
 105 the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
 106
 107 =item B<-param_enc arg>
 108
 109 This specifies how the elliptic curve parameters are encoded.
 110 Possible value are: B<named_curve>, i.e. the ec parameters are
 111 specified by an OID, or B<explicit> where the ec parameters are
 112 explicitly given (see RFC 3279 for the definition of the
 113 EC parameters structures). The default value is B<named_curve>.
 114 B<Note> the B<implicitlyCA> alternative, as specified in RFC 3279,
 115 is currently not implemented in OpenSSL.
 116
 117 =item B<-no_seed>
 118
 119 This option inhibits that the 'seed' for the parameter generation
 120 is included in the ECParameters structure (see RFC 3279).
 121
 122 =item B<-genkey>
 123
 124 This option will generate an EC private key using the specified parameters.
 125
 126 =item B<-rand file...>
 127
 128 A file or files containing random data used to seed the random number
 129 generator.
 130 Multiple files can be specified separated by an OS-dependent character.
 131 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
 132 all others.
 133
 134 =item [B<-writerand file>]
 135
 136 Writes random data to the specified I<file> upon exit.
 137 This can be used with a subsequent B<-rand> flag.
 138
 139 =item B<-engine id>
 140
 141 Specifying an engine (by its unique B<id> string) will cause B<ecparam>
 142 to attempt to obtain a functional reference to the specified engine,
 143 thus initialising it if needed. The engine will then be set as the default
 144 for all available algorithms.
 145
 146 =back
 147
 148 =head1 NOTES
 149
 150 PEM format EC parameters use the header and footer lines:
 151
 152  -----BEGIN EC PARAMETERS-----
 153  -----END EC PARAMETERS-----
 154
 155 OpenSSL is currently not able to generate new groups and therefore
 156 B<ecparam> can only create EC parameters from known (named) curves.
 157
 158 =head1 EXAMPLES
 159
 160 To create EC parameters with the group 'prime192v1':
 161
 162   openssl ecparam -out ec_param.pem -name prime192v1
 163
 164 To create EC parameters with explicit parameters:
 165
 166   openssl ecparam -out ec_param.pem -name prime192v1 -param_enc explicit
 167
 168 To validate given EC parameters:
 169
 170   openssl ecparam -in ec_param.pem -check
 171
 172 To create EC parameters and a private key:
 173
 174   openssl ecparam -out ec_key.pem -name prime192v1 -genkey
 175
 176 To change the point encoding to 'compressed':
 177
 178   openssl ecparam -in ec_in.pem -out ec_out.pem -conv_form compressed
 179
 180 To print out the EC parameters to standard output:
 181
 182   openssl ecparam -in ec_param.pem -noout -text
 183
 184 =head1 SEE ALSO
 185
 186 L<openssl(1)>,
 187 L<openssl-ec(1)>,
 188 L<openssl-dsaparam(1)>
 189
 190 =head1 COPYRIGHT
 191
 192 Copyright 2003-2019 The OpenSSL Project Authors. All Rights Reserved.
 193
 194 Licensed under the Apache License 2.0 (the "License").  You may not use
 195 this file except in compliance with the License.  You can obtain a copy
 196 in the file LICENSE in the source distribution or at
 197 L<https://www.openssl.org/source/license.html>.
 198
 199 =cut