ecparam - EC parameter manipulation and generation
openssl ecparam [-inform DER|PEM] [-outform DER|PEM] [-in filename] [-out filename] [-noout] [-text] [-C] [-check] [-name arg] [-list_curves] [-conv_form arg] [-param_enc arg] [-no_seed] [-rand file(s)] [-genkey] [-engine id]
ECPARAM(1openssl) OpenSSL ECPARAM(1openssl)
NAME
openssl-ecparam, ecparam - EC parameter manipulation and generation
SYNOPSIS
openssl ecparam [-inform DER|PEM] [-outform DER|PEM] [-in filename]
[-out filename] [-noout] [-text] [-C] [-check] [-name arg]
[-list_curves] [-conv_form arg] [-param_enc arg] [-no_seed] [-rand
file(s)] [-genkey] [-engine id]
DESCRIPTION
This command is used to manipulate or generate EC parameter files.
OPTIONS
-inform DER|PEM
This specifies the input format. The DER option uses an ASN.1 DER
encoded form compatible with RFC 3279 EcpkParameters. The PEM form
is the default format: it consists of the DER format base64 encoded
with additional header and footer lines.
-outform DER|PEM
This specifies the output format, the options have the same meaning
as the -inform option.
-in filename
This specifies the input filename to read parameters from or
standard input if this option is not specified.
-out filename
This specifies the output filename parameters to. Standard output
is used if this option is not present. The output filename should
not be the same as the input filename.
-noout
This option inhibits the output of the encoded version of the
parameters.
-text
This option prints out the EC parameters in human readable form.
-C This option converts the EC parameters into C code. The parameters
can then be loaded by calling the get_ec_group_XXX() function.
-check
Validate the elliptic curve parameters.
-name arg
Use the EC parameters with the specified 'short' name. Use
-list_curves to get a list of all currently implemented EC
parameters.
-list_curves
If this options is specified ecparam will print out a list of all
currently implemented EC parameters names and exit.
-conv_form
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 a 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_seed
This option inhibits that the 'seed' for the parameter generation
is included in the ECParameters structure (see RFC 3279).
-genkey
This option will generate a EC private key using the specified
parameters.
-rand file(s)
a file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a OS-dependent character. The
separator is ; for MS-Windows, , for OpenVMS, and : for all others.
-engine id
specifying an engine (by its unique id string) will cause ecparam
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.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
NOTES
PEM format EC parameters use the header and footer lines:
-----BEGIN EC PARAMETERS-----
-----END EC PARAMETERS-----
OpenSSL is currently not able to generate new groups and therefore
ecparam can only create EC parameters from known (named) curves.
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open source
community website at https://www.openssl.org/.
EXAMPLES
To create EC parameters with the group 'prime192v1':
openssl ecparam -out ec_param.pem -name prime192v1
To create EC parameters with explicit parameters:
openssl ecparam -out ec_param.pem -name prime192v1 -param_enc explicit
To validate given EC parameters:
openssl ecparam -in ec_param.pem -check
To create EC parameters and a private key:
openssl ecparam -out ec_key.pem -name prime192v1 -genkey
To change the point encoding to 'compressed':
openssl ecparam -in ec_in.pem -out ec_out.pem -conv_form compressed
To print out the EC parameters to standard output:
openssl ecparam -in ec_param.pem -noout -text
SEE ALSO
ec(1), dsaparam(1)
HISTORY
The ecparam command was first introduced in OpenSSL 0.9.8.
AUTHOR
Nils Larsch for the OpenSSL project (http://www.openssl.org)
1.0.2ze 2022-05-03 ECPARAM(1openssl)