Linux "ecparam" Command Line Options and Examples

EC parameter manipulation and generation

This command is used to manipulate or generate EC parameter files..

Usage:

openssl ecparam [-help] [-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]

Related Commands

ec
dsaparam

Command Line Options:

-help

Print out a usage message.


                            ecparam -help ...

-inform

This specifies the input format. The DER option uses an ASN.1 DER encoded form compatible with RFC 3279 EcpkParameters. The PEMform is the default format: it consists of the DER format base64 encoded with additional header and footer lines.


                            ecparam -inform ...

-outform

This specifies the output format, the options have the same meaning as the -inform option.


                            ecparam -outform ...

-in

This specifies the input filename to read parameters from or standard input if this option is not specified.


                            ecparam -in ...

-out

This specifies the output filename parameters to. Standard output is used if this option is not present. The output filenameshould not be the same as the input filename.


                            ecparam -out ...

-noout

This option inhibits the output of the encoded version of the parameters.


                            ecparam -noout ...

-text

This option prints out the EC parameters in human readable form.


                            ecparam -text ...

-C

This option converts the EC parameters into C code. The parameters can then be loaded by calling the get_ec_group_XXX() function.


                            ecparam -C ...

-check

Validate the elliptic curve parameters.


                            ecparam -check ...

-name

Use the EC parameters with the specified 'short' name. Use -list_curves to get a list of all currently implemented EC parameters.


                            ecparam -name ...

-list_curves

If this options is specified ecparam will print out a list of all currently implemented EC parameters names and exit.


                            ecparam -list_curves ...

-conv_form

This specifies how the points on the elliptic curve are converted into octet strings. Possible values are: compressed (thedefault value), uncompressed and hybrid. For more information regarding the point conversion forms please read the X9.62standard. Note Due to patent issues the compressed option is disabled by default for binary curves and can be enabled bydefining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at compile time.


                            ecparam -conv_form ...

-param_enc

This specifies how the elliptic curve parameters are encoded. Possible value are: named_curve, i.e. the ec parameters arespecified by an OID, or explicit where the ec parameters are explicitly given (see RFC 3279 for the definition of the ECparameters structures). The default value is named_curve. Note the implicitlyCA alternative, as specified in RFC 3279, iscurrently not implemented in OpenSSL.


                            ecparam -param_enc ...

-no_seed

This option inhibits that the 'seed' for the parameter generation is included in the ECParameters structure (see RFC 3279).


                            ecparam -no_seed ...

-genkey

This option will generate an EC private key using the specified parameters.


                            ecparam -genkey ...

-rand

a file or files containing random data used to seed the random number generator, or an EGD socket (see RAND_egd(3)). Multiplefiles can be specified separated by an OS-dependent character. The separator is ; for MS-Windows, , for OpenVMS, and : for allothers.


                            ecparam -rand ...

-engine

specifying an engine (by its unique id string) will cause ecparam to attempt to obtain a functional reference to the specifiedengine, thus initialising it if needed. The engine will then be set as the default for all available algorithms.NOTESPEM format EC parameters use the header and footer lines:


                            ecparam -engine ...