# openssl-ec(1ssl) - man - phpman

[OPENSSL-EC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-EC/1SSL/markdown)                               OpenSSL                              [OPENSSL-EC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-EC/1SSL/markdown)



## NAME
       openssl-ec - EC key processing

## SYNOPSIS
       **openssl** **ec** [**-help**] [**-inform** **DER**|**PEM**|**P12**|**ENGINE**] [**-outform** **DER**|**PEM**] [**-in** _filename_|_uri_]
       [**-passin** _arg_] [**-out** _filename_] [**-passout** _arg_] [**-des**] [**-des3**] [**-idea**] [**-text**] [**-noout**]
       [**-param**___**out**] [**-pubin**] [**-pubout**] [**-conv**___**form** _arg_] [**-param**___**enc** _arg_] [**-no**___**public**] [**-check**]
       [**-engine** _id_] [**-provider** _name_] [**-provider-path** _path_] [**-propquery** _propq_]

## DESCRIPTION
       The [**openssl-ec**(1)](https://www.chedong.com/phpMan.php/man/openssl-ec/1/markdown) command processes EC keys. They can be converted between various forms and
       their components printed out. **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 [**openssl-pkcs8**(1)](https://www.chedong.com/phpMan.php/man/openssl-pkcs8/1/markdown) command.

## OPTIONS
### -help
           Print out a usage message.

### -inform
           The key input format; unspecified by default.  See [**openssl-format-options**(1)](https://www.chedong.com/phpMan.php/man/openssl-format-options/1/markdown) for details.

### -outform
           The key output format; the default is **PEM**.  See [**openssl-format-options**(1)](https://www.chedong.com/phpMan.php/man/openssl-format-options/1/markdown) for details.

           Private keys are an SEC1 private key or PKCS#8 format.  Public keys are a
           **SubjectPublicKeyInfo** as specified in IETF RFC 3280.

### -in
           This specifies the input 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.

### -out
           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 **not** be the same as the input filename.

### -passin -passout
           The password source for the input and output file.  For more information about the format
           of **arg** see [**openssl-passphrase-options**(1)](https://www.chedong.com/phpMan.php/man/openssl-passphrase-options/1/markdown).

### -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 this
           command 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.

### -text
           Prints out the public, private key components and parameters.

### -noout
           This option prevents output of the encoded version of the key.

### -param
           Print the elliptic curve parameters.

### -pubin
           By default, a private key is read from the input file. With this option a public key is
           read instead.

### -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.

### -conv
           This specifies how the points on the elliptic curve are converted into octet strings.
           Possible values are: **compressed** (the default value), **uncompressed** 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
           This specifies how the elliptic curve parameters are encoded.  Possible value are:
           **named**___**curve**, i.e. the ec parameters are specified by an 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
           This option omits the public key components from the private key output.

### -check
           This option checks the consistency of an EC private or public key.

### -engine
           See "Engine Options" in [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown).  This option is deprecated.

### -provider
### -provider-path
### -propquery
           See "Provider Options" in [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**provider**(7)](https://www.chedong.com/phpMan.php/man/provider/7/markdown), and [**property**(7)](https://www.chedong.com/phpMan.php/man/property/7/markdown).

       The [**openssl-pkey**(1)](https://www.chedong.com/phpMan.php/man/openssl-pkey/1/markdown) command is capable of performing all the operations this command can, as
       well as supporting other public key types.

## EXAMPLES
       The documentation for the [**openssl-pkey**(1)](https://www.chedong.com/phpMan.php/man/openssl-pkey/1/markdown) command contains examples equivalent to the ones
       listed here.

       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 **explicit**:

        openssl ec -in key.pem -param_enc explicit -out keyout.pem

       To change the point conversion form to **compressed**:

        openssl ec -in key.pem -conv_form compressed -out keyout.pem

## SEE ALSO
       [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown), [**openssl-pkey**(1)](https://www.chedong.com/phpMan.php/man/openssl-pkey/1/markdown), [**openssl-ecparam**(1)](https://www.chedong.com/phpMan.php/man/openssl-ecparam/1/markdown), [**openssl-dsa**(1)](https://www.chedong.com/phpMan.php/man/openssl-dsa/1/markdown), [**openssl-rsa**(1)](https://www.chedong.com/phpMan.php/man/openssl-rsa/1/markdown)

## HISTORY
       The **-engine** option was deprecated in OpenSSL 3.0.

       The **-conv**___**form** and **-no**___**public** options are no longer supported with keys loaded from an engine
       in OpenSSL 3.0.

## COPYRIGHT
       Copyright 2003-2021 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (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 <<https://www.openssl.org/source/license.html>>.



3.0.2                                        2026-04-07                             [OPENSSL-EC(1SSL)](https://www.chedong.com/phpMan.php/man/OPENSSL-EC/1SSL/markdown)