Provided by: openssl_1.1.1c-1ubuntu4_amd64 bug


       openssl-ec, ec - EC key processing


       openssl ec [-help] [-inform PEM|DER] [-outform PEM|DER] [-in filename] [-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]


       The ec 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' ( To convert an OpenSSL EC private key
       into the PKCS#8 private key format use the pkcs8 command.


           Print out a usage message.

       -inform DER|PEM
           This specifies the input format. The DER option with a private key uses an ASN.1 DER
           encoded SEC1 private key. When used with a public key it uses the SubjectPublicKeyInfo
           structure as specified in RFC 3280.  The PEM form is the default format: it consists
           of the DER format base64 encoded with additional header and footer lines. In the case
           of a private key PKCS#8 format is also accepted.

       -outform DER|PEM
           This specifies the output format, the options have the same meaning and default as the
           -inform option.

       -in filename
           This specifies the input filename 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.

       -passin arg
           The input file password source. For more information about the format of arg see the
           PASS PHRASE ARGUMENTS section in openssl(1).

       -out filename
           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.

       -passout arg
           The output file password source. For more information about the format of arg see the
           PASS PHRASE ARGUMENTS section in openssl(1).

           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 the ec utility 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.

           Prints out the public, private key components and parameters.

           This option prevents output of the encoded version of the key.

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

           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.

           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_enc arg
           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.

           This option omits the public key components from the private key output.

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

       -engine id
           Specifying an engine (by its unique id string) will cause ec 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.


       The PEM private key format uses the header and footer lines:

        -----BEGIN EC PRIVATE KEY-----

        -----END EC PRIVATE KEY-----
       The PEM public key format uses the header and footer lines:

        -----BEGIN PUBLIC KEY-----

        -----END PUBLIC KEY-----


       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


       ecparam(1), dsa(1), rsa(1)


       Copyright 2003-2019 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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 <>.