=pod=head1 NAMEec - EC key processing=head1 SYNOPSISB<openssl> B<ec>[B<-inform PEM|DER>][B<-outform PEM|DER>][B<-in filename>][B<-passin arg>][B<-out filename>][B<-passout arg>][B<-des>][B<-des3>][B<-idea>][B<-text>][B<-noout>][B<-param_out>][B<-pubin>][B<-pubout>][B<-conv_form arg>][B<-param_enc arg>][B<-engine id>]=head1 DESCRIPTIONThe B<ec> command processes EC keys. They can be converted between variousforms and their components printed out. B<Note> OpenSSL uses the private key format specified in 'SEC 1: Elliptic Curve Cryptography'(http://www.secg.org/). To convert a OpenSSL EC private key into thePKCS#8 private key format use the B<pkcs8> command.=head1 COMMAND OPTIONS=over 4=item B<-inform DER|PEM>This specifies the input format. The B<DER> option with a private key usesan ASN.1 DER encoded SEC1 private key. When used with a public key ituses the SubjectPublicKeyInfo structur as specified in RFC 3280.The B<PEM> form is the default format: it consists of the B<DER> format base64encoded with additional header and footer lines. In the case of a private keyPKCS#8 format is also accepted.=item B<-outform DER|PEM>This specifies the output format, the options have the same meaning as the B<-inform> option.=item B<-in filename>This specifies the input filename to read a key from or standard input if thisoption is not specified. If the key is encrypted a pass phrase will beprompted for.=item B<-passin arg>the input file password source. For more information about the format of B<arg>see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.=item B<-out filename>This specifies the output filename to write a key to or standard output byis not specified. If any encryption options are set then a pass phrase will beprompted for. The output filename should B<not> be the same as the inputfilename.=item B<-passout arg>the output file password source. For more information about the format of B<arg>see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.=item B<-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 isprompted for.If none of these options is specified the key is written in plain text. Thismeans that using the B<ec> utility to read in an encrypted key with noencryption option can be used to remove the pass phrase from a key, or bysetting 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.=item B<-text>prints out the public, private key components and parameters.=item B<-noout>this option prevents output of the encoded version of the key.=item B<-modulus>this option prints out the value of the public key component of the key.=item B<-pubin>by default a private key is read from the input file: with this option apublic key is read instead.=item B<-pubout>by default a private key is output. With this option a publickey will be output instead. This option is automatically set if the input isa public key.=item B<-conv_form>This specifies how the points on the elliptic curve are convertedinto octet strings. Possible values are: B<compressed> (the defaultvalue), B<uncompressed> and B<hybrid>. For more information regardingthe point conversion forms please read the X9.62 standard.B<Note> Due to patent issues the B<compressed> option is disabledby default for binary curves and can be enabled by definingthe preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.=item B<-param_enc arg>This specifies how the elliptic curve parameters are encoded.Possible value are: B<named_curve>, i.e. the ec parameters arespecified by a OID, or B<explicit> where the ec parameters areexplicitly given (see RFC 3279 for the definition of the EC parameters structures). The default value is B<named_curve>.B<Note> the B<implicitlyCA> alternative ,as specified in RFC 3279,is currently not implemented in OpenSSL.=item B<-engine id>specifying an engine (by it's unique B<id> string) will cause B<req>to attempt to obtain a functional reference to the specified engine,thus initialising it if needed. The engine will then be set as the defaultfor all available algorithms.=back=head1 NOTESThe 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-----=head1 EXAMPLESTo encrypt a private key using triple DES: openssl ec -in key.pem -des3 -out keyout.pemTo convert a private key from PEM to DER format:  openssl ec -in key.pem -outform DER -out keyout.derTo print out the components of a private key to standard output: openssl ec -in key.pem -text -nooutTo just output the public part of a private key: openssl ec -in key.pem -pubout -out pubkey.pemTo change the parameters encoding to B<explicit>: openssl ec -in key.pem -param_enc explicit -out keyout.pemTo change the point conversion form to B<compressed>: openssl ec -in key.pem -conv_form compressed -out keyout.pem=head1 SEE ALSOL<ecparam(1)|ecparam(1)>, L<dsa(1)|dsa(1)>, L<rsa(1)|rsa(1)>=head1 HISTORYThe ec command was first introduced in OpenSSL 0.9.8.=head1 AUTHORNils Larsch for the OpenSSL project (http://www.openssl.org).=cut