32 The B<ec> command processes EC keys. They can be converted between various
33 forms and their components printed out. B<Note> OpenSSL uses the
34 private key format specified in 'SEC 1: Elliptic Curve Cryptography'
35 (http://www.secg.org/). To convert a OpenSSL EC private key into the
36 PKCS#8 private key format use the B<pkcs8> command.
38 =head1 COMMAND OPTIONS
42 =item B<-inform DER|PEM>
44 This specifies the input format. The B<DER> option with a private key uses
45 an ASN.1 DER encoded SEC1 private key. When used with a public key it
46 uses the SubjectPublicKeyInfo structure as specified in RFC 3280.
47 The B<PEM> form is the default format: it consists of the B<DER> format base64
48 encoded with additional header and footer lines. In the case of a private key
49 PKCS#8 format is also accepted.
51 =item B<-outform DER|PEM>
53 This specifies the output format, the options have the same meaning as the
58 This specifies the input filename to read a key from or standard input if this
59 option is not specified. If the key is encrypted a pass phrase will be
64 the input file password source. For more information about the format of B<arg>
65 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
67 =item B<-out filename>
69 This specifies the output filename to write a key to or standard output by
70 is not specified. If any encryption options are set then a pass phrase will be
71 prompted for. The output filename should B<not> be the same as the input
76 the output file password source. For more information about the format of B<arg>
77 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
79 =item B<-des|-des3|-idea>
81 These options encrypt the private key with the DES, triple DES, IDEA or
82 any other cipher supported by OpenSSL before outputting it. A pass phrase is
84 If none of these options is specified the key is written in plain text. This
85 means that using the B<ec> utility to read in an encrypted key with no
86 encryption option can be used to remove the pass phrase from a key, or by
87 setting the encryption options it can be use to add or change the pass phrase.
88 These options can only be used with PEM format output files.
92 prints out the public, private key components and parameters.
96 this option prevents output of the encoded version of the key.
100 this option prints out the value of the public key component of the key.
104 by default a private key is read from the input file: with this option a
105 public key is read instead.
109 by default a private key is output. With this option a public
110 key will be output instead. This option is automatically set if the input is
115 This specifies how the points on the elliptic curve are converted
116 into octet strings. Possible values are: B<compressed> (the default
117 value), B<uncompressed> and B<hybrid>. For more information regarding
118 the point conversion forms please read the X9.62 standard.
119 B<Note> Due to patent issues the B<compressed> option is disabled
120 by default for binary curves and can be enabled by defining
121 the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time.
123 =item B<-param_enc arg>
125 This specifies how the elliptic curve parameters are encoded.
126 Possible value are: B<named_curve>, i.e. the ec parameters are
127 specified by a OID, or B<explicit> where the ec parameters are
128 explicitly given (see RFC 3279 for the definition of the
129 EC parameters structures). The default value is B<named_curve>.
130 B<Note> the B<implicitlyCA> alternative ,as specified in RFC 3279,
131 is currently not implemented in OpenSSL.
135 This option omits the public key components from the private key output.
139 this option checks the consistency of an EC private or public key.
143 specifying an engine (by its unique B<id> string) will cause B<ec>
144 to attempt to obtain a functional reference to the specified engine,
145 thus initialising it if needed. The engine will then be set as the default
146 for all available algorithms.
152 The PEM private key format uses the header and footer lines:
154 -----BEGIN EC PRIVATE KEY-----
155 -----END EC PRIVATE KEY-----
157 The PEM public key format uses the header and footer lines:
159 -----BEGIN PUBLIC KEY-----
160 -----END PUBLIC KEY-----
164 To encrypt a private key using triple DES:
166 openssl ec -in key.pem -des3 -out keyout.pem
168 To convert a private key from PEM to DER format:
170 openssl ec -in key.pem -outform DER -out keyout.der
172 To print out the components of a private key to standard output:
174 openssl ec -in key.pem -text -noout
176 To just output the public part of a private key:
178 openssl ec -in key.pem -pubout -out pubkey.pem
180 To change the parameters encoding to B<explicit>:
182 openssl ec -in key.pem -param_enc explicit -out keyout.pem
184 To change the point conversion form to B<compressed>:
186 openssl ec -in key.pem -conv_form compressed -out keyout.pem
190 L<ecparam(1)>, L<dsa(1)>, L<rsa(1)>