ec.pod revision 160815
1=pod 2 3=head1 NAME 4 5ec - EC key processing 6 7=head1 SYNOPSIS 8 9B<openssl> B<ec> 10[B<-inform PEM|DER>] 11[B<-outform PEM|DER>] 12[B<-in filename>] 13[B<-passin arg>] 14[B<-out filename>] 15[B<-passout arg>] 16[B<-des>] 17[B<-des3>] 18[B<-idea>] 19[B<-text>] 20[B<-noout>] 21[B<-param_out>] 22[B<-pubin>] 23[B<-pubout>] 24[B<-conv_form arg>] 25[B<-param_enc arg>] 26[B<-engine id>] 27 28=head1 DESCRIPTION 29 30The B<ec> command processes EC keys. They can be converted between various 31forms and their components printed out. B<Note> OpenSSL uses the 32private key format specified in 'SEC 1: Elliptic Curve Cryptography' 33(http://www.secg.org/). To convert a OpenSSL EC private key into the 34PKCS#8 private key format use the B<pkcs8> command. 35 36=head1 COMMAND OPTIONS 37 38=over 4 39 40=item B<-inform DER|PEM> 41 42This specifies the input format. The B<DER> option with a private key uses 43an ASN.1 DER encoded SEC1 private key. When used with a public key it 44uses the SubjectPublicKeyInfo structur as specified in RFC 3280. 45The B<PEM> form is the default format: it consists of the B<DER> format base64 46encoded with additional header and footer lines. In the case of a private key 47PKCS#8 format is also accepted. 48 49=item B<-outform DER|PEM> 50 51This specifies the output format, the options have the same meaning as the 52B<-inform> option. 53 54=item B<-in filename> 55 56This specifies the input filename to read a key from or standard input if this 57option is not specified. If the key is encrypted a pass phrase will be 58prompted for. 59 60=item B<-passin arg> 61 62the input file password source. For more information about the format of B<arg> 63see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 64 65=item B<-out filename> 66 67This specifies the output filename to write a key to or standard output by 68is not specified. If any encryption options are set then a pass phrase will be 69prompted for. The output filename should B<not> be the same as the input 70filename. 71 72=item B<-passout arg> 73 74the output file password source. For more information about the format of B<arg> 75see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 76 77=item B<-des|-des3|-idea> 78 79These options encrypt the private key with the DES, triple DES, IDEA or 80any other cipher supported by OpenSSL before outputting it. A pass phrase is 81prompted for. 82If none of these options is specified the key is written in plain text. This 83means that using the B<ec> utility to read in an encrypted key with no 84encryption option can be used to remove the pass phrase from a key, or by 85setting the encryption options it can be use to add or change the pass phrase. 86These options can only be used with PEM format output files. 87 88=item B<-text> 89 90prints out the public, private key components and parameters. 91 92=item B<-noout> 93 94this option prevents output of the encoded version of the key. 95 96=item B<-modulus> 97 98this option prints out the value of the public key component of the key. 99 100=item B<-pubin> 101 102by default a private key is read from the input file: with this option a 103public key is read instead. 104 105=item B<-pubout> 106 107by default a private key is output. With this option a public 108key will be output instead. This option is automatically set if the input is 109a public key. 110 111=item B<-conv_form> 112 113This specifies how the points on the elliptic curve are converted 114into octet strings. Possible values are: B<compressed> (the default 115value), B<uncompressed> and B<hybrid>. For more information regarding 116the point conversion forms please read the X9.62 standard. 117B<Note> Due to patent issues the B<compressed> option is disabled 118by default for binary curves and can be enabled by defining 119the preprocessor macro B<OPENSSL_EC_BIN_PT_COMP> at compile time. 120 121=item B<-param_enc arg> 122 123This specifies how the elliptic curve parameters are encoded. 124Possible value are: B<named_curve>, i.e. the ec parameters are 125specified by a OID, or B<explicit> where the ec parameters are 126explicitly given (see RFC 3279 for the definition of the 127EC parameters structures). The default value is B<named_curve>. 128B<Note> the B<implicitlyCA> alternative ,as specified in RFC 3279, 129is currently not implemented in OpenSSL. 130 131=item B<-engine id> 132 133specifying an engine (by it's unique B<id> string) will cause B<req> 134to attempt to obtain a functional reference to the specified engine, 135thus initialising it if needed. The engine will then be set as the default 136for all available algorithms. 137 138=back 139 140=head1 NOTES 141 142The PEM private key format uses the header and footer lines: 143 144 -----BEGIN EC PRIVATE KEY----- 145 -----END EC PRIVATE KEY----- 146 147The PEM public key format uses the header and footer lines: 148 149 -----BEGIN PUBLIC KEY----- 150 -----END PUBLIC KEY----- 151 152=head1 EXAMPLES 153 154To encrypt a private key using triple DES: 155 156 openssl ec -in key.pem -des3 -out keyout.pem 157 158To convert a private key from PEM to DER format: 159 160 openssl ec -in key.pem -outform DER -out keyout.der 161 162To print out the components of a private key to standard output: 163 164 openssl ec -in key.pem -text -noout 165 166To just output the public part of a private key: 167 168 openssl ec -in key.pem -pubout -out pubkey.pem 169 170To change the parameters encoding to B<explicit>: 171 172 openssl ec -in key.pem -param_enc explicit -out keyout.pem 173 174To change the point conversion form to B<compressed>: 175 176 openssl ec -in key.pem -conv_form compressed -out keyout.pem 177 178=head1 SEE ALSO 179 180L<ecparam(1)|ecparam(1)>, L<dsa(1)|dsa(1)>, L<rsa(1)|rsa(1)> 181 182=head1 HISTORY 183 184The ec command was first introduced in OpenSSL 0.9.8. 185 186=head1 AUTHOR 187 188Nils Larsch for the OpenSSL project (http://www.openssl.org). 189 190=cut 191