1EC(1)                               OpenSSL                              EC(1)
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NAME

6       ec - EC key processing
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SYNOPSIS

9       openssl ec [-inform PEM|DER] [-outform PEM|DER] [-in filename] [-passin
10       arg] [-out filename] [-passout arg] [-des] [-des3] [-idea] [-text]
11       [-noout] [-param_out] [-pubin] [-pubout] [-conv_form arg] [-param_enc
12       arg] [-engine id]
13

DESCRIPTION

15       The ec command processes EC keys. They can be converted between various
16       forms and their components printed out. Note OpenSSL uses the private
17       key format specified in 'SEC 1: Elliptic Curve Cryptography'
18       (http://www.secg.org/). To convert a OpenSSL EC private key into the
19       PKCS#8 private key format use the pkcs8 command.
20

COMMAND OPTIONS

22       -inform DER|PEM
23           This specifies the input format. The DER option with a private key
24           uses an ASN.1 DER encoded SEC1 private key. When used with a public
25           key it uses the SubjectPublicKeyInfo structur as specified in RFC
26           3280.  The PEM form is the default format: it consists of the DER
27           format base64 encoded with additional header and footer lines. In
28           the case of a private key PKCS#8 format is also accepted.
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30       -outform DER|PEM
31           This specifies the output format, the options have the same meaning
32           as the -inform option.
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34       -in filename
35           This specifies the input filename to read a key from or standard
36           input if this option is not specified. If the key is encrypted a
37           pass phrase will be prompted for.
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39       -passin arg
40           the input file password source. For more information about the
41           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
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43       -out filename
44           This specifies the output filename to write a key to or standard
45           output by is not specified. If any encryption options are set then
46           a pass phrase will be prompted for. The output filename should not
47           be the same as the input filename.
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49       -passout arg
50           the output file password source. For more information about the
51           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
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53       -des|-des3|-idea
54           These options encrypt the private key with the DES, triple DES,
55           IDEA or any other cipher supported by OpenSSL before outputting it.
56           A pass phrase is prompted for.  If none of these options is
57           specified the key is written in plain text. This means that using
58           the ec utility to read in an encrypted key with no encryption
59           option can be used to remove the pass phrase from a key, or by
60           setting the encryption options it can be use to add or change the
61           pass phrase.  These options can only be used with PEM format output
62           files.
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64       -text
65           prints out the public, private key components and parameters.
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67       -noout
68           this option prevents output of the encoded version of the key.
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70       -pubin
71           by default a private key is read from the input file: with this
72           option a public key is read instead.
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74       -pubout
75           by default a private key is output. With this option a public key
76           will be output instead. This option is automatically set if the
77           input is a public key.
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79       -conv_form
80           This specifies how the points on the elliptic curve are converted
81           into octet strings. Possible values are: compressed (the default
82           value), uncompressed and hybrid. For more information regarding the
83           point conversion forms please read the X9.62 standard.  Note Due to
84           patent issues the compressed option is disabled by default for
85           binary curves and can be enabled by defining the preprocessor macro
86           OPENSSL_EC_BIN_PT_COMP at compile time.
87
88       -param_enc arg
89           This specifies how the elliptic curve parameters are encoded.
90           Possible value are: named_curve, i.e. the ec parameters are
91           specified by a OID, or explicit where the ec parameters are
92           explicitly given (see RFC 3279 for the definition of the EC
93           parameters structures). The default value is named_curve.  Note the
94           implicitlyCA alternative ,as specified in RFC 3279, is currently
95           not implemented in OpenSSL.
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97       -engine id
98           specifying an engine (by its unique id string) will cause ec to
99           attempt to obtain a functional reference to the specified engine,
100           thus initialising it if needed. The engine will then be set as the
101           default for all available algorithms.
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NOTES

104       The PEM private key format uses the header and footer lines:
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106        -----BEGIN EC PRIVATE KEY-----
107        -----END EC PRIVATE KEY-----
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109       The PEM public key format uses the header and footer lines:
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111        -----BEGIN PUBLIC KEY-----
112        -----END PUBLIC KEY-----
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EXAMPLES

115       To encrypt a private key using triple DES:
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117        openssl ec -in key.pem -des3 -out keyout.pem
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119       To convert a private key from PEM to DER format:
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121        openssl ec -in key.pem -outform DER -out keyout.der
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123       To print out the components of a private key to standard output:
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125        openssl ec -in key.pem -text -noout
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127       To just output the public part of a private key:
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129        openssl ec -in key.pem -pubout -out pubkey.pem
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131       To change the parameters encoding to explicit:
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133        openssl ec -in key.pem -param_enc explicit -out keyout.pem
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135       To change the point conversion form to compressed:
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137        openssl ec -in key.pem -conv_form compressed -out keyout.pem
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SEE ALSO

140       ecparam(1), dsa(1), rsa(1)
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HISTORY

143       The ec command was first introduced in OpenSSL 0.9.8.
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AUTHOR

146       Nils Larsch for the OpenSSL project (http://www.openssl.org).
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1501.0.1e                            2017-03-22                             EC(1)
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