6 rsa - RSA key processing tool
11 [B<-inform PEM|NET|DER>]
12 [B<-outform PEM|NET|DER>]
37 The B<rsa> command processes RSA keys. They can be converted between various
38 forms and their components printed out. B<Note> this command uses the
39 traditional SSLeay compatible format for private key encryption: newer
40 applications should use the more secure PKCS#8 format using the B<pkcs8>
43 =head1 COMMAND OPTIONS
47 =item B<-inform DER|NET|PEM>
49 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
50 form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format.
51 The B<PEM> form is the default format: it consists of the B<DER> format base64
52 encoded with additional header and footer lines. On input PKCS#8 format private
53 keys are also accepted. The B<NET> form is a format is described in the B<NOTES>
56 =item B<-outform DER|NET|PEM>
58 This specifies the output format, the options have the same meaning as the
63 This specifies the input filename to read a key from or standard input if this
64 option is not specified. If the key is encrypted a pass phrase will be
69 the input file password source. For more information about the format of B<arg>
70 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
72 =item B<-out filename>
74 This specifies the output filename to write a key to or standard output if this
75 option is not specified. If any encryption options are set then a pass phrase
76 will be prompted for. The output filename should B<not> be the same as the input
79 =item B<-passout password>
81 the output file password source. For more information about the format of B<arg>
82 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
86 use the modified NET algorithm used with some versions of Microsoft IIS and SGC
89 =item B<-aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea>
91 These options encrypt the private key with the specified
92 cipher before outputting it. A pass phrase is prompted for.
93 If none of these options is specified the key is written in plain text. This
94 means that using the B<rsa> utility to read in an encrypted key with no
95 encryption option can be used to remove the pass phrase from a key, or by
96 setting the encryption options it can be use to add or change the pass phrase.
97 These options can only be used with PEM format output files.
101 prints out the various public or private key components in
102 plain text in addition to the encoded version.
106 this option prevents output of the encoded version of the key.
110 this option prints out the value of the modulus of the key.
114 this option checks the consistency of an RSA private key.
118 by default a private key is read from the input file: with this
119 option a public key is read instead.
123 by default a private key is output: with this option a public
124 key will be output instead. This option is automatically set if
125 the input is a public key.
129 specifying an engine (by it's unique B<id> string) will cause B<req>
130 to attempt to obtain a functional reference to the specified engine,
131 thus initialising it if needed. The engine will then be set as the default
132 for all available algorithms.
138 The PEM private key format uses the header and footer lines:
140 -----BEGIN RSA PRIVATE KEY-----
141 -----END RSA PRIVATE KEY-----
143 The PEM public key format uses the header and footer lines:
145 -----BEGIN PUBLIC KEY-----
146 -----END PUBLIC KEY-----
148 The B<NET> form is a format compatible with older Netscape servers
149 and Microsoft IIS .key files, this uses unsalted RC4 for its encryption.
150 It is not very secure and so should only be used when necessary.
152 Some newer version of IIS have additional data in the exported .key
153 files. To use these with the utility, view the file with a binary editor
154 and look for the string "private-key", then trace back to the byte
155 sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data
156 from this point onwards to another file and use that as the input
157 to the B<rsa> utility with the B<-inform NET> option. If you get
158 an error after entering the password try the B<-sgckey> option.
162 To remove the pass phrase on an RSA private key:
164 openssl rsa -in key.pem -out keyout.pem
166 To encrypt a private key using triple DES:
168 openssl rsa -in key.pem -des3 -out keyout.pem
170 To convert a private key from PEM to DER format:
172 openssl rsa -in key.pem -outform DER -out keyout.der
174 To print out the components of a private key to standard output:
176 openssl rsa -in key.pem -text -noout
178 To just output the public part of a private key:
180 openssl rsa -in key.pem -pubout -out pubkey.pem
184 The command line password arguments don't currently work with
187 There should be an option that automatically handles .key files,
188 without having to manually edit them.
192 L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>,
193 L<gendsa(1)|gendsa(1)>