6 rsa - RSA key processing tool
11 [B<-inform PEM|NET|DER>]
12 [B<-outform PEM|NET|DER>]
29 The B<rsa> command processes RSA keys. They can be converted between various
30 forms and their components printed out. B<Note> this command uses the
31 traditional SSLeay compatible format for private key encryption: newer
32 applications should use the more secure PKCS#8 format using the B<pkcs8>
35 =head1 COMMAND OPTIONS
39 =item B<-inform DER|NET|PEM>
41 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
42 form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format.
43 The B<PEM> form is the default format: it consists of the B<DER> format base64
44 encoded with additional header and footer lines. On input PKCS#8 format private
45 keys are also accepted. The B<NET> form is a format compatible with older Netscape
46 servers and MS IIS, this uses unsalted RC4 for its encryption. It is not very
47 secure and so should only be used when necessary.
49 =item B<-outform DER|NET|PEM>
51 This specifies the output format, the options have the same meaning as the
56 This specifies the input filename to read a key from or standard input if this
57 option is not specified. If the key is encrypted a pass phrase will be
62 the input file password source. For more information about the format of B<arg>
63 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
65 =item B<-out filename>
67 This specifies the output filename to write a key to or standard output if this
68 option is not specified. If any encryption options are set then a pass phrase
69 will be prompted for. The output filename should B<not> be the same as the input
72 =item B<-passout password>
74 the output file password source. For more information about the format of B<arg>
75 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
77 =item B<-des|-des3|-idea>
79 These options encrypt the private key with the DES, triple DES, or the
80 IDEA ciphers respectively before outputting it. A pass phrase is prompted for.
81 If none of these options is specified the key is written in plain text. This
82 means that using the B<rsa> utility to read in an encrypted key with no
83 encryption option can be used to remove the pass phrase from a key, or by
84 setting the encryption options it can be use to add or change the pass phrase.
85 These options can only be used with PEM format output files.
89 prints out the various public or private key components in
90 plain text in addition to the encoded version.
94 this option prevents output of the encoded version of the key.
98 this option prints out the value of the modulus of the key.
102 this option checks the consistency of an RSA private key.
106 by default a private key is read from the input file: with this
107 option a public key is read instead.
111 by default a private key is output: with this option a public
112 key will be output instead. This option is automatically set if
113 the input is a public key.
119 The PEM private key format uses the header and footer lines:
121 -----BEGIN RSA PRIVATE KEY-----
122 -----END RSA PRIVATE KEY-----
124 The PEM public key format uses the header and footer lines:
126 -----BEGIN PUBLIC KEY-----
127 -----END PUBLIC KEY-----
131 To remove the pass phrase on an RSA private key:
133 openssl rsa -in key.pem -out keyout.pem
135 To encrypt a private key using triple DES:
137 openssl rsa -in key.pem -des3 -out keyout.pem
139 To convert a private key from PEM to DER format:
141 openssl rsa -in key.pem -outform DER -out keyout.der
143 To print out the components of a private key to standard output:
145 openssl rsa -in key.pem -text -noout
147 To just output the public part of a private key:
149 openssl rsa -in key.pem -pubout -out pubkey.pem
153 L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>,
154 L<gendsa(1)|gendsa(1)>