7 rsa - RSA key processing tool
12 [B<-inform PEM|NET|DER>]
13 [B<-outform PEM|NET|DER>]
35 [B<-RSAPublicKey_out>]
40 The B<rsa> command processes RSA keys. They can be converted between various
41 forms and their components printed out. B<Note> this command uses the
42 traditional SSLeay compatible format for private key encryption: newer
43 applications should use the more secure PKCS#8 format using the B<pkcs8>
46 =head1 COMMAND OPTIONS
50 =item B<-inform DER|NET|PEM>
52 This specifies the input format. The B<DER> option uses an ASN1 DER encoded
53 form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format.
54 The B<PEM> form is the default format: it consists of the B<DER> format base64
55 encoded with additional header and footer lines. On input PKCS#8 format private
56 keys are also accepted. The B<NET> form is a format is described in the B<NOTES>
59 =item B<-outform DER|NET|PEM>
61 This specifies the output format, the options have the same meaning as the
66 This specifies the input filename to read a key from or standard input if this
67 option is not specified. If the key is encrypted a pass phrase will be
72 the input file password source. For more information about the format of B<arg>
73 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
75 =item B<-out filename>
77 This specifies the output filename to write a key to or standard output if this
78 option is not specified. If any encryption options are set then a pass phrase
79 will be prompted for. The output filename should B<not> be the same as the input
82 =item B<-passout password>
84 the output file password source. For more information about the format of B<arg>
85 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
89 use the modified NET algorithm used with some versions of Microsoft IIS and SGC
92 =item B<-aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea>
94 These options encrypt the private key with the specified
95 cipher before outputting it. A pass phrase is prompted for.
96 If none of these options is specified the key is written in plain text. This
97 means that using the B<rsa> utility to read in an encrypted key with no
98 encryption option can be used to remove the pass phrase from a key, or by
99 setting the encryption options it can be use to add or change the pass phrase.
100 These options can only be used with PEM format output files.
104 prints out the various public or private key components in
105 plain text in addition to the encoded version.
109 this option prevents output of the encoded version of the key.
113 this option prints out the value of the modulus of the key.
117 this option checks the consistency of an RSA private key.
121 by default a private key is read from the input file: with this
122 option a public key is read instead.
126 by default a private key is output: with this option a public
127 key will be output instead. This option is automatically set if
128 the input is a public key.
130 =item B<-RSAPublicKey_in>, B<-RSAPublicKey_out>
132 like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead.
136 specifying an engine (by its unique B<id> string) will cause B<rsa>
137 to attempt to obtain a functional reference to the specified engine,
138 thus initialising it if needed. The engine will then be set as the default
139 for all available algorithms.
145 The PEM private key format uses the header and footer lines:
147 -----BEGIN RSA PRIVATE KEY-----
148 -----END RSA PRIVATE KEY-----
150 The PEM public key format uses the header and footer lines:
152 -----BEGIN PUBLIC KEY-----
153 -----END PUBLIC KEY-----
155 The PEM B<RSAPublicKey> format uses the header and footer lines:
157 -----BEGIN RSA PUBLIC KEY-----
158 -----END RSA PUBLIC KEY-----
160 The B<NET> form is a format compatible with older Netscape servers
161 and Microsoft IIS .key files, this uses unsalted RC4 for its encryption.
162 It is not very secure and so should only be used when necessary.
164 Some newer version of IIS have additional data in the exported .key
165 files. To use these with the utility, view the file with a binary editor
166 and look for the string "private-key", then trace back to the byte
167 sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data
168 from this point onwards to another file and use that as the input
169 to the B<rsa> utility with the B<-inform NET> option. If you get
170 an error after entering the password try the B<-sgckey> option.
174 To remove the pass phrase on an RSA private key:
176 openssl rsa -in key.pem -out keyout.pem
178 To encrypt a private key using triple DES:
180 openssl rsa -in key.pem -des3 -out keyout.pem
182 To convert a private key from PEM to DER format:
184 openssl rsa -in key.pem -outform DER -out keyout.der
186 To print out the components of a private key to standard output:
188 openssl rsa -in key.pem -text -noout
190 To just output the public part of a private key:
192 openssl rsa -in key.pem -pubout -out pubkey.pem
194 Output the public part of a private key in B<RSAPublicKey> format:
196 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
200 The command line password arguments don't currently work with
203 There should be an option that automatically handles .key files,
204 without having to manually edit them.
208 L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>,
209 L<gendsa(1)|gendsa(1)>