1 2=pod 3 4=head1 NAME 5 6rsa - RSA key processing tool 7 8=head1 SYNOPSIS 9 10B<openssl> B<rsa> 11[B<-inform PEM|NET|DER>] 12[B<-outform PEM|NET|DER>] 13[B<-in filename>] 14[B<-passin arg>] 15[B<-out filename>] 16[B<-passout arg>] 17[B<-sgckey>] 18[B<-des>] 19[B<-des3>] 20[B<-idea>] 21[B<-text>] 22[B<-noout>] 23[B<-modulus>] 24[B<-check>] 25[B<-pubin>] 26[B<-pubout>] 27[B<-engine id>] 28 29=head1 DESCRIPTION 30 31The B<rsa> command processes RSA keys. They can be converted between various 32forms and their components printed out. B<Note> this command uses the 33traditional SSLeay compatible format for private key encryption: newer 34applications should use the more secure PKCS#8 format using the B<pkcs8> 35utility. 36 37=head1 COMMAND OPTIONS 38 39=over 4 40 41=item B<-inform DER|NET|PEM> 42 43This specifies the input format. The B<DER> option uses an ASN1 DER encoded 44form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format. 45The B<PEM> form is the default format: it consists of the B<DER> format base64 46encoded with additional header and footer lines. On input PKCS#8 format private 47keys are also accepted. The B<NET> form is a format is described in the B<NOTES> 48section. 49 50=item B<-outform DER|NET|PEM> 51 52This specifies the output format, the options have the same meaning as the 53B<-inform> option. 54 55=item B<-in filename> 56 57This specifies the input filename to read a key from or standard input if this 58option is not specified. If the key is encrypted a pass phrase will be 59prompted for. 60 61=item B<-passin arg> 62 63the input file password source. For more information about the format of B<arg> 64see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 65 66=item B<-out filename> 67 68This specifies the output filename to write a key to or standard output if this 69option is not specified. If any encryption options are set then a pass phrase 70will be prompted for. The output filename should B<not> be the same as the input 71filename. 72 73=item B<-passout password> 74 75the output file password source. For more information about the format of B<arg> 76see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 77 78=item B<-sgckey> 79 80use the modified NET algorithm used with some versions of Microsoft IIS and SGC 81keys. 82 83=item B<-des|-des3|-idea> 84 85These options encrypt the private key with the DES, triple DES, or the 86IDEA ciphers respectively before outputting it. A pass phrase is prompted for. 87If none of these options is specified the key is written in plain text. This 88means that using the B<rsa> utility to read in an encrypted key with no 89encryption option can be used to remove the pass phrase from a key, or by 90setting the encryption options it can be use to add or change the pass phrase. 91These options can only be used with PEM format output files. 92 93=item B<-text> 94 95prints out the various public or private key components in 96plain text in addition to the encoded version. 97 98=item B<-noout> 99 100this option prevents output of the encoded version of the key. 101 102=item B<-modulus> 103 104this option prints out the value of the modulus of the key. 105 106=item B<-check> 107 108this option checks the consistency of an RSA private key. 109 110=item B<-pubin> 111 112by default a private key is read from the input file: with this 113option a public key is read instead. 114 115=item B<-pubout> 116 117by default a private key is output: with this option a public 118key will be output instead. This option is automatically set if 119the input is a public key. 120 121=item B<-engine id> 122 123specifying an engine (by it's unique B<id> string) will cause B<req> 124to attempt to obtain a functional reference to the specified engine, 125thus initialising it if needed. The engine will then be set as the default 126for all available algorithms. 127 128=back 129 130=head1 NOTES 131 132The PEM private key format uses the header and footer lines: 133 134 -----BEGIN RSA PRIVATE KEY----- 135 -----END RSA PRIVATE KEY----- 136 137The PEM public key format uses the header and footer lines: 138 139 -----BEGIN PUBLIC KEY----- 140 -----END PUBLIC KEY----- 141 142The B<NET> form is a format compatible with older Netscape servers 143and Microsoft IIS .key files, this uses unsalted RC4 for its encryption. 144It is not very secure and so should only be used when necessary. 145 146Some newer version of IIS have additional data in the exported .key 147files. To use these with the utility, view the file with a binary editor 148and look for the string "private-key", then trace back to the byte 149sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data 150from this point onwards to another file and use that as the input 151to the B<rsa> utility with the B<-inform NET> option. If you get 152an error after entering the password try the B<-sgckey> option. 153 154=head1 EXAMPLES 155 156To remove the pass phrase on an RSA private key: 157 158 openssl rsa -in key.pem -out keyout.pem 159 160To encrypt a private key using triple DES: 161 162 openssl rsa -in key.pem -des3 -out keyout.pem 163 164To convert a private key from PEM to DER format: 165 166 openssl rsa -in key.pem -outform DER -out keyout.der 167 168To print out the components of a private key to standard output: 169 170 openssl rsa -in key.pem -text -noout 171 172To just output the public part of a private key: 173 174 openssl rsa -in key.pem -pubout -out pubkey.pem 175 176=head1 BUGS 177 178The command line password arguments don't currently work with 179B<NET> format. 180 181There should be an option that automatically handles .key files, 182without having to manually edit them. 183 184=head1 SEE ALSO 185 186L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>, 187L<gendsa(1)|gendsa(1)> 188 189=cut 190