rsa.pod revision 264331
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<-RSAPublicKey_in>] 28[B<-RSAPublicKey_out>] 29[B<-engine id>] 30 31=head1 DESCRIPTION 32 33The B<rsa> command processes RSA keys. They can be converted between various 34forms and their components printed out. B<Note> this command uses the 35traditional SSLeay compatible format for private key encryption: newer 36applications should use the more secure PKCS#8 format using the B<pkcs8> 37utility. 38 39=head1 COMMAND OPTIONS 40 41=over 4 42 43=item B<-inform DER|NET|PEM> 44 45This specifies the input format. The B<DER> option uses an ASN1 DER encoded 46form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format. 47The B<PEM> form is the default format: it consists of the B<DER> format base64 48encoded with additional header and footer lines. On input PKCS#8 format private 49keys are also accepted. The B<NET> form is a format is described in the B<NOTES> 50section. 51 52=item B<-outform DER|NET|PEM> 53 54This specifies the output format, the options have the same meaning as the 55B<-inform> option. 56 57=item B<-in filename> 58 59This specifies the input filename to read a key from or standard input if this 60option is not specified. If the key is encrypted a pass phrase will be 61prompted for. 62 63=item B<-passin arg> 64 65the input file password source. For more information about the format of B<arg> 66see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 67 68=item B<-out filename> 69 70This specifies the output filename to write a key to or standard output if this 71option is not specified. If any encryption options are set then a pass phrase 72will be prompted for. The output filename should B<not> be the same as the input 73filename. 74 75=item B<-passout password> 76 77the output file password source. For more information about the format of B<arg> 78see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 79 80=item B<-sgckey> 81 82use the modified NET algorithm used with some versions of Microsoft IIS and SGC 83keys. 84 85=item B<-des|-des3|-idea> 86 87These options encrypt the private key with the DES, triple DES, or the 88IDEA ciphers respectively before outputting it. A pass phrase is prompted for. 89If none of these options is specified the key is written in plain text. This 90means that using the B<rsa> utility to read in an encrypted key with no 91encryption option can be used to remove the pass phrase from a key, or by 92setting the encryption options it can be use to add or change the pass phrase. 93These options can only be used with PEM format output files. 94 95=item B<-text> 96 97prints out the various public or private key components in 98plain text in addition to the encoded version. 99 100=item B<-noout> 101 102this option prevents output of the encoded version of the key. 103 104=item B<-modulus> 105 106this option prints out the value of the modulus of the key. 107 108=item B<-check> 109 110this option checks the consistency of an RSA private key. 111 112=item B<-pubin> 113 114by default a private key is read from the input file: with this 115option a public key is read instead. 116 117=item B<-pubout> 118 119by default a private key is output: with this option a public 120key will be output instead. This option is automatically set if 121the input is a public key. 122 123=item B<-RSAPublicKey_in>, B<-RSAPublicKey_out> 124 125like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead. 126 127=item B<-engine id> 128 129specifying an engine (by its unique B<id> string) will cause B<rsa> 130to attempt to obtain a functional reference to the specified engine, 131thus initialising it if needed. The engine will then be set as the default 132for all available algorithms. 133 134=back 135 136=head1 NOTES 137 138The PEM private key format uses the header and footer lines: 139 140 -----BEGIN RSA PRIVATE KEY----- 141 -----END RSA PRIVATE KEY----- 142 143The PEM public key format uses the header and footer lines: 144 145 -----BEGIN PUBLIC KEY----- 146 -----END PUBLIC KEY----- 147 148The PEM B<RSAPublicKey> format uses the header and footer lines: 149 150 -----BEGIN RSA PUBLIC KEY----- 151 -----END RSA PUBLIC KEY----- 152 153The B<NET> form is a format compatible with older Netscape servers 154and Microsoft IIS .key files, this uses unsalted RC4 for its encryption. 155It is not very secure and so should only be used when necessary. 156 157Some newer version of IIS have additional data in the exported .key 158files. To use these with the utility, view the file with a binary editor 159and look for the string "private-key", then trace back to the byte 160sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data 161from this point onwards to another file and use that as the input 162to the B<rsa> utility with the B<-inform NET> option. If you get 163an error after entering the password try the B<-sgckey> option. 164 165=head1 EXAMPLES 166 167To remove the pass phrase on an RSA private key: 168 169 openssl rsa -in key.pem -out keyout.pem 170 171To encrypt a private key using triple DES: 172 173 openssl rsa -in key.pem -des3 -out keyout.pem 174 175To convert a private key from PEM to DER format: 176 177 openssl rsa -in key.pem -outform DER -out keyout.der 178 179To print out the components of a private key to standard output: 180 181 openssl rsa -in key.pem -text -noout 182 183To just output the public part of a private key: 184 185 openssl rsa -in key.pem -pubout -out pubkey.pem 186 187Output the public part of a private key in B<RSAPublicKey> format: 188 189 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem 190 191=head1 BUGS 192 193The command line password arguments don't currently work with 194B<NET> format. 195 196There should be an option that automatically handles .key files, 197without having to manually edit them. 198 199=head1 SEE ALSO 200 201L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>, 202L<gendsa(1)|gendsa(1)> 203 204=cut 205