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<-aes128>] 19[B<-aes192>] 20[B<-aes256>] 21[B<-camellia128>] 22[B<-camellia192>] 23[B<-camellia256>] 24[B<-des>] 25[B<-des3>] 26[B<-idea>] 27[B<-text>] 28[B<-noout>] 29[B<-modulus>] 30[B<-check>] 31[B<-pubin>] 32[B<-pubout>] 33[B<-RSAPublicKey_in>] 34[B<-RSAPublicKey_out>] 35[B<-engine id>] 36 37=head1 DESCRIPTION 38 39The B<rsa> command processes RSA keys. They can be converted between various 40forms and their components printed out. B<Note> this command uses the 41traditional SSLeay compatible format for private key encryption: newer 42applications should use the more secure PKCS#8 format using the B<pkcs8> 43utility. 44 45=head1 COMMAND OPTIONS 46 47=over 4 48 49=item B<-inform DER|NET|PEM> 50 51This specifies the input format. The B<DER> option uses an ASN1 DER encoded 52form compatible with the PKCS#1 RSAPrivateKey or SubjectPublicKeyInfo format. 53The B<PEM> form is the default format: it consists of the B<DER> format base64 54encoded with additional header and footer lines. On input PKCS#8 format private 55keys are also accepted. The B<NET> form is a format is described in the B<NOTES> 56section. 57 58=item B<-outform DER|NET|PEM> 59 60This specifies the output format, the options have the same meaning as the 61B<-inform> option. 62 63=item B<-in filename> 64 65This specifies the input filename to read a key from or standard input if this 66option is not specified. If the key is encrypted a pass phrase will be 67prompted for. 68 69=item B<-passin arg> 70 71the input file password source. For more information about the format of B<arg> 72see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 73 74=item B<-out filename> 75 76This specifies the output filename to write a key to or standard output if this 77option is not specified. If any encryption options are set then a pass phrase 78will be prompted for. The output filename should B<not> be the same as the input 79filename. 80 81=item B<-passout password> 82 83the output file password source. For more information about the format of B<arg> 84see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 85 86=item B<-sgckey> 87 88use the modified NET algorithm used with some versions of Microsoft IIS and SGC 89keys. 90 91=item B<-aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea> 92 93These options encrypt the private key with the specified 94cipher before outputting it. A pass phrase is prompted for. 95If none of these options is specified the key is written in plain text. This 96means that using the B<rsa> utility to read in an encrypted key with no 97encryption option can be used to remove the pass phrase from a key, or by 98setting the encryption options it can be use to add or change the pass phrase. 99These options can only be used with PEM format output files. 100 101=item B<-text> 102 103prints out the various public or private key components in 104plain text in addition to the encoded version. 105 106=item B<-noout> 107 108this option prevents output of the encoded version of the key. 109 110=item B<-modulus> 111 112this option prints out the value of the modulus of the key. 113 114=item B<-check> 115 116this option checks the consistency of an RSA private key. 117 118=item B<-pubin> 119 120by default a private key is read from the input file: with this 121option a public key is read instead. 122 123=item B<-pubout> 124 125by default a private key is output: with this option a public 126key will be output instead. This option is automatically set if 127the input is a public key. 128 129=item B<-RSAPublicKey_in>, B<-RSAPublicKey_out> 130 131like B<-pubin> and B<-pubout> except B<RSAPublicKey> format is used instead. 132 133=item B<-engine id> 134 135specifying an engine (by its unique B<id> string) will cause B<rsa> 136to attempt to obtain a functional reference to the specified engine, 137thus initialising it if needed. The engine will then be set as the default 138for all available algorithms. 139 140=back 141 142=head1 NOTES 143 144The PEM private key format uses the header and footer lines: 145 146 -----BEGIN RSA PRIVATE KEY----- 147 -----END RSA PRIVATE KEY----- 148 149The PEM public key format uses the header and footer lines: 150 151 -----BEGIN PUBLIC KEY----- 152 -----END PUBLIC KEY----- 153 154The PEM B<RSAPublicKey> format uses the header and footer lines: 155 156 -----BEGIN RSA PUBLIC KEY----- 157 -----END RSA PUBLIC KEY----- 158 159The B<NET> form is a format compatible with older Netscape servers 160and Microsoft IIS .key files, this uses unsalted RC4 for its encryption. 161It is not very secure and so should only be used when necessary. 162 163Some newer version of IIS have additional data in the exported .key 164files. To use these with the utility, view the file with a binary editor 165and look for the string "private-key", then trace back to the byte 166sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data 167from this point onwards to another file and use that as the input 168to the B<rsa> utility with the B<-inform NET> option. If you get 169an error after entering the password try the B<-sgckey> option. 170 171=head1 EXAMPLES 172 173To remove the pass phrase on an RSA private key: 174 175 openssl rsa -in key.pem -out keyout.pem 176 177To encrypt a private key using triple DES: 178 179 openssl rsa -in key.pem -des3 -out keyout.pem 180 181To convert a private key from PEM to DER format: 182 183 openssl rsa -in key.pem -outform DER -out keyout.der 184 185To print out the components of a private key to standard output: 186 187 openssl rsa -in key.pem -text -noout 188 189To just output the public part of a private key: 190 191 openssl rsa -in key.pem -pubout -out pubkey.pem 192 193Output the public part of a private key in B<RSAPublicKey> format: 194 195 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem 196 197=head1 BUGS 198 199The command line password arguments don't currently work with 200B<NET> format. 201 202There should be an option that automatically handles .key files, 203without having to manually edit them. 204 205=head1 SEE ALSO 206 207L<pkcs8(1)|pkcs8(1)>, L<dsa(1)|dsa(1)>, L<genrsa(1)|genrsa(1)>, 208L<gendsa(1)|gendsa(1)> 209 210=cut 211