RSA(1) OpenSSL RSA(1) NNAAMMEE rsa - RSA key processing tool SSYYNNOOPPSSIISS ooppeennssssll rrssaa [--iinnffoorrmm PPEEMM||NNEETT||DDEERR] [--oouuttffoorrmm PPEEMM||NNEETT||DDEERR] [--iinn ffiilleennaammee] [--ppaassssiinn aarrgg] [--oouutt ffiilleennaammee] [--ppaassssoouutt aarrgg] [--ssggcckkeeyy] [--aaeess112288] [--aaeess119922] [--aaeess225566] [--ccaammeelllliiaa112288] [--ccaammeelllliiaa119922] [--ccaammeelllliiaa225566] [--ddeess] [--ddeess33] [--iiddeeaa] [--tteexxtt] [--nnoooouutt] [--mmoodduulluuss] [--cchheecckk] [--ppuubbiinn] [--ppuubboouutt] [--RRSSAAPPuubblliiccKKeeyy__iinn] [--RRSSAAPPuubblliiccKKeeyy__oouutt] [--eennggiinnee iidd] DDEESSCCRRIIPPTTIIOONN The rrssaa command processes RSA keys. They can be converted between vari- ous forms and their components printed out. NNoottee this command uses the traditional SSLeay compatible format for private key encryption: newer applications should use the more secure PKCS#8 format using the ppkkccss88 utility. CCOOMMMMAANNDD OOPPTTIIOONNSS --iinnffoorrmm DDEERR||NNEETT||PPEEMM This specifies the input format. The DDEERR option uses an ASN1 DER encoded form compatible with the PKCS#1 RSAPrivateKey or Subject- PublicKeyInfo format. The PPEEMM form is the default format: it con- sists of the DDEERR format base64 encoded with additional header and footer lines. On input PKCS#8 format private keys are also accepted. The NNEETT form is a format is described in the NNOOTTEESS sec- tion. --oouuttffoorrmm DDEERR||NNEETT||PPEEMM This specifies the output format, the options have the same meaning as the --iinnffoorrmm option. --iinn ffiilleennaammee This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for. --ppaassssiinn aarrgg the input file password source. For more information about the for- mat of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in _o_p_e_n_s_s_l(1). --oouutt ffiilleennaammee This specifies the output filename to write a key to or standard output if this option is not specified. If any encryption options are set then a pass phrase will be prompted for. The output file- name should nnoott be the same as the input filename. --ppaassssoouutt ppaasssswwoorrdd the output file password source. For more information about the format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in _o_p_e_n_s_s_l(1). --ssggcckkeeyy use the modified NET algorithm used with some versions of Microsoft IIS and SGC keys. --aaeess112288||--aaeess119922||--aaeess225566||--ccaammeelllliiaa112288||--ccaammeelllliiaa119922||--ccaammeell-- lliiaa225566||--ddeess||--ddeess33||--iiddeeaa These options encrypt the private key with the specified cipher before outputting it. A pass phrase is prompted for. If none of these options is specified the key is written in plain text. This means that using the rrssaa utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use to add or change the pass phrase. These options can only be used with PEM format output files. --tteexxtt prints out the various public or private key components in plain text in addition to the encoded version. --nnoooouutt this option prevents output of the encoded version of the key. --mmoodduulluuss this option prints out the value of the modulus of the key. --cchheecckk this option checks the consistency of an RSA private key. --ppuubbiinn by default a private key is read from the input file: with this option a public key is read instead. --ppuubboouutt by default a private key is output: with this option a public key will be output instead. This option is automatically set if the input is a public key. --RRSSAAPPuubblliiccKKeeyy__iinn, --RRSSAAPPuubblliiccKKeeyy__oouutt like --ppuubbiinn and --ppuubboouutt except RRSSAAPPuubblliiccKKeeyy format is used instead. --eennggiinnee iidd specifying an engine (by its unique iidd string) will cause rrssaa to attempt to obtain a functional reference to the specified engine, thus initialising it if needed. The engine will then be set as the default for all available algorithms. NNOOTTEESS The PEM private key format uses the header and footer lines: -----BEGIN RSA PRIVATE KEY----- -----END RSA PRIVATE KEY----- The PEM public key format uses the header and footer lines: -----BEGIN PUBLIC KEY----- -----END PUBLIC KEY----- The PEM RRSSAAPPuubblliiccKKeeyy format uses the header and footer lines: -----BEGIN RSA PUBLIC KEY----- -----END RSA PUBLIC KEY----- The NNEETT form is a format compatible with older Netscape servers and Mi- crosoft IIS .key files, this uses unsalted RC4 for its encryption. It is not very secure and so should only be used when necessary. Some newer version of IIS have additional data in the exported .key files. To use these with the utility, view the file with a binary edi- tor and look for the string "private-key", then trace back to the byte sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data from this point onwards to another file and use that as the input to the rrssaa utility with the --iinnffoorrmm NNEETT option. If you get an error after entering the password try the --ssggcckkeeyy option. EEXXAAMMPPLLEESS To remove the pass phrase on an RSA private key: openssl rsa -in key.pem -out keyout.pem To encrypt a private key using triple DES: openssl rsa -in key.pem -des3 -out keyout.pem To convert a private key from PEM to DER format: openssl rsa -in key.pem -outform DER -out keyout.der To print out the components of a private key to standard output: openssl rsa -in key.pem -text -noout To just output the public part of a private key: openssl rsa -in key.pem -pubout -out pubkey.pem Output the public part of a private key in RRSSAAPPuubblliiccKKeeyy format: openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem BBUUGGSS The command line password arguments don't currently work with NNEETT for- mat. There should be an option that automatically handles .key files, with- out having to manually edit them. SSEEEE AALLSSOO _p_k_c_s_8(1), _d_s_a(1), _g_e_n_r_s_a(1), _g_e_n_d_s_a(1) 1.0.1u 2016-09-22 RSA(1)