diff options
Diffstat (limited to 'openssl/doc/apps/rsautl.pod')
| -rw-r--r-- | openssl/doc/apps/rsautl.pod | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/openssl/doc/apps/rsautl.pod b/openssl/doc/apps/rsautl.pod new file mode 100644 index 000000000..1a498c2f6 --- /dev/null +++ b/openssl/doc/apps/rsautl.pod @@ -0,0 +1,183 @@ +=pod + +=head1 NAME + +rsautl - RSA utility + +=head1 SYNOPSIS + +B<openssl> B<rsautl> +[B<-in file>] +[B<-out file>] +[B<-inkey file>] +[B<-pubin>] +[B<-certin>] +[B<-sign>] +[B<-verify>] +[B<-encrypt>] +[B<-decrypt>] +[B<-pkcs>] +[B<-ssl>] +[B<-raw>] +[B<-hexdump>] +[B<-asn1parse>] + +=head1 DESCRIPTION + +The B<rsautl> command can be used to sign, verify, encrypt and decrypt +data using the RSA algorithm. + +=head1 COMMAND OPTIONS + +=over 4 + +=item B<-in filename> + +This specifies the input filename to read data from or standard input +if this option is not specified. + +=item B<-out filename> + +specifies the output filename to write to or standard output by +default. + +=item B<-inkey file> + +the input key file, by default it should be an RSA private key. + +=item B<-pubin> + +the input file is an RSA public key. + +=item B<-certin> + +the input is a certificate containing an RSA public key. + +=item B<-sign> + +sign the input data and output the signed result. This requires +and RSA private key. + +=item B<-verify> + +verify the input data and output the recovered data. + +=item B<-encrypt> + +encrypt the input data using an RSA public key. + +=item B<-decrypt> + +decrypt the input data using an RSA private key. + +=item B<-pkcs, -oaep, -ssl, -raw> + +the padding to use: PKCS#1 v1.5 (the default), PKCS#1 OAEP, +special padding used in SSL v2 backwards compatible handshakes, +or no padding, respectively. +For signatures, only B<-pkcs> and B<-raw> can be used. + +=item B<-hexdump> + +hex dump the output data. + +=item B<-asn1parse> + +asn1parse the output data, this is useful when combined with the +B<-verify> option. + +=back + +=head1 NOTES + +B<rsautl> because it uses the RSA algorithm directly can only be +used to sign or verify small pieces of data. + +=head1 EXAMPLES + +Sign some data using a private key: + + openssl rsautl -sign -in file -inkey key.pem -out sig + +Recover the signed data + + openssl rsautl -verify -in sig -inkey key.pem + +Examine the raw signed data: + + openssl rsautl -verify -in file -inkey key.pem -raw -hexdump + + 0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................ + 0070 - ff ff ff ff 00 68 65 6c-6c 6f 20 77 6f 72 6c 64 .....hello world + +The PKCS#1 block formatting is evident from this. If this was done using +encrypt and decrypt the block would have been of type 2 (the second byte) +and random padding data visible instead of the 0xff bytes. + +It is possible to analyse the signature of certificates using this +utility in conjunction with B<asn1parse>. Consider the self signed +example in certs/pca-cert.pem . Running B<asn1parse> as follows yields: + + openssl asn1parse -in pca-cert.pem + + 0:d=0 hl=4 l= 742 cons: SEQUENCE + 4:d=1 hl=4 l= 591 cons: SEQUENCE + 8:d=2 hl=2 l= 3 cons: cont [ 0 ] + 10:d=3 hl=2 l= 1 prim: INTEGER :02 + 13:d=2 hl=2 l= 1 prim: INTEGER :00 + 16:d=2 hl=2 l= 13 cons: SEQUENCE + 18:d=3 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption + 29:d=3 hl=2 l= 0 prim: NULL + 31:d=2 hl=2 l= 92 cons: SEQUENCE + 33:d=3 hl=2 l= 11 cons: SET + 35:d=4 hl=2 l= 9 cons: SEQUENCE + 37:d=5 hl=2 l= 3 prim: OBJECT :countryName + 42:d=5 hl=2 l= 2 prim: PRINTABLESTRING :AU + .... + 599:d=1 hl=2 l= 13 cons: SEQUENCE + 601:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption + 612:d=2 hl=2 l= 0 prim: NULL + 614:d=1 hl=3 l= 129 prim: BIT STRING + + +The final BIT STRING contains the actual signature. It can be extracted with: + + openssl asn1parse -in pca-cert.pem -out sig -noout -strparse 614 + +The certificate public key can be extracted with: + + openssl x509 -in test/testx509.pem -pubkey -noout >pubkey.pem + +The signature can be analysed with: + + openssl rsautl -in sig -verify -asn1parse -inkey pubkey.pem -pubin + + 0:d=0 hl=2 l= 32 cons: SEQUENCE + 2:d=1 hl=2 l= 12 cons: SEQUENCE + 4:d=2 hl=2 l= 8 prim: OBJECT :md5 + 14:d=2 hl=2 l= 0 prim: NULL + 16:d=1 hl=2 l= 16 prim: OCTET STRING + 0000 - f3 46 9e aa 1a 4a 73 c9-37 ea 93 00 48 25 08 b5 .F...Js.7...H%.. + +This is the parsed version of an ASN1 DigestInfo structure. It can be seen that +the digest used was md5. The actual part of the certificate that was signed can +be extracted with: + + openssl asn1parse -in pca-cert.pem -out tbs -noout -strparse 4 + +and its digest computed with: + + openssl md5 -c tbs + MD5(tbs)= f3:46:9e:aa:1a:4a:73:c9:37:ea:93:00:48:25:08:b5 + +which it can be seen agrees with the recovered value above. + +=head1 SEE ALSO + +L<dgst(1)|dgst(1)>, L<rsa(1)|rsa(1)>, L<genrsa(1)|genrsa(1)> |