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OPENSSL-RSAUTL(1ossl)               OpenSSL              OPENSSL-RSAUTL(1ossl)


       openssl-rsautl - RSA command


       openssl rsautl [-help] [-in file] [-passin arg] [-rev] [-out file]
       [-inkey filename|uri] [-keyform DER|PEM|P12|ENGINE] [-pubin] [-certin]
       [-sign] [-verify] [-encrypt] [-decrypt] [-pkcs] [-x931] [-oaep] [-raw]
       [-hexdump] [-asn1parse] [-engine id] [-rand files] [-writerand file]
       [-provider name] [-provider-path path] [-propquery propq]


       This command has been deprecated.  The openssl-pkeyutl(1) command
       should be used instead.

       This command can be used to sign, verify, encrypt and decrypt data
       using the RSA algorithm.


           Print out a usage message.

       -in filename
           This specifies the input filename to read data from or standard
           input if this option is not specified.

       -passin arg
           The passphrase used in the output file.  See see

           Reverse the order of the input.

       -out filename
           Specifies the output filename to write to or standard output by

       -inkey filename|uri
           The input key, by default it should be an RSA private key.

       -keyform DER|PEM|P12|ENGINE
           The key format; unspecified by default.  See
           openssl-format-options(1) for details.

           By default a private key is read from the key input.  With this
           option a public key is read instead.  If the input contains no
           public key but a private key, its public part is used.

           The input is a certificate containing an RSA public key.

           Sign the input data and output the signed result. This requires an
           RSA private key.

           Verify the input data and output the recovered data.

           Encrypt the input data using an RSA public key.

           Decrypt the input data using an RSA private key.

       -pkcs, -oaep, -x931, -raw
           The padding to use: PKCS#1 v1.5 (the default), PKCS#1 OAEP, ANSI
           X9.31, or no padding, respectively.  For signatures, only -pkcs and
           -raw can be used.

           Note: because of protection against Bleichenbacher attacks,
           decryption using PKCS#1 v1.5 mode will not return errors in case
           padding check failed.  Use -raw and inspect the returned value
           manually to check if the padding is correct.

           Hex dump the output data.

           Parse the ASN.1 output data, this is useful when combined with the
           -verify option.

       -engine id
           See "Engine Options" in openssl(1).  This option is deprecated.

       -rand files, -writerand file
           See "Random State Options" in openssl(1) for details.

       -provider name
       -provider-path path
       -propquery propq
           See "Provider Options" in openssl(1), provider(7), and property(7).


       Since this command uses the RSA algorithm directly, it can only be used
       to sign or verify small pieces of data.


       Examples equivalent to these can be found in the documentation for the
       non-deprecated openssl-pkeyutl(1) command.

       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 sig -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
       command in conjunction with openssl-asn1parse(1). Consider the self
       signed example in certs/pca-cert.pem. Running openssl-asn1parse(1) 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

        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.


       openssl(1), openssl-pkeyutl(1), openssl-dgst(1), openssl-rsa(1),


       This command was deprecated in OpenSSL 3.0.

       The -engine option was deprecated in OpenSSL 3.0.


       Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at

3.2.0                             2023-11-23             OPENSSL-RSAUTL(1ossl)

openssl 3.2.0 - Generated Wed Nov 29 08:15:57 CST 2023
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