{ "mode": "man", "parameter": "openssl-rsautl", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl-rsautl/1/json", "generated": "2026-08-11T09:13:27Z", "synopsis": "openssl rsautl [-help] [-in file] [-passin arg] [-rev] [-out file] [-inkey filename|uri]\n[-keyform DER|PEM|P12|ENGINE] [-pubin] [-certin] [-sign] [-verify] [-encrypt] [-decrypt]\n[-pkcs] [-x931] [-oaep] [-raw] [-hexdump] [-asn1parse] [-engine id] [-rand files] [-writerand\nfile] [-provider name] [-provider-path path] [-propquery propq]", "sections": { "NAME": { "content": "openssl-rsautl - RSA command\n", "subsections": [] }, "SYNOPSIS": { "content": "openssl rsautl [-help] [-in file] [-passin arg] [-rev] [-out file] [-inkey filename|uri]\n[-keyform DER|PEM|P12|ENGINE] [-pubin] [-certin] [-sign] [-verify] [-encrypt] [-decrypt]\n[-pkcs] [-x931] [-oaep] [-raw] [-hexdump] [-asn1parse] [-engine id] [-rand files] [-writerand\nfile] [-provider name] [-provider-path path] [-propquery propq]\n", "subsections": [] }, "DESCRIPTION": { "content": "This command has been deprecated. The openssl-pkeyutl(1) command should be used instead.\n\nThis command can be used to sign, verify, encrypt and decrypt data using the RSA algorithm.\n", "subsections": [] }, "OPTIONS": { "content": "", "subsections": [ { "name": "-help", "content": "Print out a usage message.\n" }, { "name": "-in _", "content": "This specifies the input filename to read data from or standard input if this option is\nnot specified.\n" }, { "name": "-passin _", "content": "The passphrase used in the output file. See see openssl-passphrase-options(1).\n" }, { "name": "-rev", "content": "Reverse the order of the input.\n" }, { "name": "-out _", "content": "Specifies the output filename to write to or standard output by default.\n" }, { "name": "-inkey _", "content": "The input key, by default it should be an RSA private key.\n" }, { "name": "-keyform DER", "content": "The key format; unspecified by default. See openssl-format-options(1) for details.\n" }, { "name": "-pubin", "content": "The input file is an RSA public key.\n" }, { "name": "-certin", "content": "The input is a certificate containing an RSA public key.\n" }, { "name": "-sign", "content": "Sign the input data and output the signed result. This requires an RSA private key.\n" }, { "name": "-verify", "content": "Verify the input data and output the recovered data.\n" }, { "name": "-encrypt", "content": "Encrypt the input data using an RSA public key.\n" }, { "name": "-decrypt", "content": "Decrypt the input data using an RSA private key.\n" }, { "name": "-pkcs -oaep -x931 -raw", "content": "The padding to use: PKCS#1 v1.5 (the default), PKCS#1 OAEP, ANSI X9.31, or no padding,\nrespectively. For signatures, only -pkcs and -raw can be used.\n\nNote: because of protection against Bleichenbacher attacks, decryption using PKCS#1 v1.5\nmode will not return errors in case padding check failed. Use -raw and inspect the\nreturned value manually to check if the padding is correct.\n" }, { "name": "-hexdump", "content": "Hex dump the output data.\n" }, { "name": "-asn1parse", "content": "Parse the ASN.1 output data, this is useful when combined with the -verify option.\n" }, { "name": "-engine _", "content": "See \"Engine Options\" in openssl(1). This option is deprecated.\n" }, { "name": "-rand _ -writerand _", "content": "See \"Random State Options\" in openssl(1) for details.\n" }, { "name": "-provider _", "content": "" }, { "name": "-provider-path _", "content": "" }, { "name": "-propquery _", "content": "See \"Provider Options\" in openssl(1), provider(7), and property(7).\n" } ] }, "NOTES": { "content": "Since this command uses the RSA algorithm directly, it can only be used to sign or verify\nsmall pieces of data.\n", "subsections": [] }, "EXAMPLES": { "content": "Examples equivalent to these can be found in the documentation for the non-deprecated\nopenssl-pkeyutl(1) command.\n\nSign some data using a private key:\n\nopenssl rsautl -sign -in file -inkey key.pem -out sig\n\nRecover the signed data\n\nopenssl rsautl -verify -in sig -inkey key.pem\n\nExamine the raw signed data:\n\nopenssl rsautl -verify -in sig -inkey key.pem -raw -hexdump\n\n0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................\n0070 - ff ff ff ff 00 68 65 6c-6c 6f 20 77 6f 72 6c 64 .....hello world\n\nThe PKCS#1 block formatting is evident from this. If this was done using encrypt and decrypt\nthe block would have been of type 2 (the second byte) and random padding data visible instead\nof the 0xff bytes.\n\nIt is possible to analyse the signature of certificates using this command in conjunction\nwith openssl-asn1parse(1). Consider the self signed example in certs/pca-cert.pem. Running\nopenssl-asn1parse(1) as follows yields:\n\nopenssl asn1parse -in pca-cert.pem\n\n0:d=0 hl=4 l= 742 cons: SEQUENCE\n4:d=1 hl=4 l= 591 cons: SEQUENCE\n8:d=2 hl=2 l= 3 cons: cont [ 0 ]\n10:d=3 hl=2 l= 1 prim: INTEGER :02\n13:d=2 hl=2 l= 1 prim: INTEGER :00\n16:d=2 hl=2 l= 13 cons: SEQUENCE\n18:d=3 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption\n29:d=3 hl=2 l= 0 prim: NULL\n31:d=2 hl=2 l= 92 cons: SEQUENCE\n33:d=3 hl=2 l= 11 cons: SET\n35:d=4 hl=2 l= 9 cons: SEQUENCE\n37:d=5 hl=2 l= 3 prim: OBJECT :countryName\n42:d=5 hl=2 l= 2 prim: PRINTABLESTRING :AU\n....\n599:d=1 hl=2 l= 13 cons: SEQUENCE\n601:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption\n612:d=2 hl=2 l= 0 prim: NULL\n614:d=1 hl=3 l= 129 prim: BIT STRING\n\nThe final BIT STRING contains the actual signature. It can be extracted with:\n\nopenssl asn1parse -in pca-cert.pem -out sig -noout -strparse 614\n\nThe certificate public key can be extracted with:\n\nopenssl x509 -in test/testx509.pem -pubkey -noout >pubkey.pem\n\nThe signature can be analysed with:\n\nopenssl rsautl -in sig -verify -asn1parse -inkey pubkey.pem -pubin\n\n0:d=0 hl=2 l= 32 cons: SEQUENCE\n2:d=1 hl=2 l= 12 cons: SEQUENCE\n4:d=2 hl=2 l= 8 prim: OBJECT :md5\n14:d=2 hl=2 l= 0 prim: NULL\n16:d=1 hl=2 l= 16 prim: OCTET STRING\n0000 - f3 46 9e aa 1a 4a 73 c9-37 ea 93 00 48 25 08 b5 .F...Js.7...H%..\n\nThis is the parsed version of an ASN1 DigestInfo structure. It can be seen that the digest\nused was md5. The actual part of the certificate that was signed can be extracted with:\n\nopenssl asn1parse -in pca-cert.pem -out tbs -noout -strparse 4\n\nand its digest computed with:\n\nopenssl md5 -c tbs\nMD5(tbs)= f3:46:9e:aa:1a:4a:73:c9:37:ea:93:00:48:25:08:b5\n\nwhich it can be seen agrees with the recovered value above.\n", "subsections": [] }, "SEE ALSO": { "content": "openssl(1), openssl-pkeyutl(1), openssl-dgst(1), openssl-rsa(1), openssl-genrsa(1)\n", "subsections": [] }, "HISTORY": { "content": "This command was deprecated in OpenSSL 3.0.\n\nThe -engine option was deprecated in OpenSSL 3.0.\n", "subsections": [] }, "COPYRIGHT": { "content": "Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.\n\nLicensed under the Apache License 2.0 (the \"License\"). You may not use this file except in\ncompliance with the License. You can obtain a copy in the file LICENSE in the source\ndistribution or at .\n\n3.0.13 2026-07-29 OPENSSL-RSAUTL(1SSL)", "subsections": [] } }, "summary": "openssl-rsautl - RSA command", "flags": [ { "flag": "", "long": null, "arg": null, "description": "Print out a usage message." }, { "flag": "", "long": null, "arg": null, "description": "This specifies the input filename to read data from or standard input if this option is not specified." }, { "flag": "", "long": null, "arg": null, "description": "The passphrase used in the output file. See see openssl-passphrase-options(1)." }, { "flag": "", "long": null, "arg": null, "description": "Reverse the order of the input." }, { "flag": "", "long": null, "arg": null, "description": "Specifies the output filename to write to or standard output by default." }, { "flag": "", "long": null, "arg": null, "description": "The input key, by default it should be an RSA private key." }, { "flag": "", "long": null, "arg": null, "description": "The key format; unspecified by default. See openssl-format-options(1) for details." }, { "flag": "", "long": null, "arg": null, "description": "The input file is an RSA public key." }, { "flag": "", "long": null, "arg": null, "description": "The input is a certificate containing an RSA public key." }, { "flag": "", "long": null, "arg": null, "description": "Sign the input data and output the signed result. This requires an RSA private key." }, { "flag": "", "long": null, "arg": null, "description": "Verify the input data and output the recovered data." }, { "flag": "", "long": null, "arg": null, "description": "Encrypt the input data using an RSA public key." }, { "flag": "", "long": null, "arg": null, "description": "Decrypt the input data using an RSA private key." }, { "flag": "", "long": null, "arg": null, "description": "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." }, { "flag": "", "long": null, "arg": null, "description": "Hex dump the output data." }, { "flag": "", "long": null, "arg": null, "description": "Parse the ASN.1 output data, this is useful when combined with the -verify option." }, { "flag": "", "long": null, "arg": null, "description": "See \"Engine Options\" in openssl(1). This option is deprecated." }, { "flag": "", "long": null, "arg": null, "description": "See \"Random State Options\" in openssl(1) for details." }, { "flag": "", "long": null, "arg": null, "description": "" }, { "flag": "", "long": null, "arg": null, "description": "" }, { "flag": "", "long": null, "arg": null, "description": "See \"Provider Options\" in openssl(1), provider(7), and property(7)." } ], "examples": [ "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 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." ], "see_also": [ { "name": "openssl", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl/1/json" }, { "name": "openssl-pkeyutl", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl-pkeyutl/1/json" }, { "name": "openssl-dgst", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl-dgst/1/json" }, { "name": "openssl-rsa", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl-rsa/1/json" }, { "name": "openssl-genrsa", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/openssl-genrsa/1/json" } ] }