rsautl.pod 5.8 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220
  1. =pod
  2. =head1 NAME
  3. openssl-rsautl,
  4. rsautl - RSA utility
  5. =head1 SYNOPSIS
  6. B<openssl> B<rsautl>
  7. [B<-help>]
  8. [B<-in file>]
  9. [B<-out file>]
  10. [B<-inkey file>]
  11. [B<-keyform PEM|DER|ENGINE>]
  12. [B<-pubin>]
  13. [B<-certin>]
  14. [B<-sign>]
  15. [B<-verify>]
  16. [B<-encrypt>]
  17. [B<-decrypt>]
  18. [B<-rand file...>]
  19. [B<-writerand file>]
  20. [B<-pkcs>]
  21. [B<-ssl>]
  22. [B<-raw>]
  23. [B<-hexdump>]
  24. [B<-asn1parse>]
  25. =head1 DESCRIPTION
  26. The B<rsautl> command can be used to sign, verify, encrypt and decrypt
  27. data using the RSA algorithm.
  28. =head1 OPTIONS
  29. =over 4
  30. =item B<-help>
  31. Print out a usage message.
  32. =item B<-in filename>
  33. This specifies the input filename to read data from or standard input
  34. if this option is not specified.
  35. =item B<-out filename>
  36. Specifies the output filename to write to or standard output by
  37. default.
  38. =item B<-inkey file>
  39. The input key file, by default it should be an RSA private key.
  40. =item B<-keyform PEM|DER|ENGINE>
  41. The key format PEM, DER or ENGINE.
  42. =item B<-pubin>
  43. The input file is an RSA public key.
  44. =item B<-certin>
  45. The input is a certificate containing an RSA public key.
  46. =item B<-sign>
  47. Sign the input data and output the signed result. This requires
  48. an RSA private key.
  49. =item B<-verify>
  50. Verify the input data and output the recovered data.
  51. =item B<-encrypt>
  52. Encrypt the input data using an RSA public key.
  53. =item B<-decrypt>
  54. Decrypt the input data using an RSA private key.
  55. =item B<-rand file...>
  56. A file or files containing random data used to seed the random number
  57. generator.
  58. Multiple files can be specified separated by an OS-dependent character.
  59. The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
  60. all others.
  61. =item [B<-writerand file>]
  62. Writes random data to the specified I<file> upon exit.
  63. This can be used with a subsequent B<-rand> flag.
  64. =item B<-pkcs, -oaep, -ssl, -raw>
  65. The padding to use: PKCS#1 v1.5 (the default), PKCS#1 OAEP,
  66. special padding used in SSL v2 backwards compatible handshakes,
  67. or no padding, respectively.
  68. For signatures, only B<-pkcs> and B<-raw> can be used.
  69. =item B<-hexdump>
  70. Hex dump the output data.
  71. =item B<-asn1parse>
  72. Parse the ASN.1 output data, this is useful when combined with the
  73. B<-verify> option.
  74. =back
  75. =head1 NOTES
  76. B<rsautl> because it uses the RSA algorithm directly can only be
  77. used to sign or verify small pieces of data.
  78. =head1 EXAMPLES
  79. Sign some data using a private key:
  80. openssl rsautl -sign -in file -inkey key.pem -out sig
  81. Recover the signed data
  82. openssl rsautl -verify -in sig -inkey key.pem
  83. Examine the raw signed data:
  84. openssl rsautl -verify -in sig -inkey key.pem -raw -hexdump
  85. 0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  86. 0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  87. 0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  88. 0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  89. 0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  90. 0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  91. 0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
  92. 0070 - ff ff ff ff 00 68 65 6c-6c 6f 20 77 6f 72 6c 64 .....hello world
  93. The PKCS#1 block formatting is evident from this. If this was done using
  94. encrypt and decrypt the block would have been of type 2 (the second byte)
  95. and random padding data visible instead of the 0xff bytes.
  96. It is possible to analyse the signature of certificates using this
  97. utility in conjunction with B<asn1parse>. Consider the self signed
  98. example in certs/pca-cert.pem . Running B<asn1parse> as follows yields:
  99. openssl asn1parse -in pca-cert.pem
  100. 0:d=0 hl=4 l= 742 cons: SEQUENCE
  101. 4:d=1 hl=4 l= 591 cons: SEQUENCE
  102. 8:d=2 hl=2 l= 3 cons: cont [ 0 ]
  103. 10:d=3 hl=2 l= 1 prim: INTEGER :02
  104. 13:d=2 hl=2 l= 1 prim: INTEGER :00
  105. 16:d=2 hl=2 l= 13 cons: SEQUENCE
  106. 18:d=3 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption
  107. 29:d=3 hl=2 l= 0 prim: NULL
  108. 31:d=2 hl=2 l= 92 cons: SEQUENCE
  109. 33:d=3 hl=2 l= 11 cons: SET
  110. 35:d=4 hl=2 l= 9 cons: SEQUENCE
  111. 37:d=5 hl=2 l= 3 prim: OBJECT :countryName
  112. 42:d=5 hl=2 l= 2 prim: PRINTABLESTRING :AU
  113. ....
  114. 599:d=1 hl=2 l= 13 cons: SEQUENCE
  115. 601:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption
  116. 612:d=2 hl=2 l= 0 prim: NULL
  117. 614:d=1 hl=3 l= 129 prim: BIT STRING
  118. The final BIT STRING contains the actual signature. It can be extracted with:
  119. openssl asn1parse -in pca-cert.pem -out sig -noout -strparse 614
  120. The certificate public key can be extracted with:
  121. openssl x509 -in test/testx509.pem -pubkey -noout >pubkey.pem
  122. The signature can be analysed with:
  123. openssl rsautl -in sig -verify -asn1parse -inkey pubkey.pem -pubin
  124. 0:d=0 hl=2 l= 32 cons: SEQUENCE
  125. 2:d=1 hl=2 l= 12 cons: SEQUENCE
  126. 4:d=2 hl=2 l= 8 prim: OBJECT :md5
  127. 14:d=2 hl=2 l= 0 prim: NULL
  128. 16:d=1 hl=2 l= 16 prim: OCTET STRING
  129. 0000 - f3 46 9e aa 1a 4a 73 c9-37 ea 93 00 48 25 08 b5 .F...Js.7...H%..
  130. This is the parsed version of an ASN1 DigestInfo structure. It can be seen that
  131. the digest used was md5. The actual part of the certificate that was signed can
  132. be extracted with:
  133. openssl asn1parse -in pca-cert.pem -out tbs -noout -strparse 4
  134. and its digest computed with:
  135. openssl md5 -c tbs
  136. MD5(tbs)= f3:46:9e:aa:1a:4a:73:c9:37:ea:93:00:48:25:08:b5
  137. which it can be seen agrees with the recovered value above.
  138. =head1 SEE ALSO
  139. L<dgst(1)>, L<rsa(1)>, L<genrsa(1)>
  140. =head1 COPYRIGHT
  141. Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
  142. Licensed under the Apache License 2.0 (the "License"). You may not use
  143. this file except in compliance with the License. You can obtain a copy
  144. in the file LICENSE in the source distribution or at
  145. L<https://www.openssl.org/source/license.html>.
  146. =cut