Standard preamble:
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..
.... Set up some character translations and predefined strings. \*(-- will
give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
double quote, and \*(R" will give a right double quote. \*(C+ will
give a nicer C++. Capital omega is used to do unbreakable dashes and
therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
nothing in troff, for use with C<>.
.tr \(*W- . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.
If the F register is >0, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.
Avoid warning from groff about undefined register 'F'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF
Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} ========================================================================
Title "RSAUTL 1"
way too many mistakes in technical documents.
.Vb 1 openssl rsautl -sign -in file -inkey key.pem -out sig .Ve
Recover the signed data
.Vb 1 openssl rsautl -verify -in sig -inkey key.pem .Ve
Examine the raw signed data:
.Vb 1 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 .Ve
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 asn1parse. Consider the self signed example in certs/pca-cert.pem . Running asn1parse as follows yields:
.Vb 1 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 .Ve
The final \s-1BIT STRING\s0 contains the actual signature. It can be extracted with:
.Vb 1 openssl asn1parse -in pca-cert.pem -out sig -noout -strparse 614 .Ve
The certificate public key can be extracted with:
.Vb 1 openssl x509 -in test/testx509.pem -pubkey -noout >pubkey.pem .Ve
The signature can be analysed with:
.Vb 1 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%.. .Ve
This is the parsed version of an \s-1ASN1\s0 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:
.Vb 1 openssl asn1parse -in pca-cert.pem -out tbs -noout -strparse 4 .Ve
and its digest computed with:
.Vb 2 openssl md5 -c tbs MD5(tbs)= f3:46:9e:aa:1a:4a:73:c9:37:ea:93:00:48:25:08:b5 .Ve
which it can be seen agrees with the recovered value above.
Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.