openssl: Adjust manual pages for 1.0.1m.
[dragonfly.git] / secure / lib / libcrypto / man / CMS_verify.3
CommitLineData
5a44c043 1.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
01185282
PA
2.\"
3.\" Standard preamble:
4.\" ========================================================================
5.de Sp \" Vertical space (when we can't use .PP)
6.if t .sp .5v
7.if n .sp
8..
9.de Vb \" Begin verbatim text
10.ft CW
11.nf
12.ne \\$1
13..
14.de Ve \" End verbatim text
15.ft R
16.fi
17..
18.\" Set up some character translations and predefined strings. \*(-- will
19.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20.\" double quote, and \*(R" will give a right double quote. \*(C+ will
21.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23.\" nothing in troff, for use with C<>.
24.tr \(*W-
25.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
26.ie n \{\
27. ds -- \(*W-
28. ds PI pi
29. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
31. ds L" ""
32. ds R" ""
33. ds C` ""
34. ds C' ""
35'br\}
36.el\{\
37. ds -- \|\(em\|
38. ds PI \(*p
39. ds L" ``
40. ds R" ''
5a44c043
SW
41. ds C`
42. ds C'
01185282
PA
43'br\}
44.\"
45.\" Escape single quotes in literal strings from groff's Unicode transform.
46.ie \n(.g .ds Aq \(aq
47.el .ds Aq '
48.\"
49.\" If the F register is turned on, we'll generate index entries on stderr for
50.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51.\" entries marked with X<> in POD. Of course, you'll have to process the
52.\" output yourself in some meaningful fashion.
5a44c043
SW
53.\"
54.\" Avoid warning from groff about undefined register 'F'.
55.de IX
01185282 56..
5a44c043
SW
57.nr rF 0
58.if \n(.g .if rF .nr rF 1
59.if (\n(rF:(\n(.g==0)) \{
60. if \nF \{
61. de IX
62. tm Index:\\$1\t\\n%\t"\\$2"
01185282 63..
5a44c043
SW
64. if !\nF==2 \{
65. nr % 0
66. nr F 2
67. \}
68. \}
01185282 69.\}
5a44c043 70.rr rF
01185282
PA
71.\"
72.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
73.\" Fear. Run. Save yourself. No user-serviceable parts.
74. \" fudge factors for nroff and troff
75.if n \{\
76. ds #H 0
77. ds #V .8m
78. ds #F .3m
79. ds #[ \f1
80. ds #] \fP
81.\}
82.if t \{\
83. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
84. ds #V .6m
85. ds #F 0
86. ds #[ \&
87. ds #] \&
88.\}
89. \" simple accents for nroff and troff
90.if n \{\
91. ds ' \&
92. ds ` \&
93. ds ^ \&
94. ds , \&
95. ds ~ ~
96. ds /
97.\}
98.if t \{\
99. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
100. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
101. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
102. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
103. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
104. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
105.\}
106. \" troff and (daisy-wheel) nroff accents
107.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
108.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
109.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
110.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
111.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
112.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
113.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
114.ds ae a\h'-(\w'a'u*4/10)'e
115.ds Ae A\h'-(\w'A'u*4/10)'E
116. \" corrections for vroff
117.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
118.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
119. \" for low resolution devices (crt and lpr)
120.if \n(.H>23 .if \n(.V>19 \
121\{\
122. ds : e
123. ds 8 ss
124. ds o a
125. ds d- d\h'-1'\(ga
126. ds D- D\h'-1'\(hy
127. ds th \o'bp'
128. ds Th \o'LP'
129. ds ae ae
130. ds Ae AE
131.\}
132.rm #[ #] #H #V #F C
133.\" ========================================================================
134.\"
135.IX Title "CMS_verify 3"
5a44c043 136.TH CMS_verify 3 "2015-03-19" "1.0.1m" "OpenSSL"
01185282
PA
137.\" For nroff, turn off justification. Always turn off hyphenation; it makes
138.\" way too many mistakes in technical documents.
139.if n .ad l
140.nh
141.SH "NAME"
142.Vb 1
143\& CMS_verify \- verify a CMS SignedData structure
144.Ve
145.SH "SYNOPSIS"
146.IX Header "SYNOPSIS"
147.Vb 1
148\& #include <openssl/cms.h>
149\&
150\& int CMS_verify(CMS_ContentInfo *cms, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata, BIO *out, unsigned int flags);
151\&
152\& STACK_OF(X509) *CMS_get0_signers(CMS_ContentInfo *cms);
153.Ve
154.SH "DESCRIPTION"
155.IX Header "DESCRIPTION"
156\&\fICMS_verify()\fR verifies a \s-1CMS\s0 SignedData structure. \fBcms\fR is the CMS_ContentInfo
157structure to verify. \fBcerts\fR is a set of certificates in which to search for
158the signing certificate(s). \fBstore\fR is a trusted certificate store used for
159chain verification. \fBindata\fR is the detached content if the content is not
5a44c043 160present in \fBcms\fR. The content is written to \fBout\fR if it is not \s-1NULL.\s0
01185282
PA
161.PP
162\&\fBflags\fR is an optional set of flags, which can be used to modify the verify
163operation.
164.PP
165\&\fICMS_get0_signers()\fR retrieves the signing certificate(s) from \fBcms\fR, it must
166be called after a successful \fICMS_verify()\fR operation.
167.SH "VERIFY PROCESS"
168.IX Header "VERIFY PROCESS"
169Normally the verify process proceeds as follows.
170.PP
171Initially some sanity checks are performed on \fBcms\fR. The type of \fBcms\fR must
172be SignedData. There must be at least one signature on the data and if
173the content is detached \fBindata\fR cannot be \fB\s-1NULL\s0\fR.
174.PP
175An attempt is made to locate all the signing certificate(s), first looking in
176the \fBcerts\fR parameter (if it is not \s-1NULL\s0) and then looking in any
177certificates contained in the \fBcms\fR structure itself. If any signing
178certificate cannot be located the operation fails.
179.PP
180Each signing certificate is chain verified using the \fBsmimesign\fR purpose and
181the supplied trusted certificate store. Any internal certificates in the message
182are used as untrusted CAs. If \s-1CRL\s0 checking is enabled in \fBstore\fR any internal
183CRLs are used in addition to attempting to look them up in \fBstore\fR. If any
184chain verify fails an error code is returned.
185.PP
186Finally the signed content is read (and written to \fBout\fR is it is not \s-1NULL\s0)
187and the signature's checked.
188.PP
189If all signature's verify correctly then the function is successful.
190.PP
191Any of the following flags (ored together) can be passed in the \fBflags\fR
192parameter to change the default verify behaviour.
193.PP
194If \fB\s-1CMS_NOINTERN\s0\fR is set the certificates in the message itself are not
195searched when locating the signing certificate(s). This means that all the
196signing certificates must be in the \fBcerts\fR parameter.
197.PP
198If \fB\s-1CMS_NOCRL\s0\fR is set and \s-1CRL\s0 checking is enabled in \fBstore\fR then any
199CRLs in the message itself are ignored.
200.PP
201If the \fB\s-1CMS_TEXT\s0\fR flag is set \s-1MIME\s0 headers for type \fBtext/plain\fR are deleted
202from the content. If the content is not of type \fBtext/plain\fR then an error is
203returned.
204.PP
205If \fB\s-1CMS_NO_SIGNER_CERT_VERIFY\s0\fR is set the signing certificates are not
206verified.
207.PP
208If \fB\s-1CMS_NO_ATTR_VERIFY\s0\fR is set the signed attributes signature is not
209verified.
210.PP
211If \fB\s-1CMS_NO_CONTENT_VERIFY\s0\fR is set then the content digest is not checked.
212.SH "NOTES"
213.IX Header "NOTES"
214One application of \fB\s-1CMS_NOINTERN\s0\fR is to only accept messages signed by
215a small number of certificates. The acceptable certificates would be passed
216in the \fBcerts\fR parameter. In this case if the signer is not one of the
217certificates supplied in \fBcerts\fR then the verify will fail because the
218signer cannot be found.
219.PP
220In some cases the standard techniques for looking up and validating
221certificates are not appropriate: for example an application may wish to
222lookup certificates in a database or perform customised verification. This
223can be achieved by setting and verifying the signers certificates manually
224using the signed data utility functions.
225.PP
226Care should be taken when modifying the default verify behaviour, for example
227setting \fB\s-1CMS_NO_CONTENT_VERIFY\s0\fR will totally disable all content verification
228and any modified content will be considered valid. This combination is however
229useful if one merely wishes to write the content to \fBout\fR and its validity
230is not considered important.
231.PP
232Chain verification should arguably be performed using the signing time rather
233than the current time. However since the signing time is supplied by the
234signer it cannot be trusted without additional evidence (such as a trusted
235timestamp).
236.SH "RETURN VALUES"
237.IX Header "RETURN VALUES"
238\&\fICMS_verify()\fR returns 1 for a successful verification and zero if an error
239occurred.
240.PP
241\&\fICMS_get0_signers()\fR returns all signers or \s-1NULL\s0 if an error occurred.
242.PP
243The error can be obtained from \fIERR_get_error\fR\|(3)
244.SH "BUGS"
245.IX Header "BUGS"
246The trusted certificate store is not searched for the signing certificate,
247this is primarily due to the inadequacies of the current \fBX509_STORE\fR
248functionality.
249.PP
250The lack of single pass processing means that the signed content must all
251be held in memory if it is not detached.
252.SH "SEE ALSO"
253.IX Header "SEE ALSO"
254\&\fIERR_get_error\fR\|(3), \fICMS_sign\fR\|(3)
255.SH "HISTORY"
256.IX Header "HISTORY"
257\&\fICMS_verify()\fR was added to OpenSSL 0.9.8