summaryrefslogtreecommitdiffstats
path: root/secure/lib/libcrypto/man/PKCS7_encrypt.3
blob: 74011b6f3082052a7f89f10cc4ccb126eb534047 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
.\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.28)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" 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 C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    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\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, 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.
.ie \nF \{\
.    de IX
.    tm Index:\\$1\t\\n%\t"\\$2"
..
.    nr % 0
.    rr F
.\}
.el \{\
.    de IX
..
.\}
.\"
.\" 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
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    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
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    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
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "PKCS7_encrypt 3"
.TH PKCS7_encrypt 3 "2014-10-15" "1.0.1j" "OpenSSL"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
PKCS7_encrypt \- create a PKCS#7 envelopedData structure
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/pkcs7.h>
\&
\& PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
\&\fIPKCS7_encrypt()\fR creates and returns a PKCS#7 envelopedData structure. \fBcerts\fR
is a list of recipient certificates. \fBin\fR is the content to be encrypted.
\&\fBcipher\fR is the symmetric cipher to use. \fBflags\fR is an optional set of flags.
.SH "NOTES"
.IX Header "NOTES"
Only \s-1RSA\s0 keys are supported in PKCS#7 and envelopedData so the recipient
certificates supplied to this function must all contain \s-1RSA\s0 public keys, though
they do not have to be signed using the \s-1RSA\s0 algorithm.
.PP
\&\fIEVP_des_ede3_cbc()\fR (triple \s-1DES\s0) is the algorithm of choice for S/MIME use
because most clients will support it.
.PP
Some old \*(L"export grade\*(R" clients may only support weak encryption using 40 or 64
bit \s-1RC2\s0. These can be used by passing \fIEVP_rc2_40_cbc()\fR and \fIEVP_rc2_64_cbc()\fR
respectively.
.PP
The algorithm passed in the \fBcipher\fR parameter must support \s-1ASN1\s0 encoding of
its parameters.
.PP
Many browsers implement a \*(L"sign and encrypt\*(R" option which is simply an S/MIME
envelopedData containing an S/MIME signed message. This can be readily produced
by storing the S/MIME signed message in a memory \s-1BIO\s0 and passing it to
\&\fIPKCS7_encrypt()\fR.
.PP
The following flags can be passed in the \fBflags\fR parameter.
.PP
If the \fB\s-1PKCS7_TEXT\s0\fR flag is set \s-1MIME\s0 headers for type \fBtext/plain\fR are
prepended to the data.
.PP
Normally the supplied content is translated into \s-1MIME\s0 canonical format (as
required by the S/MIME specifications) if \fB\s-1PKCS7_BINARY\s0\fR is set no translation
occurs. This option should be used if the supplied data is in binary format
otherwise the translation will corrupt it. If \fB\s-1PKCS7_BINARY\s0\fR is set then
\&\fB\s-1PKCS7_TEXT\s0\fR is ignored.
.PP
If the \fB\s-1PKCS7_STREAM\s0\fR flag is set a partial \fB\s-1PKCS7\s0\fR structure is output
suitable for streaming I/O: no data is read from the \s-1BIO\s0 \fBin\fR.
.SH "NOTES"
.IX Header "NOTES"
If the flag \fB\s-1PKCS7_STREAM\s0\fR is set the returned \fB\s-1PKCS7\s0\fR structure is \fBnot\fR
complete and outputting its contents via a function that does not
properly finalize the \fB\s-1PKCS7\s0\fR structure will give unpredictable 
results.
.PP
Several functions including \fISMIME_write_PKCS7()\fR, \fIi2d_PKCS7_bio_stream()\fR,
\&\fIPEM_write_bio_PKCS7_stream()\fR finalize the structure. Alternatively finalization
can be performed by obtaining the streaming \s-1ASN1\s0 \fB\s-1BIO\s0\fR directly using
\&\fIBIO_new_PKCS7()\fR.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fIPKCS7_encrypt()\fR returns either a \s-1PKCS7\s0 structure or \s-1NULL\s0 if an error occurred.
The error can be obtained from \fIERR_get_error\fR\|(3).
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIERR_get_error\fR\|(3), \fIPKCS7_decrypt\fR\|(3)
.SH "HISTORY"
.IX Header "HISTORY"
\&\fIPKCS7_decrypt()\fR was added to OpenSSL 0.9.5
The \fB\s-1PKCS7_STREAM\s0\fR flag was first supported in OpenSSL 1.0.0.
OpenPOWER on IntegriCloud