Standard preamble:
========================================================================
..
.... 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 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.
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 "CMS_add1_signer 3"
way too many mistakes in technical documents.
The CMS_ContentInfo structure should be obtained from an initial call to \fICMS_sign() with the flag \s-1CMS_PARTIAL\s0 set or in the case or re-signing a valid CMS_ContentInfo SignedData structure.
If the md parameter is \s-1NULL\s0 then the default digest for the public key algorithm will be used.
Unless the \s-1CMS_REUSE_DIGEST\s0 flag is set the returned CMS_ContentInfo structure is not complete and must be finalized either by streaming (if applicable) or a call to CMS_final().
The CMS_SignerInfo_sign() function will explicitly sign a CMS_SignerInfo structure, its main use is when \s-1CMS_REUSE_DIGEST\s0 and \s-1CMS_PARTIAL\s0 flags are both set.
Any of the following flags (ored together) can be passed in the flags parameter.
If \s-1CMS_REUSE_DIGEST\s0 is set then an attempt is made to copy the content digest value from the CMS_ContentInfo structure: to add a signer to an existing structure. An error occurs if a matching digest value cannot be found to copy. The returned CMS_ContentInfo structure will be valid and finalized when this flag is set.
If \s-1CMS_PARTIAL\s0 is set in addition to \s-1CMS_REUSE_DIGEST\s0 then the CMS_SignerInfo structure will not be finalized so additional attributes can be added. In this case an explicit call to CMS_SignerInfo_sign() is needed to finalize it.
If \s-1CMS_NOCERTS\s0 is set the signer's certificate will not be included in the CMS_ContentInfo structure, the signer's certificate must still be supplied in the signcert parameter though. This can reduce the size of the signature if the signers certificate can be obtained by other means: for example a previously signed message.
The SignedData structure includes several \s-1CMS\s0 signedAttributes including the signing time, the \s-1CMS\s0 content type and the supported list of ciphers in an SMIMECapabilities attribute. If \s-1CMS_NOATTR\s0 is set then no signedAttributes will be used. If \s-1CMS_NOSMIMECAP\s0 is set then just the SMIMECapabilities are omitted.
OpenSSL will by default identify signing certificates using issuer name and serial number. If \s-1CMS_USE_KEYID\s0 is set it will use the subject key identifier value instead. An error occurs if the signing certificate does not have a subject key identifier extension.
If present the SMIMECapabilities attribute indicates support for the following algorithms in preference order: 256 bit \s-1AES,\s0 Gost R3411-94, Gost 28147-89, 192 bit \s-1AES, 128\s0 bit \s-1AES,\s0 triple \s-1DES, 128\s0 bit \s-1RC2, 64\s0 bit \s-1RC2, DES\s0 and 40 bit \s-1RC2.\s0 If any of these algorithms is not available then it will not be included: for example the \s-1GOST\s0 algorithms will not be included if the \s-1GOST ENGINE\s0 is not loaded.
\fICMS_add1_signer() returns an internal pointer to the CMS_SignerInfo structure just added, this can be used to set additional attributes before it is finalized.