CMS_get0_SignerInfos.pod revision 337982 
1=pod
2
3=head1 NAME
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5CMS_get0_SignerInfos, CMS_SignerInfo_get0_signer_id, CMS_SignerInfo_get0_signature, CMS_SignerInfo_cert_cmp, CMS_set1_signer_cert - CMS signedData signer functions.
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7=head1 SYNOPSIS
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9 #include <openssl/cms.h>
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11 STACK_OF(CMS_SignerInfo) *CMS_get0_SignerInfos(CMS_ContentInfo *cms);
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13 int CMS_SignerInfo_get0_signer_id(CMS_SignerInfo *si, ASN1_OCTET_STRING **keyid, X509_NAME **issuer, ASN1_INTEGER **sno);
14 ASN1_OCTET_STRING *CMS_SignerInfo_get0_signature(CMS_SignerInfo *si);
15 int CMS_SignerInfo_cert_cmp(CMS_SignerInfo *si, X509 *cert);
16 void CMS_SignerInfo_set1_signer_cert(CMS_SignerInfo *si, X509 *signer);
17
18=head1 DESCRIPTION
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20The function CMS_get0_SignerInfos() returns all the CMS_SignerInfo structures
21associated with a CMS signedData structure.
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23CMS_SignerInfo_get0_signer_id() retrieves the certificate signer identifier
24associated with a specific CMS_SignerInfo structure B<si>. Either the
25keyidentifier will be set in B<keyid> or B<both> issuer name and serial number
26in B<issuer> and B<sno>.
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28CMS_SignerInfo_get0_signature() retrieves the signature associated with 
29B<si> in a pointer to an ASN1_OCTET_STRING structure. This pointer returned
30corresponds to the internal signature value if B<si> so it may be read or
31modified.
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33CMS_SignerInfo_cert_cmp() compares the certificate B<cert> against the signer
34identifier B<si>. It returns zero if the comparison is successful and non zero
35if not.
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37CMS_SignerInfo_set1_signer_cert() sets the signers certificate of B<si> to
38B<signer>.
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40=head1 NOTES
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42The main purpose of these functions is to enable an application to lookup
43signers certificates using any appropriate technique when the simpler method
44of CMS_verify() is not appropriate.
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46In typical usage and application will retrieve all CMS_SignerInfo structures
47using CMS_get0_SignerInfo() and retrieve the identifier information using
48CMS. It will then obtain the signer certificate by some unspecified means
49(or return and error if it cannot be found) and set it using
50CMS_SignerInfo_set1_signer_cert().
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52Once all signer certificates have been set CMS_verify() can be used.
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54Although CMS_get0_SignerInfos() can return NULL if an error occurs B<or> if
55there are no signers this is not a problem in practice because the only
56error which can occur is if the B<cms> structure is not of type signedData
57due to application error.
58
59=head1 RETURN VALUES
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61CMS_get0_SignerInfos() returns all CMS_SignerInfo structures, or NULL there
62are no signers or an error occurs.
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64CMS_SignerInfo_get0_signer_id() returns 1 for success and 0 for failure.
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66CMS_SignerInfo_cert_cmp() returns 0 for a successful comparison and non
67zero otherwise.
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69CMS_SignerInfo_set1_signer_cert() does not return a value.
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71Any error can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>
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73=head1 SEE ALSO
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75L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_verify(3)|CMS_verify(3)>
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77=head1 HISTORY
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79These functions were first was added to OpenSSL 0.9.8
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81=cut
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