(mozilla-projects-nss-cert-findcertbyissuerandsn)=

# CERT_FindCertByIssuerAndSN

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Find a certificate in the database with the given issuer and serial number.
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## [Syntax](#syntax)

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```{code}
#include <cert.h>
CERTCertificate *CERT_FindCertByIssuerAndSN (

    CERTCertDBHandle *handle,
    CERTIssuerAndSN *issuerAndSN            );
```

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## [Parameters](#parameters)

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```{eval-rst}
+-----------------+-------------------------------------------------------------------------------+
| ``handle``      | *in* pointer to a `CERTCertDBHandle </en-US/NSS/CERTCertDBHandle>`__          |
|                 | representing the certificate database to look in                              |
+-----------------+-------------------------------------------------------------------------------+
| ``issuerAndSN`` | *in* pointer to a `CERTIssuerAndSN </en-US/NSS/CERTIssuerAndSN>`__ that must  |
|                 | be properly formed to contain the issuer name and the serial number (see      |
|                 | [Example])                                                                    |
+-----------------+-------------------------------------------------------------------------------+
```

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## [Description](#description)

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This function creates a certificate key using the `issuerAndSN` and it then uses the key to
find the matching certificate in the database.
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## [Returns](#returns)

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A pointer to a [CERTCertificate](/en-US/NSS/CERTCertificate) representing the certificate in
the database that matched the issuer and serial number, or `NULL` if none was found. The
certificate is a shallow copy, use
[CERT_DestroyCertificate](/en-US/NSS/CERT_DestroyCertificate) to decrement the reference count
on the certificate instance.
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## [Example](#example)

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```{code}
CERTIssuerAndSN issuerSN;
issuerSN.derIssuer.data = caName->data;
issuerSN.derIssuer.len = caName->len;
issuerSN.serialNumber.data = authorityKeyID->authCertSerialNumber.data;
issuerSN.serialNumber.len = authorityKeyID->authCertSerialNumber.len;
issuerCert = CERT_FindCertByIssuerAndSN(cert->dbhandle, &issuerSN);
if ( issuerCert == NULL ) {
    PORT_SetError (SEC_ERROR_UNKNOWN_ISSUER);
}
```

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## [See Also](#see_also)

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Occurrences of
`` `CERT_FindCertByIssuerAndSN `` \<<http://lxr.mozilla.org/security/ident?i=CERT_FindCertByIssuerAndSN>>\`\_\_
in the current NSS source code (generated by [LXR](http://lxr.mozilla.org/security/)).
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