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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /*

  * Code for dealing with X509.V3 extensions.

  */

 #include "cert.h"

 #include "secitem.h"

 #include "secoid.h"

 #include "secder.h"

 #include "secasn1.h"

 #include "certxutl.h"

 #include "secerr.h"

 SECStatus

 CERT_FindCertExtensionByOID(CERTCertificate *cert, SECItem *oid,

 			    SECItem *value)

 {

     return (cert_FindExtensionByOID (cert->extensions, oid, value));

 }

 SECStatus

 CERT_FindCertExtension(const CERTCertificate *cert, int tag, SECItem *value)

 {

     return (cert_FindExtension (cert->extensions, tag, value));

 }

 static void

 SetExts(void *object, CERTCertExtension **exts)

 {

     CERTCertificate *cert = (CERTCertificate *)object;

     cert->extensions = exts;

     DER_SetUInteger (cert->arena, &(cert->version), SEC_CERTIFICATE_VERSION_3);

 }

 void *

 CERT_StartCertExtensions(CERTCertificate *cert)

 {

     return (cert_StartExtensions ((void *)cert, cert->arena, SetExts));

 }

 /* find the given extension in the certificate of the Issuer of 'cert' */

 SECStatus

 CERT_FindIssuerCertExtension(CERTCertificate *cert, int tag, SECItem *value)

 {

     CERTCertificate *issuercert;

     SECStatus rv;

     issuercert = CERT_FindCertByName(cert->dbhandle, &cert->derIssuer);

     if ( issuercert ) {

 	rv = cert_FindExtension(issuercert->extensions, tag, value);

 	CERT_DestroyCertificate(issuercert);

     } else {

 	rv = SECFailure;

     }

     return(rv);

 }

 /* find a URL extension in the cert or its CA

  * apply the base URL string if it exists

  */

 char *

 CERT_FindCertURLExtension(CERTCertificate *cert, int tag, int catag)

 {

     SECStatus rv;

     SECItem urlitem = {siBuffer,0};

     SECItem baseitem = {siBuffer,0};

     SECItem urlstringitem = {siBuffer,0};

     SECItem basestringitem = {siBuffer,0};

     PLArenaPool *arena = NULL;

     PRBool hasbase;

     char *urlstring;

     char *str;

     int len;

     unsigned int i;

     urlstring = NULL;

     arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);

     if ( ! arena ) {

 	goto loser;

     }

     hasbase = PR_FALSE;

     rv = cert_FindExtension(cert->extensions, tag, &urlitem);

     if ( rv == SECSuccess ) {

 	rv = cert_FindExtension(cert->extensions, SEC_OID_NS_CERT_EXT_BASE_URL,

 				   &baseitem);

 	if ( rv == SECSuccess ) {

 	    hasbase = PR_TRUE;

 	}

     } else if ( catag ) {

 	/* if the cert doesn't have the extensions, see if the issuer does */

 	rv = CERT_FindIssuerCertExtension(cert, catag, &urlitem);

 	if ( rv != SECSuccess ) {

 	    goto loser;

 	}	    

 	rv = CERT_FindIssuerCertExtension(cert, SEC_OID_NS_CERT_EXT_BASE_URL,

 					 &baseitem);

 	if ( rv == SECSuccess ) {

 	    hasbase = PR_TRUE;

 	}

     } else {

 	goto loser;

     }

     rv = SEC_QuickDERDecodeItem(arena, &urlstringitem,

                                 SEC_ASN1_GET(SEC_IA5StringTemplate), &urlitem);

     if ( rv != SECSuccess ) {

 	goto loser;

     }

     if ( hasbase ) {

 	rv = SEC_QuickDERDecodeItem(arena, &basestringitem,

                                     SEC_ASN1_GET(SEC_IA5StringTemplate),

                                     &baseitem);

 	if ( rv != SECSuccess ) {

 	    goto loser;

 	}

     }

     len = urlstringitem.len + ( hasbase ? basestringitem.len : 0 ) + 1;

     str = urlstring = (char *)PORT_Alloc(len);

     if ( urlstring == NULL ) {

 	goto loser;

     }

     /* copy the URL base first */

     if ( hasbase ) {

 	/* if the urlstring has a : in it, then we assume it is an absolute

 	 * URL, and will not get the base string pre-pended

 	 */

 	for ( i = 0; i < urlstringitem.len; i++ ) {

 	    if ( urlstringitem.data[i] == ':' ) {

 		goto nobase;

 	    }

 	}

 	PORT_Memcpy(str, basestringitem.data, basestringitem.len);

 	str += basestringitem.len;

     }

 nobase:

     /* copy the rest (or all) of the URL */

     PORT_Memcpy(str, urlstringitem.data, urlstringitem.len);

     str += urlstringitem.len;

     *str = '\0';

     goto done;

 loser:

     if ( urlstring ) {

 	PORT_Free(urlstring);

     }

     urlstring = NULL;

 done:

     if ( arena ) {

 	PORT_FreeArena(arena, PR_FALSE);

     }

     if ( baseitem.data ) {

 	PORT_Free(baseitem.data);

     }

     if ( urlitem.data ) {

 	PORT_Free(urlitem.data);

     }

     return(urlstring);

 }

 /*

  * get the value of the Netscape Certificate Type Extension

  */

 SECStatus

 CERT_FindNSCertTypeExtension(CERTCertificate *cert, SECItem *retItem)

 {

     return (CERT_FindBitStringExtension

 	    (cert->extensions, SEC_OID_NS_CERT_EXT_CERT_TYPE, retItem));    

 }

 /*

  * get the value of a string type extension

  */

 char *

 CERT_FindNSStringExtension(CERTCertificate *cert, int oidtag)

 {

     SECItem wrapperItem, tmpItem = {siBuffer,0};

     SECStatus rv;

     PLArenaPool *arena = NULL;

     char *retstring = NULL;

     wrapperItem.data = NULL;

     tmpItem.data = NULL;

     arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);

     if ( ! arena ) {

 	goto loser;

     }

     rv = cert_FindExtension(cert->extensions, oidtag,

 			       &wrapperItem);

     if ( rv != SECSuccess ) {

 	goto loser;

     }

     rv = SEC_QuickDERDecodeItem(arena, &tmpItem,

                             SEC_ASN1_GET(SEC_IA5StringTemplate), &wrapperItem);

     if ( rv != SECSuccess ) {

 	goto loser;

     }

     retstring = (char *)PORT_Alloc(tmpItem.len + 1 );

     if ( retstring == NULL ) {

 	goto loser;

     }

     PORT_Memcpy(retstring, tmpItem.data, tmpItem.len);

     retstring[tmpItem.len] = '\0';

 loser:

     if ( arena ) {

 	PORT_FreeArena(arena, PR_FALSE);

     }

     if ( wrapperItem.data ) {

 	PORT_Free(wrapperItem.data);

     }

     return(retstring);

 }

 /*

  * get the value of the X.509 v3 Key Usage Extension

  */

 SECStatus

 CERT_FindKeyUsageExtension(CERTCertificate *cert, SECItem *retItem)

 {

     return (CERT_FindBitStringExtension(cert->extensions,

 					SEC_OID_X509_KEY_USAGE, retItem));    

 }

 /*

  * get the value of the X.509 v3 Key Usage Extension

  */

 SECStatus

 CERT_FindSubjectKeyIDExtension(CERTCertificate *cert, SECItem *retItem)

 {

     SECStatus rv;

     SECItem encodedValue = {siBuffer, NULL, 0 };

     SECItem decodedValue = {siBuffer, NULL, 0 };

     rv = cert_FindExtension

 	 (cert->extensions, SEC_OID_X509_SUBJECT_KEY_ID, &encodedValue);

     if (rv == SECSuccess) {

 	PLArenaPool * tmpArena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);

 	if (tmpArena) {

 	    rv = SEC_QuickDERDecodeItem(tmpArena, &decodedValue, 

 	                                SEC_ASN1_GET(SEC_OctetStringTemplate), 

 					&encodedValue);

 	    if (rv == SECSuccess) {

 	        rv = SECITEM_CopyItem(NULL, retItem, &decodedValue);

 	    }

 	    PORT_FreeArena(tmpArena, PR_FALSE);

 	} else {

 	    rv = SECFailure;

 	}

     }

     SECITEM_FreeItem(&encodedValue, PR_FALSE);

     return rv;

 }

 SECStatus

 CERT_FindBasicConstraintExten(CERTCertificate *cert,

 			      CERTBasicConstraints *value)

 {

     SECItem encodedExtenValue;

     SECStatus rv;

     encodedExtenValue.data = NULL;

     encodedExtenValue.len = 0;

     rv = cert_FindExtension(cert->extensions, SEC_OID_X509_BASIC_CONSTRAINTS,

 			    &encodedExtenValue);

     if ( rv != SECSuccess ) {

 	return (rv);

     }

     rv = CERT_DecodeBasicConstraintValue (value, &encodedExtenValue);

     /* free the raw extension data */

     PORT_Free(encodedExtenValue.data);

     encodedExtenValue.data = NULL;

     return(rv);

 }

 CERTAuthKeyID *

 CERT_FindAuthKeyIDExten (PLArenaPool *arena, CERTCertificate *cert)

 {

     SECItem encodedExtenValue;

     SECStatus rv;

     CERTAuthKeyID *ret;

     encodedExtenValue.data = NULL;

     encodedExtenValue.len = 0;

     rv = cert_FindExtension(cert->extensions, SEC_OID_X509_AUTH_KEY_ID,

 			    &encodedExtenValue);

     if ( rv != SECSuccess ) {

 	return (NULL);

     }

     ret = CERT_DecodeAuthKeyID (arena, &encodedExtenValue);

     PORT_Free(encodedExtenValue.data);

     encodedExtenValue.data = NULL;

     return(ret);

 }

 SECStatus

 CERT_CheckCertUsage(CERTCertificate *cert, unsigned char usage)

 {

     SECItem keyUsage;

     SECStatus rv;

     /* There is no extension, v1 or v2 certificate */

     if (cert->extensions == NULL) {

 	return (SECSuccess);

     }

     keyUsage.data = NULL;

     /* This code formerly ignored the Key Usage extension if it was

     ** marked non-critical.  That was wrong.  Since we do understand it,

     ** we are obligated to honor it, whether or not it is critical.

     */

     rv = CERT_FindKeyUsageExtension(cert, &keyUsage);

     if (rv == SECFailure) {

         rv = (PORT_GetError () == SEC_ERROR_EXTENSION_NOT_FOUND) ?

 	    SECSuccess : SECFailure;

     } else if (!(keyUsage.data[0] & usage)) {

 	PORT_SetError (SEC_ERROR_CERT_USAGES_INVALID);

 	rv = SECFailure;

     }

     PORT_Free (keyUsage.data);

     return (rv);

 }