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/*
* NSS utility functions
*
* 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/. */
#include <stdio.h>
#include <string.h>
#include "prerror.h"
#include "secitem.h"
#include "prnetdb.h"
#include "cert.h"
#include "nspr.h"
#include "secder.h"
#include "keyhi.h"
#include "nss.h"
#include "ssl.h"
#include "pk11func.h" /* for PK11_ function calls */
#include "sslimpl.h"
/* convert a CERTDistNameStr to an array ascii strings.
* we ignore caNames which we can't convert, so n could be less than nnames
* n is always set, even on failure.
* This function allows us to use the existing CERT_FilterCertListByCANames. */
static char **
ssl_DistNamesToStrings(struct CERTDistNamesStr *caNames, int *n)
{
char **names;
int i;
SECStatus rv;
PLArenaPool *arena;
*n = 0;
names = PORT_ZNewArray(char *, caNames->nnames);
if (names == NULL) {
return NULL;
}
arena = PORT_NewArena(2048);
if (arena == NULL) {
PORT_Free(names);
return NULL;
}
for (i = 0; i < caNames->nnames; ++i) {
CERTName dn;
rv = SEC_QuickDERDecodeItem(arena, &dn, SEC_ASN1_GET(CERT_NameTemplate),
caNames->names + i);
if (rv != SECSuccess) {
continue;
}
names[*n] = CERT_NameToAscii(&dn);
if (names[*n])
(*n)++;
}
PORT_FreeArena(arena, PR_FALSE);
return names;
}
/* free the dist names we allocated in the above function. n must be the
* returned n from that function. */
static void
ssl_FreeDistNamesStrings(char **strings, int n)
{
int i;
for (i = 0; i < n; i++) {
PORT_Free(strings[i]);
}
PORT_Free(strings);
}
PRBool
ssl_CertIsUsable(sslSocket *ss, CERTCertificate *cert)
{
SECStatus rv;
SSLSignatureScheme scheme;
if ((ss == NULL) || (cert == NULL)) {
return PR_FALSE;
}
/* There are two ways of handling the old style handshake:
* 1) check the actual record we are using and return true,
* if (!ss->ssl3.hs.hashType == handshake_hash_record &&
* ss->ssl3.hs.hashType == handshake_hash_single) {
* return PR_TRUE;
* 2) assume if ss->ss->ssl3.hs.clientAuthSignatureSchemesLen == 0 we are using the
* old handshake.
* There is one case where using 2 will be wrong: we somehow call this
* function outside the case where of out GetClientAuthData context.
* In that case we don't know that the 'real' peerScheme list is, so the
* best we can do is either always assume good or always assume bad.
* I think the best results is to always assume good, so we use
* option 2 here to handle that case as well.*/
if (ss->ssl3.hs.clientAuthSignatureSchemesLen == 0) {
return PR_TRUE;
}
if (ss->ssl3.hs.clientAuthSignatureSchemes == NULL) {
return PR_FALSE; /* should this really be an assert? */
}
rv = ssl_PickClientSignatureScheme(ss, cert, NULL,
ss->ssl3.hs.clientAuthSignatureSchemes,
ss->ssl3.hs.clientAuthSignatureSchemesLen,
&scheme);
if (rv != SECSuccess) {
return PR_FALSE;
}
return PR_TRUE;
}
SECStatus
ssl_FilterClientCertListBySSLSocket(sslSocket *ss, CERTCertList *certList)
{
CERTCertListNode *node;
CERTCertificate *cert;
if (!certList) {
return SECFailure;
}
node = CERT_LIST_HEAD(certList);
while (!CERT_LIST_END(node, certList)) {
cert = node->cert;
if (PR_TRUE != ssl_CertIsUsable(ss, cert)) {
/* cert doesn't match the socket criteria, remove it */
CERTCertListNode *freenode = node;
node = CERT_LIST_NEXT(node);
CERT_RemoveCertListNode(freenode);
} else {
/* this cert is good, go to the next cert */
node = CERT_LIST_NEXT(node);
}
}
return (SECSuccess);
}
/* This function can be called by the application's custom GetClientAuthHook
* to filter out any certs in the cert list that doesn't match the negotiated
* requirements of the current SSL connection.
*/
SECStatus
SSL_FilterClientCertListBySocket(PRFileDesc *fd, CERTCertList *certList)
{
sslSocket *ss = ssl_FindSocket(fd);
if (ss == NULL) {
return SECFailure;
}
return ssl_FilterClientCertListBySSLSocket(ss, certList);
}
/* This function can be called by the application's custom GetClientAuthHook
* to determine if a single certificate matches the negotiated requirements of
* the current SSL connection.
*/
PRBool
SSL_CertIsUsable(PRFileDesc *fd, CERTCertificate *cert)
{
sslSocket *ss = ssl_FindSocket(fd);
if (ss == NULL) {
return PR_FALSE;
}
return ssl_CertIsUsable(ss, cert);
}
/*
* This callback used by SSL to pull client certificate upon
* server request
*/
SECStatus
NSS_GetClientAuthData(void *arg,
PRFileDesc *fd,
struct CERTDistNamesStr *caNames,
struct CERTCertificateStr **pRetCert,
struct SECKEYPrivateKeyStr **pRetKey)
{
CERTCertificate *cert = NULL;
CERTCertList *certList = NULL;
SECKEYPrivateKey *privkey = NULL;
char *chosenNickName = (char *)arg; /* CONST */
SECStatus rv = SECFailure;
sslSocket *ss = ssl_FindSocket(fd);
if (!ss) {
return SECFailure;
}
void *pw_arg = SSL_RevealPinArg(fd);
/* first, handle any token authentication that may be needed */
if (chosenNickName && pw_arg) {
certList = PK11_FindCertsFromNickname(chosenNickName, pw_arg);
if (certList) {
CERT_FilterCertListForUserCerts(certList);
rv = CERT_FilterCertListByUsage(certList, certUsageSSLClient,
PR_FALSE);
if ((rv != SECSuccess) || CERT_LIST_EMPTY(certList)) {
CERT_DestroyCertList(certList);
certList = NULL;
}
}
}
/* otherwise look through the cache based on usage
* if chosenNickname is set, we ignore the expiration date */
if (certList == NULL) {
certList = CERT_FindUserCertsByUsage(CERT_GetDefaultCertDB(),
certUsageSSLClient,
PR_FALSE, chosenNickName == NULL,
pw_arg);
if (certList == NULL) {
return SECFailure;
}
/* filter only the certs that meet the nickname requirements */
if (chosenNickName) {
rv = CERT_FilterCertListByNickname(certList, chosenNickName,
pw_arg);
} else {
int nnames = 0;
char **names = ssl_DistNamesToStrings(caNames, &nnames);
rv = CERT_FilterCertListByCANames(certList, nnames, names,
certUsageSSLClient);
ssl_FreeDistNamesStrings(names, nnames);
}
if ((rv != SECSuccess) || CERT_LIST_EMPTY(certList)) {
CERT_DestroyCertList(certList);
return SECFailure;
}
}
/* now remove any certs that can't meet the connection requirements */
rv = ssl_FilterClientCertListBySSLSocket(ss, certList);
if ((rv != SECSuccess) || CERT_LIST_EMPTY(certList)) {
// no certs left.
CERT_DestroyCertList(certList);
return SECFailure;
}
/* now return the top cert in the list. We've strived to make the
* list ordered by the most likely usable cert, so it should be the best
* match. */
cert = CERT_DupCertificate(CERT_LIST_HEAD(certList)->cert);
CERT_DestroyCertList(certList);
privkey = PK11_FindKeyByAnyCert(cert, pw_arg);
if (privkey == NULL) {
CERT_DestroyCertificate(cert);
return SECFailure;
}
*pRetCert = cert;
*pRetKey = privkey;
return SECSuccess;
}
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