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-rw-r--r--runtime/nsd_gtls.c819
1 files changed, 768 insertions, 51 deletions
diff --git a/runtime/nsd_gtls.c b/runtime/nsd_gtls.c
index fd7a502a..e3ff3477 100644
--- a/runtime/nsd_gtls.c
+++ b/runtime/nsd_gtls.c
@@ -31,6 +31,10 @@
#include <gnutls/x509.h>
#include <gcrypt.h>
#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <pthread.h>
#include "rsyslog.h"
#include "syslogd-types.h"
@@ -56,10 +60,13 @@ MODULE_TYPE_LIB
DEFobjStaticHelpers
DEFobjCurrIf(errmsg)
DEFobjCurrIf(glbl)
+DEFobjCurrIf(net)
DEFobjCurrIf(nsd_ptcp)
static int bGlblSrvrInitDone = 0; /**< 0 - server global init not yet done, 1 - already done */
+static pthread_mutex_t mutGtlsStrerror; /**< a mutex protecting the potentially non-reentrant gtlStrerror() function */
+
/* a macro to check GnuTLS calls against unexpected errors */
#define CHKgnutls(x) \
if((gnuRet = (x)) != 0) { \
@@ -74,6 +81,335 @@ static int bGlblSrvrInitDone = 0; /**< 0 - server global init not yet done, 1 -
static gnutls_certificate_credentials xcred;
static gnutls_dh_params dh_params;
+/* read in the whole content of a file. The caller is responsible for
+ * freeing the buffer. To prevent DOS, this function can NOT read
+ * files larger than 1MB (which still is *very* large).
+ * rgerhards, 2008-05-26
+ */
+static rsRetVal
+readFile(uchar *pszFile, gnutls_datum_t *pBuf)
+{
+ int fd;
+ struct stat stat_st;
+ DEFiRet;
+
+ assert(pszFile != NULL);
+ assert(pBuf != NULL);
+
+ pBuf->data = NULL;
+
+ if((fd = open((char*)pszFile, 0)) == -1) {
+ errmsg.LogError(NO_ERRCODE, "can not read file '%s'", pszFile);
+ ABORT_FINALIZE(RS_RET_FILE_NOT_FOUND);
+
+ }
+
+ if(fstat(fd, &stat_st) == -1) {
+ errmsg.LogError(NO_ERRCODE, "can not stat file '%s'", pszFile);
+ ABORT_FINALIZE(RS_RET_FILE_NO_STAT);
+ }
+
+ /* 1MB limit */
+ if(stat_st.st_size > 1024 * 1024) {
+ errmsg.LogError(NO_ERRCODE, "file '%s' too large, max 1MB", pszFile);
+ ABORT_FINALIZE(RS_RET_FILE_TOO_LARGE);
+ }
+
+ CHKmalloc(pBuf->data = malloc(stat_st.st_size));
+ pBuf->size = stat_st.st_size;
+ if(read(fd, pBuf->data, stat_st.st_size) != stat_st.st_size) {
+ errmsg.LogError(NO_ERRCODE, "error or incomplete read of file '%s'", pszFile);
+ ABORT_FINALIZE(RS_RET_IO_ERROR);
+ }
+
+ close(fd);
+
+finalize_it:
+ if(iRet != RS_RET_OK) {
+ if(pBuf->data != NULL) {
+ free(pBuf->data);
+ pBuf->data = NULL;
+ pBuf->size = 0;
+ }
+ }
+ RETiRet;
+}
+
+
+/* Load the certificate and the private key into our own store. We need to do
+ * this in the client case, to support fingerprint authentication. In that case,
+ * we may be presented no matching root certificate, but we must provide ours.
+ * The only way to do that is via the cert callback interface, but for it we
+ * need to load certificates into our private store.
+ * rgerhards, 2008-05-26
+ */
+static rsRetVal
+gtlsLoadOurCertKey(nsd_gtls_t *pThis)
+{
+ DEFiRet;
+ int gnuRet;
+ gnutls_datum_t data = { NULL, 0 };
+ uchar *keyFile;
+ uchar *certFile;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ certFile = glbl.GetDfltNetstrmDrvrCertFile();
+ keyFile = glbl.GetDfltNetstrmDrvrKeyFile();
+
+ /* try load certificate */
+ CHKiRet(readFile(certFile, &data));
+ CHKgnutls(gnutls_x509_crt_init(&pThis->ourCert));
+ pThis->bOurCertIsInit = 1;
+ CHKgnutls(gnutls_x509_crt_import(pThis->ourCert, &data, GNUTLS_X509_FMT_PEM));
+ free(data.data);
+ data.data = NULL;
+
+ /* try load private key */
+ CHKiRet(readFile(keyFile, &data));
+ CHKgnutls(gnutls_x509_privkey_init(&pThis->ourKey));
+ pThis->bOurKeyIsInit = 1;
+ CHKgnutls(gnutls_x509_privkey_import(pThis->ourKey, &data, GNUTLS_X509_FMT_PEM));
+ free(data.data);
+
+finalize_it:
+ if(iRet != RS_RET_OK) {
+ if(data.data != NULL)
+ free(data.data);
+ if(pThis->bOurCertIsInit)
+ gnutls_x509_crt_deinit(pThis->ourCert);
+ if(pThis->bOurKeyIsInit)
+ gnutls_x509_privkey_deinit(pThis->ourKey);
+ }
+ RETiRet;
+}
+
+
+/* This callback must be associated with a session by calling
+ * gnutls_certificate_client_set_retrieve_function(session, cert_callback),
+ * before a handshake. We will always return the configured certificate,
+ * even if it does not match the peer's trusted CAs. This is necessary
+ * to use self-signed certs in fingerprint mode. And, yes, this usage
+ * of the callback is quite a hack. But it seems the only way to
+ * obey to the IETF -transport-tls I-D.
+ * Note: GnuTLS requires the function to return 0 on success and
+ * -1 on failure.
+ * rgerhards, 2008-05-27
+ */
+static int
+gtlsClientCertCallback(gnutls_session session,
+ __attribute__((unused)) const gnutls_datum* req_ca_rdn, int __attribute__((unused)) nreqs,
+ __attribute__((unused)) const gnutls_pk_algorithm* sign_algos, int __attribute__((unused)) sign_algos_length,
+ gnutls_retr_st *st)
+{
+ nsd_gtls_t *pThis;
+
+ pThis = (nsd_gtls_t*) gnutls_session_get_ptr(session);
+
+ st->type = GNUTLS_CRT_X509;
+ st->ncerts = 1;
+ st->cert.x509 = &pThis->ourCert;
+ st->key.x509 = pThis->ourKey;
+ st->deinit_all = 0;
+
+ return 0;
+}
+
+
+/* This function extracts some information about this session's peer
+ * certificate. Works for X.509 certificates only. Adds all
+ * of the info to a cstr_t, which is handed over to the caller.
+ * Caller must destruct it when no longer needed.
+ * rgerhards, 2008-05-21
+ */
+static rsRetVal
+gtlsGetCertInfo(nsd_gtls_t *pThis, cstr_t **ppStr)
+{
+ char dn[128];
+ uchar lnBuf[256];
+ size_t size;
+ unsigned int algo, bits;
+ time_t expiration_time, activation_time;
+ const gnutls_datum *cert_list;
+ unsigned cert_list_size = 0;
+ gnutls_x509_crt cert;
+ cstr_t *pStr = NULL;
+ int gnuRet;
+ DEFiRet;
+ unsigned iAltName;
+ size_t szAltNameLen;
+ char szAltName[1024]; /* this is sufficient for the DNSNAME... */
+
+ assert(ppStr != NULL);
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ if(gnutls_certificate_type_get(pThis->sess) != GNUTLS_CRT_X509)
+ return RS_RET_TLS_CERT_ERR;
+
+ cert_list = gnutls_certificate_get_peers(pThis->sess, &cert_list_size);
+
+ CHKiRet(rsCStrConstruct(&pStr));
+
+ snprintf((char*)lnBuf, sizeof(lnBuf), "peer provided %d certificate(s). ", cert_list_size);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ if(cert_list_size > 0) {
+ /* we only print information about the first certificate */
+ CHKgnutls(gnutls_x509_crt_init(&cert));
+ CHKgnutls(gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER));
+
+ CHKiRet(rsCStrAppendStr(pStr, (uchar*)"Certificate 1 info: "));
+
+ expiration_time = gnutls_x509_crt_get_expiration_time(cert);
+ activation_time = gnutls_x509_crt_get_activation_time(cert);
+ ctime_r(&activation_time, dn);
+ dn[strlen(dn) - 1] = '\0'; /* strip linefeed */
+ snprintf((char*)lnBuf, sizeof(lnBuf), "certificate valid from %s ", dn);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ ctime_r(&expiration_time, dn);
+ dn[strlen(dn) - 1] = '\0'; /* strip linefeed */
+ snprintf((char*)lnBuf, sizeof(lnBuf), "to %s; ", dn);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ /* Extract some of the public key algorithm's parameters */
+ algo = gnutls_x509_crt_get_pk_algorithm(cert, &bits);
+
+ snprintf((char*)lnBuf, sizeof(lnBuf), "Certificate public key: %s; ",
+ gnutls_pk_algorithm_get_name(algo));
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ /* names */
+ size = sizeof(dn);
+ gnutls_x509_crt_get_dn(cert, dn, &size);
+ snprintf((char*)lnBuf, sizeof(lnBuf), "DN: %s; ", dn);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ size = sizeof(dn);
+ gnutls_x509_crt_get_issuer_dn(cert, dn, &size);
+ snprintf((char*)lnBuf, sizeof(lnBuf), "Issuer DN: %s; ", dn);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+
+ /* dNSName alt name */
+ iAltName = 0;
+ while(1) { /* loop broken below */
+ szAltNameLen = sizeof(szAltName);
+ gnuRet = gnutls_x509_crt_get_subject_alt_name(cert, iAltName,
+ szAltName, &szAltNameLen, NULL);
+ if(gnuRet < 0)
+ break;
+ else if(gnuRet == GNUTLS_SAN_DNSNAME) {
+ /* we found it! */
+ snprintf((char*)lnBuf, sizeof(lnBuf), "SAN:DNSname: %s; ", szAltName);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+ /* do NOT break, because there may be multiple dNSName's! */
+ }
+ ++iAltName;
+ }
+
+ gnutls_x509_crt_deinit(cert);
+ }
+
+ CHKiRet(rsCStrFinish(pStr));
+ *ppStr = pStr;
+
+finalize_it:
+ if(iRet != RS_RET_OK) {
+ if(pStr != NULL)
+ rsCStrDestruct(&pStr);
+ }
+
+ RETiRet;
+}
+
+
+
+#if 0 /* we may need this in the future - code needs to be looked at then! */
+/* This function will print some details of the
+ * given pThis->sess.
+ */
+static rsRetVal
+print_info(nsd_gtls_t *pThis)
+{
+ const char *tmp;
+ gnutls_credentials_type cred;
+ gnutls_kx_algorithm kx;
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+ /* print the key exchange's algorithm name
+ */
+ kx = gnutls_kx_get(pThis->sess);
+ tmp = gnutls_kx_get_name(kx);
+ dbgprintf("- Key Exchange: %s\n", tmp);
+
+ /* Check the authentication type used and switch
+ * to the appropriate.
+ */
+ cred = gnutls_auth_get_type(pThis->sess);
+ switch (cred) {
+ case GNUTLS_CRD_ANON: /* anonymous authentication */
+ dbgprintf("- Anonymous DH using prime of %d bits\n",
+ gnutls_dh_get_prime_bits(pThis->sess));
+ break;
+ case GNUTLS_CRD_CERTIFICATE: /* certificate authentication */
+ /* Check if we have been using ephemeral Diffie Hellman.
+ */
+ if (kx == GNUTLS_KX_DHE_RSA || kx == GNUTLS_KX_DHE_DSS) {
+ dbgprintf("\n- Ephemeral DH using prime of %d bits\n",
+ gnutls_dh_get_prime_bits(pThis->sess));
+ }
+
+ /* if the certificate list is available, then
+ * print some information about it.
+ */
+ gtlsPrintCert(pThis);
+ break;
+ case GNUTLS_CRD_SRP: /* certificate authentication */
+ dbgprintf("GNUTLS_CRD_SRP/IA");
+ break;
+ case GNUTLS_CRD_PSK: /* certificate authentication */
+ dbgprintf("GNUTLS_CRD_PSK");
+ break;
+ case GNUTLS_CRD_IA: /* certificate authentication */
+ dbgprintf("GNUTLS_CRD_IA");
+ break;
+ } /* switch */
+
+ /* print the protocol's name (ie TLS 1.0) */
+ tmp = gnutls_protocol_get_name(gnutls_protocol_get_version(pThis->sess));
+ dbgprintf("- Protocol: %s\n", tmp);
+
+ /* print the certificate type of the peer.
+ * ie X.509
+ */
+ tmp = gnutls_certificate_type_get_name(
+ gnutls_certificate_type_get(pThis->sess));
+
+ dbgprintf("- Certificate Type: %s\n", tmp);
+
+ /* print the compression algorithm (if any)
+ */
+ tmp = gnutls_compression_get_name( gnutls_compression_get(pThis->sess));
+ dbgprintf("- Compression: %s\n", tmp);
+
+ /* print the name of the cipher used.
+ * ie 3DES.
+ */
+ tmp = gnutls_cipher_get_name(gnutls_cipher_get(pThis->sess));
+ dbgprintf("- Cipher: %s\n", tmp);
+
+ /* Print the MAC algorithms name.
+ * ie SHA1
+ */
+ tmp = gnutls_mac_get_name(gnutls_mac_get(pThis->sess));
+ dbgprintf("- MAC: %s\n", tmp);
+
+ RETiRet;
+}
+#endif
+
+
/* Convert a fingerprint to printable data. The conversion is carried out
* according IETF I-D syslog-transport-tls-12. The fingerprint string is
* returned in a new cstr object. It is the caller's responsibility to
@@ -86,18 +422,13 @@ GenFingerprintStr(uchar *pFingerprint, size_t sizeFingerprint, cstr_t **ppStr)
cstr_t *pStr = NULL;
uchar buf[4];
size_t i;
- int bAddColon = 0; /* do we need to add a colon to the fingerprint string? */
DEFiRet;
CHKiRet(rsCStrConstruct(&pStr));
+ CHKiRet(rsCStrAppendStrWithLen(pStr, (uchar*)"SHA1", 4));
for(i = 0 ; i < sizeFingerprint ; ++i) {
- if(bAddColon) {
- CHKiRet(rsCStrAppendChar(pStr, ':'));
- } else {
- bAddColon = 1; /* all but the first need a colon added */
- }
- snprintf((char*)buf, sizeof(buf), "%2.2X", pFingerprint[i]);
- CHKiRet(rsCStrAppendStrWithLen(pStr, buf, 2));
+ snprintf((char*)buf, sizeof(buf), ":%2.2X", pFingerprint[i]);
+ CHKiRet(rsCStrAppendStrWithLen(pStr, buf, 3));
}
CHKiRet(rsCStrFinish(pStr));
@@ -112,7 +443,7 @@ finalize_it:
}
-/* a thread-safe variant of gnutls_strerror - TODO: implement it!
+/* a thread-safe variant of gnutls_strerror
* The caller must free the returned string.
* rgerhards, 2008-04-30
*/
@@ -120,8 +451,9 @@ uchar *gtlsStrerror(int error)
{
uchar *pErr;
- // TODO: guard by mutex!
+ pthread_mutex_lock(&mutGtlsStrerror);
pErr = (uchar*) strdup(gnutls_strerror(error));
+ pthread_mutex_unlock(&mutGtlsStrerror);
return pErr;
}
@@ -139,6 +471,7 @@ gtlsAddOurCert(void)
int gnuRet;
uchar *keyFile;
uchar *certFile;
+ uchar *pGnuErr; /* for GnuTLS error reporting */
DEFiRet;
certFile = glbl.GetDfltNetstrmDrvrCertFile();
@@ -148,6 +481,13 @@ gtlsAddOurCert(void)
CHKgnutls(gnutls_certificate_set_x509_key_file(xcred, (char*)certFile, (char*)keyFile, GNUTLS_X509_FMT_PEM));
finalize_it:
+ if(iRet != RS_RET_OK) {
+ pGnuErr = gtlsStrerror(gnuRet);
+ errno = 0;
+ errmsg.LogError(NO_ERRCODE, "error adding our certificate. GnuTLS error %d, message: '%s', "
+ "key: '%s', cert: '%s'\n", gnuRet, pGnuErr, certFile, keyFile);
+ free(pGnuErr);
+ }
RETiRet;
}
@@ -239,7 +579,6 @@ gtlsGlblInitLstn(void)
* considered legacy. -- rgerhards, 2008-05-05
*/
/*CHKgnutls(gnutls_certificate_set_x509_crl_file(xcred, CRLFILE, GNUTLS_X509_FMT_PEM));*/
- //CHKiRet(gtlsAddOurCert());
CHKiRet(generate_dh_params());
gnutls_certificate_set_dh_params(xcred, dh_params); /* this is void */
bGlblSrvrInitDone = 1; /* we are all set now */
@@ -250,54 +589,107 @@ finalize_it:
}
-/* check the fingerprint of the remote peer's certificate.
- * rgerhards, 2008-05-08
+/* Obtain the CN from the DN field and hand it back to the caller
+ * (which is responsible for destructing it). We try to follow
+ * RFC2253 as far as it makes sense for our use-case. This function
+ * is considered a compromise providing good-enough correctness while
+ * limiting code size and complexity. If a problem occurs, we may enhance
+ * this function. A (pointer to a) certificate must be caller-provided.
+ * If no CN is contained in the cert, no string is returned
+ * (*ppstrCN remains NULL). *ppstrCN MUST be NULL on entry!
+ * rgerhards, 2008-05-22
*/
-rsRetVal
-gtlsChkFingerprint(nsd_gtls_t *pThis)
+static rsRetVal
+gtlsGetCN(nsd_gtls_t *pThis, gnutls_x509_crt *pCert, cstr_t **ppstrCN)
{
- cstr_t *pstrFingerprint = NULL;
- uchar fingerprint[20];
- size_t size;
- const gnutls_datum *cert_list;
- unsigned int list_size = 0;
- gnutls_x509_crt cert;
- int bMustDeinitCert = 0;
- int gnuRet;
- int bFoundPositiveMatch;
- permittedPeers_t *pPeer;
DEFiRet;
+ int gnuRet;
+ int i;
+ int bFound;
+ cstr_t *pstrCN = NULL;
+ size_t size;
+ /* big var the last, so we hope to have all we usually neeed within one mem cache line */
+ uchar szDN[1024]; /* this should really be large enough for any non-malicious case... */
ISOBJ_TYPE_assert(pThis, nsd_gtls);
+ assert(pCert != NULL);
+ assert(ppstrCN != NULL);
+ assert(*ppstrCN == NULL);
+
+ size = sizeof(szDN);
+ CHKgnutls(gnutls_x509_crt_get_dn(*pCert, (char*)szDN, &size));
+
+ /* now search for the CN part */
+ i = 0;
+ bFound = 0;
+ while(!bFound && szDN[i] != '\0') {
+ /* note that we do not overrun our string due to boolean shortcut
+ * operations. If we have '\0', the if does not match and evaluation
+ * stops. Order of checks is obviously important!
+ */
+ if(szDN[i] == 'C' && szDN[i+1] == 'N' && szDN[i+2] == '=') {
+ bFound = 1;
+ i += 2;
+ }
+ i++;
- /* first check if we need to do fingerprint authentication - if not, we
- * are already set ;) -- rgerhards, 2008-05-21
- */
- if(pThis->authMode != GTLS_AUTH_CERTFINGERPRINT)
- FINALIZE;
-
- /* This function only works for X.509 certificates. */
- if(gnutls_certificate_type_get(pThis->sess) != GNUTLS_CRT_X509)
- return RS_RET_TLS_CERT_ERR;
+ }
- cert_list = gnutls_certificate_get_peers(pThis->sess, &list_size);
+ if(!bFound) {
+ FINALIZE; /* we are done */
+ }
- if(list_size < 1)
- ABORT_FINALIZE(RS_RET_TLS_NO_CERT);
+ /* we found a common name, now extract it */
+ CHKiRet(rsCStrConstruct(&pstrCN));
+ while(szDN[i] != '\0' && szDN[i] != ',') {
+ if(szDN[i] == '\\') {
+ /* hex escapes are not implemented */
+ ++i; /* escape char processed */
+ if(szDN[i] == '\0')
+ ABORT_FINALIZE(RS_RET_CERT_INVALID_DN);
+ CHKiRet(rsCStrAppendChar(pstrCN, szDN[i]));
+ } else {
+ CHKiRet(rsCStrAppendChar(pstrCN, szDN[i]));
+ }
+ ++i; /* char processed */
+ }
+ CHKiRet(rsCStrFinish(pstrCN));
- /* If we reach this point, we have at least one valid certificate.
- * We always use only the first certificate. As of GnuTLS documentation, the
- * first certificate always contains the remote peer's own certificate. All other
- * certificates are issuer's certificates (up the chain). However, we do not match
- * against some issuer fingerprint but only ourselfs. -- rgerhards, 2008-05-08
+ /* we got it - we ignore the rest of the DN string (if any). So we may
+ * not detect if it contains more than one CN
*/
- CHKgnutls(gnutls_x509_crt_init(&cert));
- bMustDeinitCert = 1; /* indicate cert is initialized and must be freed on exit */
- CHKgnutls(gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER));
+
+ *ppstrCN = pstrCN;
+
+finalize_it:
+ if(iRet != RS_RET_OK) {
+ if(pstrCN != NULL)
+ rsCStrDestruct(&pstrCN);
+ }
+
+ RETiRet;
+}
+
+
+/* Check the peer's ID in fingerprint auth mode.
+ * rgerhards, 2008-05-22
+ */
+static rsRetVal
+gtlsChkPeerFingerprint(nsd_gtls_t *pThis, gnutls_x509_crt *pCert)
+{
+ uchar fingerprint[20];
+ size_t size;
+ cstr_t *pstrFingerprint = NULL;
+ int bFoundPositiveMatch;
+ permittedPeers_t *pPeer;
+ int gnuRet;
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
/* obtain the SHA1 fingerprint */
size = sizeof(fingerprint);
- CHKgnutls(gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA1, fingerprint, &size));
+ CHKgnutls(gnutls_x509_crt_get_fingerprint(*pCert, GNUTLS_DIG_SHA1, fingerprint, &size));
CHKiRet(GenFingerprintStr(fingerprint, size, &pstrFingerprint));
dbgprintf("peer's certificate SHA1 fingerprint: %s\n", rsCStrGetSzStr(pstrFingerprint));
@@ -324,9 +716,175 @@ gtlsChkFingerprint(nsd_gtls_t *pThis)
}
finalize_it:
-dbgprintf("exit fingerprint check, iRet %d\n", iRet);
if(pstrFingerprint != NULL)
rsCStrDestruct(&pstrFingerprint);
+ RETiRet;
+}
+
+
+/* Perform a match on ONE peer name obtained from the certificate. This name
+ * is checked against the set of configured credentials. *pbFoundPositiveMatch is
+ * set to 1 if the ID matches. *pbFoundPositiveMatch must have been initialized
+ * to 0 by the caller (this is a performance enhancement as we expect to be
+ * called multiple times).
+ * TODO: implemet wildcards?
+ * rgerhards, 2008-05-26
+ */
+static rsRetVal
+gtlsChkOnePeerName(nsd_gtls_t *pThis, uchar *pszPeerID, int *pbFoundPositiveMatch)
+{
+ permittedPeers_t *pPeer;
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+ assert(pszPeerID != NULL);
+ assert(pbFoundPositiveMatch != NULL);
+
+ if(pThis->pPermPeers) { /* do we have configured peer IDs? */
+ pPeer = pThis->pPermPeers;
+ while(pPeer != NULL) {
+ CHKiRet(net.PermittedPeerWildcardMatch(pPeer, pszPeerID, pbFoundPositiveMatch));
+ if(*pbFoundPositiveMatch)
+ break;
+ pPeer = pPeer->pNext;
+ }
+ } else {
+ /* we do not have configured peer IDs, so we use defaults */
+ if( pThis->pszConnectHost
+ && !strcmp((char*)pszPeerID, (char*)pThis->pszConnectHost)) {
+ *pbFoundPositiveMatch = 1;
+ }
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* Check the peer's ID in name auth mode.
+ * rgerhards, 2008-05-22
+ */
+static rsRetVal
+gtlsChkPeerName(nsd_gtls_t *pThis, gnutls_x509_crt *pCert)
+{
+ uchar lnBuf[256];
+ char szAltName[1024]; /* this is sufficient for the DNSNAME... */
+ int iAltName;
+ size_t szAltNameLen;
+ int bFoundPositiveMatch;
+ cstr_t *pStr = NULL;
+ cstr_t *pstrCN = NULL;
+ int gnuRet;
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ bFoundPositiveMatch = 0;
+ CHKiRet(rsCStrConstruct(&pStr));
+
+ /* first search through the dNSName subject alt names */
+ iAltName = 0;
+ while(!bFoundPositiveMatch) { /* loop broken below */
+ szAltNameLen = sizeof(szAltName);
+ gnuRet = gnutls_x509_crt_get_subject_alt_name(*pCert, iAltName,
+ szAltName, &szAltNameLen, NULL);
+ if(gnuRet < 0)
+ break;
+ else if(gnuRet == GNUTLS_SAN_DNSNAME) {
+ dbgprintf("subject alt dnsName: '%s'\n", szAltName);
+ snprintf((char*)lnBuf, sizeof(lnBuf), "DNSname: %s; ", szAltName);
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+ CHKiRet(gtlsChkOnePeerName(pThis, (uchar*)szAltName, &bFoundPositiveMatch));
+ /* do NOT break, because there may be multiple dNSName's! */
+ }
+ ++iAltName;
+ }
+
+ if(!bFoundPositiveMatch) {
+ /* if we did not succeed so far, we try the CN part of the DN... */
+ CHKiRet(gtlsGetCN(pThis, pCert, &pstrCN));
+ if(pstrCN != NULL) { /* NULL if there was no CN present */
+ dbgprintf("gtls noch checking auth for CN '%s'\n", rsCStrGetSzStr(pstrCN));
+ snprintf((char*)lnBuf, sizeof(lnBuf), "CN: %s; ", rsCStrGetSzStr(pstrCN));
+ CHKiRet(rsCStrAppendStr(pStr, lnBuf));
+ CHKiRet(gtlsChkOnePeerName(pThis, rsCStrGetSzStr(pstrCN), &bFoundPositiveMatch));
+ }
+ }
+
+ if(!bFoundPositiveMatch) {
+ dbgprintf("invalid peer name, not permitted to talk to it\n");
+ if(pThis->bReportAuthErr == 1) {
+ CHKiRet(rsCStrFinish(pStr));
+ errno = 0;
+ errmsg.LogError(NO_ERRCODE, "error: peer name not authorized - "
+ "not permitted to talk to it. Names: %s",
+ rsCStrGetSzStr(pStr));
+ pThis->bReportAuthErr = 0;
+ }
+ ABORT_FINALIZE(RS_RET_INVALID_FINGERPRINT);
+ }
+
+finalize_it:
+ if(pStr != NULL)
+ rsCStrDestruct(&pStr);
+ if(pstrCN != NULL)
+ rsCStrDestruct(&pstrCN);
+ RETiRet;
+}
+
+
+/* check the ID of the remote peer - used for both fingerprint and
+ * name authentication. This is common code. Will call into specific
+ * drivers once the certificate has been obtained.
+ * rgerhards, 2008-05-08
+ */
+static rsRetVal
+gtlsChkPeerID(nsd_gtls_t *pThis)
+{
+ const gnutls_datum *cert_list;
+ unsigned int list_size = 0;
+ gnutls_x509_crt cert;
+ int bMustDeinitCert = 0;
+ int gnuRet;
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ /* This function only works for X.509 certificates. */
+ if(gnutls_certificate_type_get(pThis->sess) != GNUTLS_CRT_X509)
+ return RS_RET_TLS_CERT_ERR;
+
+ cert_list = gnutls_certificate_get_peers(pThis->sess, &list_size);
+
+ if(list_size < 1) {
+ if(pThis->bReportAuthErr == 1) {
+ errno = 0;
+ errmsg.LogError(NO_ERRCODE, "error: peer did not provide a certificate, "
+ "not permitted to talk to it");
+ pThis->bReportAuthErr = 0;
+ }
+ ABORT_FINALIZE(RS_RET_TLS_NO_CERT);
+ }
+
+ /* If we reach this point, we have at least one valid certificate.
+ * We always use only the first certificate. As of GnuTLS documentation, the
+ * first certificate always contains the remote peer's own certificate. All other
+ * certificates are issuer's certificates (up the chain). We are only interested
+ * in the first certificate, which is our peer. -- rgerhards, 2008-05-08
+ */
+ CHKgnutls(gnutls_x509_crt_init(&cert));
+ bMustDeinitCert = 1; /* indicate cert is initialized and must be freed on exit */
+ CHKgnutls(gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER));
+
+ /* Now we see which actual authentication code we must call. */
+ if(pThis->authMode == GTLS_AUTH_CERTFINGERPRINT) {
+ CHKiRet(gtlsChkPeerFingerprint(pThis, &cert));
+ } else {
+ assert(pThis->authMode == GTLS_AUTH_CERTNAME);
+ CHKiRet(gtlsChkPeerName(pThis, &cert));
+ }
+
+finalize_it:
if(bMustDeinitCert)
gnutls_x509_crt_deinit(cert);
@@ -334,6 +892,130 @@ dbgprintf("exit fingerprint check, iRet %d\n", iRet);
}
+/* Verify the validity of the remote peer's certificate.
+ * rgerhards, 2008-05-21
+ */
+static rsRetVal
+gtlsChkPeerCertValidity(nsd_gtls_t *pThis)
+{
+ DEFiRet;
+ char *pszErrCause;
+ int gnuRet;
+ cstr_t *pStr;
+ unsigned stateCert;
+ const gnutls_datum *cert_list;
+ unsigned cert_list_size = 0;
+ gnutls_x509_crt cert;
+ unsigned i;
+ time_t ttCert;
+ time_t ttNow;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ /* check if we have at least one cert */
+ cert_list = gnutls_certificate_get_peers(pThis->sess, &cert_list_size);
+ if(cert_list_size < 1) {
+ errno = 0;
+ errmsg.LogError(NO_ERRCODE, "peer did not provide a certificate, not permitted to talk to it");
+ ABORT_FINALIZE(RS_RET_TLS_NO_CERT);
+ }
+
+ CHKgnutls(gnutls_certificate_verify_peers2(pThis->sess, &stateCert));
+
+ if(stateCert & GNUTLS_CERT_INVALID) {
+ /* provide error details if we have them */
+ if(stateCert & GNUTLS_CERT_SIGNER_NOT_FOUND) {
+ pszErrCause = "signer not found";
+ } else if(stateCert & GNUTLS_CERT_SIGNER_NOT_FOUND) {
+ pszErrCause = "signer is not a CA";
+ } else if(stateCert & GNUTLS_CERT_SIGNER_NOT_CA) {
+ pszErrCause = "insecure algorithm";
+ } else if(stateCert & GNUTLS_CERT_REVOKED) {
+ pszErrCause = "certificate revoked";
+ } else {
+ pszErrCause = "no specific reason";
+ }
+ errmsg.LogError(NO_ERRCODE, "not permitted to talk to peer, certificate invalid: %s",
+ pszErrCause);
+ gtlsGetCertInfo(pThis, &pStr);
+ errmsg.LogError(NO_ERRCODE, "info on invalid cert: %s", rsCStrGetSzStr(pStr));
+ rsCStrDestruct(&pStr);
+ ABORT_FINALIZE(RS_RET_CERT_INVALID);
+ }
+
+ /* get current time for certificate validation */
+ if(time(&ttNow) == -1)
+ ABORT_FINALIZE(RS_RET_SYS_ERR);
+
+ /* as it looks, we need to validate the expiration dates ourselves...
+ * We need to loop through all certificates as we need to make sure the
+ * interim certificates are also not expired.
+ */
+ for(i = 0 ; i < cert_list_size ; ++i) {
+ CHKgnutls(gnutls_x509_crt_init(&cert));
+ CHKgnutls(gnutls_x509_crt_import(cert, &cert_list[i], GNUTLS_X509_FMT_DER));
+ ttCert = gnutls_x509_crt_get_activation_time(cert);
+ if(ttCert == -1)
+ ABORT_FINALIZE(RS_RET_TLS_CERT_ERR);
+ else if(ttCert > ttNow) {
+ errmsg.LogError(NO_ERRCODE, "not permitted to talk to peer: certificate %d not yet active", i);
+ gtlsGetCertInfo(pThis, &pStr);
+ errmsg.LogError(NO_ERRCODE, "info on invalid cert: %s", rsCStrGetSzStr(pStr));
+ rsCStrDestruct(&pStr);
+ ABORT_FINALIZE(RS_RET_CERT_NOT_YET_ACTIVE);
+ }
+
+ ttCert = gnutls_x509_crt_get_expiration_time(cert);
+ if(ttCert == -1)
+ ABORT_FINALIZE(RS_RET_TLS_CERT_ERR);
+ else if(ttCert < ttNow) {
+ errmsg.LogError(NO_ERRCODE, "not permitted to talk to peer: certificate %d expired", i);
+ gtlsGetCertInfo(pThis, &pStr);
+ errmsg.LogError(NO_ERRCODE, "info on invalid cert: %s", rsCStrGetSzStr(pStr));
+ rsCStrDestruct(&pStr);
+ ABORT_FINALIZE(RS_RET_CERT_EXPIRED);
+ }
+ gnutls_x509_crt_deinit(cert);
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* check if it is OK to talk to the remote peer
+ * rgerhards, 2008-05-21
+ */
+rsRetVal
+gtlsChkPeerAuth(nsd_gtls_t *pThis)
+{
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, nsd_gtls);
+
+ /* call the actual function based on current auth mode */
+ switch(pThis->authMode) {
+ case GTLS_AUTH_CERTNAME:
+ /* if we check the name, we must ensure the cert is valid */
+ CHKiRet(gtlsChkPeerCertValidity(pThis));
+ CHKiRet(gtlsChkPeerID(pThis));
+ break;
+ case GTLS_AUTH_CERTFINGERPRINT:
+ CHKiRet(gtlsChkPeerID(pThis));
+ break;
+ case GTLS_AUTH_CERTVALID:
+ CHKiRet(gtlsChkPeerCertValidity(pThis));
+ break;
+ case GTLS_AUTH_CERTANON:
+ FINALIZE;
+ break;
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
/* globally de-initialize GnuTLS */
static rsRetVal
gtlsGlblExit(void)
@@ -389,7 +1071,7 @@ gtlsSetTransportPtr(nsd_gtls_t *pThis, int sock)
BEGINobjConstruct(nsd_gtls) /* be sure to specify the object type also in END macro! */
iRet = nsd_ptcp.Construct(&pThis->pTcp);
pThis->bReportAuthErr = 1;
-CHKiRet(gtlsAddOurCert());
+ CHKiRet(gtlsAddOurCert());
finalize_it:
ENDobjConstruct(nsd_gtls)
@@ -404,6 +1086,15 @@ CODESTARTobjDestruct(nsd_gtls)
if(pThis->pTcp != NULL) {
nsd_ptcp.Destruct(&pThis->pTcp);
}
+
+ if(pThis->pszConnectHost != NULL) {
+ free(pThis->pszConnectHost);
+ }
+
+ if(pThis->bOurCertIsInit)
+ gnutls_x509_crt_deinit(pThis->ourCert);
+ if(pThis->bOurKeyIsInit)
+ gnutls_x509_privkey_deinit(pThis->ourKey);
ENDobjDestruct(nsd_gtls)
@@ -434,6 +1125,7 @@ finalize_it:
/* Set the authentication mode. For us, the following is supported:
* anon - no certificate checks whatsoever (discouraged, but supported)
+ * x509/certvalid - (just) check certificate validity
* x509/fingerprint - certificate fingerprint
* x509/name - cerfificate name check
* mode == NULL is valid and defaults to x509/name
@@ -450,6 +1142,8 @@ SetAuthMode(nsd_t *pNsd, uchar *mode)
pThis->authMode = GTLS_AUTH_CERTNAME;
} else if(!strcasecmp((char*) mode, "x509/fingerprint")) {
pThis->authMode = GTLS_AUTH_CERTFINGERPRINT;
+ } else if(!strcasecmp((char*) mode, "x509/certvalid")) {
+ pThis->authMode = GTLS_AUTH_CERTVALID;
} else if(!strcasecmp((char*) mode, "anon")) {
pThis->authMode = GTLS_AUTH_CERTANON;
} else {
@@ -723,7 +1417,8 @@ Connect(nsd_t *pNsd, int family, uchar *port, uchar *host)
nsd_gtls_t *pThis = (nsd_gtls_t*) pNsd;
int sock;
int gnuRet;
- static const int cert_type_priority[3] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 };
+ /* TODO: later? static const int cert_type_priority[3] = { GNUTLS_CRT_X509, GNUTLS_CRT_OPENPGP, 0 };*/
+ static const int cert_type_priority[2] = { GNUTLS_CRT_X509, 0 };
DEFiRet;
ISOBJ_TYPE_assert(pThis, nsd_gtls);
@@ -740,6 +1435,15 @@ Connect(nsd_t *pNsd, int family, uchar *port, uchar *host)
pThis->bHaveSess = 1;
pThis->bIsInitiator = 1;
+ /* in the client case, we need to set a callback that ensures our certificate
+ * will be presented to the server even if it is not signed by one of the server's
+ * trusted roots. This is necessary to support fingerprint authentication.
+ */
+ /* store a pointer to ourselfs (needed by callback) */
+ gnutls_session_set_ptr(pThis->sess, (void*)pThis);
+ CHKiRet(gtlsLoadOurCertKey(pThis)); /* first load .pem files */
+ gnutls_certificate_client_set_retrieve_function(xcred, gtlsClientCertCallback);
+
/* Use default priorities */
CHKgnutls(gnutls_set_default_priority(pThis->sess));
CHKgnutls(gnutls_certificate_type_set_priority(pThis->sess, cert_type_priority));
@@ -751,12 +1455,21 @@ Connect(nsd_t *pNsd, int family, uchar *port, uchar *host)
CHKiRet(nsd_ptcp.GetSock(pThis->pTcp, &sock));
gtlsSetTransportPtr(pThis, sock);
+ /* we need to store the hostname as an alternate mean of authentication if no
+ * permitted peer names are given. Using the hostname is quite useful. It permits
+ * auto-configuration of security if a commen root cert is present. -- rgerhards, 2008-05-26
+ */
+ CHKmalloc(pThis->pszConnectHost = (uchar*)strdup((char*)host));
+
/* and perform the handshake */
CHKgnutls(gnutls_handshake(pThis->sess));
dbgprintf("GnuTLS handshake succeeded\n");
- /* now check if the remote peer is permitted to talk to us */
- CHKiRet(gtlsChkFingerprint(pThis));
+ /* now check if the remote peer is permitted to talk to us - ideally, we
+ * should do this during the handshake, but GnuTLS does not yet provide
+ * the necessary callbacks -- rgerhards, 2008-05-26
+ */
+ CHKiRet(gtlsChkPeerAuth(pThis));
finalize_it:
if(iRet != RS_RET_OK) {
@@ -808,6 +1521,7 @@ CODESTARTObjClassExit(nsd_gtls)
/* release objects we no longer need */
objRelease(nsd_ptcp, LM_NSD_PTCP_FILENAME);
+ objRelease(net, LM_NET_FILENAME);
objRelease(glbl, CORE_COMPONENT);
objRelease(errmsg, CORE_COMPONENT);
ENDObjClassExit(nsd_gtls)
@@ -821,6 +1535,7 @@ BEGINObjClassInit(nsd_gtls, 1, OBJ_IS_LOADABLE_MODULE) /* class, version */
/* request objects we use */
CHKiRet(objUse(errmsg, CORE_COMPONENT));
CHKiRet(objUse(glbl, CORE_COMPONENT));
+ CHKiRet(objUse(net, LM_NET_FILENAME));
CHKiRet(objUse(nsd_ptcp, LM_NSD_PTCP_FILENAME));
/* now do global TLS init stuff */
@@ -835,6 +1550,7 @@ BEGINmodExit
CODESTARTmodExit
nsdsel_gtlsClassExit();
nsd_gtlsClassExit();
+ pthread_mutex_destroy(&mutGtlsStrerror);
ENDmodExit
@@ -852,6 +1568,7 @@ CODESTARTmodInit
CHKiRet(nsd_gtlsClassInit(pModInfo)); /* must be done after tcps_sess, as we use it */
CHKiRet(nsdsel_gtlsClassInit(pModInfo)); /* must be done after tcps_sess, as we use it */
+ pthread_mutex_init(&mutGtlsStrerror, NULL);
ENDmodInit
/* vi:set ai:
*/
generated by cgit (git 2.34.1) at 2024-05-21 11:44:38 +0000