Re: [libvirt] [PATCH 4/4] Fix validation of CA certificate chains

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; The code added to validate CA certificates did not take into account the possibility that the cacert.pem file can contain multiple (concatenated) cert data blocks. Extend the code for loading CA certs to use the gnutls APIs for loading cert lists. Add test cases to check that multi-level trees of certs will validate correctly. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- src/rpc/virnettlscontext.c | 73 ++++++++++++++++++++++++++++++++++---------- tests/virnettlscontexttest.c | 59 +++++++++++++++++++++++++++++++++++ tests/virnettlshelpers.c | 34 +++++++++++++++++++++ tests/virnettlshelpers.h | 3 ++ tests/virnettlssessiontest.c | 63 ++++++++++++++++++++++++++++++++++++-- 5 files changed, 214 insertions(+), 18 deletions(-) diff --git a/src/rpc/virnettlscontext.c b/src/rpc/virnettlscontext.c index af0ec21..55fb7d0 100644 --- a/src/rpc/virnettlscontext.c +++ b/src/rpc/virnettlscontext.c

+#define MAX_CERTS 16 static int virNetTLSContextSanityCheckCredentials(bool isServer, const char *cacertFile, const char *certFile) { gnutls_x509_crt_t cert = NULL; - gnutls_x509_crt_t cacert = NULL; + gnutls_x509_crt_t cacerts[MAX_CERTS]; + size_t ncacerts = MAX_CERTS; + size_t i; int ret = -1; if ((access(certFile, R_OK) == 0) && - !(cert = virNetTLSContextLoadCertFromFile(certFile, isServer, false))) + !(cert = virNetTLSContextLoadCertFromFile(certFile, isServer))) goto cleanup; if ((access(cacertFile, R_OK) == 0) && - !(cacert = virNetTLSContextLoadCertFromFile(cacertFile, isServer, false))) + virNetTLSContextLoadCACertListFromFile(cacertFile, cacerts, &ncacerts) < 0) goto cleanup; if (cert && virNetTLSContextCheckCert(cert, certFile, isServer, false) < 0) goto cleanup; - if (cacert && - virNetTLSContextCheckCert(cacert, cacertFile, isServer, true) < 0) - goto cleanup; + for (i = 0 ; i < ncacerts ; i++) {

+ if (virNetTLSContextCheckCert(cacerts[i], cacertFile, isServer, true) < 0) + goto cleanup; + } - if (cert && cacert && - virNetTLSContextCheckCertPair(cert, certFile, cacert, cacertFile, isServer) < 0) + VIR_DEBUG("Here"); + if (cert && ncacerts && + virNetTLSContextCheckCertPair(cert, certFile, cacerts, ncacerts, cacertFile, isServer) < 0) { + VIR_DEBUG("there"); goto cleanup; + } ret = 0; cleanup: if (cert) gnutls_x509_crt_deinit(cert); - if (cacert) - gnutls_x509_crt_deinit(cacert); + for (i = 0 ; i < ncacerts ; i++)

+ gnutls_x509_crt_deinit(cacerts[i]); return ret; }

diff --git a/tests/virnettlshelpers.c b/tests/virnettlshelpers.c index 8236e82..baf043a 100644 --- a/tests/virnettlshelpers.c +++ b/tests/virnettlshelpers.c @@ -406,6 +406,40 @@ testTLSGenerateCert(struct testTLSCertReq *req, } +void testTLSWriteCertChain(const char *filename, + gnutls_x509_crt_t *certs, + size_t ncerts) +{ + size_t i; + int fd; + int err; + static char buffer[1024*1024]; + size_t size; + + if ((fd = open(filename, O_WRONLY|O_CREAT, 0600)) < 0) { + VIR_WARN("Failed to open %s", filename); + abort(); + } + + for (i = 0 ; i < ncerts ; i++) {

+ size = sizeof(buffer); + if ((err = gnutls_x509_crt_export(certs[i], GNUTLS_X509_FMT_PEM, buffer, &size) < 0)) { + VIR_WARN("Failed to export certificate %s", gnutls_strerror(err)); + unlink(filename); + abort(); + } +