2 files changed, 154 insertions, 0 deletions
diff --git a/src/libdnssec/p11/p11.c b/src/libdnssec/p11/p11.c
new file mode 100644
index 0000000..07f34f2
--- /dev/null
+++ b/src/libdnssec/p11/p11.c
@@ -0,0 +1,113 @@
+/*  Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <gnutls/pkcs11.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libdnssec/p11/p11.h"
+#include "libdnssec/error.h"
+
+#ifdef ENABLE_PKCS11
+
+#define PKCS11_MODULES_MAX 16
+
+static char *pkcs11_modules[PKCS11_MODULES_MAX] = { 0 };
+static int pkcs11_modules_count = 0;
+
+static int map_result(int gnutls_result)
+{
+	return gnutls_result == GNUTLS_E_SUCCESS ? DNSSEC_EOK : DNSSEC_ERROR;
+}
+
+int p11_init(void)
+{
+	int r = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL);
+	return map_result(r);
+}
+
+int p11_reinit(void)
+{
+	int r = gnutls_pkcs11_reinit();
+	return map_result(r);
+}
+
+int p11_load_module(const char *module)
+{
+	for (int i = 0; i < pkcs11_modules_count; i++) {
+		if (strcmp(pkcs11_modules[i], module) == 0) {
+			return DNSSEC_EOK;
+		}
+	}
+
+	assert(pkcs11_modules_count <= PKCS11_MODULES_MAX);
+	if (pkcs11_modules_count == PKCS11_MODULES_MAX) {
+		return DNSSEC_P11_TOO_MANY_MODULES;
+	}
+
+	char *copy = strdup(module);
+	if (!copy) {
+		return DNSSEC_ENOMEM;
+	}
+
+	int r = gnutls_pkcs11_add_provider(module, NULL);
+	if (r != GNUTLS_E_SUCCESS) {
+		free(copy);
+		return DNSSEC_P11_FAILED_TO_LOAD_MODULE;
+	}
+
+	pkcs11_modules[pkcs11_modules_count] = copy;
+	pkcs11_modules_count += 1;
+
+	return DNSSEC_EOK;
+}
+
+void p11_cleanup(void)
+{
+	for (int i = 0; i < pkcs11_modules_count; i++) {
+		free(pkcs11_modules[i]);
+		pkcs11_modules[i] = NULL;
+	}
+
+	pkcs11_modules_count = 0;
+
+	gnutls_pkcs11_deinit();
+}
+
+#else
+
+int p11_init(void)
+{
+	return DNSSEC_EOK;
+}
+
+int p11_reinit(void)
+{
+	return DNSSEC_EOK;
+}
+
+int p11_load_module(const char *module)
+{
+	return DNSSEC_NOT_IMPLEMENTED_ERROR;
+}
+
+void p11_cleanup(void)
+{
+	// this function intentionally left blank
+}
+
+#endif
diff --git a/src/libdnssec/p11/p11.h b/src/libdnssec/p11/p11.h
new file mode 100644
index 0000000..a0f9969
--- /dev/null
+++ b/src/libdnssec/p11/p11.h
@@ -0,0 +1,41 @@
+/*  Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+/*!
+ * Initialize PKCS11 global context.
+ */
+int p11_init(void);
+
+/*!
+ * Reinitialize PKCS11 global context after fork().
+ */
+int p11_reinit(void);
+
+/*!
+ * Load PKCS11 module unless the module was already loaded.
+ *
+ * Duplicates are detected based on the module path.
+ */
+int p11_load_module(const char *name);
+
+/*!
+ * Clenaup PKCS11 global context.
+ *
+ * Should be called when the library is deinitialized to prevent memory leaks.
+ */
+void p11_cleanup(void);