Add preliminary API for rsa verify to lua.

1 files changed, 393 insertions, 0 deletions

diff --git a/src/lua/lua_rsa.c b/src/lua/lua_rsa.c
new file mode 100644
index 000000000..b9b4e907c
--- /dev/null
+++ b/src/lua/lua_rsa.c
@@ -0,0 +1,393 @@
+/* Copyright (c) 2013, Vsevolod Stakhov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *       * Redistributions of source code must retain the above copyright
+ *         notice, this list of conditions and the following disclaimer.
+ *       * Redistributions in binary form must reproduce the above copyright
+ *         notice, this list of conditions and the following disclaimer in the
+ *         documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/**
+ * @file lua_rsa.c
+ * This module exports routines to load rsa keys, check inline or external
+ * rsa signatures. It assumes sha256 based signatures.
+ */
+
+#include "lua_common.h"
+
+#ifdef HAVE_OPENSSL
+#include <openssl/err.h>
+#include <openssl/sha.h>
+#include <openssl/rsa.h>
+#include <openssl/pem.h>
+
+LUA_FUNCTION_DEF (rsa_key, load);
+LUA_FUNCTION_DEF (rsa_key, create);
+LUA_FUNCTION_DEF (rsa_key, gc);
+LUA_FUNCTION_DEF (rsa_signature, create);
+LUA_FUNCTION_DEF (rsa_signature, load);
+LUA_FUNCTION_DEF (rsa_signature, gc);
+LUA_FUNCTION_DEF (rsa, check_memory);
+LUA_FUNCTION_DEF (rsa, check_file);
+
+static const struct luaL_reg    rsalib_f[] = {
+	LUA_INTERFACE_DEF (rsa, check_memory),
+	LUA_INTERFACE_DEF (rsa, check_file),
+	{NULL, NULL}
+};
+
+static const struct luaL_reg rsakeylib_f[] = {
+		LUA_INTERFACE_DEF (rsa_key, load),
+		LUA_INTERFACE_DEF (rsa_key, create),
+		{NULL, NULL}
+};
+
+static const struct luaL_reg rsakeylib_m[] = {
+		{"__tostring", lua_class_tostring},
+		{"__gc", lua_rsa_key_gc},
+		{NULL, NULL}
+};
+
+static const struct luaL_reg rsasignlib_f[] = {
+		LUA_INTERFACE_DEF (rsa_signature, load),
+		LUA_INTERFACE_DEF (rsa_signature, create),
+		{NULL, NULL}
+};
+
+static const struct luaL_reg rsasignlib_m[] = {
+		{"__tostring", lua_class_tostring},
+		{"__gc", lua_rsa_signature_gc},
+		{NULL, NULL}
+};
+
+static RSA *
+lua_check_rsa_key (lua_State * L, int pos)
+{
+	void                           *ud = luaL_checkudata (L, pos, "rspamd{rsa_key}");
+
+	luaL_argcheck (L, ud != NULL, 1, "'rsa_key' expected");
+	return ud ? *((RSA **)ud) : NULL;
+}
+
+static gpointer
+lua_check_rsa_sign (lua_State * L, int pos)
+{
+	void                           *ud = luaL_checkudata (L, pos, "rspamd{rsa_signature}");
+
+	luaL_argcheck (L, ud != NULL, 1, "'rsa_signature' expected");
+	return ud ? *((gpointer *)ud) : NULL;
+}
+
+static gint
+lua_rsa_key_load (lua_State *L)
+{
+	RSA	*rsa = NULL, **prsa;
+	const gchar *filename;
+	FILE *f;
+
+	filename = luaL_checkstring (L, 1);
+	if (filename != NULL) {
+		f = fopen (filename, "r");
+		if (f == NULL) {
+			msg_err ("cannot open pubkey from file: %s, %s", filename, strerror (errno));
+			lua_pushnil (L);
+		}
+		else {
+			if (! PEM_read_RSA_PUBKEY (f, &rsa, NULL, NULL)) {
+				msg_err ("cannot open pubkey from file: %s, %s", filename,
+						ERR_error_string (ERR_get_error (), NULL));
+				lua_pushnil (L);
+			}
+			else {
+				prsa = lua_newuserdata (L, sizeof (RSA *));
+				lua_setclass (L, "rspamd{rsa_key}", -1);
+				*prsa = rsa;
+			}
+			fclose (f);
+		}
+	}
+	else {
+		lua_pushnil (L);
+	}
+	return 1;
+}
+
+static gint
+lua_rsa_key_create (lua_State *L)
+{
+	RSA	*rsa = NULL, **prsa;
+	const gchar *buf;
+	BIO *bp;
+
+	buf = luaL_checkstring (L, 1);
+	if (buf != NULL) {
+		bp = BIO_new_mem_buf ((void *)buf, -1);
+
+		if (! PEM_read_bio_RSA_PUBKEY (bp, &rsa, NULL, NULL)) {
+			msg_err ("cannot parse pubkey: %s",
+					ERR_error_string (ERR_get_error (), NULL));
+			lua_pushnil (L);
+		}
+		else {
+			prsa = lua_newuserdata (L, sizeof (RSA *));
+			lua_setclass (L, "rspamd{rsa_key}", -1);
+			*prsa = rsa;
+		}
+		BIO_free (bp);
+	}
+	else {
+		lua_pushnil (L);
+	}
+	return 1;
+}
+
+static gint
+lua_rsa_key_gc (lua_State *L)
+{
+	RSA *rsa = lua_check_rsa_key (L, 1);
+
+	if (rsa != NULL) {
+		RSA_free (rsa);
+	}
+
+	return 0;
+}
+
+static gint
+lua_rsa_signature_load (lua_State *L)
+{
+	gchar *sig, **psig;
+	const gchar *filename;
+	FILE *f;
+	gint siglen;
+
+	siglen = g_checksum_type_get_length (G_CHECKSUM_SHA256);
+	filename = luaL_checkstring (L, 1);
+	if (filename != NULL) {
+		f = fopen (filename, "r");
+		if (f == NULL) {
+			msg_err ("cannot open signature file: %s, %s", filename, strerror (errno));
+			lua_pushnil (L);
+		}
+		else {
+			sig = g_malloc (siglen * 2 + 1);
+			if (fread (sig, siglen * 2, 1, f) == 1) {
+				sig[siglen * 2] = '\0';
+				psig = lua_newuserdata (L, sizeof (gchar *));
+				lua_setclass (L, "rspamd{rsa_signature}", -1);
+				*psig = sig;
+			}
+			else {
+				msg_err ("cannot read signature file: %s, %s", filename, strerror (errno));
+				g_free (sig);
+				lua_pushnil (L);
+			}
+			fclose (f);
+		}
+	}
+	else {
+		lua_pushnil (L);
+	}
+	return 1;
+}
+
+static gint
+lua_rsa_signature_create (lua_State *L)
+{
+	gchar *sig, **psig;
+	const gchar *data;
+	guint siglen;
+
+	siglen = g_checksum_type_get_length (G_CHECKSUM_SHA256);
+	data = luaL_checkstring (L, 1);
+	if (data != NULL) {
+		sig = g_malloc (siglen * 2 + 1);
+		if (strlen (data) == siglen * 2) {
+			memcpy (sig, data, siglen * 2);
+			sig[siglen * 2] = '\0';
+			psig = lua_newuserdata (L, sizeof (gchar *));
+			lua_setclass (L, "rspamd{rsa_signature}", -1);
+			*psig = sig;
+		}
+		else {
+			msg_err ("cannot read signature string: %s", data);
+			g_free (sig);
+			lua_pushnil (L);
+		}
+	}
+
+	return 1;
+}
+
+static gint
+lua_rsa_signature_gc (lua_State *L)
+{
+	gpointer sig = lua_check_rsa_sign (L, 1);
+
+	if (sig != NULL) {
+		g_free (sig);
+	}
+
+	return 0;
+}
+
+/**
+ * Check memory using specified rsa key and signature
+ *
+ * arguments:
+ * (rsa_key, rsa_signature, string)
+ *
+ * returns:
+ * true - if string match rsa signature
+ * false - otherwise
+ */
+static gint
+lua_rsa_check_memory (lua_State *L)
+{
+	RSA *rsa;
+	gpointer signature;
+	const gchar *data;
+	gchar *data_sig;
+	gint ret, siglen;
+
+	siglen = g_checksum_type_get_length (G_CHECKSUM_SHA256);
+
+	rsa = lua_check_rsa_key (L, 1);
+	signature = lua_check_rsa_sign (L, 2);
+	data = luaL_checkstring (L, 3);
+
+	if (rsa != NULL && signature != NULL && data != NULL) {
+		data_sig = g_compute_checksum_for_string (G_CHECKSUM_SHA256, data, -1);
+		ret = RSA_verify (NID_sha1, signature, siglen * 2, data_sig, strlen (data_sig), rsa);
+		if (ret == 0) {
+			lua_pushboolean (L, FALSE);
+		}
+		else {
+			lua_pushboolean (L, TRUE);
+		}
+	}
+	else {
+		lua_pushnil (L);
+	}
+
+	return 1;
+}
+
+/**
+ * Check memory using specified rsa key and signature
+ *
+ * arguments:
+ * (rsa_key, rsa_signature, string)
+ *
+ * returns:
+ * true - if string match rsa signature
+ * false - otherwise
+ */
+static gint
+lua_rsa_check_file (lua_State *L)
+{
+	RSA *rsa;
+	gpointer signature;
+	const gchar *filename;
+	gchar *data = NULL, *data_sig;
+	gint ret, siglen;
+	gint fd;
+	struct stat st;
+
+	siglen = g_checksum_type_get_length (G_CHECKSUM_SHA256);
+
+	rsa = lua_check_rsa_key (L, 1);
+	signature = lua_check_rsa_sign (L, 2);
+	filename = luaL_checkstring (L, 3);
+
+	if (rsa != NULL && signature != NULL && data != NULL) {
+		fd = open (filename, O_RDONLY);
+		if (fd == -1) {
+			msg_err ("cannot open file %s: %s", filename, strerror (errno));
+			lua_pushnil (L);
+		}
+		else {
+			if (fstat (fd, &st) == -1 ||
+					(data = mmap (NULL,  st.st_size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+				msg_err ("cannot mmap file %s: %s", filename, strerror (errno));
+				lua_pushnil (L);
+			}
+			else {
+				data_sig = g_compute_checksum_for_data (G_CHECKSUM_SHA256, data, st.st_size);
+				ret = RSA_verify (NID_sha1, signature, siglen * 2, data_sig, strlen (data_sig), rsa);
+				if (ret == 0) {
+					lua_pushboolean (L, FALSE);
+				}
+				else {
+					lua_pushboolean (L, TRUE);
+				}
+				munmap (data, st.st_size);
+			}
+			close (fd);
+		}
+	}
+	else {
+		lua_pushnil (L);
+	}
+
+	return 1;
+}
+
+gint
+luaopen_rsa (lua_State * L)
+{
+	luaL_newmetatable (L, "rspamd{rsa_key}");
+	lua_pushstring (L, "__index");
+	lua_pushvalue (L, -2);
+	lua_settable (L, -3);
+
+	lua_pushstring (L, "class");
+	lua_pushstring (L, "rspamd{rsa_key}");
+	lua_rawset (L, -3);
+
+	luaL_register (L, NULL, rsakeylib_m);
+	luaL_register (L, "rsa_key", rsakeylib_f);
+
+	luaL_newmetatable (L, "rspamd{rsa_signature}");
+	lua_pushstring (L, "__index");
+	lua_pushvalue (L, -2);
+	lua_settable (L, -3);
+
+	lua_pushstring (L, "class");
+	lua_pushstring (L, "rspamd{rsa_signature}");
+	lua_rawset (L, -3);
+
+	luaL_register (L, NULL, rsasignlib_m);
+	luaL_register (L, "rsa_signature", rsasignlib_f);
+
+	luaL_register (L, "rsa", rsalib_f);
+
+	return 1;
+}
+
+#else
+gint
+luaopen_rsa (lua_State * L)
+{
+	msg_info ("this rspamd version is not linked against openssl, therefore no "
+			"RSA support is available");
+
+	return 1;
+
+}
+#endif