Add Lua shim providing SHA1 and SHA256

Signed-off-by: Tobias Ulmer <tu@emlix.com>

diff --git a/generic/lsha.c b/generic/lsha.c
new file mode 100644 (file)
index 0000000..1fa8f7c
--- /dev/null
+++ b/generic/lsha.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2016 emlix GmbH, see file AUTHORS
+ *
+ * This file is part of e2factory, the emlix embedded build system.
+ * For more information see http://www.e2factory.org
+ *
+ * e2factory is a registered trademark of emlix GmbH.
+ *
+ * e2factory 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.
+ */
+
+#include "lua.h"
+#include "lualib.h"
+#include "lauxlib.h"
+
+#include "sha1.h"
+#include "sha2.h"
+
+#define TYPE_SHA1 "SHA1_CTX"
+#define TYPE_SHA256 "SHA256_CTX"
+
+int
+lsha1_init(lua_State *L)
+{
+       SHA1_CTX *ctx = lua_newuserdata(L, sizeof(SHA1_CTX));
+       luaL_newmetatable(L, TYPE_SHA1);
+       lua_setmetatable(L, 1);
+       SHA1Init(ctx);
+       return 1;
+}
+
+int
+lsha1_update(lua_State *L)
+{
+       SHA1_CTX *ctx;
+       const char* data;
+       size_t sz;
+
+       luaL_checktype(L, 1, LUA_TUSERDATA);
+       ctx = luaL_checkudata(L, 1, TYPE_SHA1);
+       luaL_checktype(L, 2, LUA_TSTRING);
+       /* guard luaL_checklstring against number */
+       data = luaL_checklstring(L, 2, &sz);
+       if (sz > UINT_MAX)
+               return luaL_error(L, "sha1_update: data exceeds UINT_MAX");
+       SHA1Update(ctx, (unsigned char *)data, sz);
+       return 0;
+}
+
+int
+lsha1_final(lua_State *L)
+{
+       SHA1_CTX *ctx;
+       unsigned char digest[20];
+       const char *hexdigits = "0123456789abcdef";
+       char strdigest[40+1];
+       int i, j;
+
+       luaL_checktype(L, 1, LUA_TUSERDATA);
+       ctx = luaL_checkudata(L, 1, TYPE_SHA1);
+
+       SHA1Final(digest, ctx);
+
+       for (i = 0, j = 0; i < 20; i++) {
+               strdigest[j++] = hexdigits[(digest[i] & 0xf0) >> 4];
+               strdigest[j++] = hexdigits[digest[i] & 0x0f];
+       }
+       strdigest[j] = '\0';
+
+       lua_pushstring(L, strdigest);
+       return 1;
+}
+
+int
+lsha256_init(lua_State *L)
+{
+       SHA256_CTX *ctx = lua_newuserdata(L, sizeof(SHA256_CTX));
+       luaL_newmetatable(L, TYPE_SHA256);
+       lua_setmetatable(L, 1);
+
+       SHA256_Init(ctx);
+       return 1;
+}
+
+int
+lsha256_update(lua_State *L)
+{
+       SHA256_CTX *ctx;
+       const char* data;
+       size_t sz;
+
+       luaL_checktype(L, 1, LUA_TUSERDATA);
+       ctx = luaL_checkudata(L, 1, TYPE_SHA256);
+       luaL_checktype(L, 2, LUA_TSTRING);
+       /* guard luaL_checklstring against number */
+       data = luaL_checklstring(L, 2, &sz);
+       SHA256_Update(ctx, (const u_int8_t *)data, sz);
+       return 0;
+}
+
+int
+lsha256_final(lua_State *L)
+{
+       SHA256_CTX *ctx;
+       char digest[SHA256_DIGEST_STRING_LENGTH];
+
+       luaL_checktype(L, 1, LUA_TUSERDATA);
+       ctx = luaL_checkudata(L, 1, TYPE_SHA256);
+
+       SHA256_End(ctx, digest);
+       lua_pushstring(L, digest);
+       return 1;
+}
+
+static luaL_reg lib[] = {
+       { "sha1_init",          lsha1_init },
+       { "sha1_update",        lsha1_update },
+       { "sha1_final",         lsha1_final },
+       { "sha256_init",        lsha256_init },
+       { "sha256_update",      lsha256_update },
+       { "sha256_final",       lsha256_final },
+       { NULL,         NULL }
+};
+
+int
+luaopen_lsha(lua_State *L)
+{
+       luaL_Reg *next;
+
+       lua_newtable(L);
+       for (next = lib; next->name != NULL; next++) {
+               lua_pushcfunction(L, next->func);
+               lua_setfield(L, -2, next->name);
+       }
+
+       return 1;
+}