diff --git a/app/include/user_modules.h b/app/include/user_modules.h index c52e487019..03599f3405 100644 --- a/app/include/user_modules.h +++ b/app/include/user_modules.h @@ -23,6 +23,7 @@ #define LUA_USE_MODULES_COAP #define LUA_USE_MODULES_CRYPTO #define LUA_USE_MODULES_DHT +#define LUA_USE_MODULES_ENCODER //#define LUA_USE_MODULES_ENDUSER_SETUP // USE_DNS in dhcpserver.h needs to be enabled for this module to work. #define LUA_USE_MODULES_FILE #define LUA_USE_MODULES_GPIO diff --git a/app/modules/crypto.c b/app/modules/crypto.c index d48e3e3daf..87b1814694 100644 --- a/app/modules/crypto.c +++ b/app/modules/crypto.c @@ -37,7 +37,29 @@ static int crypto_sha1( lua_State* L ) return 1; } +#ifdef LUA_USE_MODULES_ENCODER +static int call_encoder( lua_State* L, const char *function ) { + if (lua_gettop(L) != 1) { + luaL_error(L, "%s must have one argument", function); + } + lua_getfield(L, LUA_GLOBALSINDEX, "encoder"); + if (!lua_istable(L, -1) && !lua_isrotable(L, -1)) { // also need table just in case encoder has been overloaded + luaL_error(L, "Cannot find encoder.%s", function); + } + lua_getfield(L, -1, function); + lua_insert(L, 1); //move function below the argument + lua_pop(L, 1); //and dump the encoder rotable from stack. + lua_call(L,1,1); // call encoder.xxx(string) + return 1; +} +static int crypto_base64_encode (lua_State* L) { + return call_encoder(L, "toBase64"); +} +static int crypto_hex_encode (lua_State* L) { + return call_encoder(L, "toHex"); +} +#else static const char* bytes64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; /** * encoded = crypto.toBase64(raw) @@ -84,7 +106,7 @@ static int crypto_hex_encode( lua_State* L) c_free(out); return 1; } - +#endif /** * masked = crypto.mask(message, mask) * diff --git a/app/modules/encoder.c b/app/modules/encoder.c new file mode 100644 index 0000000000..9590627a2a --- /dev/null +++ b/app/modules/encoder.c @@ -0,0 +1,159 @@ +// Module encoders + +#include "module.h" +#include "lauxlib.h" +#include "lmem.h" +#include "c_string.h" +#define BASE64_INVALID '\xff' +#define BASE64_PADDING '=' +#define ISBASE64(c) (unbytes64[c] != BASE64_INVALID) + +static const uint8 b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +static uint8 *toBase64 ( lua_State* L, const uint8 *msg, size_t *len){ + size_t i, n = *len; + + if (!n) // handle empty string case + return NULL; + + uint8 * q, *out = (uint8 *)luaM_malloc(L, (n + 2) / 3 * 4); + uint8 bytes64[sizeof(b64)]; + c_memcpy(bytes64, b64, sizeof(b64)); //Avoid lots of flash unaligned fetches + + for (i = 0, q = out; i < n; i += 3) { + int a = msg[i]; + int b = (i + 1 < n) ? msg[i + 1] : 0; + int c = (i + 2 < n) ? msg[i + 2] : 0; + *q++ = bytes64[a >> 2]; + *q++ = bytes64[((a & 3) << 4) | (b >> 4)]; + *q++ = (i + 1 < n) ? bytes64[((b & 15) << 2) | (c >> 6)] : BASE64_PADDING; + *q++ = (i + 2 < n) ? bytes64[(c & 63)] : BASE64_PADDING; + } + *len = q - out; + return out; +} + +static uint8 *fromBase64 ( lua_State* L, const uint8 *enc_msg, size_t *len){ + int i, n = *len, blocks = (n>>2), pad = 0; + const uint8 *p; + uint8 unbytes64[UCHAR_MAX+1], *msg, *q; + + if (!n) // handle empty string case + return NULL; + + if (n & 3) + luaL_error (L, "Invalid base64 string"); + + c_memset(unbytes64, BASE64_INVALID, sizeof(unbytes64)); + for (i = 0; i < sizeof(b64)-1; i++) unbytes64[b64[i]] = i; // sequential so no exceptions + + if (enc_msg[n-1] == BASE64_PADDING) { + pad = (enc_msg[n-2] != BASE64_PADDING) ? 1 : 2; + blocks--; //exclude padding block + } + + for (i = 0; i < n - pad; i++) if (!ISBASE64(enc_msg[i])) luaL_error (L, "Invalid base64 string"); + unbytes64[BASE64_PADDING] = 0; + + msg = q = (uint8 *) luaM_malloc(L, 1+ (3 * n / 4)); + for (i = 0, p = enc_msg; i> 4); + *q++ = (b << 4) | (c >> 2); + *q++ = (c << 6) | d; + } + + if (pad) { //now process padding block bytes + uint8 a = unbytes64[*p++]; + uint8 b = unbytes64[*p++]; + *q++ = (a << 2) | (b >> 4); + if (pad == 1) *q++ = (b << 4) | (unbytes64[*p] >> 2); + } + *len = q - msg; + return msg; +} + +static inline uint8 to_hex_nibble(uint8 b) { + return b + ( b < 10 ? '0' : 'a' - 10 ); + } + +static uint8 *toHex ( lua_State* L, const uint8 *msg, size_t *len){ + int i, n = *len; + uint8 *q, *out = (uint8 *)luaM_malloc(L, n * 2); + for (i = 0, q = out; i < n; i++) { + *q++ = to_hex_nibble(msg[i] >> 4); + *q++ = to_hex_nibble(msg[i] & 0xf); + } + *len = 2*n; + return out; +} + +static uint8 *fromHex ( lua_State* L, const uint8 *msg, size_t *len){ + int i, n = *len; + const uint8 *p; + uint8 b, *q, *out = (uint8 *)luaM_malloc(L, n * 2); + uint8 c; + + if (n &1) + luaL_error (L, "Invalid hex string"); + + for (i = 0, p = msg, q = out; i < n; i++) { + if (*p >= '0' && *p <= '9') { + b = *p++ - '0'; + } else if (*p >= 'a' && *p <= 'f') { + b = *p++ - ('a' - 10); + } else if (*p >= 'A' && *p <= 'F') { + b = *p++ - ('A' - 10); + } else { + luaL_error (L, "Invalid hex string"); + } + if ((i&1) == 0) { + c = b<<4; + } else { + *q++ = c+ b; + } + } + *len = n>>1; + return out; +} + +// All encoder functions are of the form: +// Lua: output_string = encoder.function(input_string) +// Where input string maybe empty, but not nil +// Hence these all call the do_func wrapper +static int do_func (lua_State *L, uint8 * (*conv_func)(lua_State *, const uint8 *, size_t *)) { + size_t l; + const uint8 *input = luaL_checklstring(L, 1, &l); +// luaL_argcheck(L, l>0, 1, "input string empty"); + uint8 *output = conv_func(L, input, &l); + + if (output) { + lua_pushlstring(L, output, l); + luaM_free(L, output); + } else { + lua_pushstring(L, ""); + } + return 1; +} + +#define DECLARE_FUNCTION(f) static int encoder_ ## f (lua_State *L) \ +{ return do_func(L, f); } + + DECLARE_FUNCTION(fromBase64); + DECLARE_FUNCTION(toBase64); + DECLARE_FUNCTION(fromHex); + DECLARE_FUNCTION(toHex); + +// Module function map +static const LUA_REG_TYPE encoder_map[] = { + { LSTRKEY("fromBase64"), LFUNCVAL(encoder_fromBase64) }, + { LSTRKEY("toBase64"), LFUNCVAL(encoder_toBase64) }, + { LSTRKEY("fromHex"), LFUNCVAL(encoder_fromHex) }, + { LSTRKEY("toHex"), LFUNCVAL(encoder_toHex) }, + { LNILKEY, LNILVAL } +}; + +NODEMCU_MODULE(ENCODER, "encoder", encoder_map, NULL); diff --git a/docs/en/modules/encoder.md b/docs/en/modules/encoder.md new file mode 100644 index 0000000000..a57bc6b3a7 --- /dev/null +++ b/docs/en/modules/encoder.md @@ -0,0 +1,79 @@ +# encoder Module + +The encoder modules provides various functions for encoding and decoding byte data. + +## encoder.toBase64() + +Provides a Base64 representation of a (binary) Lua string. + +#### Syntax +`b64 = encoder.toBase64(binary)` + +#### Parameters +`binary` input string to Base64 encode + +#### Return +A Base64 encoded string. + +#### Example +```lua +print(encoder.toBase64(crypto.hash("sha1","abc"))) +``` + +## encoder.fromBase64() + +Decodes a Base64 representation of a (binary) Lua string back into the original string. An error is +thrown if the string is not a valid base64 encoding. + +#### Syntax +`binary_string = encoder.toBase64(b64)` + +#### Parameters +`b64` Base64 encoded input string + +#### Return +The decoded Lua (binary) string. + +#### Example +```lua +print(encoder.fromBase64(encoder.toBase64("hello world"))) +``` + +## encoder.toHex() + +Provides an ASCII hex representation of a (binary) Lua string. Each byte in the input string is +represented as two hex characters in the output. + +#### Syntax +`hexstr = encoder.toHex(binary)` + +#### Parameters +`binary` input string to get hex representation for + +#### Returns +An ASCII hex string. + +#### Example +```lua +print(encoder.toHex(crypto.hash("sha1","abc"))) +``` + +## encoder.fromHex() + +Returns the Lua binary string decode of a ASCII hex string. Each byte in the output string is +represented as two hex characters in the input. An error is thrown if the string is not a +valid base64 encoding. + +#### Syntax +`binary = encoder.fromHex(hexstr)` + +#### Parameters +`hexstr` An ASCII hex string. + +#### Returns +Decoded string of hex representation. + +#### Example +```lua +print(encoder.fromHex("6a6a6a"))) +``` diff --git a/mkdocs.yml b/mkdocs.yml index 91dce90a61..006e42dd25 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -43,6 +43,7 @@ pages: - 'coap': 'en/modules/coap.md' - 'crypto': 'en/modules/crypto.md' - 'dht': 'en/modules/dht.md' + - 'encoder': 'en/modules/encoder.md' - 'enduser setup': 'en/modules/enduser-setup.md' - 'file': 'en/modules/file.md' - 'gpio': 'en/modules/gpio.md'