Add strToBytes, bytesToStr, rc4 #8

Author: surunzi

DOC.md

@@ -1414,6 +1414,19 @@ Bubble sort implementation.
 bubbleSort([2, 1]); // -> [1, 2]
 ```
 
+## bytesToStr 
+
+Convert bytes to string.
+
+|Name  |Type  |Desc         |
+|------|------|-------------|
+|str   |array |Bytes array  |
+|return|string|Result string|
+
+```javascript
+bytesToStr([108, 105, 99, 105, 97]); // -> 'licia'
+```
+
 ## callbackify 
 
 Convert a function that returns a Promise to a function following the error-first callback style.
@@ -4600,6 +4613,29 @@ range(5); // -> [0, 1, 2, 3, 4]
 range(0, 5, 2) // -> [0, 2, 4]
 ```
 
+## rc4 
+
+RC4 symmetric encryption implementation.
+
+### encrypt
+
+RC4 encryption, result as base64 string.
+
+### decrypt
+
+RC4 decryption, pass base64 string as input.
+
+|Name  |Type  |Desc                            |
+|------|------|--------------------------------|
+|key   |string|Secret key                      |
+|str   |string|String to be encrypted/decrypted|
+|return|string|Encrypted/decrypted string      |
+
+```javascript
+rc4.encrypt('licia', 'Hello world'); // -> 'j9y2VpSfR3AdNN8='
+rc4.decrypt('licia', 'j9y2VpSfR3AdNN8='); // -> 'Hello world'
+```
+
 ## ready 
 
 Invoke callback when dom is ready, similar to jQuery ready.
@@ -5075,6 +5111,19 @@ String hash function using djb2.
 strHash('test'); // -> 2090770981
 ```
 
+## strToBytes 
+
+Convert string into bytes.
+
+|Name  |Type  |Desc             |
+|------|------|-----------------|
+|str   |string|String to convert|
+|return|array |Bytes array      |
+
+```javascript
+strToBytes('licia'); // -> [108, 105, 99, 105, 97]
+```
+
 ## stringify 
 
 JSON stringify with support for circular object, function etc.

b/bytesToStr.i18n.md

@@ -0,0 +1,8 @@
+## CN
+
+将字节数组转换为字符串。
+
+|参数名|类型|说明|
+|-----|----|---|
+|str|array|字节数组|
+|return|string|目标字符串|

b/bytesToStr.js

@@ -0,0 +1,30 @@
+/* Convert bytes to string.
+ *
+ * |Name  |Type  |Desc         |
+ * |------|------|-------------|
+ * |str   |array |Bytes array  |
+ * |return|string|Result string|
+ */
+
+/* example
+ * bytesToStr([108, 105, 99, 105, 97]); // -> 'licia'
+ */
+
+/* module
+ * env: all
+ * test: all
+ */
+
+/* typescript
+ * export default function bytesToStr(bytes: number[]): string
+ */
+
+function exports(bytes) {
+    const str = [];
+
+    for (let i = 0, len = bytes.length; i < len; i++) {
+        str.push(String.fromCharCode(bytes[i]));
+    }
+
+    return str.join('');
+}

b/bytesToStr.test.js

@@ -0,0 +1,3 @@
+it('basic', function() {
+    expect(bytesToStr([108, 105, 99, 105, 97])).to.equal('licia');
+});

doc/DOC_CN.md

@@ -1409,6 +1409,19 @@ btoa('Hello World'); // -> 'SGVsbG8gV29ybGQ='
 bubbleSort([2, 1]); // -> [1, 2]
 ```
 
+## bytesToStr
+
+将字节数组转换为字符串。
+
+|参数名|类型|说明|
+|-----|----|---|
+|str|array|字节数组|
+|return|string|目标字符串|
+
+```javascript
+bytesToStr([108, 105, 99, 105, 97]); // -> 'licia'
+```
+
 ## callbackify
 
 将返回 Promise 的函数转换为使用回调的函数。
@@ -4594,6 +4607,29 @@ range(5); // -> [0, 1, 2, 3, 4]
 range(0, 5, 2) // -> [0, 2, 4]
 ```
 
+## rc4
+
+RC4 对称加密算法实现。
+
+### encrypt
+
+RC4 加密，结果表示为 base64 字符串。
+
+### decrypt
+
+RC4 解密，传入 base64 字符串。
+
+|参数名|类型|说明|
+|-----|----|---|
+|key|string|密钥|
+|str|string|源字符串|
+|return|string|目标字符串|
+
+```javascript
+rc4.encrypt('licia', 'Hello world'); // -> 'j9y2VpSfR3AdNN8='
+rc4.decrypt('licia', 'j9y2VpSfR3AdNN8='); // -> 'Hello world'
+```
+
 ## ready
 
 dom 准备好时调用回调函数，类似于 jQuery 的 ready 方法。
@@ -5069,6 +5105,19 @@ startWith('ab', 'a'); // -> true
 strHash('test'); // -> 2090770981
 ```
 
+## strToBytes
+
+将字符串转换为字节数组。
+
+|参数名|类型|说明|
+|-----|----|---|
+|str|string|目标字符串|
+|return|array|字节数组|
+
+```javascript
+strToBytes('licia'); // -> [108, 105, 99, 105, 97]
+```
+
 ## stringify
 
 JSON 序列化，支持循环引用和函数。

index.json

@@ -510,6 +510,12 @@
         "env": "all",
         "test": "all"
     },
+    "bytesToStr": {
+        "description": "Convert bytes to string.",
+        "dependencies": [],
+        "env": "all",
+        "test": "all"
+    },
     "callbackify": {
         "description": "Convert a function that returns a Promise to a function following the error-first callback style.",
         "dependencies": [
@@ -1813,7 +1819,8 @@
     "md5": {
         "description": "MD5 implementation.",
         "dependencies": [
-            "utf8"
+            "utf8",
+            "strToBytes"
         ],
         "env": "all",
         "test": "all"
@@ -2157,6 +2164,17 @@
         "env": "all",
         "test": "all"
     },
+    "rc4": {
+        "description": "RC4 symmetric encryption implementation.",
+        "dependencies": [
+            "utf8",
+            "base64",
+            "bytesToStr",
+            "strToBytes"
+        ],
+        "env": "all",
+        "test": "all"
+    },
     "ready": {
         "description": "Invoke callback when dom is ready, similar to jQuery ready.",
         "dependencies": [],
@@ -2421,6 +2439,12 @@
         "env": "all",
         "test": "all"
     },
+    "strToBytes": {
+        "description": "Convert string into bytes.",
+        "dependencies": [],
+        "env": "all",
+        "test": "all"
+    },
     "stringify": {
         "description": "JSON stringify with support for circular object, function etc.",
         "dependencies": [

m/md5.js

@@ -19,11 +19,11 @@
  * export declare function md5(msg: string): string
  */
 
-_('utf8');
+_('utf8 strToBytes');
 
 // https://github.com/pvorb/node-md5
 function exports(msg) {
-    const bytes = stringToBytes(msg);
+    const bytes = strToBytes(utf8.encode(msg));
     const m = bytesToWords(bytes);
     const l = bytes.length * 8;
 
@@ -178,18 +178,6 @@ function rotl(n, b) {
     return (n << b) | (n >>> (32 - b));
 }
 
-function stringToBytes(msg) {
-    const bytes = [];
-
-    msg = utf8.encode(msg);
-
-    for (let i = 0, len = msg.length; i < len; i++) {
-        bytes.push(msg.charCodeAt(i) & 0xff);
-    }
-
-    return bytes;
-}
-
 function bytesToWords(bytes) {
     const words = [];
 

package.json

@@ -6,7 +6,7 @@
     "licia": "./bin/licia.js"
   },
   "scripts": {
-    "ci": "npm run update && npm run lint && npm test",
+    "ci": "npm run lint && npm test",
     "update": "licia update",
     "pack": "licia pack",
     "lint": "eslint $/*.js [a-z]/*.js",

r/rc4.i18n.md

@@ -0,0 +1,17 @@
+## CN
+
+RC4 对称加密算法实现。
+
+### encrypt
+
+RC4 加密，结果表示为 base64 字符串。
+
+### decrypt
+
+RC4 解密，传入 base64 字符串。
+
+|参数名|类型|说明|
+|-----|----|---|
+|key|string|密钥|
+|str|string|源字符串|
+|return|string|目标字符串|

r/rc4.js

@@ -0,0 +1,93 @@
+/* RC4 symmetric encryption implementation.
+ * 
+ * ### encrypt
+ * 
+ * RC4 encryption, result as base64 string.
+ * 
+ * ### decrypt
+ * 
+ * RC4 decryption, pass base64 string as input.
+ * 
+ * |Name  |Type  |Desc                            |
+ * |------|------|--------------------------------|
+ * |key   |string|Secret key                      |
+ * |str   |string|String to be encrypted/decrypted|
+ * |return|string|Encrypted/decrypted string      |
+ */
+
+/* example 
+ * rc4.encrypt('licia', 'Hello world'); // -> 'j9y2VpSfR3AdNN8='
+ * rc4.decrypt('licia', 'j9y2VpSfR3AdNN8='); // -> 'Hello world'
+ */
+
+/* module
+ * env: all
+ * test: all
+ */
+
+/* typescript
+ * export declare const rc4: {
+ *     encrypt(key: string, str: string): string
+ *     decrypt(key: string, str: string): string
+ * }
+ */
+
+_('utf8 base64 bytesToStr strToBytes');
+
+exports = {
+    encrypt: function(key, str) {
+        return rc4(key, str, false);
+    },
+    decrypt: function(key, str) {
+        return rc4(key, str, true);
+    }
+};
+
+function rc4(key, str, decrypt) {
+    key = strToBytes(utf8.encode(key));
+    if (!decrypt) {
+        str = strToBytes(utf8.encode(str));
+    } else {
+        str = base64.decode(str);
+    }
+
+    const result = [];
+    const s = [];
+    let j = 0;
+    let i = 0;
+    let x;
+
+    for (i = 0; i < 256; i++) {
+        s[i] = i;
+    }
+    for (i = 0; i < 256; i++) {
+        j = (j + s[i] + key[i % key.length]) % 256;
+        x = s[i];
+        s[i] = s[j];
+        s[j] = x;
+    }
+    i = 0;
+    j = 0;
+    for (let y = 0, len = str.length; y < len; y++) {
+        i = (i + 1) % 256;
+        j = (j + s[i]) % 256;
+        x = s[i];
+        s[i] = s[j];
+        s[j] = x;
+        result.push(str[y] ^ s[(s[i] + s[j]) % 256]);
+    }
+
+    return !decrypt ? base64.encode(result) : utf8.decode(bytesToStr(result));
+}
+
+function stringToBytes(msg) {
+    const bytes = [];
+
+    msg = utf8.encode(msg);
+
+    for (let i = 0, len = msg.length; i < len; i++) {
+        bytes.push(msg.charCodeAt(i) & 0xff);
+    }
+
+    return bytes;
+}