supplement gmsm-sm2js sm2互操作示例

README.md

@@ -8,6 +8,64 @@
 ## SM2
 目前实现：签名结果为**r || s**的拼接；加密结果为**C1 || C3 || C2**拼接，且C1没有点格式前缀字节。为了与其它系统兼容，需要进一步处理。具体使用方法，请参考[sm2_test.js](https://github.com/emmansun/sm4js/blob/master/src/sm2_test.js "sm2_test.js")
 
+和[gmsm-sm2js](https://github.com/emmansun/sm2js)互操作示例：
+```javascript
+const test = require('tape')
+const rs = require('jsrsasign')
+const sm2 = require('gmsm-sm2js')
+const sjclsm = require('gmsm-sm4js')
+const sjcl = require('sjcl-with-all')
+sjclsm.bindKDF(sjcl)
+sjclsm.bindSM3(sjcl)
+sjclsm.bindSM2(sjcl)
+
+const sm2PrivateKeyEncryptedPKCS8 = `
+-----BEGIN ENCRYPTED PRIVATE KEY-----
+MIH2MGEGCSqGSIb3DQEFDTBUMDQGCSqGSIb3DQEFDDAnBBDa6ckWJNP3QBD7MIF8
+4nVqAgEQAgEQMA0GCSqBHM9VAYMRAgUAMBwGCCqBHM9VAWgCBBDMUgr+5Y/XN2g9
+mPGiISzGBIGQytwK98/ET4WrS0H7AsUri6FTqztrzAvgzFl3+s9AsaYtUlzE3EzE
+x6RWxo8kpKO2yj0a/Jh9WZCD4XAcoZ9aMopiWlOdpXJr/iQlMGdirCYIoF37lHMc
+jZHNffmk4ii7NxCfjrzpiFq4clYsNMXeSEnq1tuOEur4kYcjHYSIFc9bPG656a60
++SIJsJuPFi0f
+-----END ENCRYPTED PRIVATE KEY-----`
+
+test('Parse PKCS8 encrypted SM2 private key and work with sjcl based implementation', function (t) {
+  const key = rs.KEYUTIL.getKeyFromEncryptedPKCS8PEM(sm2PrivateKeyEncryptedPKCS8, 'Password1')
+  const SM2PublicKey = sjcl.ecc.sm2.publicKey
+  const pk = new SM2PublicKey(
+    sjcl.codec.hex.toBits(
+      key.pubKeyHex.substring(2)
+    )
+  )
+  const serialized = pk.serialize()
+  t.equals(serialized.type, 'sm2')
+  t.equals(serialized.secretKey, false)
+  t.equals(
+    serialized.point,
+    '8356e642a40ebd18d29ba3532fbd9f3bbee8f027c3f6f39a5ba2f870369f9988981f5efe55d1c5cdf6c0ef2b070847a14f7fdf4272a8df09c442f3058af94ba1'
+  )
+  t.equals(serialized.curve, 'sm2p256v1')
+
+  const keys = sjcl.ecc.sm2.generateKeys(
+    sjcl.codec.hex.toBits(key.prvKeyHex)
+  )
+  const testString = 'send reinforcements, we\'re going to advance'
+
+  // gmsm-sm2js encrypt, gmsm-sm4js decrypt
+  let ciphertext = sm2.encrypt(key.pubKeyHex, testString)
+  let plaintext = keys.sec.decrypt(sjcl.codec.hex.toBits(ciphertext.substring(2)))
+  t.equals(sjcl.codec.utf8String.fromBits(plaintext), testString)
+
+  // gmsm-sm4js encrypt, gmsm-sm2js decrypt
+  ciphertext = keys.pub.encrypt(testString)
+  ciphertext = '04'+sjcl.codec.hex.fromBits(ciphertext)
+  plaintext = sm2.decryptHex(key.prvKeyHex, ciphertext)
+  t.equals(Buffer.from(plaintext, 'hex').toString('ascii'), testString)
+
+  t.end()
+})
+```
+
 ## SM3
 位于**sjcl.hash.sm3**中，使用方式和其它哈希算法相同。具体使用方法，请参考[sm3_test.js](https://github.com/emmansun/sm4js/blob/master/src/sm3_test.js "sm3_test.js")
 

src/sm2.js

@@ -62,7 +62,7 @@ function bindSM2 (sjcl) {
   sjcl.ecc.sm2 = {
     /** sm2 publicKey.
      * @constructor
-     * @augments sjcl.ecc.basicKey.publicKey
+     * @param {point} point the point on the sm2 curve
      */
     publicKey: function (point) {
       this._curve = sm2Curve
@@ -96,7 +96,7 @@ function bindSM2 (sjcl) {
     },
     /** sm2 secretKey
      * @constructor
-     * @augments sjcl.ecc.basicKey.secretKey
+     * @param {bn|bitArray} exponent The private key big number
      */
     secretKey: function (exponent) {
       if (exponent instanceof Array) {