Node.js ecdh.setPublicKey() 方法
ecdh.getPublicKey()方法是加密模块中 ECDH 类的内置应用程序编程接口，用于设置椭圆曲线 Diffie-Hellman (ECDH) 对象的公钥。可以使用encoding参数指定密钥的编码。
通常不需要此方法，因为在应用程序中需要计算共享密钥时，可以使用generateKeys()和setPrivateKey() 方法。 如果公钥对指定曲线无效，则会引发错误。
句法：
ecdh.setPublicKey( publicKey, encoding )参数：此方法接受上面提到的两个参数，如下所述：
- publicKey：这是需要设置的公钥。它可以以字符串、ArrayBuffer、Buffer、TypedArray 或 DataView 的格式给出。
- encoding：这是一个字符串值，指定返回值的编码。它是一个可选参数。
下面的例子演示了这种方法：
示例 1：
Javascript
const crypto = require('crypto');
// Generate an ECDH object for geekOne
const geekOne = crypto.createECDH('secp521r1');
// Generate a temporary ECDH object
// for generating a public key
const tmpECDH = crypto.createECDH('secp521r1');
// Get a temporary public key as a
// Buffer for demonstration
let tempECDHPublicKey = tmpECDH.generateKeys();
// Set the public key to be equal to the
// above generated key in the Buffer format
geekOne.setPublicKey(tempECDHPublicKey);
// Get the public key that was set
let geekOnePublicKey = geekOne.getPublicKey();
console.log("Public Key of Geek A is:",
geekOnePublicKey);Javascript
const crypto = require('crypto');
// Generate an ECDH object for geekOne
const geekOne = crypto.createECDH('secp521r1');
// Generate a key with the encryption
// type as SHA256
let hashObj = crypto.createHash('sha256');
let tempPublicKey =
hashObj.update('thisisapublickey', 'utf8').digest();
// Display the generated key
console.log("The generated key is:", tempPublicKey);
// Attempt to set the public key to
// be equal to the above generated key
geekOne.setPublicKey(tempPublicKey);输出：
Public Key of Geek One is:
示例 2：在此示例中，生成的密钥是不同的曲线。因此，当使用此方法设置此键时，它会引发错误，因为它与 ECDH 对象的曲线不匹配。
Javascript
const crypto = require('crypto');
// Generate an ECDH object for geekOne
const geekOne = crypto.createECDH('secp521r1');
// Generate a key with the encryption
// type as SHA256
let hashObj = crypto.createHash('sha256');
let tempPublicKey =
hashObj.update('thisisapublickey', 'utf8').digest();
// Display the generated key
console.log("The generated key is:", tempPublicKey);
// Attempt to set the public key to
// be equal to the above generated key
geekOne.setPublicKey(tempPublicKey);
输出：
The generated key is:
node:internal/crypto/diffiehellman:231
this[kHandle].setPublicKey(key);
^
Error: Failed to convert Buffer to EC_POINT
at ECDH.setPublicKey (node:internal/crypto/diffiehellman:231:17)
at Object.
at Module._compile (node:internal/modules/cjs/loader:1095:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1124:10)
at Module.load (node:internal/modules/cjs/loader:975:32)
at Function.Module._load (node:internal/modules/cjs/loader:816:12)
at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:12)
at node:internal/main/run_main_module:17:47 {
code: ‘ERR_CRYPTO_OPERATION_FAILED’
}
参考： https://nodejs.org/api/crypto.html#crypto_ecdh_setpublickey_publickey_encoding