ecdh.setPublicKey(publicKey[, encoding])

• publicKey <string> | <Buffer> | <TypedArray> | <DataView>
• encoding <string> publicKey 字符串的编码。

设置 EC Diffie-Hellman 公钥。 如果提供了 encoding，则 publicKey 应该是字符串；否则应为 Buffer、TypedArray 或 DataView。

通常没有理由调用这个方法，因为 ECDH 只需要一个私钥和对方的公钥来计算共享秘密。 通常会调用 ecdh.generateKeys() 或 ecdh.setPrivateKey()。 ecdh.setPrivateKey() 方法尝试生成与正在设置的私钥相关联的公共点/密钥。

示例（获取共享密钥）：

const crypto = require('crypto');
const alice = crypto.createECDH('secp256k1');
const bob = crypto.createECDH('secp256k1');

// 这是指定 Alice 以前的私钥之一的快捷方式。
// 在实际应用中使用这种可预测的私钥是不明智的。
alice.setPrivateKey(
  crypto.createHash('sha256').update('alice', 'utf8').digest()
);

// Bob 使用新生成的加密强伪随机密钥对
bob.generateKeys();

const aliceSecret = alice.computeSecret(bob.getPublicKey(), null, 'hex');
const bobSecret = bob.computeSecret(alice.getPublicKey(), null, 'hex');

// aliceSecret 和 bobSecret 应该是相同的共享秘密值
console.log(aliceSecret === bobSecret);

• publicKey <string> | <Buffer> | <TypedArray> | <DataView>
• encoding <string> The encoding of the publicKey string.

Sets the EC Diffie-Hellman public key. If encoding is provided publicKey is expected to be a string; otherwise a Buffer, TypedArray, or DataView is expected.

There is not normally a reason to call this method because ECDH only requires a private key and the other party's public key to compute the shared secret. Typically either ecdh.generateKeys() or ecdh.setPrivateKey() will be called. The ecdh.setPrivateKey() method attempts to generate the public point/key associated with the private key being set.

Example (obtaining a shared secret):

const crypto = require('crypto');
const alice = crypto.createECDH('secp256k1');
const bob = crypto.createECDH('secp256k1');

// This is a shortcut way of specifying one of Alice's previous private
// keys. It would be unwise to use such a predictable private key in a real
// application.
alice.setPrivateKey(
  crypto.createHash('sha256').update('alice', 'utf8').digest()
);

// Bob uses a newly generated cryptographically strong
// pseudorandom key pair
bob.generateKeys();

const aliceSecret = alice.computeSecret(bob.getPublicKey(), null, 'hex');
const bobSecret = bob.computeSecret(alice.getPublicKey(), null, 'hex');

// aliceSecret and bobSecret should be the same shared secret value
console.log(aliceSecret === bobSecret);