Bouncy Castle ECIES压缩格式

Question

Cipher iesCipher = Cipher.getInstance("ECIESWITHAES-CBC");
iesCipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] ciphertext = iesCipher.doFinal(plaintext);

0x04 || coordinate x || coordinate y || PKCS5 padded ciphertext || 20-byte HMAC-digest

Answer 1

我通过将BCIESParameterSpec中的UsePointCompress标志设置为True来解决这一问题。

点压缩标志默认为false。

不幸的是，这个标志不是他们的ECIESTest的一部分，所以我使用了他们的加密模式配置（派生、编码和初始化向量）来试用标志：

byte[] derivation = Hex.decode("202122232425262728292a2b2c2d2e2f");
byte[] encoding = Hex.decode("303132333435363738393a3b3c3d3e3f");
byte[] nonce = Hex.decode("000102030405060708090a0b0c0d0e0f");

Cipher c = Cipher.getInstance("ECIESwithAES-CBC", "BC");
IESParameterSpec params = new IESParameterSpec(derivation, encoding, 128, 128, nonce, true);
c.init(Cipher.ENCRYPT_MODE, publicKey, params);
byte[] ciphertext = c.doFinal(plaintext);

0x02 || coordinate x || PKCS5 padded ciphertext || 20-byte HMAC-digest
0x03 || coordinate x || PKCS5 padded ciphertext || 20-byte HMAC-digest