※系統環境：
openssl 1.0.2g
Java8

※狀況概述：
我設計一個網頁來作認証使用，由網頁端提供私鑰與隨機字串，
讓使用者用私鑰來加密字串後，再傳回網頁端並使用公鑰來解密進行認證。

目前我在網頁端(Java)進行加密/解密測試都可以正常運作，但在模擬客戶端測試時，
由客戶端使用openssl用私鑰加密字串傳回網頁端時，發現網頁端解密都會失敗。

※程式碼：
網頁端產生私鑰:
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();

Base64.getEncoder().encodeToString(rsaPrivateKey.getEncoded()); //私鑰
Base64.getEncoder().encodeToString(rsaPublicKey.getEncoded()); //公鑰

網頁端(Java):
String PRIVATE_KEY = "MII........vCF4="; //私鑰
String PUBLIC_KEY = "MII.......wIDAQAB";//公鑰
String STRING = "u8xeve.....x82NA=="; //加密過後字串
String str = "XXXXXX"; //隨機字串
byte[] result;

//[測試] 私鑰加密
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(PRIVATE_KEY));
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-256AndMGF1Padding");
OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT);
cipher.init(Cipher.ENCRYPT_MODE, privateKey, oaepParameterSpec);
result = cipher.doFinal(Base64.getDecoder().decode(str));
System.out.println("Result : " + Base64.getEncoder().encodeToString(result));

//公鑰解密
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(PUBLIC_KEY));
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-256AndMGF1Padding");
OAEPParameterSpec oaepParameterSpec = new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT);
cipher.init(Cipher.DECRYPT_MODE, publicKey, oaepParameterSpec);
result = cipher.doFinal(STRING.getBytes());
System.out.println("Result : " + Base64.getEncoder().encodeToString(result));


客戶端(openssl):
# encr.txt - 隨機字串
# private.pem - 私鑰(需要在檔案開頭與結尾各加上
# '-----BEGIN PRIVATE KEY-----'與'-----END PRIVATE KEY-----')

openssl pkeyutl -in encr.txt -encrypt -inkey private.pem \
-pkeyopt rsa_padding_mode:oaep -pkeyopt rsa_oaep_md:sha256 \
-pkeyopt rsa_mgf1_md:sha256 |openssl base64

※錯誤訊息：
cipher.doFinal(Base64.getDecoder().decode(str)) <-- unable to decrypt block

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※ 編輯: kuangs (59.115.97.79 臺灣), 12/31/2019 14:48:17
※ 編輯: kuangs (59.115.97.79 臺灣), 12/31/2019 14:50:02