我认为 JCA 替代 JCE 很简单。然而，编写一些测试代码来获取我系统上的所有提供程序表明情况并非如此。

我注意到以下几点:

1. 一些算法有多个提供者(例如:MD5withRSA 在 SunRsaSign 以及 SunJSSE 中)
2. JCA 似乎有类型 的算法，这些算法超出了 JCE 的范围

第 1 项很有意义，因为 JCA(对我而言)是一个可供选择的 JCE 提供程序库/数组。

第 2 项有点令人困惑，因为它表明 JCA 并不是一组“相同”的 JCE 提供者；对于任何“种类”的提供者，无论是否连接 JCE，它都是某种形式的水坑。

那么，JCA、它的提供者和 JCE 之间的工作关系是什么？这些提供商是否也存在于独立的孤岛中，或者它们是否相互“构建”/相互依赖？

对于那些对代码和提示这个问题的结果感兴趣的人，下面列出了它

import java.security.Provider;
import java.security.Security;
import java.util.ArrayList;

public class ConsoleListJca 
{
    public static void main(String[] args) 
    {
        for (Provider provider : Security.getProviders()) 
        {
            System.out.println("Provider: " + provider.getName() + " (ver " + provider.getVersion() + ")");
            System.out.print("  Algorithms: ");
            ArrayList<String> algos = new ArrayList<String>();
            for (Provider.Service service : provider.getServices()) 
            {
                algos.add(String.format( "%s (%s)", service.getAlgorithm(), service.getType()));
            }
            java.util.Collections.sort(algos);
            String algorsStr = algos.toString();
            // remove [ and ] from ArrayList's toString()
            algorsStr = algorsStr.substring(1, algorsStr.length()-1); 
            System.out.println(algorsStr);
            System.out.println();
        }
    }
}

结果(针对 SO 格式化)是

Provider: SUN (ver 1.7)
  Algorithms: CaseExactJKS (KeyStore), Collection (CertStore), DSA (AlgorithmParameterGenerator), 
              DSA (AlgorithmParameters), DSA (KeyFactory), DSA (KeyPairGenerator), 
              JKS (KeyStore), JavaLoginConfig (Configuration), JavaPolicy (Policy), 
              LDAP (CertStore), MD2 (MessageDigest), MD5 (MessageDigest), NONEwithDSA (Signature), 
              NativePRNG (SecureRandom), PKIX (CertPathBuilder), PKIX (CertPathValidator), 
              SHA (MessageDigest), SHA-256 (MessageDigest), SHA-384 (MessageDigest), 
              SHA-512 (MessageDigest), SHA1PRNG (SecureRandom), SHA1withDSA (Signature), 
              X.509 (CertificateFactory), com.sun.security.IndexedCollection (CertStore)

Provider: SunRsaSign (ver 1.7)
  Algorithms: MD2withRSA (Signature), MD5withRSA (Signature), RSA (KeyFactory), RSA (KeyPairGenerator), 
              SHA1withRSA (Signature), SHA256withRSA (Signature), SHA384withRSA (Signature), 
              SHA512withRSA (Signature)

Provider: SunEC (ver 1.7)
  Algorithms: EC (AlgorithmParameters), EC (KeyFactory), EC (KeyPairGenerator), ECDH (KeyAgreement), 
              NONEwithECDSA (Signature), SHA1withECDSA (Signature), SHA256withECDSA (Signature), 
              SHA384withECDSA (Signature), SHA512withECDSA (Signature)

Provider: SunJSSE (ver 1.7)
  Algorithms: Default (SSLContext), MD2withRSA (Signature), MD5andSHA1withRSA (Signature), 
              MD5withRSA (Signature), NewSunX509 (KeyManagerFactory), PKCS12 (KeyStore), 
              PKIX (TrustManagerFactory), RSA (KeyFactory), RSA (KeyPairGenerator), 
              SHA1withRSA (Signature), SunX509 (KeyManagerFactory), SunX509 (TrustManagerFactory), 
              TLSv1 (SSLContext), TLSv1.1 (SSLContext), TLSv1.2 (SSLContext)

Provider: SunJCE (ver 1.7)
  Algorithms: AES (AlgorithmParameters), AES (Cipher), AES (KeyGenerator), AESWrap (Cipher), 
              ARCFOUR (Cipher), ARCFOUR (KeyGenerator), Blowfish (AlgorithmParameters), 
              Blowfish (Cipher), Blowfish (KeyGenerator), DES (AlgorithmParameters), 
              DES (Cipher), DES (KeyGenerator), DES (SecretKeyFactory), DESede (AlgorithmParameters), 
              DESede (Cipher), DESede (KeyGenerator), DESede (SecretKeyFactory), DESedeWrap (Cipher), 
              DiffieHellman (AlgorithmParameterGenerator), DiffieHellman (AlgorithmParameters), 
              DiffieHellman (KeyAgreement), DiffieHellman (KeyFactory), 
              DiffieHellman (KeyPairGenerator), HmacMD5 (KeyGenerator), HmacMD5 (Mac), 
              HmacPBESHA1 (Mac), HmacSHA1 (KeyGenerator), HmacSHA1 (Mac), HmacSHA256 (KeyGenerator), 
              HmacSHA256 (Mac), HmacSHA384 (KeyGenerator), HmacSHA384 (Mac), HmacSHA512 (KeyGenerator), 
              HmacSHA512 (Mac), JCEKS (KeyStore), OAEP (AlgorithmParameters), PBE (AlgorithmParameters), 
              PBEWithMD5AndDES (AlgorithmParameters), PBEWithMD5AndDES (Cipher), 
              PBEWithMD5AndDES (SecretKeyFactory), PBEWithMD5AndTripleDES (AlgorithmParameters), 
              PBEWithMD5AndTripleDES (Cipher), PBEWithMD5AndTripleDES (SecretKeyFactory), 
              PBEWithSHA1AndDESede (AlgorithmParameters), PBEWithSHA1AndDESede (Cipher), 
              PBEWithSHA1AndDESede (SecretKeyFactory), PBEWithSHA1AndRC2_40 (AlgorithmParameters), 
              PBEWithSHA1AndRC2_40 (Cipher), PBEWithSHA1AndRC2_40 (SecretKeyFactory), 
              PBKDF2WithHmacSHA1 (SecretKeyFactory), RC2 (AlgorithmParameters), RC2 (Cipher), 
              RC2 (KeyGenerator), RSA (Cipher), SslMacMD5 (Mac), SslMacSHA1 (Mac), 
              SunTls12Prf (KeyGenerator), SunTlsKeyMaterial (KeyGenerator), SunTlsMasterSecret (KeyGenerator), 
              SunTlsPrf (KeyGenerator), SunTlsRsaPremasterSecret (KeyGenerator)

Provider: SunJGSS (ver 1.7)
  Algorithms: 1.2.840.113554.1.2.2 (GssApiMechanism), 1.3.6.1.5.5.2 (GssApiMechanism)

Provider: SunSASL (ver 1.7)
  Algorithms: CRAM-MD5 (SaslClientFactory), CRAM-MD5 (SaslServerFactory), DIGEST-MD5 (SaslClientFactory), 
              DIGEST-MD5 (SaslServerFactory), EXTERNAL (SaslClientFactory), GSSAPI (SaslClientFactory), 
              GSSAPI (SaslServerFactory), NTLM (SaslClientFactory), NTLM (SaslServerFactory), PLAIN (SaslClientFactory)

Provider: XMLDSig (ver 1.0)
  Algorithms: DOM (KeyInfoFactory), DOM (XMLSignatureFactory), 
              http://www.w3.org/2000/09/xmldsig#base64 (TransformService), 
              http://www.w3.org/2000/09/xmldsig#enveloped-signature (TransformService), 
              http://www.w3.org/2001/10/xml-exc-c14n# (TransformService), 
              http://www.w3.org/2001/10/xml-exc-c14n#WithComments (TransformService), 
              http://www.w3.org/2002/06/xmldsig-filter2 (TransformService), 
              http://www.w3.org/2006/12/xml-c14n11 (TransformService), 
              http://www.w3.org/2006/12/xml-c14n11#WithComments (TransformService), 
              http://www.w3.org/TR/1999/REC-xpath-19991116 (TransformService), 
              http://www.w3.org/TR/1999/REC-xslt-19991116 (TransformService), 
              http://www.w3.org/TR/2001/REC-xml-c14n-20010315 (TransformService), 
              http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments (TransformService)

Provider: SunPCSC (ver 1.7)
  Algorithms: PC/SC (TerminalFactory)

Provider: Apple (ver 1.1)
  Algorithms: KeychainStore (KeyStore)

最佳答案

JCA 和 JCE 的基本区别在于 JCE 是 JCA 的扩展，而不是替代品。 JCA 包括类似 MessageDigest 的类, SecureRandom , KeyFactory , Signature和 KeyStore . JCE添加更多的密码学类别，例如 Cipher , KeyGeneration , Mac和 KeyGeneration . JCA 和 JCE 之间的区别在很大程度上已经消失，因为 JCE 随标准运行时一起提供已有一段时间了。

JCA/JCE旨在将加密实现与抽象分开。它是一个基于提供商的架构，您可以在其中插入您选择的提供商，例如 BouncyCastle ，它比标准 Java 运行时中包含的提供程序提供的加密算法支持更多。

关于java - JCA、它的提供者和 JCE 之间的关系？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21029527/