java – 证书注册过程

1)客户端生成密钥对,私有和公共密钥对

2)客户端生成CSR(证书签名请求),其包括诸如公共名称和公钥之类的属性.使用私钥对其进行签名并将其发送到服务器

3)服务器使用CSR数据构建X509证书,使用CA私钥对其进行处理并将X509返回给客户端

4)客户端将私钥和证书存储在KeyStore中

What CA generate?

x509证书

What is P12 file

包含密钥库的PKCS#12格式(.pfx,.p12)文件

what is .cer file contain

DER或PEM格式的证书(非私钥)的公共部分

已编辑 – Android上的CSR生成

Gradle依赖项

compile 'com.madgag.spongycastle:core:1.51.0.0'
compile 'com.madgag.spongycastle:pkix:1.51.0.0'

生成KeyPair和CSR

//Generate KeyPair
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(KEY_SIZE,new SecureRandom());
KeyPair keyPair = keyGen.generateKeyPair();

//Generate CSR in PKCS#10 format encoded in DER
PKCS10CertificationRequest csr = CsrHelper.generateCSR(keyPair,commonname);
byte  CSRder[] = csr.getEncoded();

公用事业

public class CsrHelper {

  private final static String DEFAULT_SIGNATURE_ALGORITHM = "SHA256withRSA";
  private final static String CN_PATTERN = "CN=%s,O=Aralink,OU=OrgUnit";

  private static class JCESigner implements ContentSigner {

        private static Map<String,AlgorithmIdentifier> ALGOS = new HashMap<String,AlgorithmIdentifier>();

        static {
            ALGOS.put("SHA256withRSA".toLowerCase(),new AlgorithmIdentifier(
                    new ASN1ObjectIdentifier("1.2.840.113549.1.1.11")));
            ALGOS.put("SHA1withRSA".toLowerCase(),new AlgorithmIdentifier(
                    new ASN1ObjectIdentifier("1.2.840.113549.1.1.5")));

        }

        private String mAlgo;
        private Signature signature;
        private ByteArrayOutputStream outputStream;

        public JCESigner(PrivateKey privateKey,String sigAlgo) {
            //Utils.throwIfNull(privateKey,sigAlgo);
            mAlgo = sigAlgo.toLowerCase();
            try {
                this.outputStream = new ByteArrayOutputStream();
                this.signature = Signature.getInstance(sigAlgo);
                this.signature.initSign(privateKey);
            } catch (GeneralSecurityException gse) {
                throw new IllegalArgumentException(gse.getMessage());
            }
        }

        @Override
        public AlgorithmIdentifier getAlgorithmIdentifier() {
            AlgorithmIdentifier id = ALGOS.get(mAlgo);
            if (id == null) {
                throw new IllegalArgumentException("Does not support algo: " +
                        mAlgo);
            }
            return id;
        }

        @Override
        public OutputStream getOutputStream() {
            return outputStream;
        }

        @Override
        public byte[] getSignature() {
            try {
                signature.update(outputStream.toByteArray());
                return signature.sign();
            } catch (GeneralSecurityException gse) {
                gse.printStackTrace();
                return null;
            }
        }
    }

//Create the certificate signing request (CSR) from private and public keys
public static PKCS10CertificationRequest generateCSR(KeyPair keyPair,String cn) throws IOException,OperatorCreationException {
        String principal = String.format(CN_PATTERN,cn);

        ContentSigner signer = new JCESigner (keyPair.getPrivate(),DEFAULT_SIGNATURE_ALGORITHM);

        PKCS10CertificationRequestBuilder csrBuilder = new JcaPKCS10CertificationRequestBuilder(
                new X500Name(principal),keyPair.getPublic());
        ExtensionsGenerator extensionsGenerator = new ExtensionsGenerator();
        extensionsGenerator.addExtension(Extension.basicConstraints,true,new BasicConstraints(
                true));
        csrBuilder.addAttribute(PKCSObjectIdentifiers.pkcs_9_at_extensionRequest,extensionsGenerator.generate());
        PKCS10CertificationRequest csr = csrBuilder.build(signer);

        return csr;
    }
}