超文本傳輸安全協(xié)議（英語：Hypertext Transfer Protocol Secure扼褪，縮寫：HTTPS，也被稱為HTTP over TLS啸胧，HTTP over SSL或HTTP Secure）是一種網(wǎng)絡安全傳輸協(xié)議。

OkHttp：Java 平臺上的新一代 HTTP 客戶端

安卓官方文檔 https://developer.android.google.cn/develop/index.html

Chrome 中通過 HTTPS 加載的頁面百分比

一個 HTTPS 示例

假設您有一個由知名 CA 發(fā)放證書的網(wǎng)絡服務器，那么，您可以使用如下簡單代碼發(fā)起安全的請求：

URL url = new URL("https://wikipedia.org");
URLConnection urlConnection = url.openConnection();
InputStream in = urlConnection.getInputStream();
copyInputStreamToOutputStream(in, System.out);

使用未知的證書頒發(fā)機構或者自簽署的服務器證書可以參考官方文檔拷泽，中文的喲
https://developer.android.google.cn/training/articles/security-ssl.html

Retrofit OkHttp HTTPS

官方 WIKI 關于使用 HTTPS 的介紹 https://github.com/square/okhttp/wiki/HTTPS

Show Code CustomTrust

import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.util.Arrays;
import java.util.Collection;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

import okhttp3.CertificatePinner;
import okio.Buffer;

public final class CustomTrust {

    public final X509TrustManager trustManager;
    public final SSLSocketFactory sslSocketFactory;

    public CustomTrust() {
        try {
            trustManager = trustManagerForCertificates(trustedCertificatesInputStream());
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, new TrustManager[]{trustManager}, null);
            sslSocketFactory = sslContext.getSocketFactory();
        } catch (GeneralSecurityException e) {
            throw new RuntimeException(e);
        }
    }

    /**
    * Returns an input stream containing one or more certificate PEM files. This implementation just
    * embeds the PEM files in Java strings; most applications will instead read this from a resource
    * file that gets bundled with the application.
    */
    private InputStream trustedCertificatesInputStream() {
        // PEM files for root certificates of Comodo and Entrust. These two CAs are sufficient to view
        // https://publicobject.com (Comodo) and https://squareup.com (Entrust). But they aren't
        // sufficient to connect to most HTTPS sites including https://godaddy.com and https://visa.com.
        // Typically developers will need to get a PEM file from their organization's TLS administrator.
        String comodoRsaCertificationAuthority = ""
                + "-----BEGIN CERTIFICATE-----\n"
                + "MIIF2DCCA8CgAwIBAgIQTKr5yttjb+Af907YWwOGnTANBgkqhkiG9w0BAQwFADCB\n"
                + "hTELMAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4G\n"
                + "A1UEBxMHU2FsZm9yZDEaMBgGA1UEChMRQ09NT0RPIENBIExpbWl0ZWQxKzApBgNV\n"
                + "BAMTIkNPTU9ETyBSU0EgQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkwHhcNMTAwMTE5\n"
                + "MDAwMDAwWhcNMzgwMTE4MjM1OTU5WjCBhTELMAkGA1UEBhMCR0IxGzAZBgNVBAgT\n"
                + "EkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR\n"
                + "Q09NT0RPIENBIExpbWl0ZWQxKzApBgNVBAMTIkNPTU9ETyBSU0EgQ2VydGlmaWNh\n"
                + "dGlvbiBBdXRob3JpdHkwggIiMA0GCSqGSIb3DQEBAQUAA4ICDwAwggIKAoICAQCR\n"
                + "6FSS0gpWsawNJN3Fz0RndJkrN6N9I3AAcbxT38T6KhKPS38QVr2fcHK3YX/JSw8X\n"
                + "pz3jsARh7v8Rl8f0hj4K+j5c+ZPmNHrZFGvnnLOFoIJ6dq9xkNfs/Q36nGz637CC\n"
                + "9BR++b7Epi9Pf5l/tfxnQ3K9DADWietrLNPtj5gcFKt+5eNu/Nio5JIk2kNrYrhV\n"
                + "/erBvGy2i/MOjZrkm2xpmfh4SDBF1a3hDTxFYPwyllEnvGfDyi62a+pGx8cgoLEf\n"
                + "Zd5ICLqkTqnyg0Y3hOvozIFIQ2dOciqbXL1MGyiKXCJ7tKuY2e7gUYPDCUZObT6Z\n"
                + "+pUX2nwzV0E8jVHtC7ZcryxjGt9XyD+86V3Em69FmeKjWiS0uqlWPc9vqv9JWL7w\n"
                + "qP/0uK3pN/u6uPQLOvnoQ0IeidiEyxPx2bvhiWC4jChWrBQdnArncevPDt09qZah\n"
                + "SL0896+1DSJMwBGB7FY79tOi4lu3sgQiUpWAk2nojkxl8ZEDLXB0AuqLZxUpaVIC\n"
                + "u9ffUGpVRr+goyhhf3DQw6KqLCGqR84onAZFdr+CGCe01a60y1Dma/RMhnEw6abf\n"
                + "Fobg2P9A3fvQQoh/ozM6LlweQRGBY84YcWsr7KaKtzFcOmpH4MN5WdYgGq/yapiq\n"
                + "crxXStJLnbsQ/LBMQeXtHT1eKJ2czL+zUdqnR+WEUwIDAQABo0IwQDAdBgNVHQ4E\n"
                + "FgQUu69+Aj36pvE8hI6t7jiY7NkyMtQwDgYDVR0PAQH/BAQDAgEGMA8GA1UdEwEB\n"
                + "/wQFMAMBAf8wDQYJKoZIhvcNAQEMBQADggIBAArx1UaEt65Ru2yyTUEUAJNMnMvl\n"
                + "wFTPoCWOAvn9sKIN9SCYPBMtrFaisNZ+EZLpLrqeLppysb0ZRGxhNaKatBYSaVqM\n"
                + "4dc+pBroLwP0rmEdEBsqpIt6xf4FpuHA1sj+nq6PK7o9mfjYcwlYRm6mnPTXJ9OV\n"
                + "2jeDchzTc+CiR5kDOF3VSXkAKRzH7JsgHAckaVd4sjn8OoSgtZx8jb8uk2Intzna\n"
                + "FxiuvTwJaP+EmzzV1gsD41eeFPfR60/IvYcjt7ZJQ3mFXLrrkguhxuhoqEwWsRqZ\n"
                + "CuhTLJK7oQkYdQxlqHvLI7cawiiFwxv/0Cti76R7CZGYZ4wUAc1oBmpjIXUDgIiK\n"
                + "boHGhfKppC3n9KUkEEeDys30jXlYsQab5xoq2Z0B15R97QNKyvDb6KkBPvVWmcke\n"
                + "jkk9u+UJueBPSZI9FoJAzMxZxuY67RIuaTxslbH9qh17f4a+Hg4yRvv7E491f0yL\n"
                + "S0Zj/gA0QHDBw7mh3aZw4gSzQbzpgJHqZJx64SIDqZxubw5lT2yHh17zbqD5daWb\n"
                + "QOhTsiedSrnAdyGN/4fy3ryM7xfft0kL0fJuMAsaDk527RH89elWsn2/x20Kk4yl\n"
                + "0MC2Hb46TpSi125sC8KKfPog88Tk5c0NqMuRkrF8hey1FGlmDoLnzc7ILaZRfyHB\n"
                + "NVOFBkpdn627G190\n"
                + "-----END CERTIFICATE-----\n";
        String entrustRootCertificateAuthority = ""
                + "-----BEGIN CERTIFICATE-----\n"
                + "MIIEkTCCA3mgAwIBAgIERWtQVDANBgkqhkiG9w0BAQUFADCBsDELMAkGA1UEBhMC\n"
                + "VVMxFjAUBgNVBAoTDUVudHJ1c3QsIEluYy4xOTA3BgNVBAsTMHd3dy5lbnRydXN0\n"
                + "Lm5ldC9DUFMgaXMgaW5jb3Jwb3JhdGVkIGJ5IHJlZmVyZW5jZTEfMB0GA1UECxMW\n"
                + "KGMpIDIwMDYgRW50cnVzdCwgSW5jLjEtMCsGA1UEAxMkRW50cnVzdCBSb290IENl\n"
                + "cnRpZmljYXRpb24gQXV0aG9yaXR5MB4XDTA2MTEyNzIwMjM0MloXDTI2MTEyNzIw\n"
                + "NTM0MlowgbAxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1FbnRydXN0LCBJbmMuMTkw\n"
                + "NwYDVQQLEzB3d3cuZW50cnVzdC5uZXQvQ1BTIGlzIGluY29ycG9yYXRlZCBieSBy\n"
                + "ZWZlcmVuY2UxHzAdBgNVBAsTFihjKSAyMDA2IEVudHJ1c3QsIEluYy4xLTArBgNV\n"
                + "BAMTJEVudHJ1c3QgUm9vdCBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTCCASIwDQYJ\n"
                + "KoZIhvcNAQEBBQADggEPADCCAQoCggEBALaVtkNC+sZtKm9I35RMOVcF7sN5EUFo\n"
                + "Nu3s/poBj6E4KPz3EEZmLk0eGrEaTsbRwJWIsMn/MYszA9u3g3s+IIRe7bJWKKf4\n"
                + "4LlAcTfFy0cOlypowCKVYhXbR9n10Cv/gkvJrT7eTNuQgFA/CYqEAOwwCj0Yzfv9\n"
                + "KlmaI5UXLEWeH25DeW0MXJj+SKfFI0dcXv1u5x609mhF0YaDW6KKjbHjKYD+JXGI\n"
                + "rb68j6xSlkuqUY3kEzEZ6E5Nn9uss2rVvDlUccp6en+Q3X0dgNmBu1kmwhH+5pPi\n"
                + "94DkZfs0Nw4pgHBNrziGLp5/V6+eF67rHMsoIV+2HNjnogQi+dPa2MsCAwEAAaOB\n"
                + "sDCBrTAOBgNVHQ8BAf8EBAMCAQYwDwYDVR0TAQH/BAUwAwEB/zArBgNVHRAEJDAi\n"
                + "gA8yMDA2MTEyNzIwMjM0MlqBDzIwMjYxMTI3MjA1MzQyWjAfBgNVHSMEGDAWgBRo\n"
                + "kORnpKZTgMeGZqTx90tD+4S9bTAdBgNVHQ4EFgQUaJDkZ6SmU4DHhmak8fdLQ/uE\n"
                + "vW0wHQYJKoZIhvZ9B0EABBAwDhsIVjcuMTo0LjADAgSQMA0GCSqGSIb3DQEBBQUA\n"
                + "A4IBAQCT1DCw1wMgKtD5Y+iRDAUgqV8ZyntyTtSx29CW+1RaGSwMCPeyvIWonX9t\n"
                + "O1KzKtvn1ISMY/YPyyYBkVBs9F8U4pN0wBOeMDpQ47RgxRzwIkSNcUesyBrJ6Zua\n"
                + "AGAT/3B+XxFNSRuzFVJ7yVTav52Vr2ua2J7p8eRDjeIRRDq/r72DQnNSi6q7pynP\n"
                + "9WQcCk3RvKqsnyrQ/39/2n3qse0wJcGE2jTSW3iDVuycNsMm4hH2Z0kdkquM++v/\n"
                + "eu6FSqdQgPCnXEqULl8FmTxSQeDNtGPPAUO6nIPcj2A781q0tHuu2guQOHXvgR1m\n"
                + "0vdXcDazv/wor3ElhVsT/h5/WrQ8\n"
                + "-----END CERTIFICATE-----\n";
        return new Buffer()
                .writeUtf8(comodoRsaCertificationAuthority)
                .writeUtf8(entrustRootCertificateAuthority)
                .inputStream();
    }

    /**
    * Returns a trust manager that trusts {@code certificates} and none other. HTTPS services whose
    * certificates have not been signed by these certificates will fail with a {@code
    * SSLHandshakeException}.
    * <p>
    * <p>This can be used to replace the host platform's built-in trusted certificates with a custom
    * set. This is useful in development where certificate authority-trusted certificates aren't
    * available. Or in production, to avoid reliance on third-party certificate authorities.
    * <p>
    * <p>See also {@link CertificatePinner}, which can limit trusted certificates while still using
    * the host platform's built-in trust store.
    * <p>
    * <h3>Warning: Customizing Trusted Certificates is Dangerous!</h3>
    * <p>
    * <p>Relying on your own trusted certificates limits your server team's ability to update their
    * TLS certificates. By installing a specific set of trusted certificates, you take on additional
    * operational complexity and limit your ability to migrate between certificate authorities. Do
    * not use custom trusted certificates in production without the blessing of your server's TLS
    * administrator.
    */
    private X509TrustManager trustManagerForCertificates(InputStream in)
            throws GeneralSecurityException {
        CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
        Collection<? extends Certificate> certificates = certificateFactory.generateCertificates(in);
        if (certificates.isEmpty()) {
            throw new IllegalArgumentException("expected non-empty set of trusted certificates");
        }

        // Put the certificates a key store.
        char[] password = "password".toCharArray(); // Any password will work.
        KeyStore keyStore = newEmptyKeyStore(password);
        int index = 0;
        for (Certificate certificate : certificates) {
            String certificateAlias = Integer.toString(index++);
            keyStore.setCertificateEntry(certificateAlias, certificate);
        }

        // Use it to build an X509 trust manager.
        KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(
                KeyManagerFactory.getDefaultAlgorithm());
        keyManagerFactory.init(keyStore, password);
        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(
                TrustManagerFactory.getDefaultAlgorithm());
        trustManagerFactory.init(keyStore);
        TrustManager[] trustManagers = trustManagerFactory.getTrustManagers();
        if (trustManagers.length != 1 || !(trustManagers[0] instanceof X509TrustManager)) {
            throw new IllegalStateException("Unexpected default trust managers:"
                    + Arrays.toString(trustManagers));
        }
        return (X509TrustManager) trustManagers[0];
    }

    private KeyStore newEmptyKeyStore(char[] password) throws GeneralSecurityException {
        try {
            KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
            InputStream in = null; // By convention, 'null' creates an empty key store.
            keyStore.load(in, password);
            return keyStore;
        } catch (IOException e) {
            throw new AssertionError(e);
        }
    }

}

構建客戶端

static RequestService newClient() {
    CustomTrust ct = new CustomTrust();
    OkHttpClient client = new OkHttpClient.Builder()
            .addInterceptor(chain -> {
                // 請求頭
                Request request = chain.request().newBuilder()
                        .addHeader("X-CRM-Application-Id", RequestConstants.APPLICATION_ID)
                        .addHeader("X-CRM-Version", RequestConstants.VERSION)
                        .addHeader("Content-Type", RequestConstants.JSON_TYPE)
                        .build();
                return chain.proceed(request);
            })
            // 超時時間
            .readTimeout(5, TimeUnit.MINUTES)
            .connectTimeout(5, TimeUnit.MINUTES)
            // HTTPS
            .sslSocketFactory(ct.sslSocketFactory, ct.trustManager)
            // Hostname domain.com not verified
            .hostnameVerifier((s, sslSession) -> true)
            .build();

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(RequestConstants.BASE_URL)
            .client(client)
             // FastJson
            .addConverterFactory(FastJsonConvertFactory.create())
             // RxJava2
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .build();

    return retrofit.create(RequestService.class);
}

參考資料：

• HTTP將被標為不安全
• 向越來越多的HTTPS致敬疫鹊！
• OkHttp 示例代碼