您可以在运行时信任特定的证书。 只需从服务器下载，放入资产，然后使用ssl-utils-android像这样加载:

OkHttpClient client = new OkHttpClient();
SSLContext sslContext = SslUtils.getSslContextForCertificateFile(context, "BPClass2RootCA-sha2.cer");
client.setSslSocketFactory(sslContext.getSocketFactory());

在上面的例子中，我使用了OkHttpClient，但是SSLContext可以用于Java中的任何客户端。

如果你有任何问题，请提出来。我是这个小图书馆的作者。

@Chrispix的解决方案是危险的!相信所有的证书允许任何人做一个人在中间攻击!只要向客户端发送任何证书，它就会接受它!

将您的证书添加到自定义信任管理器，如本文所述:通过HTTPS使用HttpClient信任所有证书

虽然使用自定义证书建立安全连接有点复杂，但它将为您带来所需的ssl加密安全，而没有中间人攻击的危险!

有时，当管理员错误地设置证书时，会发生这种情况 点击此处查看URL https://www.sslshopper.com/ssl-checker.html

在我的例子中，出现了一个错误

证书在所有浏览器中都不受信任。您可能需要安装中间证书/链证书以将其链接到受信任的根证书。了解关于此错误的更多信息。您可以按照GlobalSign针对您的服务器平台的证书安装说明来解决这个问题。注意中级证书部分。

使用https://www.ssllabs.com/ssltest/测试域。

Shihab Uddin在Kotlin的解决方案。

import java.security.SecureRandom
import java.security.cert.X509Certificate
import javax.net.ssl.*
import javax.security.cert.CertificateException

object {

    val okHttpClient: OkHttpClient
    val gson: Gson
    val retrofit: Retrofit

    init {

        okHttpClient = getOkHttpBuilder()
            // Other parameters like connectTimeout(15, TimeUnit.SECONDS)
            .build()

        gson = GsonBuilder().setLenient().create()

        retrofit = Retrofit.Builder()
            .baseUrl(BASE_URL)
            .client(okHttpClient)
            .addConverterFactory(GsonConverterFactory.create(gson))
            .build()
    }

    fun getOkHttpBuilder(): OkHttpClient.Builder =
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            OkHttpClient().newBuilder()
        } else {
            // Workaround for the error "Caused by: com.android.org.bouncycastle.jce.exception.ExtCertPathValidatorException: Could not validate certificate: Certificate expired at".
            getUnsafeOkHttpClient()
        }

    private fun getUnsafeOkHttpClient(): OkHttpClient.Builder =
        try {
            // Create a trust manager that does not validate certificate chains
            val trustAllCerts: Array<TrustManager> = arrayOf(
                object : X509TrustManager {
                    @Throws(CertificateException::class)
                    override fun checkClientTrusted(chain: Array<X509Certificate?>?,
                                                    authType: String?) = Unit

                    @Throws(CertificateException::class)
                    override fun checkServerTrusted(chain: Array<X509Certificate?>?,
                                                    authType: String?) = Unit

                    override fun getAcceptedIssuers(): Array<X509Certificate> = arrayOf()
                }
            )
            // Install the all-trusting trust manager
            val sslContext: SSLContext = SSLContext.getInstance("SSL")
            sslContext.init(null, trustAllCerts, SecureRandom())
            // Create an ssl socket factory with our all-trusting manager
            val sslSocketFactory: SSLSocketFactory = sslContext.socketFactory
            val builder = OkHttpClient.Builder()
            builder.sslSocketFactory(sslSocketFactory,
                trustAllCerts[0] as X509TrustManager)
            builder.hostnameVerifier { _, _ -> true }
            builder
        } catch (e: Exception) {
            throw RuntimeException(e)
        }
}

如果你使用Glide，同样的错误也会出现，图像不会显示。要克服它，请参阅Glide - javax.net.ssl.SSLHandshakeException: java.security. cert.certpathvalidatorexcexception:未找到认证路径的信任锚以及如何为Glide设置OkHttpClient。

@GlideModule
class MyAppGlideModule : AppGlideModule() {

    val okHttpClient = Api.getOkHttpBuilder().build() // Api is the class written above.
    // It is better to create okHttpClient here and not use Api.okHttpClient,
    // because their settings may differ. For instance, it can use its own
    // `addInterceptor` and `addNetworkInterceptor` that can affect on a read JSON.


    override fun registerComponents(context: Context, glide: Glide, registry: Registry) {
        registry.replace(GlideUrl::class.java, InputStream::class.java,
            OkHttpUrlLoader.Factory(okHttpClient))
    }
}

build.gradle:

// Glide.
implementation 'com.github.bumptech.glide:glide:4.11.0'
implementation 'com.github.bumptech.glide:okhttp3-integration:4.11.0'
kapt 'com.github.bumptech.glide:compiler:4.11.0'

更新

我还在API 16模拟器上得到了另一个错误:

SSL23_GET_SERVER_HELLO:tlsv1警报协议版本 (外部/ openssl / ssl / s23_clnt.c: 741”。

阅读1和2，我修改代码如下:

okHttpClient = getOkHttpBuilder().build()

private fun getOkHttpBuilder(): OkHttpClient.Builder {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
        Security.insertProviderAt(Conscrypt.newProvider(), 1)
    }
    return OkHttpClient().newBuilder()
}

// build.gradle:
implementation 'org.conscrypt:conscrypt-android:2.5.1'

我还从MyApplication中删除了这些行:

try {
    ProviderInstaller.installIfNeeded(applicationContext)
    val sslContext = SSLContext.getInstance("TLSv1.2")
    sslContext.init(null, null, null)
    sslContext.createSSLEngine()
} catch (e: GooglePlayServicesRepairableException) {
    Timber.e(e.stackTraceToString())
    // Prompt the user to install/update/enable Google Play services.
    GoogleApiAvailability.getInstance().showErrorNotification(this, e.connectionStatusCode)
} catch (e: GooglePlayServicesNotAvailableException) {
    Timber.e(e.stackTraceToString())
    // Prompt the user to install/update/enable Google Play services.
    // GoogleApiAvailability.getInstance().showErrorNotification(this, e.errorCode)
} catch (e: NoSuchAlgorithmException) {
    Timber.e(e.stackTraceToString())
} catch (e: KeyManagementException) {
    Timber.e(e.stackTraceToString())
}

但是这个库给apk增加了3.4 Mb。

我在从Android客户端连接到Kurento服务器时遇到了同样的问题。 Kurento服务器使用jks证书，所以我必须将pem转换为它。 作为转换的输入，我使用cert.pem文件，它会导致这样的错误。 但如果使用全链。pem，而不是cert.pem - all是OK的。

如果你使用了改装，你需要定制你的OkHttpClient。

retrofit =新的retrofit . builder () .baseUrl (ApplicationData.FINAL_URL) .build .client (getUnsafeOkHttpClient () ()) .addConverterFactory (GsonConverterFactory.create ()) .build ();

完整代码如下。

public class RestAdapter {

    private static Retrofit retrofit = null;
    private static ApiInterface apiInterface;

    public static OkHttpClient.Builder getUnsafeOkHttpClient() {
        try {
            // Create a trust manager that does not validate certificate chains
            final TrustManager[] trustAllCerts = new TrustManager[]{
                new X509TrustManager() {
                    @Override
                    public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                    }

                    @Override
                    public void checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                    }

                    @Override
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return new java.security.cert.X509Certificate[]{};
                    }
                }
            };
    
                // Install the all-trusting trust manager
                final SSLContext sslContext = SSLContext.getInstance("SSL");
                sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
    
                // Create an ssl socket factory with our all-trusting manager
                final SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();
    
                OkHttpClient.Builder builder = new OkHttpClient.Builder();
                builder.sslSocketFactory(sslSocketFactory, (X509TrustManager) trustAllCerts[0]);
                builder.hostnameVerifier(new HostnameVerifier() {
                    @Override
                    public boolean verify(String hostname, SSLSession session) {
                        return true;
                    }
                });
                return builder;
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
        
        public static ApiInterface getApiClient() {
            if (apiInterface == null) {
    
                try {
                    retrofit = new Retrofit.Builder()
                            .baseUrl(ApplicationData.FINAL_URL)
                            .client(getUnsafeOkHttpClient().build())
                            .addConverterFactory(GsonConverterFactory.create())
                            .build();
    
                } catch (Exception e) {
    
                    e.printStackTrace();
                }
    
    
                apiInterface = retrofit.create(ApiInterface.class);
            }
            return apiInterface;
        }
        
    }