Luckily, the solution is simple. Open a terminal and execute the following commands
The first command retrieves the certificate from libraries.minecraft.net, the second imports it into the java certificate store.
- echo -n | openssl s_client -connect libraries.minecraft.net:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/minecraft.crt
- sudo keytool -import -trustcacerts -keystore /etc/ssl/certs/java/cacerts -storepass changeit -noprompt -alias mycert -file /tmp/minecraft.crt
reference: http://stackoverflow.com/questions/11617210/how-to-properly-import-a-selfsigned-certificate-into-java-keystore-that-is-avail
Detailed error log before the fix:
[20:52:56 WARN]: Couldn't download https://libraries.minecraft.net/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.jar for job 'Version & Libraries' javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.ssl.Alerts.getSSLException(Alerts.java:192) ~[?:1.8.0_45] at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1937) ~[?:1.8.0_45] at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) ~[?:1.8.0_45] at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) ~[?:1.8.0_45] at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1478) ~[?:1.8.0_45] at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:212) ~[?:1.8.0_45] at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979) ~[?:1.8.0_45] at sun.security.ssl.Handshaker.process_record(Handshaker.java:914) ~[?:1.8.0_45] at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1050) ~[?:1.8.0_45] at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1363) ~[?:1.8.0_45] at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1391) ~[?:1.8.0_45] at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1375) ~[?:1.8.0_45] at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563) ~[?:1.8.0_45] at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185) ~[?:1.8.0_45] at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1512) ~[?:1.8.0_45] at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440) ~[?:1.8.0_45] at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) ~[?:1.8.0_45] at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338) ~[?:1.8.0_45] at com.mojang.launcher.updater.download.ChecksummedDownloadable.download(ChecksummedDownloadable.java:49) ~[launcher_mcpatched.jar:?] at com.mojang.launcher.updater.download.DownloadJob.popAndDownload(DownloadJob.java:109) [launcher_mcpatched.jar:?] at com.mojang.launcher.updater.download.DownloadJob.access$000(DownloadJob.java:12) [launcher_mcpatched.jar:?] at com.mojang.launcher.updater.download.DownloadJob$1.run(DownloadJob.java:86) [launcher_mcpatched.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_45] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_45] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_45] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_45] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45] Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:387) ~[?:1.8.0_45] at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292) ~[?:1.8.0_45] at sun.security.validator.Validator.validate(Validator.java:260) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124) ~[?:1.8.0_45] at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1460) ~[?:1.8.0_45] ... 22 more Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:145) ~[?:1.8.0_45] at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131) ~[?:1.8.0_45] at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280) ~[?:1.8.0_45] at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382) ~[?:1.8.0_45] at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292) ~[?:1.8.0_45] at sun.security.validator.Validator.validate(Validator.java:260) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229) ~[?:1.8.0_45] at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124) ~[?:1.8.0_45] at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1460) ~[?:1.8.0_45] ... 22 more [20:52:56 ERROR]: Gave up trying to download https://libraries.minecraft.net/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.jar for job 'Version & Libraries' [20:52:56 ERROR]: Job 'Version & Libraries' finished with 31 failure(s)! (took 0:00:02.233)
