B4J Question b4j pop3 error

Beja

Expert
Licensed User
Hi,
The example used to work fine long time ago (a few years).. today it threw errors as follows.
Any advice or help appreciated.
Following is the error I received in the app window:
=====================================
04/28/2016 19:24:08: Error: (SunCertPathBuilderException) sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
=====================================

Following are the complete logs:
Program started.
Checking mails
javax.net.ssl.SSLException: Connection has been shutdown: 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.SSLSocketImpl.checkEOF(SSLSocketImpl.java:1541)
at sun.security.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1553)
at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:71)
at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141)
at java.io_OutputStreamWriter.flush(OutputStreamWriter.java:229)
at java.io.BufferedWriter.flush(BufferedWriter.java:254)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:239)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:282)
at org.apache.commons.net.pop3.POP3Client.logout(POP3Client.java:235)
at anywheresoftware.b4a.net.POPWrapper.CloseNow(POPWrapper.java:302)
at anywheresoftware.b4a.net.POPWrapper$1.run(POPWrapper.java:147)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: 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)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1497)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:212)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:928)
at sun.security.ssl.AppInputStream.read(AppInputStream.java:105)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.read(BufferedReader.java:182)
at org.apache.commons.net.io.CRLFLineReader.readLine(CRLFLineReader.java:59)
at org.apache.commons.net.pop3.POP3.__getReply(POP3.java:114)
at org.apache.commons.net.pop3.POP3._connectAction_(POP3.java:151)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:173)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:193)
at anywheresoftware.b4a.net.POPWrapper.connectIfNeeded(POPWrapper.java:114)
at anywheresoftware.b4a.net.POPWrapper.access$2(POPWrapper.java:107)
at anywheresoftware.b4a.net.POPWrapper$1.run(POPWrapper.java:133)
... 5 more
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)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1479)
... 26 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)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
... 32 more
Error: (SunCertPathBuilderException) sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
javax.net.ssl.SSLException: Connection has been shutdown: 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.SSLSocketImpl.checkEOF(SSLSocketImpl.java:1541)
at sun.security.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1553)
at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:71)
at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141)
at java.io_OutputStreamWriter.flush(OutputStreamWriter.java:229)
at java.io.BufferedWriter.flush(BufferedWriter.java:254)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:239)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:282)
at org.apache.commons.net.pop3.POP3Client.logout(POP3Client.java:235)
at anywheresoftware.b4a.net.POPWrapper.CloseNow(POPWrapper.java:302)
at anywheresoftware.b4a.net.POPWrapper$4.run(POPWrapper.java:286)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: 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)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1497)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:212)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:928)
at sun.security.ssl.AppInputStream.read(AppInputStream.java:105)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.read(BufferedReader.java:182)
at org.apache.commons.net.io.CRLFLineReader.readLine(CRLFLineReader.java:59)
at org.apache.commons.net.pop3.POP3.__getReply(POP3.java:114)
at org.apache.commons.net.pop3.POP3._connectAction_(POP3.java:151)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:173)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:193)
at anywheresoftware.b4a.net.POPWrapper.connectIfNeeded(POPWrapper.java:114)
at anywheresoftware.b4a.net.POPWrapper.access$2(POPWrapper.java:107)
at anywheresoftware.b4a.net.POPWrapper$1.run(POPWrapper.java:133)
... 5 more
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)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1479)
... 26 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)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
... 32 more
javax.net.ssl.SSLException: Connection has been shutdown: 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.SSLSocketImpl.checkEOF(SSLSocketImpl.java:1541)
at sun.security.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1553)
at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:71)
at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141)
at java.io_OutputStreamWriter.flush(OutputStreamWriter.java:229)
at java.io.BufferedWriter.flush(BufferedWriter.java:254)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:239)
at org.apache.commons.net.pop3.POP3.sendCommand(POP3.java:282)
at org.apache.commons.net.pop3.POP3Client.logout(POP3Client.java:235)
at anywheresoftware.b4a.net.POPWrapper.CloseNow(POPWrapper.java:302)
at anywheresoftware.b4a.net.POPWrapper$4.run(POPWrapper.java:286)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: 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)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1497)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:212)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:928)
at sun.security.ssl.AppInputStream.read(AppInputStream.java:105)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.read(BufferedReader.java:182)
at org.apache.commons.net.io.CRLFLineReader.readLine(CRLFLineReader.java:59)
at org.apache.commons.net.pop3.POP3.__getReply(POP3.java:114)
at org.apache.commons.net.pop3.POP3._connectAction_(POP3.java:151)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:173)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:193)
at anywheresoftware.b4a.net.POPWrapper.connectIfNeeded(POPWrapper.java:114)
at anywheresoftware.b4a.net.POPWrapper.access$2(POPWrapper.java:107)
at anywheresoftware.b4a.net.POPWrapper$1.run(POPWrapper.java:133)
... 5 more
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)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1479)
... 26 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)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
... 32 more
 

Beja

Expert
Licensed User
Thanks Bill
1- I am using yahoo mail (not gMail)
2- Windows 10 (upgrade) 64 bit
3- The app is pop3 not smtp
4- Erel's pop3 example was working fine a few years ago.. I just tried to run it again without change.
5- The only change in the dev env is the Windows and b4j versions

Best.
 
Upvote 0

billzhan

Active Member
Licensed User
It seems like a certification issue

https://www.b4x.com/android/forum/t...ndroid-using-b4j-email-app.60785/#post-383889

https://blogs.oracle.com/gc/entry/unable_to_find_valid_certification
Don't panic. All you need to do is to add the server certificate to your trusted Java key store if your client is written in Java. You might be wondering how as if you can not access the machine where the server is installed. There is a simple program can help you. Please download the Java program and run

% java InstallCert _web_site_hostname_

B4X:
java -cp InstallCert.jar InstallCert pop.mail.yahoo.com:995
 
Upvote 0
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