Debugging : unable to find valid certification path to requested target

SSL can be a pain some times. Recently I was getting the following Exception continuously no-matter what ever certificate I import to the client-truststore. So it took the best out of me to debug and find-out the real issue behind this. In this post I'll explain how one can debug a SSL connection issue.

org.apache.axis2.AxisFault: 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 org.apache.axis2.AxisFault.makeFault(AxisFault.java:430)
 at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:78)
 at org.apache.axis2.transport.http.AxisRequestEntity.writeRequest(AxisRequestEntity.java:84)
 at org.apache.commons.httpclient.methods.EntityEnclosingMethod.writeRequestBody(EntityEnclosingMethod.java:499)
 at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2114)
 at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)
 at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
 at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
 at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
 at org.apache.axis2.transport.http.AbstractHTTPSender.executeMethod(AbstractHTTPSender.java:622)
 at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:193)
 at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
 at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:451)
 at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:278)
 at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:442)
 at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:430)
 at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:225)
 at org.apache.axis2.client.OperationClient.execute(OperationClient.java:149)
 at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:554)
 at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:530)
 at SecurityClient.runSecurityClient(SecurityClient.java:99)
 at SecurityClient.main(SecurityClient.java:34)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:483)
 at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Caused by: javax.xml.stream.XMLStreamException: 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 com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.close(XMLStreamWriterImpl.java:378)
 at org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper.close(XMLStreamWriterWrapper.java:46)
 at org.apache.axiom.om.impl.MTOMXMLStreamWriter.close(MTOMXMLStreamWriter.java:188)
 at org.apache.axiom.om.impl.dom.NodeImpl.serializeAndConsume(NodeImpl.java:844)
 at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:74)
 ... 25 more
Caused by: 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:1509)
 at sun.security.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1521)
 at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:71)
 at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
 at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
 at org.apache.commons.httpclient.ChunkedOutputStream.flush(ChunkedOutputStream.java:191)
 at com.sun.xml.internal.stream.writers.UTF8OutputStreamWriter.flush(UTF8OutputStreamWriter.java:138)
 at com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.close(XMLStreamWriterImpl.java:376)
 ... 29 more
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:1917)
 at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:301)
 at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:295)
 at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1369)
 at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:156)
 at sun.security.ssl.Handshaker.processLoop(Handshaker.java:925)
 at sun.security.ssl.Handshaker.process_record(Handshaker.java:860)
 at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1043)
 at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1343)
 at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:728)
 at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
 at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
 at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
 at org.apache.commons.httpclient.ChunkedOutputStream.flush(ChunkedOutputStream.java:191)
 at com.sun.xml.internal.stream.writers.UTF8OutputStreamWriter.flush(UTF8OutputStreamWriter.java:138)
 at com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.flush(XMLStreamWriterImpl.java:397)
 at org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper.flush(XMLStreamWriterWrapper.java:50)
 at org.apache.axiom.om.impl.MTOMXMLStreamWriter.flush(MTOMXMLStreamWriter.java:198)
 at org.apache.axiom.om.impl.dom.NodeImpl.serializeAndConsume(NodeImpl.java:842)
 ... 26 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:1351)
 ... 41 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)
 ... 47 more
org.apache.axis2.AxisFault: 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 org.apache.axis2.AxisFault.makeFault(AxisFault.java:430)
 at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:78)
 at org.apache.axis2.transport.http.AxisRequestEntity.writeRequest(AxisRequestEntity.java:84)
 at org.apache.commons.httpclient.methods.EntityEnclosingMethod.writeRequestBody(EntityEnclosingMethod.java:499)
 at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2114)
 at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)
 at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
 at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
 at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
 at org.apache.axis2.transport.http.AbstractHTTPSender.executeMethod(AbstractHTTPSender.java:622)
 at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:193)
 at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
 at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:451)
 at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:278)
 at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:442)
 at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:430)
 at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:225)
 at org.apache.axis2.client.OperationClient.execute(OperationClient.java:149)
 at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:554)
 at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:530)
 at SecurityClient.runSecurityClient(SecurityClient.java:99)
 at SecurityClient.main(SecurityClient.java:34)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:483)
 at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Caused by: javax.xml.stream.XMLStreamException: 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 com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.close(XMLStreamWriterImpl.java:378)
 at org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper.close(XMLStreamWriterWrapper.java:46)
 at org.apache.axiom.om.impl.MTOMXMLStreamWriter.close(MTOMXMLStreamWriter.java:188)
 at org.apache.axiom.om.impl.dom.NodeImpl.serializeAndConsume(NodeImpl.java:844)
 at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:74)
 ... 25 more
Caused by: 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:1509)
 at sun.security.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1521)
 at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:71)
 at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
 at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
 at org.apache.commons.httpclient.ChunkedOutputStream.flush(ChunkedOutputStream.java:191)
 at com.sun.xml.internal.stream.writers.UTF8OutputStreamWriter.flush(UTF8OutputStreamWriter.java:138)
 at com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.close(XMLStreamWriterImpl.java:376)
 ... 29 more
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:1917)
 at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:301)
 at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:295)
 at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1369)
 at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:156)
 at sun.security.ssl.Handshaker.processLoop(Handshaker.java:925)
 at sun.security.ssl.Handshaker.process_record(Handshaker.java:860)
 at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1043)
 at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1343)
 at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:728)
 at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
 at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
 at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
 at org.apache.commons.httpclient.ChunkedOutputStream.flush(ChunkedOutputStream.java:191)
 at com.sun.xml.internal.stream.writers.UTF8OutputStreamWriter.flush(UTF8OutputStreamWriter.java:138)
 at com.sun.xml.internal.stream.writers.XMLStreamWriterImpl.flush(XMLStreamWriterImpl.java:397)
 at org.apache.axiom.util.stax.wrapper.XMLStreamWriterWrapper.flush(XMLStreamWriterWrapper.java:50)
 at org.apache.axiom.om.impl.MTOMXMLStreamWriter.flush(MTOMXMLStreamWriter.java:198)
 at org.apache.axiom.om.impl.dom.NodeImpl.serializeAndConsume(NodeImpl.java:842)
 ... 26 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:1351)
 ... 41 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)
 ... 47 more
Exception in thread "main" java.lang.NullPointerException
 at SecurityClient.main(SecurityClient.java:38)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:483)
 at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

I'm assuming that you have parsed the certificate importing step which is the most common cause for this issue. You simply need to import the servers public certificate to the Java clients trust-store. To import a certificate you can use the following keytool commnad.

keytool -import -v -alias wso2 -file nginx.crt -keystore client-truststore.jks -storepass wso2carbon

Its important to know when the client is making  a SSL Connection what happens.
Following image depicts the SSL handshake process.

If you haven't enabled Mutual SSL the step 4 will be skipped in SSL handshake. When the server receives a client hello the server will reply with the servers public certificate and the client will validate whether this certificate is available in the clients trust-store to make sure the client is talking with the actual server. (To avoid Man in the Middle attack). This is where the above error will be thrown. If the client is not able to find the servers certificate in the trust-store it will break the handshake and will start complaining.


So How can we debug this issue. First let make sure that your trust-store has the actual certificate. To do that you can list all the ertificates in the client-trust store.

#If you do not know the alias

keytool -list -v -keystore keystore.jks

#If you know the alias

keytool -list -v -keystore keystore.jks -alias abc.com

If the certificate is not available we need to import the certificate. Also makesure you don't have multiple certificates with same CN  (Common Name) if you are using wildcard certificates.

So what if you have the certificate but you are still getting this issue. So lets make sure that the Server or Load Balancer is sending the correct certificate. In my case I have a NginX server running and my client is connecting through NginX.

To check the servers certificate you can use the openssl client. Simply execute the following in your terminlal.

openssl s_client -connect wso2.com:443

If everything is working correctly your certificates CN should match the servers Host name.

[yasassri@yasassri-device wso2esb-analytics-5.0.0]$ openssl s_client -connect wso2.com:443
CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance EV Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert SHA2 High Assurance Server CA
verify return:1
depth=0 C = US, ST = California, L = Palo Alto, O = "WSO2, Inc.", CN = *.wso2.com
verify return:1
---
Certificate chain
 0 s:/C=US/ST=California/L=Palo Alto/O=WSO2, Inc./CN=*.wso2.com
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=California/L=Palo Alto/O=WSO2, Inc./CN=*.wso2.com
issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
---
No client certificate CA names sent
Peer signing digest: SHA512
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 3240 bytes and written 327 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES256-GCM-SHA384
    Session-ID: 43BD18F9F2D84C05ECFF44189DBFA7E94D3FB569EDBABB79864BCE5E715698E3
    Session-ID-ctx: 
    Master-Key: 23934BED53F879565B01055F9C9FA98CF8DFA8E8E4F1C5FD07C5630D4A68C60CC7B3D15D2AC5E3DEFED7DC0A442BBEEC
    Key-Arg   : None
    Krb5 Principal: None
    PSK identity: None
    PSK identity hint: None
    TLS session ticket lifetime hint: 300 (seconds)
    TLS session ticket:
    0000 - 71 59 c8 ea 79 a8 4e 76-65 1f ed ca 8d 71 3f d3   qY..y.Nve....q?.
    0010 - f7 cd 68 b8 03 75 6d b2-73 66 e1 90 2c 22 92 fd   ..h..um.sf..,"..
    0020 - 19 7d 98 c5 0a bb 82 b1-b0 84 3b 37 c0 72 57 c3   .}........;7.rW.
    0030 - c0 e1 9d d2 bf 7d 7d 8f-ce 3e af 5d 13 4d b9 c2   .....}}..>.].M..
    0040 - bd e0 8f c9 1a 58 d3 48-8e 04 96 5c c0 50 3a a6   .....X.H...\.P:.
    0050 - bc 74 18 89 95 49 e6 d9-7d 5d 7d 1a 0b 77 56 7b   .t...I..}]}..wV{
    0060 - f5 2b 87 6c af 4a 3d 16-61 a8 f9 b5 46 e6 c2 9f   .+.l.J=.a...F...
    0070 - cb 4f 11 52 d9 30 ea 62-d3 31 49 0e 8f 32 6b 58   .O.R.0.b.1I..2kX
    0080 - 9f 45 ab db 71 7b 29 7e-24 1d 0f d8 fa 67 59 39   .E..q{)~$....gY9
    0090 - 6f f3 23 1b 43 64 c9 45-c8 7f b7 33 2e 01 e8 0a   o.#.Cd.E...3....
    00a0 - f5 85 79 64 69 b9 3c af-33 63 26 2f 36 a2 5b 63   ..ydi.<.3c&/6.[c

    Start Time: 1484740335
    Timeout   : 300 (sec)
    Verify return code: 0 (ok)
---
closed

What if your certificate is different????? Why and How? In my case I had a similar issue, my NginX server was sending me the wrong certificate. After debuging a lot it turn out, that my client is using SSLv2. So let me explain this further.

In my NginX configurations I have configured multiple certificates for multiple servers. So I figured-out that the NginX sending me the certificate of a different server. So Why?  It turns out in older days it was not possible to add multiple certificates to same IP+PORT. In the SSL handshake level there is no way for the server to know whether you are calling foo.com or bar.com. But in later iterrations in SSL, in TLS 1.2+ there is a concept called SNI(Server Name Identifier) with SNI the client can send the servers hostname at the SSL handshake level. So since my client was using SSLv2, NginX didn't have a clue to send the correct certificate so it randomly sends the certificate which matches first. In my case it was done in alphabetical order.

So the correct fix for this is to use later SSL protocols like TLS. Or you can simply move different servers to different ports in NginX so nginX will always have a single certificate to deal with. Aother workaround is to import all the certificates to client-truststore.

In my case I moves some servers to different ports in NginX since I didn't have any control over the clients. So how can I use SNI when connecting with openssl client. You can simply use the following command for this.

openssl s_client -servername wso2.com -connect wso2.com:443

So hope this will help someone. Drop a comment if you have any queries.