llaves socket SSL

[cucuru]

hola! estoy intentando crear mi aplicación con Sockets SSL, y parece ser que mi error está en la negociación de las claves, esto es lo que hago (en cliente igual que en el servidor):

Código:

keytool -genkey -alias clave -keyalg RSA -keystore /ruta/almacenClaves 

keytool -certreq -keyalg RSA -alias clave -file /ruta/clave.txt -keystore almacenClaves

para ejecutar, en el servidor hago:

Código:

java -Djavax.net.ssl.keyStore=almacenClaves -Djavax.net.ssl.keyStorePassword=contrasena serverSSL

y en el cliente

Código:

java -Djavax.net.ssl.trustStore=almacenClaves -Djavax.net.ssl.trustStorePassword=contrasena clientSSL

me salen estas excepciones, en el servidor:

Código:

javax.net.ssl.SSLException: Received fatal alert: internal_error
        at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:190)
        at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:136)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1720)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:954)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1138)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:753)
        at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:75)
        at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:50)
        at java.io.DataInputStream.readUnsignedShort(DataInputStream.java:320)
        at java.io.DataInputStream.readUTF(DataInputStream.java:572)
        at java.io.DataInputStream.readUTF(DataInputStream.java:547)
        at serverSSL.main(serverSSL.java:24)

en el cliente:

Código:

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.net.ssl.internal.ssl.Alerts.getSSLException(Unknown Source)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(Unknown Source)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Unknown Source)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Unknown Source)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(Unknown Source)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(Unknown Source)
	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Unknown Source)
	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Unknown Source)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(Unknown Source)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(Unknown Source)
	at com.sun.net.ssl.internal.ssl.AppOutputStream.write(Unknown Source)
	at java.io.DataOutputStream.write(Unknown Source)
	at java.io.DataOutputStream.writeUTF(Unknown Source)
	at java.io.DataOutputStream.writeUTF(Unknown Source)
	at clientSSL.main(clientSSL.java:27)
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(Unknown Source)
	at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
	at sun.security.validator.Validator.validate(Unknown Source)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.validate(Unknown Source)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
	... 12 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
	at java.security.cert.CertPathBuilder.build(Unknown Source)
	... 18 more

¿qué paso estoy haciendo mal?

Gracias!!!