InstallCert.java Java program written by Andreas Sterbenz, and posted on a blog in Oct, 2006: https://blogs.oracle.com/gc/entry/unable_to_find_valid_certification Link to Java program in Andreas' blog no longer works, but the source was linked in another blog: https://web.archive.org/web/20190831085142/http://nodsw.com/blog/leeland/2006/12/06-no-more-unable-find-valid-certification-path-requested-target Usage: Need to compile, first: javac InstallCert.java Note: since java 11, you can run it directly without compiling it first: java --source 11 InstallCert.java <args> # Access server, and retrieve certificate (accept default certificate 1) java InstallCert [--proxy=proxyHost:proxyPort] <host>[:port] [passphrase] # Extract certificate from created jssecacerts keystore keytool -exportcert -alias [host]-1 -keystore jssecacerts -storepass changeit -file [host].cer # Import certificate into system keystore keytool -importcert -alias [host] -keystore [path to system keystore] -storepass changeit -file [host].cer # Example: java InstallCert woot.com:443 Loading KeyStore /usr/lib/jvm/java-6-sun-1.6.0.26/jre/lib/security/cacerts... Opening connection to woot.com:443... Starting SSL handshake... 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 <...> Server sent 1 certificate(s): 1 Subject O=Woot Inc, C=US, ST=Texas, L=Carrollton, CN=*.woot.com Issuer CN=SecureTrust CA, O=SecureTrust Corporation, C=US sha1 4b 46 ca 6b 83 05 b3 51 ff c6 e7 9c fd b3 9b e3 3f 2e c4 53 md5 e8 a5 88 1b d5 67 bb fc 88 cc b1 c5 2b ac c4 7d Enter certificate to add to trusted keystore or 'q' to quit: [1] [enter] [ [ Version: V3 Subject: O=Woot Inc, C=US, ST=Texas, L=Carrollton, CN=*.woot.com Signature Algorithm: SHA1withRSA, OID = 1.2.840.113549.1.1.5 <...> Added certificate to keystore 'jssecacerts' using alias 'woot.com-1' keytool -exportcert -alias woot.com-1 -keystore jssecacerts -storepass changeit -file woot.com.cer Certificate stored in file <woot.com.cer> (sudo) keytool -importcert -alias woot.com -keystore /usr/lib/jvm/java-6-sun-1.6.0.26/jre/lib/security/cacerts -storepass changeit -file woot.com.cer Owner: O=Woot Inc, C=US, ST=Texas, L=Carrollton, CN=*.woot.com Issuer: CN=SecureTrust CA, O=SecureTrust Corporation, C=US <...> Trust this certificate? [no]: yes Certificate was added to keystore