{"id":579,"date":"2004-03-20T18:40:54","date_gmt":"2004-03-20T22:40:54","guid":{"rendered":"http:\/\/wordpress.cephas.net\/?p=579"},"modified":"2004-03-20T18:40:54","modified_gmt":"2004-03-20T22:40:54","slug":"java-pgp","status":"publish","type":"post","link":"https:\/\/cephas.net\/blog\/2004\/03\/20\/java-pgp\/","title":{"rendered":"Java & PGP"},"content":{"rendered":"

One of the Java projects I’m working on required that the application encrypted certain pieces of information (not files, but strings) using PGP, and from what I can tell, there aren’t a whole lot of libraries and\/or examples out there. The one I saw mentioned most frequently was the Bouncy Castle Crypto API<\/a>, but in the short time that I looked through the documentation<\/a> and the examples (org.bouncycastle.openpgp.examples), I saw nothing that looked like it would help me. So I downloaded PGP 6.5.8 (the version we’ve standardized on at work) from pgpi.org<\/a> and hacked away at a version that works from the command line. Here’s the result:
\n
\nString information = \"The random text information I want to encrypt.\";
\nString filename = \"tempfile.txt\";
\n\/\/ path to where I have pgp installed
\nString directory = \"c:\\\\pgp6.5.8\\\\\";
\n\/\/ my pgp key
\nString pgpkey = \"aaron.s.johnson@gmail.com\";
\n\/\/ create a file and write the string to it
\nFile outputfile = new File(directory + filename);
\nFileWriter out = new FileWriter(outputfile);
\nout.write(information.toCharArray());
\nout.close();
\n\/\/ get a runtime object
\nRuntime<\/a> rt = Runtime.getRuntime();
\n\/\/ execute pgp from the command line
\n\/\/ e=encrypt a=ascii t=text file w=wipe the file
\nProcess process = rt.exec(directory + \"pgp -eatw \" + directory + filename + \" \" + pgpkey);
\n\/\/ wait for the execution to end
\nprocess.waitFor();
\n\/\/ read the armored ASCII file
\nFile inputfile = new File(directory + filename + \".asc\");
\nBufferedReader isr = new BufferedReader(new FileReader(inputfile));
\nStringBuffer decrypted = new StringBuffer();
\nString line = \"\";
\nwhile ((line = isr.readLine()) != null) {
\n  decrypted.append(line + \"\\n\");
\n}
\n\/\/ close the reader
\nisr.close();
\ninputfile.delete();
\n\/\/ print out the encrypted string for kicks
\nSystem.out.println(decrypted.toString());
\n<\/code>
\nA quick summary. The PGP executable assumes that you’re encrypting and decrypting files, so I first take the string that I want to encrypt and write it to a text file using the File<\/a> and FileWriter<\/a> classes. Then I use the Runtime<\/a> class to execute PGP from the command line, which encrypts the file and deletes the original plain text unencrypted file that I just created. I call the waitFor()<\/a> method on the Process<\/a> to make sure that the execution is complete, and then I read in resulting armored ASCII file using the File<\/a>, FileReader<\/a> and BufferedReader<\/a> classes. Finally, I delete the armored ASCII file. Obviously in production you’d want to use a unique name for the file so that you don’t overwrite or delete a file that another thread just created. Other than that, are there any issues that I missed?<\/p>\n","protected":false},"excerpt":{"rendered":"

One of the Java projects I’m working on required that the application encrypted certain pieces of information (not files, but strings) using PGP, and from what I can tell, there aren’t a whole lot of libraries and\/or examples out there. The one I saw mentioned most frequently was the Bouncy Castle Crypto API, but in … Continue reading Java & PGP<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts\/579"}],"collection":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/comments?post=579"}],"version-history":[{"count":0,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/posts\/579\/revisions"}],"wp:attachment":[{"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/media?parent=579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/categories?post=579"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cephas.net\/blog\/wp-json\/wp\/v2\/tags?post=579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}