public String verify(JarFile jar, String... algorithms) throws IOException {
if (algorithms == null || algorithms.length == 0) algorithms = new String[] {"MD5", "SHA"};
else if (algorithms.length == 1 && algorithms[0].equals("-")) return null;
try {
Manifest m = jar.getManifest();
if (m.getEntries().isEmpty()) return "No name sections";
for (Enumeration<JarEntry> e = jar.entries(); e.hasMoreElements(); ) {
JarEntry je = e.nextElement();
if (MANIFEST_ENTRY.matcher(je.getName()).matches()) continue;
Attributes nameSection = m.getAttributes(je.getName());
if (nameSection == null) return "No name section for " + je.getName();
for (String algorithm : algorithms) {
try {
MessageDigest md = MessageDigest.getInstance(algorithm);
String expected = nameSection.getValue(algorithm + "-Digest");
if (expected != null) {
byte digest[] = Base64.decodeBase64(expected);
copy(jar.getInputStream(je), md);
if (!Arrays.equals(digest, md.digest()))
return "Invalid digest for "
+ je.getName()
+ ", "
+ expected
+ " != "
+ Base64.encodeBase64(md.digest());
} else reporter.error("could not find digest for " + algorithm + "-Digest");
} catch (NoSuchAlgorithmException nsae) {
return "Missing digest algorithm " + algorithm;
}
}
}
} catch (Exception e) {
return "Failed to verify due to exception: " + e.getMessage();
}
return null;
}
private void getAlgorithms(String[] digestNames, MessageDigest[] algorithms) {
for (int i = 0; i < algorithms.length; i++) {
String name = digestNames[i];
try {
algorithms[i] = MessageDigest.getInstance(name);
} catch (NoSuchAlgorithmException e) {
error(
"Specified digest algorithm "
+ digestNames[i]
+ ", but not such algorithm was found: "
+ e);
}
}
}