Reduce pbe digest dependencies.

- Custom builds should include digest algorithms they require.
- Throw errors as needed if algorithms do not exist.

Author: davidlehn

lib/pbe.js

@@ -21,7 +21,7 @@ var forge = require('./forge');
 require('./aes');
 require('./asn1');
 require('./des');
-require('./md.all');
+require('./md');
 require('./oids');
 require('./pbkdf2');
 require('./pem');
@@ -643,6 +643,9 @@ pki.pbe.generatePkcs12Key = function(password, salt, id, iter, n, md) {
   var j, l;
 
   if(typeof md === 'undefined' || md === null) {
+    if(!('sha1' in forge.md)) {
+      throw new Error('"sha1" hash algorithm unavailable.');
+    }
     md = forge.md.sha1.create();
   }
 
@@ -929,6 +932,9 @@ pki.pbe.getCipherForPKCS12PBE = function(oid, params, password) {
  */
 pki.pbe.opensslDeriveBytes = function(password, salt, dkLen, md) {
   if(typeof md === 'undefined' || md === null) {
+    if(!('md5' in forge.md)) {
+      throw new Error('"md5" hash algorithm unavailable.');
+    }
     md = forge.md.md5.create();
   }
   if(salt === null) {
@@ -983,6 +989,9 @@ function prfAlgorithmToMessageDigest(prfAlgorithm) {
       'hmacWithSHA512'];
     throw error;
   }
+  if(!factory || !(prfAlgorithm in factory)) {
+    throw new Error('Unknown hash algorithm: ' + prfAlgorithm);
+  }
   return factory[prfAlgorithm].create();
 }