Generate 2b hashes by default

BREAKING CHANGE: This library was not affected by the bug that led to
incrementing the bcrypt version from 2a to 2b, but nowadays most
implementations use 2b, including the native bcrypt binding, so this
change aligns with them. Existing hashes will continue to work, but
test logic that generates hashes and compares them literally might need
to be updated to account for the new default.

index.js

@@ -91,7 +91,7 @@ export function genSaltSync(rounds, seed_length) {
     else if (rounds > 31)
         rounds = 31;
     var salt = [];
-    salt.push("$2a$");
+    salt.push("$2b$");
     if (rounds < 10)
         salt.push("0");
     salt.push(rounds.toString());
@@ -228,7 +228,7 @@ export function compareSync(s, hash) {
         throw Error("Illegal arguments: "+(typeof s)+', '+(typeof hash));
     if (hash.length !== 60)
         return false;
-    return safeStringCompare(hashSync(s, hash.substr(0, hash.length-31)), hash);
+    return safeStringCompare(hashSync(s, hash.substring(0, hash.length-31)), hash);
 }
 
 /**

tests/index.js

@@ -51,13 +51,13 @@ const tests = [
     },
     function compareSync(done) {
         var salt1 = bcrypt.genSaltSync(),
-            hash1 = bcrypt.hashSync("hello", salt1); // $2a$
-        var salt2 = bcrypt.genSaltSync().replace(/\$2a\$/, "$2y$"),
+            hash1 = bcrypt.hashSync("hello", salt1); // $2b$
+        var salt2 = bcrypt.genSaltSync().replace(/\$2b\$/, "$2y$"),
             hash2 = bcrypt.hashSync("world", salt2);
-        var salt3 = bcrypt.genSaltSync().replace(/\$2a\$/, "$2b$"),
+        var salt3 = bcrypt.genSaltSync().replace(/\$2b\$/, "$2a$"),
             hash3 = bcrypt.hashSync("hello world", salt3);
 
-        assert.strictEqual(hash1.substring(0,4), "$2a$");
+        assert.strictEqual(hash1.substring(0,4), "$2b$");
         assert(bcrypt.compareSync("hello", hash1));
         assert(!bcrypt.compareSync("hello", hash2));
         assert(!bcrypt.compareSync("hello", hash3));
@@ -67,7 +67,7 @@ const tests = [
         assert(!bcrypt.compareSync("world", hash1));
         assert(!bcrypt.compareSync("world", hash3));
 
-        assert.strictEqual(hash3.substring(0,4), "$2b$");
+        assert.strictEqual(hash3.substring(0,4), "$2a$");
         assert(bcrypt.compareSync("hello world", hash3));
         assert(!bcrypt.compareSync("hello world", hash1));
         assert(!bcrypt.compareSync("hello world", hash2));
@@ -160,24 +160,24 @@ const tests = [
         assert.equal(hash1, hash2);
         done();
     },
-    // function compat_roundsOOB(done) {
-    //     var salt1 = bcrypt.genSaltSync(0), // $10$ like not set
-    //         salt2 = binding.genSaltSync(0);
-    //     assert.strictEqual(salt1.substring(0, 7), "$2a$10$");
-    //     assert.strictEqual(salt2.substring(0, 7), "$2a$10$");
+    function compat_roundsOOB(done) {
+        var salt1 = bcrypt.genSaltSync(0), // $10$ like not set
+            salt2 = binding.genSaltSync(0);
+        assert.strictEqual(salt1.substring(0, 7), "$2b$10$");
+        assert.strictEqual(salt2.substring(0, 7), "$2b$10$");
 
-    //     salt1 = bcrypt.genSaltSync(3); // $04$ is lower cap
-    //     salt2 = bcrypt.genSaltSync(3);
-    //     assert.strictEqual(salt1.substring(0, 7), "$2a$04$");
-    //     assert.strictEqual(salt2.substring(0, 7), "$2a$04$");
+        salt1 = bcrypt.genSaltSync(3); // $04$ is lower cap
+        salt2 = bcrypt.genSaltSync(3);
+        assert.strictEqual(salt1.substring(0, 7), "$2b$04$");
+        assert.strictEqual(salt2.substring(0, 7), "$2b$04$");
 
-    //     salt1 = bcrypt.genSaltSync(32); // $31$ is upper cap
-    //     salt2 = bcrypt.genSaltSync(32);
-    //     assert.strictEqual(salt1.substring(0, 7), "$2a$31$");
-    //     assert.strictEqual(salt2.substring(0, 7), "$2a$31$");
+        salt1 = bcrypt.genSaltSync(32); // $31$ is upper cap
+        salt2 = bcrypt.genSaltSync(32);
+        assert.strictEqual(salt1.substring(0, 7), "$2b$31$");
+        assert.strictEqual(salt2.substring(0, 7), "$2b$31$");
 
-    //     done();
-    // }
+        done();
+    }
 ]
 
 function next() {