diff --git a/phpseclib/Crypt/Salsa20.php b/phpseclib/Crypt/Salsa20.php
index d76af6af..6c3faeca 100644
--- a/phpseclib/Crypt/Salsa20.php
+++ b/phpseclib/Crypt/Salsa20.php
@@ -341,7 +341,9 @@ class Salsa20 extends StreamCipher
         } else {
             $buffer = &$this->debuffer;
         }
-        if (strlen($buffer['ciphertext'])) {
+        if (!strlen($buffer['ciphertext'])) {
+            $ciphertext = '';
+        } else {
             $ciphertext = $text ^ Strings::shift($buffer['ciphertext'], strlen($text));
             $text = substr($text, strlen($ciphertext));
             if (!strlen($text)) {
diff --git a/tests/Unit/Crypt/ChaCha20Test.php b/tests/Unit/Crypt/ChaCha20Test.php
index 67acaae7..ab5c784b 100644
--- a/tests/Unit/Crypt/ChaCha20Test.php
+++ b/tests/Unit/Crypt/ChaCha20Test.php
@@ -93,11 +93,10 @@ class Unit_Crypt_ChaCha20Test extends PhpseclibTestCase
         $expected = pack('H*', $expected);
 
         $c = new ChaCha20;
+        $c->setPoly1305Key($key);
         $r = new \ReflectionClass(get_class($c));
-        $p = $r->getProperty('poly1305Key');
-        $p->setAccessible(true);
-        $p->setValue($c, $key);
-
+        // this unit test is testing Poly1305 independent of ChaCha20, which phpseclib doesn't
+        // really support, hence this hackish approach
         $m = $r->getMethod('poly1305');
         $m->setAccessible(true);
         $result = $m->invokeArgs($c, [$plaintext]);
@@ -108,7 +107,7 @@ class Unit_Crypt_ChaCha20Test extends PhpseclibTestCase
     // see https://tools.ietf.org/html/rfc8439#section-2.6.2
     public function test262()
     {
-        $key = implode('', range("\80", "\x9f"));
+        $key = implode('', range("\x80", "\x9f"));
 
         $nonce = '00 00 00 00 00 01 02 03 04 05 06 07';
         $nonce = str_replace(' ', '', $nonce);
@@ -119,25 +118,26 @@ class Unit_Crypt_ChaCha20Test extends PhpseclibTestCase
         $expected = str_replace(' ', '', $expected);
         $expected = pack('H*', $expected);
 
-        $engines = ['PHP', 'OpenSSL', 'libsodium'];
-        foreach ($engines as $engine) {
-            $c = new ChaCha20();
-            $c->setKey($key);
-            $c->setNonce($nonce);
-            //$c->setCounter(0);
-            $c->setPreferredEngine($engine);
-            if ($c->getEngine() != $engine) {
-                continue;
-            }
-            $result = $c->encrypt($plaintext);
-            $this->assertSame($expected, $result, "Failed asserting that ciphertext matches expected value with $engine engine");
-        }
+        $c = new ChaCha20();
+        $c->setKey($key);
+        $c->setNonce($nonce);
+
+        $r = new \ReflectionClass(get_class($c));
+        $m = $r->getMethod('createPoly1305Key');
+        $m->setAccessible(true);
+        $result = $m->invoke($c);
+
+        $p = $r->getProperty('poly1305Key');
+        $p->setAccessible(true);
+        $actual = $p->getValue($c);
+
+        $this->assertSame($expected, $actual, 'Failed asserting that the poly1305 key is what it ought to be');
     }
 
     // https://tools.ietf.org/html/rfc8439#section-2.8.2
     public function test282()
     {
-        $key = implode('', range("\80", "\x9f"));
+        $key = implode('', range("\x80", "\x9f"));
 
         $nonce = "\x07\0\0\0" . "\x40\x41\x42\x43\x44\x45\x46\x47";
 
@@ -160,7 +160,7 @@ class Unit_Crypt_ChaCha20Test extends PhpseclibTestCase
         $expected = pack('H*', $expected);
 
         $tag = '1a:e1:0b:59:4f:09:e2:6a:7e:90:2e:cb:d0:60:06:91';
-        $tag = str_replace(' ', '', $tag);
+        $tag = str_replace(':', '', $tag);
         $tag = pack('H*', $tag);
 
         $engines = ['PHP', 'OpenSSL', 'libsodium'];
diff --git a/tests/Unit/Crypt/Salsa20Test.php b/tests/Unit/Crypt/Salsa20Test.php
index 8d2f8a3f..678d82ba 100644
--- a/tests/Unit/Crypt/Salsa20Test.php
+++ b/tests/Unit/Crypt/Salsa20Test.php
@@ -133,9 +133,7 @@ class Unit_Crypt_Salsa20Test extends PhpseclibTestCase
 
         foreach ($engines as $engine) {
             foreach ($tests as $test) {
-                foreach ($test['output'] as $output) {
-                    $result[] = [$engine, $test['key'], $output['iv'], $output['result']];
-                }
+                $result[] = [$engine, $test['key'], $test['iv'], $test['result']];
             }
         }
 
@@ -147,7 +145,7 @@ class Unit_Crypt_Salsa20Test extends PhpseclibTestCase
      */
     public function testVectors($engine, $key, $iv, $expected)
     {
-        $cipher = new Salsa();
+        $cipher = new Salsa20();
         $cipher->setPreferredEngine($engine);
         $cipher->setKey(pack('H*', $key));
         $cipher->setNonce(pack('H*', $iv));