diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 22e4d965..099e1ec0 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -1441,7 +1441,7 @@ class ASN1
                         return false;
                     }
                     break;
-                case ($c & 0x80000000) != 0:
+                case ($c & (PHP_INT_SIZE == 8 ? 0x80000000 : (1 << 31))) != 0:
                     return false;
                 case $c >= 0x04000000:
                     $v .= chr(0x80 | ($c & 0x3F));
diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index 05ce2642..77c1bba6 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -871,7 +871,7 @@ class SFTP extends SSH2
 
         $error = $this->status_codes[$status];
 
-        if ($this->version > 2 || strlen($response) < 4) {
+        if ($this->version > 2) {
             extract(unpack('Nlength', $this->_string_shift($response, 4)));
             $this->sftp_errors[] = $error . ': ' . $this->_string_shift($response, $length);
         } else {