Merge pull request #145 from aidantwoods/fix/length-checks

Error if received message is too short
paragonie · Oct 27, 2021 · 46d19c1 · 46d19c1
2 parents c47dfed + 0ab75c2
commit 46d19c1
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Showing 5 changed files with 65 additions and 0 deletions.
diff --git a/src/Exception/ExceptionCode.php b/src/Exception/ExceptionCode.php
@@ -38,6 +38,7 @@ abstract class ExceptionCode
     const INVOKED_RAW_ON_MULTIKEY          = 0x3142EE1C;
     const KEY_NOT_IN_KEYRING               = 0x3142EE1D;
     const UNDEFINED_PROPERTY               = 0x3142EE1E;
+    const INVALID_MESSAGE_LENGTH           = 0x3142EE1F;
 
     /**
      * @param int $code
@@ -92,6 +93,8 @@ public static function explainErrorCode(int $code): string
                 return "The key you requested is not in this keyring.";
             case self::UNDEFINED_PROPERTY:
                 return "An expected property was not defined at runtime.";
+            case self::INVALID_MESSAGE_LENGTH:
+                return "The recieved PASETO was too short to be valid.";
 
             default:
                 return 'Unknown error code';

diff --git a/src/Protocol/Version1.php b/src/Protocol/Version1.php
@@ -347,6 +347,14 @@ public static function verify(
         // PASETO Version 1 - Verify - Step 4:
         $decoded = Base64UrlSafe::decode(Binary::safeSubstr($signMsg, $headerLength));
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= self::SIGN_SIZE) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $message = Binary::safeSubstr($decoded, 0, $len - self::SIGN_SIZE);
         $signature = Binary::safeSubstr($decoded, $len - self::SIGN_SIZE);
 
@@ -473,6 +481,14 @@ public static function aeadDecrypt(
             );
         }
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= self::NONCE_SIZE + self::MAC_SIZE) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $nonce = Binary::safeSubstr($decoded, 0, self::NONCE_SIZE);
         $ciphertext = Binary::safeSubstr(
             $decoded,

diff --git a/src/Protocol/Version2.php b/src/Protocol/Version2.php
@@ -333,6 +333,13 @@ public static function verify(
         $decoded = Base64UrlSafe::decode(Binary::safeSubstr($signMsg, $headerLength));
         $len = Binary::safeStrlen($decoded);
 
+        if ($len <= SODIUM_CRYPTO_SIGN_BYTES) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         // PASETO Version 2 - Verify - Step 4:
         // Separate the decoded bundle into the message and signature.
         $message = Binary::safeSubstr(
@@ -459,6 +466,14 @@ public static function aeadDecrypt(
             );
         }
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= SODIUM_CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $nonce = Binary::safeSubstr(
             $decoded,
             0,

diff --git a/src/Protocol/Version3.php b/src/Protocol/Version3.php
@@ -359,6 +359,14 @@ public static function verify(
         // PASETO Version 3 - Verify - Step 4:
         $decoded = Base64UrlSafe::decode(Binary::safeSubstr($signMsg, $headerLength));
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= self::SIGN_SIZE) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $message = Binary::safeSubstr($decoded, 0, $len - self::SIGN_SIZE);
         $signature = Binary::safeSubstr($decoded, $len - self::SIGN_SIZE);
 
@@ -502,6 +510,14 @@ public static function aeadDecrypt(
             );
         }
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= self::NONCE_SIZE + self::MAC_SIZE) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $nonce = Binary::safeSubstr($decoded, 0, self::NONCE_SIZE);
         $ciphertext = Binary::safeSubstr(
             $decoded,

diff --git a/src/Protocol/Version4.php b/src/Protocol/Version4.php
@@ -329,6 +329,13 @@ public static function verify(
         $decoded = Base64UrlSafe::decode(Binary::safeSubstr($signMsg, $headerLength));
         $len = Binary::safeStrlen($decoded);
 
+        if ($len <= SODIUM_CRYPTO_SIGN_BYTES) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         // Separate the decoded bundle into the message and signature.
         $message = Binary::safeSubstr(
             $decoded,
@@ -465,6 +472,14 @@ public static function aeadDecrypt(
             );
         }
         $len = Binary::safeStrlen($decoded);
+
+        if ($len <= self::NONCE_SIZE + self::MAC_SIZE) {
+            throw new PasetoException(
+                'Invalid message length.',
+                ExceptionCode::INVALID_MESSAGE_LENGTH
+            );
+        }
+
         $nonce = Binary::safeSubstr($decoded, 0, self::NONCE_SIZE);
         $ciphertext = Binary::safeSubstr(
             $decoded,