1 files changed, 61 insertions, 5 deletions

diff --git a/guzzlehttp/psr7/src/MessageTrait.php b/guzzlehttp/psr7/src/MessageTrait.php
index 99203bb4..0ac8663d 100644
--- a/guzzlehttp/psr7/src/MessageTrait.php
+++ b/guzzlehttp/psr7/src/MessageTrait.php
@@ -157,17 +157,22 @@ trait MessageTrait
         }
     }
 
+    /**
+     * @param mixed $value
+     *
+     * @return string[]
+     */
     private function normalizeHeaderValue($value)
     {
         if (!is_array($value)) {
-            return $this->trimHeaderValues([$value]);
+            return $this->trimAndValidateHeaderValues([$value]);
         }
 
         if (count($value) === 0) {
             throw new \InvalidArgumentException('Header value can not be an empty array.');
         }
 
-        return $this->trimHeaderValues($value);
+        return $this->trimAndValidateHeaderValues($value);
     }
 
     /**
@@ -178,13 +183,13 @@ trait MessageTrait
      * header-field = field-name ":" OWS field-value OWS
      * OWS          = *( SP / HTAB )
      *
-     * @param string[] $values Header values
+     * @param mixed[] $values Header values
      *
      * @return string[] Trimmed header values
      *
      * @see https://tools.ietf.org/html/rfc7230#section-3.2.4
      */
-    private function trimHeaderValues(array $values)
+    private function trimAndValidateHeaderValues(array $values)
     {
         return array_map(function ($value) {
             if (!is_scalar($value) && null !== $value) {
@@ -194,10 +199,20 @@ trait MessageTrait
                 ));
             }
 
-            return trim((string) $value, " \t");
+            $trimmed = trim((string) $value, " \t");
+            $this->assertValue($trimmed);
+
+            return $trimmed;
         }, array_values($values));
     }
 
+    /**
+     * @see https://tools.ietf.org/html/rfc7230#section-3.2
+     *
+     * @param mixed $header
+     *
+     * @return void
+     */
     private function assertHeader($header)
     {
         if (!is_string($header)) {
@@ -210,5 +225,46 @@ trait MessageTrait
         if ($header === '') {
             throw new \InvalidArgumentException('Header name can not be empty.');
         }
+
+        if (! preg_match('/^[a-zA-Z0-9\'`#$%&*+.^_|~!-]+$/', $header)) {
+            throw new \InvalidArgumentException(
+                sprintf(
+                    '"%s" is not valid header name',
+                    $header
+                )
+            );
+        }
+    }
+
+    /**
+     * @param string $value
+     *
+     * @return void
+     *
+     * @see https://tools.ietf.org/html/rfc7230#section-3.2
+     *
+     * field-value    = *( field-content / obs-fold )
+     * field-content  = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+     * field-vchar    = VCHAR / obs-text
+     * VCHAR          = %x21-7E
+     * obs-text       = %x80-FF
+     * obs-fold       = CRLF 1*( SP / HTAB )
+     */
+    private function assertValue($value)
+    {
+        // The regular expression intentionally does not support the obs-fold production, because as
+        // per RFC 7230#3.2.4:
+        //
+        // A sender MUST NOT generate a message that includes
+        // line folding (i.e., that has any field-value that contains a match to
+        // the obs-fold rule) unless the message is intended for packaging
+        // within the message/http media type.
+        //
+        // Clients must not send a request with line folding and a server sending folded headers is
+        // likely very rare. Line folding is a fairly obscure feature of HTTP/1.1 and thus not accepting
+        // folding is not likely to break any legitimate use case.
+        if (! preg_match('/^[\x20\x09\x21-\x7E\x80-\xFF]*$/', $value)) {
+            throw new \InvalidArgumentException(sprintf('"%s" is not valid header value', $value));
+        }
     }
 }