diff --git a/include/polarssl/x509.h b/include/polarssl/x509.h
index 6f0fe02709..1f062e9b74 100644
--- a/include/polarssl/x509.h
+++ b/include/polarssl/x509.h
@@ -593,6 +593,19 @@ int x509parse_dhmfile( dhm_context *rsa, const char *path );
  */
 int x509parse_dn_gets( char *buf, size_t size, const x509_name *dn );
 
+/**
+ * \brief          Store the certificate serial in printable form into buf;
+ *                 no more than size characters will be written.
+ *
+ * \param buf      Buffer to write to
+ * \param size     Maximum size of buffer
+ * \param serial   The X509 serial to represent
+ *
+ * \return         The amount of data written to the buffer, or -1 in
+ *                 case of an error.
+ */
+int x509parse_serial_gets( char *buf, size_t size, const x509_buf *serial );
+
 /**
  * \brief          Returns an informational string about the
  *                 certificate.
diff --git a/library/x509parse.c b/library/x509parse.c
index 6dae943048..b37c4c2176 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -2305,13 +2305,38 @@ int x509parse_dn_gets( char *buf, size_t size, const x509_name *dn )
     return( size - n );
 }
 
+/*
+ * Store the serial in printable form into buf; no more
+ * than size characters will be written
+ */
+int x509parse_serial_gets( char *buf, size_t size, const x509_buf *serial )
+{
+    int i, ret, nr, n;
+    char *p;
+
+    p = buf;
+    n = size;
+
+    nr = ( serial->len <= 32 )
+        ? serial->len  : 32;
+
+    for( i = 0; i < nr; i++ )
+    {
+        ret = snprintf( p, n, "%02X%s",
+                serial->p[i], ( i < nr - 1 ) ? ":" : "" );
+        SAFE_SNPRINTF();
+    }
+
+    return( size - n );
+}
+
 /*
  * Return an informational string about the certificate.
  */
 int x509parse_cert_info( char *buf, size_t size, const char *prefix,
                          const x509_cert *crt )
 {
-    int i, n, nr, ret;
+    int n, ret;
     char *p;
 
     p = buf;
@@ -2324,15 +2349,8 @@ int x509parse_cert_info( char *buf, size_t size, const char *prefix,
                                prefix );
     SAFE_SNPRINTF();
 
-    nr = ( crt->serial.len <= 32 )
-        ? crt->serial.len  : 32;
-
-    for( i = 0; i < nr; i++ )
-    {
-        ret = snprintf( p, n, "%02X%s",
-                crt->serial.p[i], ( i < nr - 1 ) ? ":" : "" );
-        SAFE_SNPRINTF();
-    }
+    ret = x509parse_serial_gets( p, n, &crt->serial);
+    SAFE_SNPRINTF();
 
     ret = snprintf( p, n, "\n%sissuer name   : ", prefix );
     SAFE_SNPRINTF();