Move definition of MBEDTLS_CIPHER_MODE_STREAM
Move definition of `MBEDTLS_CIPHER_MODE_STREAM` to header file
(`mbedtls_cipher_internal.h`), because it is used by more than
one file. Raised by TrinityTonic in #1719
diff --git a/include/mbedtls/cipher_internal.h b/include/mbedtls/cipher_internal.h
index 6c58bcc..88baa82 100644
--- a/include/mbedtls/cipher_internal.h
+++ b/include/mbedtls/cipher_internal.h
@@ -33,6 +33,10 @@
#include "cipher.h"
+#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
+#define MBEDTLS_CIPHER_MODE_STREAM
+#endif
+
#ifdef __cplusplus
extern "C" {
#endif
diff --git a/library/cipher.c b/library/cipher.c
index cf82a82..fe34929 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -45,10 +45,6 @@
#include "mbedtls/ccm.h"
#endif
-#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER)
-#define MBEDTLS_CIPHER_MODE_STREAM
-#endif
-
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;