Implement two-valued handle type
diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index 476bce1..64cd7b5 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -126,9 +126,16 @@
 /**
  * \brief           Public key information and operations
  */
+#if defined(MBEDTLS_PK_SINGLE_TYPE)
+typedef enum {
+    MBEDTLS_PK_INVALID_HANDLE,
+    MBEDTLS_PK_UNIQUE_VALID_HANDLE,
+} mbedtls_pk_handle_t;
+#else /* MBEDTLS_PK_SINGLE_TYPE */
 typedef struct mbedtls_pk_info_t mbedtls_pk_info_t;
 typedef const mbedtls_pk_info_t *mbedtls_pk_handle_t;
 #define MBEDTLS_PK_INVALID_HANDLE ( (mbedtls_pk_handle_t) NULL )
+#endif /* MBEDTLS_PK_SINGLE_TYPE */
 
 /**
  * \brief           Public key container
diff --git a/include/mbedtls/pk_internal.h b/include/mbedtls/pk_internal.h
index 65bd8e9..fcf4887 100644
--- a/include/mbedtls/pk_internal.h
+++ b/include/mbedtls/pk_internal.h
@@ -242,6 +242,7 @@
 } mbedtls_rsa_alt_context;
 #endif
 
+#if !defined(MBEDTLS_PK_SINGLE_TYPE)
 #if defined(MBEDTLS_RSA_C)
 extern const mbedtls_pk_info_t mbedtls_rsa_info;
 #endif
@@ -262,5 +263,6 @@
 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 extern const mbedtls_pk_info_t mbedtls_rsa_alt_info;
 #endif
+#endif /* MBEDTLS_PK_SINGLE_TYPE */
 
 #endif /* MBEDTLS_PK_WRAP_H */