pki: Make ssh_key_is_public() a public function.

include/libssh/libssh.h

@@ -422,6 +422,8 @@ LIBSSH_API void ssh_key_free (ssh_key key);
 LIBSSH_API enum ssh_keytypes_e ssh_key_type(ssh_key key);
 LIBSSH_API const char *ssh_key_type_to_char(enum ssh_keytypes_e type);
 LIBSSH_API enum ssh_keytypes_e ssh_key_type_from_name(const char *name);
+LIBSSH_API int ssh_key_is_public(ssh_key k);
+
 LIBSSH_API int ssh_pki_import_privkey_base64(ssh_key key, ssh_session session,
                                 const char *b64_key, const char *passphrase);
 LIBSSH_API int ssh_userauth_pki_pubkey(ssh_session session, const char *username,

include/libssh/pki.h

@@ -39,7 +39,6 @@ struct ssh_key_struct {
 #endif
 };
 
-#define ssh_key_is_public(k) (k && k->flags & SSH_KEY_FLAG_PUBLIC)
 #define ssh_key_is_private(k) (k && k->flags & SSH_KEY_FLAG_PRIVATE)
 
 void ssh_key_clean (ssh_key key);

src/pki.c

@@ -150,6 +150,21 @@ enum ssh_keytypes_e ssh_key_type_from_name(const char *name) {
   return SSH_KEYTYPE_UNKNOWN;
 }
 
+/**
+ * @brief Check if the key has/is a public key.
+ *
+ * @param[in] k         The key to check.
+ *
+ * @return              1 if it is a public key, 0 if not.
+ */
+int ssh_key_is_public(ssh_key k) {
+    if (k == NULL) {
+        return 0;
+    }
+
+    return (k->flags & SSH_KEY_FLAG_PUBLIC);
+}
+
 /**
  * @brief import a key from a file
  * @param[out]  key      the ssh_key to update