Add new API function ssh_userauth_privatekey_file().

Signed-off-by: Vic Lee <llyzs@163.com>
Signed-off-by: Andreas Schneider <mail@cynapses.org>

include/libssh/libssh.h

@@ -433,6 +433,8 @@ LIBSSH_API int ssh_userauth_none(ssh_session session, const char *username);
 LIBSSH_API int ssh_userauth_offer_pubkey(ssh_session session, const char *username, int type, ssh_string publickey);
 LIBSSH_API int ssh_userauth_password(ssh_session session, const char *username, const char *password);
 LIBSSH_API int ssh_userauth_pubkey(ssh_session session, const char *username, ssh_string publickey, ssh_private_key privatekey);
+LIBSSH_API int ssh_userauth_privatekey_file(ssh_session session, const char *username,
+    const char *filename, const char *passphrase);
 LIBSSH_API const char *ssh_version(int req_version);
 LIBSSH_API int ssh_write_knownhost(ssh_session session);
 

libssh/auth.c

@@ -594,6 +594,72 @@ error:
   return rc;
 }
 
+/**
+ * @brief Try to authenticate through a private key file.
+ *
+ * @param session       The ssh session to use.
+ *
+ * @param username      The username to authenticate. You can specify NULL if
+ *                      ssh_option_set_username() has been used. You cannot try
+ *                      two different logins in a row.
+ *
+ * @param filename      Filename containing the private key.
+ *
+ * @param passphrase    Passphrase to decrypt the private key. Set to null if
+ *                      none is needed or it is unknown.
+ *
+ * @returns SSH_AUTH_ERROR:   A serious error happened.\n
+ *          SSH_AUTH_DENIED:  Authentication failed: use another method.\n
+ *          SSH_AUTH_PARTIAL: You've been partially authenticated, you still
+ *                            have to use another method.\n
+ *          SSH_AUTH_SUCCESS: Authentication successful.
+ *
+ * @see publickey_from_file()
+ * @see privatekey_from_file()
+ * @see privatekey_free()
+ * @see ssh_userauth_pubkey()
+ */
+int ssh_userauth_privatekey_file(ssh_session session, const char *username,
+    const char *filename, const char *passphrase) {
+  char *pubkeyfile = NULL;
+  ssh_string pubkey = NULL;
+  ssh_private_key privkey = NULL;
+  int type = 0;
+  int rc = SSH_AUTH_ERROR;
+
+  enter_function();
+
+  pubkeyfile = malloc(strlen(filename) + 1 + 4);
+  if (pubkeyfile == NULL) {
+    leave_function();
+    return SSH_AUTH_ERROR;
+  }
+  sprintf(pubkeyfile, "%s.pub", filename);
+
+  pubkey = publickey_from_file(session, pubkeyfile, &type);
+  if (pubkey == NULL) {
+    ssh_log(session, SSH_LOG_RARE, "Public key file %s not found. Trying to generate it.", pubkeyfile);
+    /* auto-detect the key type with type=0 */
+    privkey = privatekey_from_file(session, filename, 0, passphrase);
+  } else {
+    ssh_log(session, SSH_LOG_RARE, "Public key file %s loaded.", pubkeyfile);
+    privkey = privatekey_from_file(session, filename, type, passphrase);
+  }
+  if (privkey == NULL) {
+    goto error;
+  }
+  /* ssh_userauth_pubkey is responsible for taking care of null-pubkey */
+  rc = ssh_userauth_pubkey(session, username, pubkey, privkey);
+  privatekey_free(privkey);
+
+error:
+  SAFE_FREE(pubkeyfile);
+  string_free(pubkey);
+
+  leave_function();
+  return rc;
+}
+
 #ifndef _WIN32
 /**
  * @brief Try to authenticate through public key with an ssh agent.