X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=client_common.c;h=f8ee80c9d7a01956769284eaa117f1606c59cd76;hb=d440a71683940a58747de6dc32643db452d9cf54;hp=094b93be85addc7882a1bfc8d65110ce128ec215;hpb=8919784065fdfd210dc25e4ab31c6fa92f9e3219;p=paraslash.git

diff --git a/client_common.c b/client_common.c
index 094b93be..f8ee80c9 100644
--- a/client_common.c
+++ b/client_common.c
@@ -50,13 +50,12 @@ void client_close(struct client_task *ct)
 }
 
 /*
- * The preselect hook for server commands.
+ * This function asks the scheduler to monitor a file descriptor which
+ * corresponds to an active connection. The descriptor is monitored for either
+ * reading or writing, depending on the state of the connection.
  *
- * The task pointer must contain a pointer to the initialized client data
- * structure as it is returned by client_open().
- *
- * This function checks the state of the connection and adds the file descriptor
- * of the connection to the read or write fd set of s accordingly.
+ * The context pointer is assumed to refer to a client task structure that was
+ * initialized earlier by client_open().
  */
 static void client_pre_select(struct sched *s, void *context)
 {
@@ -86,7 +85,7 @@ static void client_pre_select(struct sched *s, void *context)
 			else if (ret > 0)
 				para_fd_set(ct->scc.fd, &s->wfds, &s->max_fileno);
 		}
-		/* fallthrough */
+		__attribute__ ((fallthrough));
 	case CL_EXECUTING:
 		if (ct->btrn[0]) {
 			ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
@@ -259,13 +258,21 @@ static int send_sb_command(struct client_task *ct)
 	return send_sb(ct, 0, command, len, SBD_COMMAND, false);
 }
 
+static bool has_feature(const char *feature, struct client_task *ct)
+{
+	return find_arg(feature, ct->features) >= 0? true : false;
+}
+
 /*
- * The post select hook for client commands.
+ * This function reads or writes to the socket file descriptor which
+ * corresponds to an established connection between the client and the server.
+ * It depends on the current state of the connection and on the readiness of
+ * the socket file descriptor which type of I/O is going to be performed.
+ * Besides the initial handshake and authentication, the function sends the
+ * server command and receives the output from the server, if any.
  *
- * Depending on the current state of the connection and the status of the read
- * and write fd sets of s, this function performs the necessary steps to
- * authenticate the connection, to send the command given by t->private_data
- * and to receive para_server's output, if any.
+ * The context pointer refers to a client task structure that was initialized
+ * earlier by client_open().
  */
 static int client_post_select(struct sched *s, void *context)
 {
@@ -288,16 +295,25 @@ static int client_post_select(struct sched *s, void *context)
 		ct->status = CL_RECEIVED_WELCOME;
 		return 0;
 	case CL_RECEIVED_WELCOME: /* send auth command */
+		{
+		/*
+		 * Use sha256 iff the server announced the feature. After 0.7.0
+		 * we may request and use the feature unconditionally. After
+		 * 0.8.0 we no longer need to request the feature.
+		 */
+		bool has_sha256;
 		if (!FD_ISSET(ct->scc.fd, &s->wfds))
 			return 0;
-		sprintf(buf, AUTH_REQUEST_MSG "%s sideband,aes_ctr128",
-			ct->user);
+		has_sha256 = has_feature("sha256", ct);
+		sprintf(buf, AUTH_REQUEST_MSG "%s%s", ct->user, has_sha256?
+			" sha256" : "");
 		PARA_INFO_LOG("--> %s\n", buf);
 		ret = write_buffer(ct->scc.fd, buf);
 		if (ret < 0)
 			goto out;
 		ct->status = CL_SENT_AUTH;
 		return 0;
+		}
 	case CL_SENT_AUTH:
 		/*
 		 * Receive challenge and session keys, decrypt the challenge and
@@ -318,24 +334,34 @@ static int client_post_select(struct sched *s, void *context)
 		}
 		n = sbb.iov.iov_len;
 		PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
-		ret = priv_decrypt(ct->key_file, crypt_buf,
+		ret = apc_priv_decrypt(ct->key_file, crypt_buf,
 			sbb.iov.iov_base, n);
 		free(sbb.iov.iov_base);
 		if (ret < 0)
 			goto out;
-		ct->challenge_hash = para_malloc(HASH_SIZE);
-		hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
-		ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
-		ct->scc.recv = sc_new(crypt_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
+		ct->challenge_hash = para_malloc(HASH2_SIZE);
+
+		if (has_feature("sha256", ct)) {
+			hash2_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
+			hash2_to_asc(ct->challenge_hash, buf);
+		} else {
+			hash_function((char *)crypt_buf, APC_CHALLENGE_SIZE, ct->challenge_hash);
+			hash_to_asc(ct->challenge_hash, buf);
+		}
+		ct->scc.send = sc_new(crypt_buf + APC_CHALLENGE_SIZE, SESSION_KEY_LEN);
+		ct->scc.recv = sc_new(crypt_buf + APC_CHALLENGE_SIZE + SESSION_KEY_LEN,
 			SESSION_KEY_LEN);
-		hash_to_asc(ct->challenge_hash, buf);
 		PARA_INFO_LOG("--> %s\n", buf);
 		ct->status = CL_RECEIVED_CHALLENGE;
 		return 0;
 		}
 	case CL_RECEIVED_CHALLENGE:
-		ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
-			SBD_CHALLENGE_RESPONSE, false);
+		if (has_feature("sha256", ct))
+			ret = send_sb(ct, 0, ct->challenge_hash, HASH2_SIZE,
+				SBD_CHALLENGE_RESPONSE, false);
+		else
+			ret = send_sb(ct, 0, ct->challenge_hash, HASH_SIZE,
+				SBD_CHALLENGE_RESPONSE, false);
 		if (ret != 0)
 			ct->challenge_hash = NULL;
 		if (ret <= 0)
@@ -389,7 +415,7 @@ static int client_post_select(struct sched *s, void *context)
 					btr_consume(ct->btrn[1], sz);
 			}
 		}
-		/* fall through */
+		__attribute__ ((fallthrough));
 	case CL_EXECUTING:
 		if (ct->btrn[0]) {
 			ret = btr_node_status(ct->btrn[0], 0, BTR_NT_ROOT);
@@ -426,8 +452,7 @@ out:
 		return 0;
 	btr_remove_node(&ct->btrn[0]);
 	btr_remove_node(&ct->btrn[1]);
-	if (ret != -E_SERVER_CMD_SUCCESS && ret != -E_SERVER_CMD_FAILURE)
-		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+	PARA_NOTICE_LOG("closing connection (%s)\n", para_strerror(-ret));
 	if (ct->scc.fd >= 0) {
 		close(ct->scc.fd);
 		ct->scc.fd = -1;