1 files changed, 100 insertions, 0 deletions
diff --git a/svr-algo.c b/svr-algo.c
new file mode 100644
index 0000000..c0b7823
--- /dev/null
+++ b/svr-algo.c
@@ -0,0 +1,100 @@
+/*
+ * Dropbear - a SSH2 server
+ * SSH client implementation
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) 2004 by Mihnea Stoenescu
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "algo.h"
+#include "dbutil.h"
+
+/* match the first algorithm in the comma-separated list in buf which is
+ * also in localalgos[], or return NULL on failure.
+ * (*goodguess) is set to 1 if the preferred client/server algos match,
+ * 0 otherwise. This is used for checking if the kexalgo/hostkeyalgos are
+ * guessed correctly */
+algo_type * svr_buf_match_algo(buffer* buf, algo_type localalgos[],
+		int *goodguess)
+{
+
+	unsigned char * algolist = NULL;
+	unsigned char * remotealgos[MAX_PROPOSED_ALGO];
+	unsigned int len;
+	unsigned int count, i, j;
+	algo_type * ret = NULL;
+
+	*goodguess = 0;
+
+	/* get the comma-separated list from the buffer ie "algo1,algo2,algo3" */
+	algolist = buf_getstring(buf, &len);
+	/* Debug this */
+	TRACE(("buf_match_algo: %s", algolist))
+	if (len > MAX_PROPOSED_ALGO*(MAX_NAME_LEN+1)) {
+		goto out; /* just a sanity check, no other use */
+	}
+
+	/* remotealgos will contain a list of the strings parsed out */
+	/* We will have at least one string (even if it's just "") */
+	remotealgos[0] = algolist;
+	count = 1;
+	/* Iterate through, replacing ','s with NULs, to split it into
+	 * words. */
+	for (i = 0; i < len; i++) {
+		if (algolist[i] == '\0') {
+			/* someone is trying something strange */
+			goto out;
+		}
+		if (algolist[i] == ',') {
+			algolist[i] = '\0';
+			remotealgos[count] = &algolist[i+1];
+			count++;
+		}
+		if (count == MAX_PROPOSED_ALGO) {
+			break;
+		}
+	}
+
+	/* iterate and find the first match */
+	for (i = 0; i < count; i++) {
+
+		len = strlen(remotealgos[i]);
+
+		for (j = 0; localalgos[j].name != NULL; j++) {
+			if (localalgos[j].usable) {
+				if (len == strlen(localalgos[j].name) &&
+						strncmp(localalgos[j].name, remotealgos[i], len) == 0) {
+					/* set if it was a good guess */
+					if (i == 0 && j == 0) {
+						*goodguess = 1;
+					}
+					/* set the algo to return */
+					ret = &localalgos[j];
+					goto out;
+				}
+			}
+		}
+	}
+
+out:
+	m_free(algolist);
+	return ret;
+}