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authorMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
committerMatt Johnston <matt@ucc.asn.au>2004-06-01 02:46:09 +0000
commit674a60748884dc55ee7091b7c23a41240e75f73c (patch)
tree3b5a173c356f867b94df3873b57ff36d33129ea7 /svr-algo.c
Makefile.in contains updated files required
--HG-- extra : convert_revision : cc8a8c49dc70e632c352853a39801089b08149be
Diffstat (limited to 'svr-algo.c')
-rw-r--r--svr-algo.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/svr-algo.c b/svr-algo.c
new file mode 100644
index 0000000..33b9471
--- /dev/null
+++ b/svr-algo.c
@@ -0,0 +1,74 @@
+#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;
+
+ /* 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;
+ } else {
+ *goodguess = 0;
+ }
+ /* set the algo to return */
+ ret = &localalgos[j];
+ goto out;
+ }
+ }
+ }
+ }
+
+out:
+ m_free(algolist);
+ return ret;
+}