Add strict checks to hex to binary conversions.

[oweals/tinc.git] / src / protocol_auth.c

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 0ef546822146d5f8b2b5b329e7277fa8fecb2b68..3bd34a01b5743bcf3ee5d354bf4cfdde7bc5c90a 100644 (file)
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -308,7 +308,10 @@ bool metakey_h(connection_t *c) {
 
        /* Convert the challenge from hexadecimal back to binary */
 
 
        /* Convert the challenge from hexadecimal back to binary */
 

-       hex2bin(buffer, buffer, len);
+       if(!hex2bin(buffer, buffer, len)) {
+               logger(LOG_ERR, "Got bad %s from %s(%s): %s", "METAKEY", c->name, c->hostname, "invalid key");
+               return false;
+       }

 
        /* Decrypt the meta key */
 
 
        /* Decrypt the meta key */
 


@@ -426,7 +429,10 @@ bool challenge_h(connection_t *c) {
 
        /* Convert the challenge from hexadecimal back to binary */
 
 
        /* Convert the challenge from hexadecimal back to binary */
 

-       hex2bin(buffer, c->mychallenge, len);
+       if(!hex2bin(buffer, c->mychallenge, len)) {
+               logger(LOG_ERR, "Got bad %s from %s(%s): %s", "CHALLENGE", c->name, c->hostname, "invalid challenge");
+               return false;
+       }

 
        c->allow_request = CHAL_REPLY;
 
 
        c->allow_request = CHAL_REPLY;
 


@@ -480,7 +486,10 @@ bool chal_reply_h(connection_t *c) {
 
        /* Convert the hash to binary format */
 
 
        /* Convert the hash to binary format */
 

-       hex2bin(hishash, hishash, c->outdigest->md_size);
+       if(!hex2bin(hishash, hishash, c->outdigest->md_size)) {
+               logger(LOG_ERR, "Got bad %s from %s(%s): %s", "CHAL_REPLY", c->name, c->hostname, "invalid hash");
+               return false;
+       }

 
        /* Calculate the hash from the challenge we sent */
 
 
        /* Calculate the hash from the challenge we sent */