Merge pull request #7146 from bakersdozen123/fix/custom-ssh-heap-overflow

ssh: fix custom ssh heap buffer overflow

src/libgit2/transports/credential.c

@@ -161,7 +161,7 @@ static void ssh_custom_free(struct git_credential *cred)
 
 	if (c->publickey) {
 		/* Zero the memory which previously held the publickey */
-		size_t key_len = strlen(c->publickey);
+		size_t key_len = c->publickey_len;
 		git__memzero(c->publickey, key_len);
 		git__free(c->publickey);
 	}