tor-gencert --passphrase-fd improperly checks for newline

How to trigger:

$ tor-gencert --create-identity-key --passphrase-fd 0 < /dev/null

It depends on your system what will happen now: assert, not enough memory, or nothing.

This patch properly checks if memchr call returns NULL:

 src/tools/tor-gencert.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/tools/tor-gencert.c b/src/tools/tor-gencert.c
index e833aa9..d4c8c0d 100644
--- a/src/tools/tor-gencert.c
+++ b/src/tools/tor-gencert.c
@@ -103,6 +103,10 @@ load_passphrase(void)
     return -1;
   }
   cp = memchr(buf, '\n', n);
+  if (cp == NULL) {
+    log_err(LD_GENERAL, "Couldn't read from passphrase fd: missing newline");
+    return -1;
+  }
   passphrase_len = cp-buf;
   passphrase = tor_strndup(buf, passphrase_len);
   memwipe(buf, 0, sizeof(buf));

---

Trac:
Username: junglefowl