From 21ce3491dd39485eac35ad850257a20fc99f330d Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Fri, 21 Oct 2016 17:19:59 +0100
Subject: [PATCH] Clear random buf in olm_init_outbound_group_session
All the other methods clear their random inputs. This one needs to do the same,
to reduce the risk of the randomness being used elsewhere and leaking key info.
---
include/olm/outbound_group_session.h | 2 +-
src/outbound_group_session.c | 13 ++++++++-----
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/include/olm/outbound_group_session.h b/include/olm/outbound_group_session.h
index 90ccca3..663f1d2 100644
--- a/include/olm/outbound_group_session.h
+++ b/include/olm/outbound_group_session.h
@@ -96,7 +96,7 @@ size_t olm_init_outbound_group_session_random_length(
*/
size_t olm_init_outbound_group_session(
OlmOutboundGroupSession *session,
- uint8_t const * random, size_t random_length
+ uint8_t *random, size_t random_length
);
/**
diff --git a/src/outbound_group_session.c b/src/outbound_group_session.c
index 4e4561a..ae45694 100644
--- a/src/outbound_group_session.c
+++ b/src/outbound_group_session.c
@@ -154,20 +154,23 @@ size_t olm_init_outbound_group_session_random_length(
size_t olm_init_outbound_group_session(
OlmOutboundGroupSession *session,
- uint8_t const * random, size_t random_length
+ uint8_t *random, size_t random_length
) {
+ const uint8_t *random_ptr = random;
+
if (random_length < olm_init_outbound_group_session_random_length(session)) {
/* Insufficient random data for new session */
session->last_error = OLM_NOT_ENOUGH_RANDOM;
return (size_t)-1;
}
- megolm_init(&(session->ratchet), random, 0);
- random += MEGOLM_RATCHET_LENGTH;
+ megolm_init(&(session->ratchet), random_ptr, 0);
+ random_ptr += MEGOLM_RATCHET_LENGTH;
- _olm_crypto_ed25519_generate_key(random, &(session->signing_key));
- random += ED25519_RANDOM_LENGTH;
+ _olm_crypto_ed25519_generate_key(random_ptr, &(session->signing_key));
+ random_ptr += ED25519_RANDOM_LENGTH;
+ _olm_unset(random, random_length);
return 0;
}
--
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