From 9e8d603d14561095fb8d08871319a315d3bf6763 Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Fri, 2 Aug 2019 19:12:34 +0200 Subject: lib: Add per-message encryption with OpenSSL This adds a per-message symmetric encryption using the OpenSSL library. At flow allocation, an Elliptic Curve Diffie-Hellman exchange is performed to derive a shared secret, which is then hashed using SHA3-256 to be used as a key for symmetric AES-256 encryption. Each message on an encrypted flow adds a small crypto header that includes a random 128-bit Initialization Vector (IV). If the server does not have OpenSSL enabled, the flow allocation will fail with an -ECRYPT error. Future optimizations are to piggyback the public keys on the flow allocation message, and to enable per-flow encryption that maintains the context of the encryption over multiple packets and doesn't require sending IVs. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/udp/main.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/ipcpd/udp') diff --git a/src/ipcpd/udp/main.c b/src/ipcpd/udp/main.c index a1dcb602..f6aa57d1 100644 --- a/src/ipcpd/udp/main.c +++ b/src/ipcpd/udp/main.c @@ -91,6 +91,7 @@ struct mgmt_msg { uint32_t loss; uint32_t ber; uint32_t max_gap; + uint32_t cypher_s; } __attribute__((packed)); struct mgmt_frame { @@ -209,6 +210,7 @@ static int ipcp_udp_port_alloc(int skfd, msg->ber = hton32(qs.ber); msg->in_order = qs.in_order; msg->max_gap = hton32(qs.max_gap); + msg->cypher_s = hton32(qs.cypher_s); memcpy(msg + 1, dst, ipcp_dir_hash_len()); @@ -383,6 +385,8 @@ static int ipcp_udp_mgmt_frame(const uint8_t * buf, qs.ber = ntoh32(msg->ber); qs.in_order = msg->in_order; qs.max_gap = ntoh32(msg->max_gap); + qs.cypher_s = ntoh16(msg->cypher_s); + return ipcp_udp_port_req(&c_saddr, ntoh32(msg->s_eid), (uint8_t *) (msg + 1), qs); case FLOW_REPLY: -- cgit v1.2.3