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prepared header iv encryption handling

pull/279/head
Logan007 4 years ago
parent
commit
a6915fd6af
  1. 7
      include/header_encryption.h
  2. 4
      include/n2n.h
  3. 16
      src/header_encryption.c

7
include/header_encryption.h

@ -21,7 +21,10 @@ uint32_t packet_header_decrypt (uint8_t packet[], uint16_t packet_len,
char * community_name, he_context_t * ctx);
int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_t * ctx);
int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_t * ctx,
uint16_t checksum);
void packet_header_setup_key (const char * community_name, he_context_t ** ctx);
void packet_header_setup_key (const char * community_name, he_context_t ** ctx,
he_context_t ** ctx_iv);

4
include/n2n.h

@ -221,6 +221,7 @@ typedef struct n2n_edge_conf {
n2n_community_t community_name; /**< The community. 16 full octets. */
uint8_t header_encryption; /**< Header encryption indicator. */
he_context_t *header_encryption_ctx; /**< Header encryption cipher context. */
he_context_t *header_iv_ctx; /**< Header IV ecnryption cipher context, REMOVE as soon as seperte fileds for checksum and replay protection available */
n2n_transform_t transop_id; /**< The transop to use. */
uint16_t compression; /**< Compress outgoing data packets before encryption */
uint16_t num_routes; /**< Number of routes in routes */
@ -255,7 +256,8 @@ struct sn_community
{
char community[N2N_COMMUNITY_SIZE];
uint8_t header_encryption; /* Header encryption indicator. */
he_context_t *header_encryption_ctx; /* Header encryption cipher context. */
he_context_t *header_encryption_ctx; /* Header encryption cipher context. */
he_context_t *header_iv_ctx; /* Header IV ecnryption cipher context, REMOVE as soon as seperte fileds for checksum and replay protection available */
struct peer_info *edges; /* Link list of registered edges. */
UT_hash_handle hh; /* makes this structure hashable */

16
src/header_encryption.c

@ -56,9 +56,11 @@ uint32_t packet_header_decrypt (uint8_t packet[], uint16_t packet_len,
/* ********************************************************************** */
int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_t * ctx) {
int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_t * ctx,
uint16_t checksum) {
uint8_t iv[16];
uint16_t *iv16 = (uint16_t*)&iv;
uint32_t *iv32 = (uint32_t*)&iv;
uint64_t *iv64 = (uint64_t*)&iv;
const uint32_t magic = 0x6E326E21; // = ASCII "n2n!"
@ -71,7 +73,8 @@ int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_
memcpy (&packet[16], &packet[00], 4);
iv64[0] = n2n_rand ();
iv32[2] = n2n_rand ();
iv16[4] = n2n_rand ();
iv16[5] = htobe16 (checksum);
iv32[3] = htobe32 (magic);
memcpy (packet, iv, 16);
@ -83,11 +86,18 @@ int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_
/* ********************************************************************** */
void packet_header_setup_key (const char * community_name, he_context_t ** ctx) {
void packet_header_setup_key (const char * community_name, he_context_t ** ctx,
he_context_t ** ctx_iv) {
uint8_t key[16];
pearson_hash_128 (key, (uint8_t*)community_name, N2N_COMMUNITY_SIZE);
*ctx = (he_context_t*)calloc(1, sizeof (speck_context_t));
speck_expand_key_he (key, (speck_context_t*)*ctx);
// hash again and use last 96 bit (skipping 4 bytes) as key for IV encryption
// REMOVE as soon as checksum and replay protection get their own fields
pearson_hash_128 (key, key, sizeof (key));
*ctx_iv = (he_context_t*)calloc(1, sizeof (speck_context_t));
speck_expand_key_he_iv (&key[4], (speck_context_t*)*ctx_iv);
}

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