diff --git a/CMakeLists.txt b/CMakeLists.txt index a1eb4c6..324bac0 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -61,8 +61,12 @@ add_library(n2n n2n.c transform_null.c transform_tf.c transform_aes.c + transform_cc20.c + transform_speck.c + speck.c random_numbers.c pearson.c + header_encryption.c tuntap_freebsd.c tuntap_netbsd.c tuntap_linux.c diff --git a/Makefile.in b/Makefile.in index 5b5a19d..1bca92c 100644 --- a/Makefile.in +++ b/Makefile.in @@ -51,7 +51,7 @@ N2N_LIB=libn2n.a N2N_OBJS=n2n.o wire.o minilzo.o twofish.o speck.o \ edge_utils.o sn_utils.o \ transform_null.o transform_tf.o transform_aes.o transform_cc20.o transform_speck.o \ - pearson.o \ + header_encryption.o pearson.o \ tuntap_freebsd.o tuntap_netbsd.o tuntap_linux.o random_numbers.o \ tuntap_osx.o LIBS_EDGE+=$(LIBS_EDGE_OPT) diff --git a/header_encryption.c b/header_encryption.c index e263cfc..8f7ab97 100644 --- a/header_encryption.c +++ b/header_encryption.c @@ -1,35 +1,38 @@ -#include -#include +#include "header_encryption.h" + +#include -// #include "n2n_wire.h" // n2n_community_t #include "n2n.h" -#include "speck.h" +#include "random_numbers.h" +#include "pearson.h" #include "portable_endian.h" -uint32_t decryt_packet_header (uint8_t packet[], uint8_t packet_len, - char * community_name, speck_ctx * ctx) { +#include + + +uint32_t packet_header_decrypt (uint8_t packet[], uint8_t packet_len, + char * community_name, he_context_t * ctx) { // assemble IV // the last four are ASCII "n2n!" and do not get overwritten uint8_t iv[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x6E, 0x32, 0x6E, 0x21 }; - // the first 96 bits of the packet are used padded with ASCII "n2n!" + // the first 96 bits of the packet get padded with ASCII "n2n!" // to full 128 bit IV - memcopy (iv, packet, 12); - - // alternatively, consider: pearson_hash_128 (iv, packet, 12) + memcpy (iv, packet, 12); + // alternatively, consider: pearson_hash_128 (iv, packet, 12); // try community name as possible key and check for magic bytes uint32_t magic = 0x6E326E00; // ="n2n_" uint32_t test_magic; // check for magic bytes and resonable value in header len field - speck_he ((uint8_t*)&test_magic, &packet[12], 4, iv, ctx); + speck_he ((uint8_t*)&test_magic, &packet[12], 4, iv, (speck_context_t*)ctx); test_magic = be32toh (test_magic); if ( ((test_magic << 8) == magic) && ((test_magic >> 24) <= packet_len) // (test_masgic >> 24) is header_len ) { - speck_he (&packet[12], &packet[12], (test_magic >> 24) - 12, iv, ctx); + speck_he (&packet[12], &packet[12], (test_magic >> 24) - 12, iv, (speck_context_t*)ctx); // restore original packet order memcpy (&packet[0], &packet[16], 4); memcpy (&packet[4], community_name, N2N_COMMUNITY_SIZE); @@ -39,7 +42,7 @@ uint32_t decryt_packet_header (uint8_t packet[], uint8_t packet_len, } -int32_t decryt_packet_header_if_required (uint8_t packet[], uint16_t packet_len, +int32_t packet_header_decrypt_if_required (uint8_t packet[], uint16_t packet_len, struct sn_community *communities) { if (packet_len < 20) @@ -58,8 +61,12 @@ int32_t decryt_packet_header_if_required (uint8_t packet[], uint16_t packet_len, ) { // most probably unencrypted - return (1); + // TODO: + // !!! make sure, no downgrading happens here !!! + // NOT FOR DEFINETLY ENCRYPTED COMMUNITIES / NO DOWNGRADE, NO INJECTION + + return (HEADER_ENCRYPTION_NONE); } else { // most probably encrypted @@ -67,24 +74,23 @@ int32_t decryt_packet_header_if_required (uint8_t packet[], uint16_t packet_len, int32_t ret; struct sn_community *c, *tmp; HASH_ITER (hh, communities, c, tmp) { - // check if this is an encrypted community - if ( ret = decrypt_packet_header (packet, packet_len, c->community, c-> ctx) ) { - // no upgrade from unencrypted to encrypted - if (c->header_encryption == 1) - return (-2); + // skip the definitely unencrypted communities + if (c->header_encryption == HEADER_ENCRYPTION_NONE) + continue; + if ( (ret = packet_header_decrypt (packet, packet_len, c->community, &(c->header_encryption_ctx))) ) { // set to 'encrypted' - c->header_encryption = 2; + c->header_encryption = HEADER_ENCRYPTION_ENABLED; // no need to test any further - return (2); + return (HEADER_ENCRYPTION_ENABLED); } } - // no match + // no matching key/community return (-3); } } -int32_t encryt_packet_header (uint8_t packet[], uint8_t header_len, speck_ctx * ctx) { +int32_t packet_header_encrypt (uint8_t packet[], uint8_t header_len, he_context_t * ctx) { if (header_len < 20) return (-1); @@ -100,5 +106,16 @@ int32_t encryt_packet_header (uint8_t packet[], uint8_t header_len, speck_ctx * iv[12] = header_len; - speck_he (&packet[12], &packet[12], header_len - 12, iv, ctx); + speck_he (&packet[12], &packet[12], header_len - 12, iv, (speck_context_t*)ctx); + + return (0); +} + + +void packet_header_setup_key (char * community_name, he_context_t * ctx) { + + uint8_t key[16]; + pearson_hash_128 (key, (uint8_t*)community_name, N2N_COMMUNITY_SIZE); + + speck_expand_key_he (key, ctx); } diff --git a/header_encryption.h b/header_encryption.h new file mode 100644 index 0000000..f8a31cb --- /dev/null +++ b/header_encryption.h @@ -0,0 +1,17 @@ +#include + +#include "speck.h" +typedef speck_context_t he_context_t; + + +#define HEADER_ENCRYPTION_UNKNOWN 0 +#define HEADER_ENCRYPTION_NONE 1 +#define HEADER_ENCRYPTION_ENABLED 2 + + +uint32_t decrypt_packet_header (uint8_t packet[], uint8_t packet_len, + char * community_name, he_context_t * ctx); + +int32_t encryt_packet_header (uint8_t packet[], uint8_t header_len, he_context_t * ctx); + +int32_t encryt_packet_header (uint8_t packet[], uint8_t header_len, he_context_t * ctx); diff --git a/n2n.h b/n2n.h index 7737213..c503bef 100644 --- a/n2n.h +++ b/n2n.h @@ -111,6 +111,7 @@ typedef struct ether_hdr ether_hdr_t; #include #include #include "minilzo.h" +#include "header_encryption.h" #define closesocket(a) close(a) #endif /* #ifndef WIN32 */ @@ -160,6 +161,7 @@ typedef struct tuntap_dev { #define MSG_TYPE_FEDERATION 8 #define MSG_TYPE_PEER_INFO 9 #define MSG_TYPE_QUERY_PEER 10 +#define MSG_TYPE_MAX_TYPE 10 /* N2N compression indicators. */ /* Compression is disabled by default for outgoing packets if no cli @@ -225,6 +227,8 @@ typedef struct n2n_edge_conf { n2n_sn_name_t sn_ip_array[N2N_EDGE_NUM_SUPERNODES]; n2n_route_t *routes; /**< Networks to route through n2n */ 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. */ 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 */ @@ -270,7 +274,9 @@ typedef struct sn_stats struct sn_community { char community[N2N_COMMUNITY_SIZE]; - struct peer_info *edges; /* Link list of registered edges. */ + uint8_t header_encryption; /* Header encryption indicator. */ + he_context_t header_encryption_ctx; /* Header encryption cipher context. */ + struct peer_info *edges; /* Link list of registered edges. */ UT_hash_handle hh; /* makes this structure hashable */ }; diff --git a/pearson.c b/pearson.c index 0ff0e0d..76f7953 100644 --- a/pearson.c +++ b/pearson.c @@ -157,3 +157,59 @@ void pearson_hash_256 (uint8_t *out, const uint8_t *in, size_t len) { o = (uint64_t*)&out[24]; *o = lower_hash; } + + +void pearson_hash_128 (uint8_t *out, const uint8_t *in, size_t len) { + + /* initial values - astonishingly, assembling using SHIFTs and ORs (in register) + * works faster on well pipelined CPUs than loading the 64-bit value from memory. + * however, there is one advantage to loading from memory: as we also store back to + * memory at the end, we do not need to care about endianess! */ + uint8_t upper[8] = { 0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 }; + uint8_t lower[8] = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00 }; + + uint64_t upper_hash_mask = *(uint64_t*)&upper; + uint64_t lower_hash_mask = *(uint64_t*)&lower; + + uint64_t upper_hash = 0; + uint64_t lower_hash = 0; + + for (size_t i = 0; i < len; i++) { + // broadcast the character, xor into hash, make them different permutations + uint64_t c = (uint8_t)in[i]; + c |= c << 8; + c |= c << 16; + c |= c << 32; + upper_hash ^= c ^ upper_hash_mask; + lower_hash ^= c ^ lower_hash_mask; + // table lookup + uint8_t x; + uint64_t h = 0; + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + x = upper_hash; x = t[x]; upper_hash >>= 8; h |= x; h=ROR64(h,8); + upper_hash = h; + + h = 0; + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + x = lower_hash; x = t[x]; lower_hash >>= 8; h |= x; h=ROR64(h,8); + lower_hash = h; + } + // store output + uint64_t *o; + o = (uint64_t*)&out[0]; + *o = upper_hash; + o = (uint64_t*)&out[8]; + *o = lower_hash; +} diff --git a/pearson.h b/pearson.h index 5e4ca66..6aaa604 100644 --- a/pearson.h +++ b/pearson.h @@ -17,3 +17,5 @@ */ void pearson_hash_256 (uint8_t *out, const uint8_t *in, size_t len); + +void pearson_hash_128 (uint8_t *out, const uint8_t *in, size_t len); diff --git a/speck.h b/speck.h index 3b8cba5..51df36b 100644 --- a/speck.h +++ b/speck.h @@ -2,6 +2,10 @@ // taken from (and modified: removed pure crypto-stream generation and seperated key expansion) // https://github.com/nsacyber/simon-speck-supercop/blob/master/crypto_stream/speck128256ctr/ + +#ifndef SPECK_H +#define SPECK_H + #define u32 uint32_t #define u64 uint64_t @@ -61,3 +65,6 @@ int speck_he (unsigned char *out, const unsigned char *in, unsigned long long in int speck_expand_key_he (const unsigned char *k, speck_context_t *ctx); + + +#endif