/* vim: set expandtab ts=4 sw=4: */ /* * You may redistribute this program and/or modify it under the terms of * the GNU General Public License as published by the Free Software Foundation, * either version 3 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #ifndef Headers_H #define Headers_H #include "util/Assert.h" #include "util/Endian.h" #include /** * The header which switches use to decide where to route traffic. * * 1 2 3 * 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 0 | | * + Switch Label + * 4 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 8 | Type | Priority | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ #define Headers_SwitchHeader_TYPE_DATA 0 #define Headers_SwitchHeader_TYPE_CONTROL 1 #pragma pack(push) #pragma pack(4) struct Headers_SwitchHeader { /** The label, this is how the switch decides where to send the packet. Big Endian. */ uint64_t label_be; /** * Top 8 bits: messageType * See: MessageType.h * * Bottom 24 bits: priority * Anti-flooding, this is a big endian uint32_t with the high 8 bits cut off. * * This entire number is in big endian encoding. */ uint32_t lowBits_be; }; #define Headers_SwitchHeader_SIZE 12 Assert_compileTime(sizeof(struct Headers_SwitchHeader) == Headers_SwitchHeader_SIZE); #pragma pack(pop) static inline uint32_t Headers_getMessageType(const struct Headers_SwitchHeader* header) { return Endian_bigEndianToHost32(header->lowBits_be) >> 24; } static inline uint32_t Headers_getPriority(const struct Headers_SwitchHeader* header) { return Endian_bigEndianToHost32(header->lowBits_be) & ((1 << 24) - 1); } static inline void Headers_setPriorityAndMessageType(struct Headers_SwitchHeader* header, const uint32_t priority, const uint32_t messageType) { header->lowBits_be = Endian_hostToBigEndian32( (priority & ((1 << 24) - 1)) | messageType << 24 ); } /** * Header for nodes authenticating to one another. * * 1 2 3 * 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 0 | Auth Type | | * +-+-+-+-+-+-+-+-+ Hash Code + * 4 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 8 |A| Derivations |S| Additional | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * If the 'A' bit is set, the packets in the connection are to be authenticated with Poly1305. * The Auth Type and Hash Code combined make a lookup key which can be used to scan a hashtable * to see if the given password is known. It can be thought of as the "username" although it is * a derivative of the password. * The number of derivations represents how many times the hash of the password has been hashed * again. Assuming Alice and Bob have a secure shared secret and Bob and Charlie have a secure * shared secret, Bob can provide Charlie with a hash of his password with Alice which will allow * Charlie to then establish a secure connection with Alice, without relying exclusively on * asymmetrical cryptography. * * If the packet has 0 length and the 'S' bit is set then the packet is only intended for helping * to setup the Cryptoauth session and should be dropped rather than being passed to the user. */ union Headers_AuthChallenge { struct { uint8_t type; uint8_t lookup[7]; /** * High 1 bit is whether to require poly1305 packet authentication. * low 15 bits is number of derivations. */ uint16_t requirePacketAuthAndDerivationCount; uint16_t additional; } challenge; uint8_t bytes[12]; uint32_t ints[3]; }; /** Total size of the auth structure. */ #define Headers_AuthChallenge_SIZE 12 Assert_compileTime(sizeof(union Headers_AuthChallenge) == Headers_AuthChallenge_SIZE); /** The number of bytes from the beginning which identify the auth for looking up the secret. */ #define Headers_AuthChallenge_KEYSIZE 8 static inline int Headers_isPacketAuthRequired(union Headers_AuthChallenge* ac) { return ac->challenge.requirePacketAuthAndDerivationCount & Endian_hostToBigEndian16(1<<15); } static inline int Headers_isSetupPacket(union Headers_AuthChallenge* ac) { return ac->challenge.additional & Endian_hostToBigEndian16(1<<15); } static inline void Headers_setPacketAuthRequired(union Headers_AuthChallenge* ac, int require) { if (require) { ac->challenge.requirePacketAuthAndDerivationCount |= Endian_hostToBigEndian16(1<<15); } else { ac->challenge.requirePacketAuthAndDerivationCount &= Endian_hostToBigEndian16(~(1<<15)); } } static inline void Headers_setSetupPacket(union Headers_AuthChallenge* ac, int empty) { if (empty) { ac->challenge.additional |= Endian_hostToBigEndian16(1<<15); } else { ac->challenge.additional &= Endian_hostToBigEndian16(~(1<<15)); } } static inline uint16_t Headers_getAuthChallengeDerivations(union Headers_AuthChallenge* ac) { return Endian_hostToBigEndian16(ac->challenge.requirePacketAuthAndDerivationCount) & (((uint16_t)~0)>>1); } static inline void Headers_setAuthChallengeDerivations(union Headers_AuthChallenge* ac, uint16_t derivations) { ac->challenge.requirePacketAuthAndDerivationCount &= Endian_hostToBigEndian16(1<<15); ac->challenge.requirePacketAuthAndDerivationCount |= Endian_hostToBigEndian16(derivations & ~(1<<15)); } /** * This is a handshake header packet, there are 2 required to begin an encrypted connection. * * 1 2 3 * 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 0 | Session State | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 4 | | * + + * 8 | Auth Challenge | * + + * 12 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 16 | | * + + * 20 | | * + + * 24 | | * + Random Nonce + * 28 | | * + + * 32 | | * + + * 36 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 40 | | * + + * 44 | | * + + * 48 | | * + + * 52 | | * + Permanent Public Key + * 56 | | * + + * 60 | | * + + * 64 | | * + + * 68 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 72 | | * + + * 76 | | * + Poly1305 Authenticator + * 80 | | * + + * 84 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * 88 | | * + + * 92 | | * + + * 96 | | * + + * 100 | | * + Encrypted/Authenticated Temporary Public Key + * 104 | | * + + * 108 | | * + + * 112 | | * + + * 116 | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | | * + Variable Length Encrypted/Authenticated Content + * | | * * If "Session State" is equal to the bitwise complement of zero, the sender is requesting * that the recipient begin a connection with him, this is done in cases when the initiator * of the connection does not know the key for the recipient. If the entire header is not * present the recipient MUST drop the packet silently, the only field which is read in the * packet is the "Permanent Public Key" field, all others SHOULD be ignored, specifically, * content MUST not be passed on because it cannot be authenticated. The recipient of such a * packet SHOULD send back a "hello" packet if there is no established connection. * If there is already a connection over the interface, the recipient SHOULD NOT respond * but MAY allow the connection to time out faster. * * If the "Session State" field is equal to the one or two, the packet is a "hello" packet. * or a repeated hello packet. If no connection is present, one should be established and the * recipient MAY send a "key" packet in response but it is RECOMMENDED that he wait until * he has data to send first. A node who has sent a hello packet and gotten no response and * now wishes to send more data MUST send that data as more (repeat) hello packets. * * If the "Session State" field is equal to two or three, the packet is a "key" packet. * Key packets are responses to hello packets. Once a node receives a key packet it may begin * sending data packets. A node who has received a hello packet, sent a key packet and gotten * no further response who now wishes to send more data MUST send that data as more (repeat) * key packets. */ union Headers_CryptoAuth { uint32_t nonce; struct { /** * Numbers one through three are interpreted as handshake packets, UINT32_MAX is * a connectToMe packet and anything else is a nonce in a traff packet. */ uint32_t handshakeStage; /** Used for authenticating routers to one another. */ union Headers_AuthChallenge auth; /** Random nonce for the handshake. */ uint8_t nonce[24]; /** This node's permanent public key. */ uint8_t publicKey[32]; /** This is filled in when the tempKey is encrypted. */ uint8_t authenticator[16]; /** The public key to use for this session, encrypted with the private key. */ uint8_t encryptedTempKey[32]; } handshake; }; #define Headers_CryptoAuth_SIZE 120 Assert_compileTime(sizeof(union Headers_CryptoAuth) == Headers_CryptoAuth_SIZE); struct Headers_IP6Header { uint16_t versionClassAndFlowLabel; /** Big Endian. */ uint16_t flowLabelLow_be; /** Big Endian. */ uint16_t payloadLength_be; uint8_t nextHeader; uint8_t hopLimit; uint8_t sourceAddr[16]; uint8_t destinationAddr[16]; }; #define Headers_IP6Header_SIZE 40 Assert_compileTime(sizeof(struct Headers_IP6Header) == Headers_IP6Header_SIZE); struct Headers_IP6Fragment { uint8_t nextHeader; uint8_t zero; uint16_t fragmentOffsetAndMoreFragments_be; uint32_t identifier; }; #define Headers_IP6Fragment_SIZE 8 Assert_compileTime(sizeof(struct Headers_IP6Fragment) == Headers_IP6Fragment_SIZE); #define Headers_IP6Fragment_TYPE 44 static inline uint32_t Headers_IP6Fragment_getOffset(struct Headers_IP6Fragment* frag) { return Endian_bigEndianToHost16(frag->fragmentOffsetAndMoreFragments_be) >> 3; } static inline void Headers_IP6Fragment_setOffset(struct Headers_IP6Fragment* frag, uint16_t offset) { frag->fragmentOffsetAndMoreFragments_be &= Endian_hostToBigEndian16(7); frag->fragmentOffsetAndMoreFragments_be |= Endian_hostToBigEndian16(offset << 3); } static inline int Headers_IP6Fragment_hasMoreFragments(struct Headers_IP6Fragment* frag) { return frag->fragmentOffsetAndMoreFragments_be & Endian_hostToBigEndian16(1); } static inline void Headers_IP6Fragment_setMoreFragments(struct Headers_IP6Fragment* frag, int more) { if (more) { frag->fragmentOffsetAndMoreFragments_be |= Endian_hostToBigEndian16(1); } else { frag->fragmentOffsetAndMoreFragments_be &= Endian_hostToBigEndian16(0xFFFF << 1); } } struct Headers_IP4Header { uint8_t versionAndHeaderLength; uint8_t differentiatedServices; uint16_t totalLength_be; uint16_t identification_be; uint16_t flagsAndFragmentOffset; uint8_t ttl; uint8_t protocol; uint16_t checksum_be; uint8_t sourceAddr[4]; uint8_t destAddr[4]; }; #define Headers_IP4Header_SIZE 20 Assert_compileTime(sizeof(struct Headers_IP4Header) == Headers_IP4Header_SIZE); static inline int Headers_getIpVersion(void* header) { return (((uint8_t*) header)[0] & 0xF0) >> 4; } #define Headers_setIpVersion(header) \ (((uint8_t*) header)[0] |= ( \ (sizeof(*header) == Headers_IP4Header_SIZE) ? 4 : 6 \ ) << 4) struct Headers_UDPHeader { uint16_t srcPort_be; uint16_t destPort_be; uint16_t length_be; uint16_t checksum_be; }; #define Headers_UDPHeader_SIZE 8 Assert_compileTime(sizeof(struct Headers_UDPHeader) == Headers_UDPHeader_SIZE); struct Headers_ICMP6Header { uint8_t type; uint8_t code; uint16_t checksum; uint32_t additional; }; #define Headers_ICMP6Header_SIZE 8 Assert_compileTime(sizeof(struct Headers_ICMP6Header) == Headers_ICMP6Header_SIZE); /** * A message which is broadcast to signal to other nodes in the local network that they can connect. */ #define Headers_Beacon_PASSWORD_LEN 20 struct Headers_Beacon { uint32_t version_be; uint8_t password[Headers_Beacon_PASSWORD_LEN]; uint8_t publicKey[32]; }; #define Headers_Beacon_SIZE 56 Assert_compileTime(sizeof(struct Headers_Beacon) == Headers_Beacon_SIZE); #endif