Header file for onion_tap.c. More...

Macros
#define	TAP_ONIONSKIN_CHALLENGE_LEN

#define	TAP_ONIONSKIN_REPLY_LEN (DH1024_KEY_LEN+DIGEST_LEN)

Functions
int	onion_skin_TAP_create (struct crypto_pk_t router_key, struct crypto_dh_t handshake_state_out, char onion_skin_out)

int	onion_skin_TAP_server_handshake (const char onion_skin, struct crypto_pk_t private_key, struct crypto_pk_t prev_private_key, char handshake_reply_out, char *key_out, size_t key_out_len)

int	onion_skin_TAP_client_handshake (struct crypto_dh_t handshake_state, const char handshake_reply, char key_out, size_t key_out_len, const char *msg_out)

Detailed Description

Header file for onion_tap.c.

Definition in file onion_tap.h.

Macro Definition Documentation

◆ TAP_ONIONSKIN_CHALLENGE_LEN

#define TAP_ONIONSKIN_CHALLENGE_LEN

Value:

                                 (PKCS1_OAEP_PADDING_OVERHEAD+\
                                 CIPHER_KEY_LEN+\
                                 DH1024_KEY_LEN)

Definition at line 15 of file onion_tap.h.

Function Documentation

◆ onion_skin_TAP_client_handshake()

int onion_skin_TAP_client_handshake	(	crypto_dh_t *	handshake_state,
		const char *	handshake_reply,
		char *	key_out,
		size_t	key_out_len,
		const char **	msg_out
	)

Finish the client side of the DH handshake. Given the 128 byte DH reply + 20 byte hash as generated by onion_skin_server_handshake and the handshake state generated by onion_skin_create, verify H(K) with the first 20 bytes of shared key material, then generate key_out_len more bytes of shared key material and store them in key_out.

After the invocation, call crypto_dh_free on handshake_state.

Definition at line 207 of file onion_tap.c.

◆ onion_skin_TAP_create()

int onion_skin_TAP_create	(	crypto_pk_t *	dest_router_key,
		crypto_dh_t **	handshake_state_out,
		char *	onion_skin_out
	)

Given a router's 128 byte public key, stores the following in onion_skin_out:

[42 bytes] OAEP padding
[16 bytes] Symmetric key for encrypting blob past RSA
[70 bytes] g^x part 1 (inside the RSA)
[58 bytes] g^x part 2 (symmetrically encrypted)

Stores the DH private key into handshake_state_out for later completion of the handshake.

The meeting point/cookies and auth are zeroed out for now.

Definition at line 53 of file onion_tap.c.

◆ onion_skin_TAP_server_handshake()

int onion_skin_TAP_server_handshake	(	const char *	onion_skin,
		crypto_pk_t *	private_key,
		crypto_pk_t *	prev_private_key,
		char *	handshake_reply_out,
		char *	key_out,
		size_t	key_out_len
	)

Given an encrypted DH public key as generated by onion_skin_create, and the private key for this onion router, generate the reply (128-byte DH plus the first 20 bytes of shared key material), and store the next key_out_len bytes of key material in key_out.

Definition at line 105 of file onion_tap.c.

Macros