diff options
Diffstat (limited to 'src/feature/hs/hs_descriptor.h')
| -rw-r--r-- | src/feature/hs/hs_descriptor.h | 84 |
1 files changed, 75 insertions, 9 deletions
diff --git a/src/feature/hs/hs_descriptor.h b/src/feature/hs/hs_descriptor.h index bfdf7559c6..adfb94deaa 100644 --- a/src/feature/hs/hs_descriptor.h +++ b/src/feature/hs/hs_descriptor.h @@ -37,12 +37,6 @@ struct link_specifier_t; #define HS_DESC_CERT_LIFETIME (54 * 60 * 60) /* Length of the salt needed for the encrypted section of a descriptor. */ #define HS_DESC_ENCRYPTED_SALT_LEN 16 -/* Length of the secret input needed for the KDF construction which derives - * the encryption key for the encrypted data section of the descriptor. This - * adds up to 68 bytes being the blinded key, hashed subcredential and - * revision counter. */ -#define HS_DESC_ENCRYPTED_SECRET_INPUT_LEN \ - ED25519_PUBKEY_LEN + DIGEST256_LEN + sizeof(uint64_t) /* Length of the KDF output value which is the length of the secret key, * the secret IV and MAC key length which is the length of H() output. */ #define HS_DESC_ENCRYPTED_KDF_OUTPUT_LEN \ @@ -59,6 +53,17 @@ struct link_specifier_t; #define HS_DESC_ENCRYPTED_KEY_LEN CIPHER256_KEY_LEN #define HS_DESC_ENCRYPTED_BIT_SIZE (HS_DESC_ENCRYPTED_KEY_LEN * 8) +/* Length of each components in the auth client section in the descriptor. */ +#define HS_DESC_CLIENT_ID_LEN 8 +#define HS_DESC_DESCRIPTOR_COOKIE_LEN 16 +#define HS_DESC_COOKIE_KEY_LEN 32 +#define HS_DESC_COOKIE_KEY_BIT_SIZE (HS_DESC_COOKIE_KEY_LEN * 8) +#define HS_DESC_ENCRYPED_COOKIE_LEN HS_DESC_DESCRIPTOR_COOKIE_LEN + +/* The number of auth client entries in the descriptor must be the multiple + * of this constant. */ +#define HS_DESC_AUTH_CLIENT_MULTIPLE 16 + /* Type of authentication in the descriptor. */ typedef enum { HS_DESC_AUTH_ED25519 = 1 @@ -126,6 +131,20 @@ typedef struct hs_desc_intro_point_t { unsigned int cross_certified : 1; } hs_desc_intro_point_t; +/* Authorized client information located in a descriptor. */ +typedef struct hs_desc_authorized_client_t { + /* An identifier that the client will use to identify which auth client + * entry it needs to use. */ + uint8_t client_id[HS_DESC_CLIENT_ID_LEN]; + + /* An IV that is used to decrypt the encrypted descriptor cookie. */ + uint8_t iv[CIPHER_IV_LEN]; + + /* An encrypted descriptor cookie that the client needs to decrypt to use + * it to decrypt the descriptor. */ + uint8_t encrypted_cookie[HS_DESC_ENCRYPED_COOKIE_LEN]; +} hs_desc_authorized_client_t; + /* The encrypted data section of a descriptor. Obviously the data in this is * in plaintext but encrypted once encoded. */ typedef struct hs_desc_encrypted_data_t { @@ -144,6 +163,24 @@ typedef struct hs_desc_encrypted_data_t { smartlist_t *intro_points; } hs_desc_encrypted_data_t; +/* The superencrypted data section of a descriptor. Obviously the data in + * this is in plaintext but encrypted once encoded. */ +typedef struct hs_desc_superencrypted_data_t { + /* This field contains ephemeral x25519 public key which is used by + * the encryption scheme in the client authorization. */ + curve25519_public_key_t auth_ephemeral_pubkey; + + /* A list of authorized clients. Contains hs_desc_authorized_client_t + * objects. */ + smartlist_t *clients; + + /* Decoding only: The b64-decoded encrypted blob from the descriptor */ + uint8_t *encrypted_blob; + + /* Decoding only: Size of the encrypted_blob */ + size_t encrypted_blob_size; +} hs_desc_superencrypted_data_t; + /* Plaintext data that is unencrypted information of the descriptor. */ typedef struct hs_desc_plaintext_data_t { /* Version of the descriptor format. Spec specifies this field as a @@ -182,6 +219,11 @@ typedef struct hs_descriptor_t { /* Contains the plaintext part of the descriptor. */ hs_desc_plaintext_data_t plaintext_data; + /* The following contains what's in the superencrypted part of the + * descriptor. It's only encrypted in the encoded version of the descriptor + * thus the data contained in that object is in plaintext. */ + hs_desc_superencrypted_data_t superencrypted_data; + /* The following contains what's in the encrypted part of the descriptor. * It's only encrypted in the encoded version of the descriptor thus the * data contained in that object is in plaintext. */ @@ -211,6 +253,10 @@ void hs_descriptor_free_(hs_descriptor_t *desc); void hs_desc_plaintext_data_free_(hs_desc_plaintext_data_t *desc); #define hs_desc_plaintext_data_free(desc) \ FREE_AND_NULL(hs_desc_plaintext_data_t, hs_desc_plaintext_data_free_, (desc)) +void hs_desc_superencrypted_data_free_(hs_desc_superencrypted_data_t *desc); +#define hs_desc_superencrypted_data_free(desc) \ + FREE_AND_NULL(hs_desc_superencrypted_data_t, \ + hs_desc_superencrypted_data_free_, (desc)) void hs_desc_encrypted_data_free_(hs_desc_encrypted_data_t *desc); #define hs_desc_encrypted_data_free(desc) \ FREE_AND_NULL(hs_desc_encrypted_data_t, hs_desc_encrypted_data_free_, (desc)) @@ -226,14 +272,19 @@ void hs_descriptor_clear_intro_points(hs_descriptor_t *desc); MOCK_DECL(int, hs_desc_encode_descriptor,(const hs_descriptor_t *desc, const ed25519_keypair_t *signing_kp, + const uint8_t *descriptor_cookie, char **encoded_out)); int hs_desc_decode_descriptor(const char *encoded, const uint8_t *subcredential, + const curve25519_secret_key_t *client_auth_sk, hs_descriptor_t **desc_out); int hs_desc_decode_plaintext(const char *encoded, hs_desc_plaintext_data_t *plaintext); +int hs_desc_decode_superencrypted(const hs_descriptor_t *desc, + hs_desc_superencrypted_data_t *desc_out); int hs_desc_decode_encrypted(const hs_descriptor_t *desc, + const curve25519_secret_key_t *client_auth_sk, hs_desc_encrypted_data_t *desc_out); size_t hs_desc_obj_size(const hs_descriptor_t *data); @@ -243,10 +294,27 @@ hs_desc_intro_point_t *hs_desc_intro_point_new(void); void hs_desc_intro_point_free_(hs_desc_intro_point_t *ip); #define hs_desc_intro_point_free(ip) \ FREE_AND_NULL(hs_desc_intro_point_t, hs_desc_intro_point_free_, (ip)) +void hs_desc_authorized_client_free_(hs_desc_authorized_client_t *client); +#define hs_desc_authorized_client_free(client) \ + FREE_AND_NULL(hs_desc_authorized_client_t, \ + hs_desc_authorized_client_free_, (client)) link_specifier_t *hs_desc_lspec_to_trunnel( const hs_desc_link_specifier_t *spec); +hs_desc_authorized_client_t *hs_desc_build_fake_authorized_client(void); +void hs_desc_build_authorized_client(const uint8_t *subcredential, + const curve25519_public_key_t * + client_auth_pk, + const curve25519_secret_key_t * + auth_ephemeral_sk, + const uint8_t *descriptor_cookie, + hs_desc_authorized_client_t *client_out); +void hs_desc_plaintext_data_free_contents(hs_desc_plaintext_data_t *desc); +void hs_desc_superencrypted_data_free_contents( + hs_desc_superencrypted_data_t *desc); +void hs_desc_encrypted_data_free_contents(hs_desc_encrypted_data_t *desc); + #ifdef HS_DESCRIPTOR_PRIVATE /* Encoding. */ @@ -265,13 +333,11 @@ STATIC int cert_is_valid(tor_cert_t *cert, uint8_t type, STATIC int desc_sig_is_valid(const char *b64_sig, const ed25519_public_key_t *signing_pubkey, const char *encoded_desc, size_t encoded_len); -STATIC size_t decode_superencrypted(const char *message, size_t message_len, - uint8_t **encrypted_out); -STATIC void desc_plaintext_data_free_contents(hs_desc_plaintext_data_t *desc); MOCK_DECL(STATIC size_t, decrypt_desc_layer,(const hs_descriptor_t *desc, const uint8_t *encrypted_blob, size_t encrypted_blob_size, + const uint8_t *descriptor_cookie, int is_superencrypted_layer, char **decrypted_out)); |