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fix client TLS 1.3 handshake with client certificate authentication
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pass signature algorithms from certificaterequest to the location where the
certificate is sent. reported by @talex5 in
mirage/capnp-rpc#228
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@hannesm
hannesm committed Apr 22, 2021
1 parent 79728f3 commit fa780d6
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Showing 2 changed files with 28 additions and 22 deletions.
44 changes: 25 additions & 19 deletions lib/handshake_client13.ml
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,13 +96,13 @@ let answer_encrypted_extensions state (session : session_data13) server_hs_secre
in
let st =
if session.resumed then
AwaitServerFinished13 (session, server_hs_secret, client_hs_secret, log <+> raw)
AwaitServerFinished13 (session, server_hs_secret, client_hs_secret, None, log <+> raw)
else
AwaitServerCertificateRequestOrCertificate13 (session, server_hs_secret, client_hs_secret, log <+> raw)
in
Ok ({ state with machina = Client13 st }, [])

let answer_certificate state (session : session_data13) server_hs_secret client_hs_secret certs raw log =
let answer_certificate state (session : session_data13) server_hs_secret client_hs_secret sigalgs certs raw log =
(* certificates are (cs, ext) list - ext being statusrequest or signed_cert_timestamp *)
let certs = List.map fst certs in
validate_chain state.config.authenticator certs (host_name_opt state.config.peer_name) >>=
Expand All @@ -114,28 +114,29 @@ let answer_certificate state (session : session_data13) server_hs_secret client_
} in
{ session with common_session_data13 }
in
let st = AwaitServerCertificateVerify13 (session, server_hs_secret, client_hs_secret, log <+> raw) in
let st = AwaitServerCertificateVerify13 (session, server_hs_secret, client_hs_secret, sigalgs, log <+> raw) in
Ok ({ state with machina = Client13 st }, [])

let answer_certificate_verify (state : handshake_state) (session : session_data13) server_hs_secret client_hs_secret cv raw log =
let answer_certificate_verify (state : handshake_state) (session : session_data13) server_hs_secret client_hs_secret sigalgs cv raw log =
let tbs = Mirage_crypto.Hash.digest (Ciphersuite.hash13 session.ciphersuite13) log in
verify_digitally_signed state.protocol_version
~context_string:"TLS 1.3, server CertificateVerify"
state.config.signature_algorithms cv tbs
session.common_session_data13.peer_certificate >>= fun () ->
let st = AwaitServerFinished13 (session, server_hs_secret, client_hs_secret, log <+> raw) in
let st = AwaitServerFinished13 (session, server_hs_secret, client_hs_secret, sigalgs, log <+> raw) in
Ok ({ state with machina = Client13 st }, [])

let answer_certificate_request (state : handshake_state) (session : session_data13) server_hs_secret client_hs_secret _extensions raw log =
(* TODO respect extensions (sigalg, CA, OIDfilter)! *)
let answer_certificate_request (state : handshake_state) (session : session_data13) server_hs_secret client_hs_secret extensions raw log =
(* TODO respect extensions (CA, OIDfilter)! *)
let session =
let common_session_data13 = { session.common_session_data13 with client_auth = true } in
{ session with common_session_data13 }
in
let st = AwaitServerCertificate13 (session, server_hs_secret, client_hs_secret, log <+> raw) in
let sigalgs = map_find ~f:(function `SignatureAlgorithms s -> Some s | _ -> None) extensions in
let st = AwaitServerCertificate13 (session, server_hs_secret, client_hs_secret, sigalgs, log <+> raw) in
Ok ({ state with machina = Client13 st }, [])

let answer_finished state (session : session_data13) server_hs_secret client_hs_secret fin raw log =
let answer_finished state (session : session_data13) server_hs_secret client_hs_secret sigalgs fin raw log =
let hash = Ciphersuite.hash13 session.ciphersuite13 in
let f_data = Handshake_crypto13.finished hash server_hs_secret log in
guard (Cstruct.equal fin f_data) (`Fatal `BadFinished) >>= fun () ->
Expand All @@ -153,18 +154,17 @@ let answer_finished state (session : session_data13) server_hs_secret client_hs_
in
let certificate =
let cs = List.map X509.Certificate.encode_der own_certificate in
Certificate (Writer.assemble_certificates_1_3 Cstruct.empty cs)
Certificate (Writer.assemble_certificates_1_3 Cstruct.empty cs)
in
let cert_raw = Writer.assemble_handshake certificate in
let log = log <+> cert_raw in
(match own_private_key with
| None ->
Ok ([cert_raw], log)
| Some priv ->
(* TODO use sig_algs instead of None below as requested in server's certificaterequest *)
let tbs = Mirage_crypto.Hash.digest hash log in
signature `TLS_1_3 ~context_string:"TLS 1.3, client CertificateVerify"
tbs None state.config.Config.signature_algorithms priv >>| fun signed ->
tbs sigalgs state.config.Config.signature_algorithms priv >>| fun signed ->
let cv = CertificateVerify signed in
let cv_raw = Writer.assemble_handshake cv in
([ cert_raw ; cv_raw ], log <+> cv_raw))
Expand Down Expand Up @@ -246,18 +246,24 @@ let handle_handshake cs hs buf =
| Ok (None, exts) -> answer_certificate_request hs sd es ss exts buf log
| Ok (Some _, _) -> Error (`Fatal `InvalidMessage) (* during handshake, context must be empty! *)
| Error re -> Error (`Fatal (`ReaderError re)))
| AwaitServerCertificateRequestOrCertificate13 (sd, es, ss, log), Certificate cs
| AwaitServerCertificate13 (sd, es, ss, log), Certificate cs ->
| AwaitServerCertificateRequestOrCertificate13 (sd, es, ss, log), Certificate cs ->
(match parse_certificates_1_3 cs with
| Ok (con, cs) ->
(* during handshake, context must be empty! and we'll not get any new certificate from server *)
guard (Cstruct.len con = 0) (`Fatal `InvalidMessage) >>= fun () ->
answer_certificate hs sd es ss cs buf log
answer_certificate hs sd es ss None cs buf log
| Error re -> Error (`Fatal (`ReaderError re)))
| AwaitServerCertificateVerify13 (sd, es, ss, log), CertificateVerify cv ->
answer_certificate_verify hs sd es ss cv buf log
| AwaitServerFinished13 (sd, es, ss, log), Finished fin ->
answer_finished hs sd es ss fin buf log
| AwaitServerCertificate13 (sd, es, ss, sigalgs, log), Certificate cs ->
(match parse_certificates_1_3 cs with
| Ok (con, cs) ->
(* during handshake, context must be empty! and we'll not get any new certificate from server *)
guard (Cstruct.len con = 0) (`Fatal `InvalidMessage) >>= fun () ->
answer_certificate hs sd es ss sigalgs cs buf log
| Error re -> Error (`Fatal (`ReaderError re)))
| AwaitServerCertificateVerify13 (sd, es, ss, sigalgs, log), CertificateVerify cv ->
answer_certificate_verify hs sd es ss sigalgs cv buf log
| AwaitServerFinished13 (sd, es, ss, sigalgs, log), Finished fin ->
answer_finished hs sd es ss sigalgs fin buf log
| Established13, SessionTicket se -> answer_session_ticket hs se
| Established13, CertificateRequest _ ->
Error (`Fatal (`UnexpectedHandshake handshake)) (* TODO send out C, CV, F *)
Expand Down
6 changes: 3 additions & 3 deletions lib/state.ml
View file
Original file line number Diff line number Diff line change
Expand Up @@ -153,9 +153,9 @@ type client13_handshake_state =
| AwaitServerHello13 of client_hello * (group * dh_secret) list * Cstruct_sexp.t (* this is for CH1 ~> HRR ~> CH2 <~ WAIT SH *)
| AwaitServerEncryptedExtensions13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * Cstruct_sexp.t
| AwaitServerCertificateRequestOrCertificate13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * Cstruct_sexp.t
| AwaitServerCertificate13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * Cstruct_sexp.t
| AwaitServerCertificateVerify13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * Cstruct_sexp.t
| AwaitServerFinished13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * Cstruct_sexp.t
| AwaitServerCertificate13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * signature_algorithm list option * Cstruct_sexp.t
| AwaitServerCertificateVerify13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * signature_algorithm list option * Cstruct_sexp.t
| AwaitServerFinished13 of session_data13 * Cstruct_sexp.t * Cstruct_sexp.t * signature_algorithm list option * Cstruct_sexp.t
| Established13
[@@deriving sexp_of]

Expand Down

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