blob: 8daf9aa497b62ff9257f0c01fbb05d27460769de [file] [log] [blame]
use webpki;
use untrusted;
use sct;
use std;
use std::sync::Arc;
use crate::key::Certificate;
use crate::msgs::handshake::DigitallySignedStruct;
use crate::msgs::handshake::SCTList;
use crate::msgs::enums::SignatureScheme;
use crate::error::TLSError;
use crate::anchors::{DistinguishedNames, RootCertStore};
#[cfg(feature = "logging")]
use crate::log::{warn, debug};
type SignatureAlgorithms = &'static [&'static webpki::SignatureAlgorithm];
/// Which signature verification mechanisms we support. No particular
/// order.
static SUPPORTED_SIG_ALGS: SignatureAlgorithms = &[&webpki::ECDSA_P256_SHA256,
&webpki::ECDSA_P256_SHA384,
&webpki::ECDSA_P384_SHA256,
&webpki::ECDSA_P384_SHA384,
&webpki::RSA_PSS_2048_8192_SHA256_LEGACY_KEY,
&webpki::RSA_PSS_2048_8192_SHA384_LEGACY_KEY,
&webpki::RSA_PSS_2048_8192_SHA512_LEGACY_KEY,
&webpki::RSA_PKCS1_2048_8192_SHA256,
&webpki::RSA_PKCS1_2048_8192_SHA384,
&webpki::RSA_PKCS1_2048_8192_SHA512,
&webpki::RSA_PKCS1_3072_8192_SHA384];
/// Marker types. These are used to bind the fact some verification
/// (certificate chain or handshake signature) has taken place into
/// protocol states. We use this to have the compiler check that there
/// are no 'goto fail'-style elisions of important checks before we
/// reach the traffic stage.
///
/// These types are public, but cannot be directly constructed. This
/// means their origins can be precisely determined by looking
/// for their `assertion` constructors.
pub struct HandshakeSignatureValid(());
impl HandshakeSignatureValid { pub fn assertion() -> Self { Self { 0: () } } }
pub struct FinishedMessageVerified(());
impl FinishedMessageVerified { pub fn assertion() -> Self { Self { 0: () } } }
/// Zero-sized marker type representing verification of a server cert chain.
pub struct ServerCertVerified(());
impl ServerCertVerified {
/// Make a `ServerCertVerified`
pub fn assertion() -> Self { Self { 0: () } }
}
/// Zero-sized marker type representing verification of a client cert chain.
pub struct ClientCertVerified(());
impl ClientCertVerified {
/// Make a `ClientCertVerified`
pub fn assertion() -> Self { Self { 0: () } }
}
/// Something that can verify a server certificate chain
pub trait ServerCertVerifier : Send + Sync {
/// Verify a the certificate chain `presented_certs` against the roots
/// configured in `roots`. Make sure that `dns_name` is quoted by
/// the top certificate in the chain.
fn verify_server_cert(&self,
roots: &RootCertStore,
presented_certs: &[Certificate],
dns_name: webpki::DNSNameRef,
ocsp_response: &[u8]) -> Result<ServerCertVerified, TLSError>;
}
/// Something that can verify a client certificate chain
pub trait ClientCertVerifier : Send + Sync {
/// Returns `true` to enable the server to request a client certificate and
/// `false` to skip requesting a client certificate. Defaults to `true`.
fn offer_client_auth(&self) -> bool { true }
/// Returns `true` to require a client certificate and `false` to make client
/// authentication optional. Defaults to `self.offer_client_auth()`.
fn client_auth_mandatory(&self) -> bool { self.offer_client_auth() }
/// Returns the subject names of the client authentication trust anchors to
/// share with the client when requesting client authentication.
fn client_auth_root_subjects(&self) -> DistinguishedNames;
/// Verify a certificate chain `presented_certs` is rooted in `roots`.
/// Does no further checking of the certificate.
fn verify_client_cert(&self,
presented_certs: &[Certificate]) -> Result<ClientCertVerified, TLSError>;
}
pub struct WebPKIVerifier {
pub time: fn() -> Result<webpki::Time, TLSError>,
}
impl ServerCertVerifier for WebPKIVerifier {
fn verify_server_cert(&self,
roots: &RootCertStore,
presented_certs: &[Certificate],
dns_name: webpki::DNSNameRef,
ocsp_response: &[u8]) -> Result<ServerCertVerified, TLSError> {
let (cert, chain, trustroots) = prepare(roots, presented_certs)?;
let now = (self.time)()?;
let cert = cert.verify_is_valid_tls_server_cert(SUPPORTED_SIG_ALGS,
&webpki::TLSServerTrustAnchors(&trustroots), &chain, now)
.map_err(TLSError::WebPKIError)
.map(|_| cert)?;
if !ocsp_response.is_empty() {
debug!("Unvalidated OCSP response: {:?}", ocsp_response.to_vec());
}
cert.verify_is_valid_for_dns_name(dns_name)
.map_err(TLSError::WebPKIError)
.map(|_| ServerCertVerified::assertion())
}
}
impl WebPKIVerifier {
pub fn new() -> WebPKIVerifier {
WebPKIVerifier {
time: try_now,
}
}
}
fn prepare<'a, 'b>(roots: &'b RootCertStore, presented_certs: &'a [Certificate])
-> Result<(webpki::EndEntityCert<'a>,
Vec<untrusted::Input<'a>>,
Vec<webpki::TrustAnchor<'b>>), TLSError> {
if presented_certs.is_empty() {
return Err(TLSError::NoCertificatesPresented);
}
// EE cert must appear first.
let cert_der = untrusted::Input::from(&presented_certs[0].0);
let cert =
webpki::EndEntityCert::from(cert_der).map_err(TLSError::WebPKIError)?;
let chain: Vec<untrusted::Input> = presented_certs.iter()
.skip(1)
.map(|cert| untrusted::Input::from(&cert.0))
.collect();
let trustroots: Vec<webpki::TrustAnchor> = roots.roots
.iter()
.map(|x| x.to_trust_anchor())
.collect();
Ok((cert, chain, trustroots))
}
fn try_now() -> Result<webpki::Time, TLSError> {
webpki::Time::try_from(std::time::SystemTime::now())
.map_err( |_ | TLSError::FailedToGetCurrentTime)
}
/// A `ClientCertVerifier` that will ensure that every client provides a trusted
/// certificate, without any name checking.
pub struct AllowAnyAuthenticatedClient {
roots: RootCertStore,
}
impl AllowAnyAuthenticatedClient {
/// Construct a new `AllowAnyAuthenticatedClient`.
///
/// `roots` is the list of trust anchors to use for certificate validation.
pub fn new(roots: RootCertStore) -> Arc<ClientCertVerifier> {
Arc::new(AllowAnyAuthenticatedClient { roots })
}
}
impl ClientCertVerifier for AllowAnyAuthenticatedClient {
fn offer_client_auth(&self) -> bool { true }
fn client_auth_mandatory(&self) -> bool { true }
fn client_auth_root_subjects(&self) -> DistinguishedNames {
self.roots.get_subjects()
}
fn verify_client_cert(&self, presented_certs: &[Certificate])
-> Result<ClientCertVerified, TLSError> {
let (cert, chain, trustroots) = prepare(&self.roots, presented_certs)?;
let now = try_now()?;
cert.verify_is_valid_tls_client_cert(
SUPPORTED_SIG_ALGS, &webpki::TLSClientTrustAnchors(&trustroots),
&chain, now)
.map_err(TLSError::WebPKIError)
.map(|_| ClientCertVerified::assertion())
}
}
/// A `ClientCertVerifier` that will allow both anonymous and authenticated
/// clients, without any name checking.
///
/// Client authentication will be requested during the TLS handshake. If the
/// client offers a certificate then this acts like
/// `AllowAnyAuthenticatedClient`, otherwise this acts like `NoClientAuth`.
pub struct AllowAnyAnonymousOrAuthenticatedClient {
inner: AllowAnyAuthenticatedClient,
}
impl AllowAnyAnonymousOrAuthenticatedClient {
/// Construct a new `AllowAnyAnonymousOrAuthenticatedClient`.
///
/// `roots` is the list of trust anchors to use for certificate validation.
pub fn new(roots: RootCertStore) -> Arc<ClientCertVerifier> {
Arc::new(AllowAnyAnonymousOrAuthenticatedClient {
inner: AllowAnyAuthenticatedClient { roots }
})
}
}
impl ClientCertVerifier for AllowAnyAnonymousOrAuthenticatedClient {
fn offer_client_auth(&self) -> bool { self.inner.offer_client_auth() }
fn client_auth_mandatory(&self) -> bool { false }
fn client_auth_root_subjects(&self) -> DistinguishedNames {
self.inner.client_auth_root_subjects()
}
fn verify_client_cert(&self, presented_certs: &[Certificate])
-> Result<ClientCertVerified, TLSError> {
self.inner.verify_client_cert(presented_certs)
}
}
/// Turns off client authentication.
pub struct NoClientAuth;
impl NoClientAuth {
/// Constructs a `NoClientAuth` and wraps it in an `Arc`.
pub fn new() -> Arc<ClientCertVerifier> { Arc::new(NoClientAuth) }
}
impl ClientCertVerifier for NoClientAuth {
fn offer_client_auth(&self) -> bool { false }
fn client_auth_root_subjects(&self) -> DistinguishedNames {
unimplemented!();
}
fn verify_client_cert(&self, _presented_certs: &[Certificate])
-> Result<ClientCertVerified, TLSError> {
unimplemented!();
}
}
static ECDSA_SHA256: SignatureAlgorithms = &[&webpki::ECDSA_P256_SHA256,
&webpki::ECDSA_P384_SHA256];
static ECDSA_SHA384: SignatureAlgorithms = &[&webpki::ECDSA_P256_SHA384,
&webpki::ECDSA_P384_SHA384];
static RSA_SHA256: SignatureAlgorithms = &[&webpki::RSA_PKCS1_2048_8192_SHA256];
static RSA_SHA384: SignatureAlgorithms = &[&webpki::RSA_PKCS1_2048_8192_SHA384];
static RSA_SHA512: SignatureAlgorithms = &[&webpki::RSA_PKCS1_2048_8192_SHA512];
static RSA_PSS_SHA256: SignatureAlgorithms = &[&webpki::RSA_PSS_2048_8192_SHA256_LEGACY_KEY];
static RSA_PSS_SHA384: SignatureAlgorithms = &[&webpki::RSA_PSS_2048_8192_SHA384_LEGACY_KEY];
static RSA_PSS_SHA512: SignatureAlgorithms = &[&webpki::RSA_PSS_2048_8192_SHA512_LEGACY_KEY];
fn convert_scheme(scheme: SignatureScheme) -> Result<SignatureAlgorithms, TLSError> {
match scheme {
// nb. for TLS1.2 the curve is not fixed by SignatureScheme.
SignatureScheme::ECDSA_NISTP256_SHA256 => Ok(ECDSA_SHA256),
SignatureScheme::ECDSA_NISTP384_SHA384 => Ok(ECDSA_SHA384),
SignatureScheme::RSA_PKCS1_SHA256 => Ok(RSA_SHA256),
SignatureScheme::RSA_PKCS1_SHA384 => Ok(RSA_SHA384),
SignatureScheme::RSA_PKCS1_SHA512 => Ok(RSA_SHA512),
SignatureScheme::RSA_PSS_SHA256 => Ok(RSA_PSS_SHA256),
SignatureScheme::RSA_PSS_SHA384 => Ok(RSA_PSS_SHA384),
SignatureScheme::RSA_PSS_SHA512 => Ok(RSA_PSS_SHA512),
_ => {
let error_msg = format!("received unadvertised sig scheme {:?}", scheme);
Err(TLSError::PeerMisbehavedError(error_msg))
}
}
}
fn verify_sig_using_any_alg(cert: &webpki::EndEntityCert,
algs: SignatureAlgorithms,
message: &[u8],
sig: &[u8])
-> Result<(), webpki::Error> {
// TLS doesn't itself give us enough info to map to a single webpki::SignatureAlgorithm.
// Therefore, convert_algs maps to several and we try them all.
for alg in algs {
match cert.verify_signature(alg,
untrusted::Input::from(message),
untrusted::Input::from(sig)) {
Err(webpki::Error::UnsupportedSignatureAlgorithmForPublicKey) => continue,
res => return res,
}
}
Err(webpki::Error::UnsupportedSignatureAlgorithmForPublicKey)
}
/// Verify the signed `message` using the public key quoted in
/// `cert` and algorithm and signature in `dss`.
///
/// `cert` MUST have been authenticated before using this function,
/// typically using `verify_cert`.
pub fn verify_signed_struct(message: &[u8],
cert: &Certificate,
dss: &DigitallySignedStruct)
-> Result<HandshakeSignatureValid, TLSError> {
let possible_algs = convert_scheme(dss.scheme)?;
let cert_in = untrusted::Input::from(&cert.0);
let cert = webpki::EndEntityCert::from(cert_in)
.map_err(TLSError::WebPKIError)?;
verify_sig_using_any_alg(&cert, possible_algs, message, &dss.sig.0)
.map_err(TLSError::WebPKIError)
.map(|_| HandshakeSignatureValid::assertion())
}
fn convert_alg_tls13(scheme: SignatureScheme)
-> Result<&'static webpki::SignatureAlgorithm, TLSError> {
use crate::msgs::enums::SignatureScheme::*;
match scheme {
ECDSA_NISTP256_SHA256 => Ok(&webpki::ECDSA_P256_SHA256),
ECDSA_NISTP384_SHA384 => Ok(&webpki::ECDSA_P384_SHA384),
RSA_PSS_SHA256 => Ok(&webpki::RSA_PSS_2048_8192_SHA256_LEGACY_KEY),
RSA_PSS_SHA384 => Ok(&webpki::RSA_PSS_2048_8192_SHA384_LEGACY_KEY),
RSA_PSS_SHA512 => Ok(&webpki::RSA_PSS_2048_8192_SHA512_LEGACY_KEY),
_ => {
let error_msg = format!("received unsupported sig scheme {:?}", scheme);
Err(TLSError::PeerMisbehavedError(error_msg))
}
}
}
pub fn verify_tls13(cert: &Certificate,
dss: &DigitallySignedStruct,
handshake_hash: &[u8],
context_string_with_0: &[u8])
-> Result<HandshakeSignatureValid, TLSError> {
let alg = convert_alg_tls13(dss.scheme)?;
let mut msg = Vec::new();
msg.resize(64, 0x20u8);
msg.extend_from_slice(context_string_with_0);
msg.extend_from_slice(handshake_hash);
let cert_in = untrusted::Input::from(&cert.0);
let cert = webpki::EndEntityCert::from(cert_in)
.map_err(TLSError::WebPKIError)?;
cert.verify_signature(alg,
untrusted::Input::from(&msg),
untrusted::Input::from(&dss.sig.0))
.map_err(TLSError::WebPKIError)
.map(|_| HandshakeSignatureValid::assertion())
}
fn unix_time_millis() -> Result<u64, TLSError> {
std::time::SystemTime::now()
.duration_since(std::time::UNIX_EPOCH)
.map(|dur| dur.as_secs())
.map_err(|_| TLSError::FailedToGetCurrentTime)
.and_then(|secs| secs.checked_mul(1000)
.ok_or(TLSError::FailedToGetCurrentTime))
}
pub fn verify_scts(cert: &Certificate,
scts: &SCTList,
logs: &[&sct::Log]) -> Result<(), TLSError> {
let mut valid_scts = 0;
let now = unix_time_millis()?;
let mut last_sct_error = None;
for sct in scts {
#[cfg_attr(not(feature = "logging"), allow(unused_variables))]
match sct::verify_sct(&cert.0, &sct.0, now, logs) {
Ok(index) => {
debug!("Valid SCT signed by {} on {}",
logs[index].operated_by, logs[index].description);
valid_scts += 1;
}
Err(e) => {
if e.should_be_fatal() {
return Err(TLSError::InvalidSCT(e));
}
debug!("SCT ignored because {:?}", e);
last_sct_error = Some(e);
}
}
}
/* If we were supplied with some logs, and some SCTs,
* but couldn't verify any of them, fail the handshake. */
if !logs.is_empty() && !scts.is_empty() && valid_scts == 0 {
warn!("No valid SCTs provided");
return Err(TLSError::InvalidSCT(last_sct_error.unwrap()));
}
Ok(())
}
pub fn supported_verify_schemes() -> &'static [SignatureScheme] {
&[
SignatureScheme::ECDSA_NISTP384_SHA384,
SignatureScheme::ECDSA_NISTP256_SHA256,
SignatureScheme::RSA_PSS_SHA512,
SignatureScheme::RSA_PSS_SHA384,
SignatureScheme::RSA_PSS_SHA256,
SignatureScheme::RSA_PKCS1_SHA512,
SignatureScheme::RSA_PKCS1_SHA384,
SignatureScheme::RSA_PKCS1_SHA256,
]
}