From 18ebeebb3e4ddb3e376bc2ff56de5fc1042e5837 Mon Sep 17 00:00:00 2001 From: Fabian Kaczmarczyck Date: Mon, 11 Jan 2021 11:51:01 +0100 Subject: [PATCH] adds storage changes for credential management --- src/ctap/mod.rs | 12 +++- src/ctap/response.rs | 19 ++++- src/ctap/storage.rs | 164 +++++++++++++++++++++++++++++++++++-------- 3 files changed, 163 insertions(+), 32 deletions(-) diff --git a/src/ctap/mod.rs b/src/ctap/mod.rs index fe60e80..4e93210 100644 --- a/src/ctap/mod.rs +++ b/src/ctap/mod.rs @@ -848,13 +848,19 @@ where CtapState::::PIN_PROTOCOL_VERSION, ]), max_credential_count_in_list: MAX_CREDENTIAL_COUNT_IN_LIST.map(|c| c as u64), - // #TODO(106) update with version 2.1 of HMAC-secret + // TODO(#106) update with version 2.1 of HMAC-secret max_credential_id_length: Some(CREDENTIAL_ID_SIZE as u64), transports: Some(vec![AuthenticatorTransport::Usb]), algorithms: Some(vec![ES256_CRED_PARAM]), default_cred_protect: DEFAULT_CRED_PROTECT, min_pin_length: self.persistent_store.min_pin_length()?, firmware_version: None, + max_cred_blob_length: None, + // TODO(kaczmarczyck) update when extension is implemented + max_rp_ids_for_set_min_pin_length: None, + remaining_discoverable_credentials: Some( + self.persistent_store.remaining_credentials()? as u64, + ), }, )) } @@ -1015,7 +1021,7 @@ mod test { let mut ctap_state = CtapState::new(&mut rng, user_immediately_present, DUMMY_CLOCK_VALUE); let info_reponse = ctap_state.process_command(&[0x04], DUMMY_CHANNEL_ID, DUMMY_CLOCK_VALUE); - let mut expected_response = vec![0x00, 0xAA, 0x01]; + let mut expected_response = vec![0x00, 0xAB, 0x01]; // The version array differs with CTAP1, always including 2.0 and 2.1. #[cfg(not(feature = "with_ctap1"))] let version_count = 2; @@ -1039,7 +1045,7 @@ mod test { 0x65, 0x6E, 0x74, 0x50, 0x69, 0x6E, 0xF4, 0x05, 0x19, 0x04, 0x00, 0x06, 0x81, 0x01, 0x08, 0x18, 0x70, 0x09, 0x81, 0x63, 0x75, 0x73, 0x62, 0x0A, 0x81, 0xA2, 0x63, 0x61, 0x6C, 0x67, 0x26, 0x64, 0x74, 0x79, 0x70, 0x65, 0x6A, 0x70, 0x75, 0x62, 0x6C, 0x69, - 0x63, 0x2D, 0x6B, 0x65, 0x79, 0x0D, 0x04, + 0x63, 0x2D, 0x6B, 0x65, 0x79, 0x0D, 0x04, 0x14, 0x18, 0x96, ] .iter(), ); diff --git a/src/ctap/response.rs b/src/ctap/response.rs index 390b0cb..3ebab3b 100644 --- a/src/ctap/response.rs +++ b/src/ctap/response.rs @@ -107,7 +107,6 @@ impl From for cbor::Value { #[cfg_attr(test, derive(PartialEq))] #[cfg_attr(any(test, feature = "debug_ctap"), derive(Debug))] pub struct AuthenticatorGetInfoResponse { - // TODO(kaczmarczyck) add maxAuthenticatorConfigLength and defaultCredProtect pub versions: Vec, pub extensions: Option>, pub aaguid: [u8; 16], @@ -121,6 +120,9 @@ pub struct AuthenticatorGetInfoResponse { pub default_cred_protect: Option, pub min_pin_length: u8, pub firmware_version: Option, + pub max_cred_blob_length: Option, + pub max_rp_ids_for_set_min_pin_length: Option, + pub remaining_discoverable_credentials: Option, } impl From for cbor::Value { @@ -139,6 +141,9 @@ impl From for cbor::Value { default_cred_protect, min_pin_length, firmware_version, + max_cred_blob_length, + max_rp_ids_for_set_min_pin_length, + remaining_discoverable_credentials, } = get_info_response; let options_cbor: Option = options.map(|options| { @@ -163,6 +168,9 @@ impl From for cbor::Value { 0x0C => default_cred_protect.map(|p| p as u64), 0x0D => min_pin_length as u64, 0x0E => firmware_version, + 0x0F => max_cred_blob_length, + 0x10 => max_rp_ids_for_set_min_pin_length, + 0x14 => remaining_discoverable_credentials, } } } @@ -285,6 +293,9 @@ mod test { default_cred_protect: None, min_pin_length: 4, firmware_version: None, + max_cred_blob_length: None, + max_rp_ids_for_set_min_pin_length: None, + remaining_discoverable_credentials: None, }; let response_cbor: Option = ResponseData::AuthenticatorGetInfo(get_info_response).into(); @@ -314,6 +325,9 @@ mod test { default_cred_protect: Some(CredentialProtectionPolicy::UserVerificationRequired), min_pin_length: 4, firmware_version: Some(0), + max_cred_blob_length: Some(1024), + max_rp_ids_for_set_min_pin_length: Some(8), + remaining_discoverable_credentials: Some(150), }; let response_cbor: Option = ResponseData::AuthenticatorGetInfo(get_info_response).into(); @@ -331,6 +345,9 @@ mod test { 0x0C => CredentialProtectionPolicy::UserVerificationRequired as u64, 0x0D => 4, 0x0E => 0, + 0x0F => 1024, + 0x10 => 8, + 0x14 => 150, }; assert_eq!(response_cbor, Some(expected_cbor)); } diff --git a/src/ctap/storage.rs b/src/ctap/storage.rs index 28c1599..76c2fd6 100644 --- a/src/ctap/storage.rs +++ b/src/ctap/storage.rs @@ -16,6 +16,7 @@ mod key; use crate::ctap::data_formats::{ extract_array, extract_text_string, CredentialProtectionPolicy, PublicKeyCredentialSource, + PublicKeyCredentialUserEntity, }; use crate::ctap::key_material; use crate::ctap::pin_protocol_v1::PIN_AUTH_LENGTH; @@ -116,6 +117,29 @@ impl PersistentStore { Ok(()) } + /// Finds the key and value for a given credential ID. + /// + /// # Errors + /// + /// Returns `CTAP2_ERR_NO_CREDENTIALS` if the credential is not found. + fn find_credential_item( + &self, + credential_id: &[u8], + ) -> Result<(usize, PublicKeyCredentialSource), Ctap2StatusCode> { + let mut iter_result = Ok(()); + let iter = self.iter_credentials(&mut iter_result)?; + let mut credentials: Vec<(usize, PublicKeyCredentialSource)> = iter + .filter(|(_, credential)| credential.credential_id == credential_id) + .collect(); + iter_result?; + if credentials.len() > 1 { + return Err(Ctap2StatusCode::CTAP2_ERR_VENDOR_INTERNAL_ERROR); + } + credentials + .pop() + .ok_or(Ctap2StatusCode::CTAP2_ERR_NO_CREDENTIALS) + } + /// Returns the first matching credential. /// /// Returns `None` if no credentials are matched or if `check_cred_protect` is set and the first @@ -126,22 +150,17 @@ impl PersistentStore { credential_id: &[u8], check_cred_protect: bool, ) -> Result, Ctap2StatusCode> { - let mut iter_result = Ok(()); - let iter = self.iter_credentials(&mut iter_result)?; - // We don't check whether there is more than one matching credential to be able to exit - // early. - let result = iter.map(|(_, credential)| credential).find(|credential| { - credential.rp_id == rp_id && credential.credential_id == credential_id - }); - iter_result?; - if let Some(cred) = &result { - let user_verification_required = cred.cred_protect_policy - == Some(CredentialProtectionPolicy::UserVerificationRequired); - if check_cred_protect && user_verification_required { - return Ok(None); - } + let credential = match self.find_credential_item(credential_id) { + Err(Ctap2StatusCode::CTAP2_ERR_NO_CREDENTIALS) => return Ok(None), + Err(e) => return Err(e), + Ok(credential) => credential.1, + }; + let is_protected = credential.cred_protect_policy + == Some(CredentialProtectionPolicy::UserVerificationRequired); + if credential.rp_id != rp_id || (check_cred_protect && is_protected) { + return Ok(None); } - Ok(result) + Ok(Some(credential)) } /// Stores or updates a credential. @@ -196,6 +215,34 @@ impl PersistentStore { Ok(()) } + /// Deletes a credential. + /// + /// # Errors + /// + /// Returns `CTAP2_ERR_NO_CREDENTIALS` if the credential is not found. + pub fn _delete_credential(&mut self, credential_id: &[u8]) -> Result<(), Ctap2StatusCode> { + let (key, _) = self.find_credential_item(credential_id)?; + Ok(self.store.remove(key)?) + } + + /// Updates a credential's user information. + /// + /// # Errors + /// + /// Returns `CTAP2_ERR_NO_CREDENTIALS` if the credential is not found. + pub fn _update_credential( + &mut self, + credential_id: &[u8], + user: PublicKeyCredentialUserEntity, + ) -> Result<(), Ctap2StatusCode> { + let (key, mut credential) = self.find_credential_item(credential_id)?; + credential.user_name = user.user_name; + credential.user_display_name = user.user_display_name; + credential.user_icon = user.user_icon; + let value = serialize_credential(credential)?; + Ok(self.store.insert(key, &value)?) + } + /// Returns the list of matching credentials. /// /// Does not return credentials that are not discoverable if `check_cred_protect` is set. @@ -221,7 +268,6 @@ impl PersistentStore { } /// Returns the number of credentials. - #[cfg(test)] pub fn count_credentials(&self) -> Result { let mut iter_result = Ok(()); let iter = self.iter_credentials(&mut iter_result)?; @@ -230,10 +276,17 @@ impl PersistentStore { Ok(result) } + /// Returns the estimated number of credentials that can still be stored. + pub fn remaining_credentials(&self) -> Result { + MAX_SUPPORTED_RESIDENTIAL_KEYS + .checked_sub(self.count_credentials()?) + .ok_or(Ctap2StatusCode::CTAP2_ERR_VENDOR_INTERNAL_ERROR) + } + /// Iterates through the credentials. /// /// If an error is encountered during iteration, it is written to `result`. - fn iter_credentials<'a>( + pub fn iter_credentials<'a>( &'a self, result: &'a mut Result<(), Ctap2StatusCode>, ) -> Result, Ctap2StatusCode> { @@ -494,7 +547,7 @@ impl From for Ctap2StatusCode { } /// Iterator for credentials. -struct IterCredentials<'a> { +pub struct IterCredentials<'a> { /// The store being iterated. store: &'a persistent_store::Store, @@ -629,6 +682,66 @@ mod test { assert!(persistent_store.count_credentials().unwrap() > 0); } + #[test] + fn test_delete_credential() { + let mut rng = ThreadRng256 {}; + let mut persistent_store = PersistentStore::new(&mut rng); + assert_eq!(persistent_store.count_credentials().unwrap(), 0); + + let mut credential_ids = vec![]; + for i in 0..MAX_SUPPORTED_RESIDENTIAL_KEYS { + let user_handle = i.to_ne_bytes().to_vec(); + let credential_source = create_credential_source(&mut rng, "example.com", user_handle); + credential_ids.push(credential_source.credential_id.clone()); + assert!(persistent_store.store_credential(credential_source).is_ok()); + assert_eq!(persistent_store.count_credentials().unwrap(), i + 1); + } + let mut count = persistent_store.count_credentials().unwrap(); + for credential_id in credential_ids { + assert!(persistent_store._delete_credential(&credential_id).is_ok()); + count -= 1; + assert_eq!(persistent_store.count_credentials().unwrap(), count); + } + } + + #[test] + fn test_update_credential() { + let mut rng = ThreadRng256 {}; + let mut persistent_store = PersistentStore::new(&mut rng); + let user = PublicKeyCredentialUserEntity { + // User ID is ignored. + user_id: vec![0x00], + user_name: Some("name".to_string()), + user_display_name: Some("display_name".to_string()), + user_icon: Some("icon".to_string()), + }; + assert_eq!( + persistent_store._update_credential(&[0x1D], user.clone()), + Err(Ctap2StatusCode::CTAP2_ERR_NO_CREDENTIALS) + ); + + let credential_source = create_credential_source(&mut rng, "example.com", vec![0x1D]); + let credential_id = credential_source.credential_id.clone(); + assert!(persistent_store.store_credential(credential_source).is_ok()); + let stored_credential = persistent_store + .find_credential("example.com", &credential_id, false) + .unwrap() + .unwrap(); + assert_eq!(stored_credential.user_name, None); + assert_eq!(stored_credential.user_display_name, None); + assert_eq!(stored_credential.user_icon, None); + assert!(persistent_store + ._update_credential(&credential_id, user.clone()) + .is_ok()); + let stored_credential = persistent_store + .find_credential("example.com", &credential_id, false) + .unwrap() + .unwrap(); + assert_eq!(stored_credential.user_name, user.user_name); + assert_eq!(stored_credential.user_display_name, user.user_display_name); + assert_eq!(stored_credential.user_icon, user.user_icon); + } + #[test] fn test_credential_order() { let mut rng = ThreadRng256 {}; @@ -645,17 +758,14 @@ mod test { } #[test] - #[allow(clippy::assertions_on_constants)] fn test_fill_store() { let mut rng = ThreadRng256 {}; let mut persistent_store = PersistentStore::new(&mut rng); assert_eq!(persistent_store.count_credentials().unwrap(), 0); - // To make this test work for bigger storages, implement better int -> Vec conversion. - assert!(MAX_SUPPORTED_RESIDENTIAL_KEYS < 256); for i in 0..MAX_SUPPORTED_RESIDENTIAL_KEYS { - let credential_source = - create_credential_source(&mut rng, "example.com", vec![i as u8]); + let user_handle = i.to_ne_bytes().to_vec(); + let credential_source = create_credential_source(&mut rng, "example.com", user_handle); assert!(persistent_store.store_credential(credential_source).is_ok()); assert_eq!(persistent_store.count_credentials().unwrap(), i + 1); } @@ -675,7 +785,6 @@ mod test { } #[test] - #[allow(clippy::assertions_on_constants)] fn test_overwrite() { let mut rng = ThreadRng256 {}; let mut persistent_store = PersistentStore::new(&mut rng); @@ -699,11 +808,10 @@ mod test { &[expected_credential] ); - // To make this test work for bigger storages, implement better int -> Vec conversion. - assert!(MAX_SUPPORTED_RESIDENTIAL_KEYS < 256); + let mut persistent_store = PersistentStore::new(&mut rng); for i in 0..MAX_SUPPORTED_RESIDENTIAL_KEYS { - let credential_source = - create_credential_source(&mut rng, "example.com", vec![i as u8]); + let user_handle = i.to_ne_bytes().to_vec(); + let credential_source = create_credential_source(&mut rng, "example.com", user_handle); assert!(persistent_store.store_credential(credential_source).is_ok()); assert_eq!(persistent_store.count_credentials().unwrap(), i + 1); }