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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/origin-trial-token/lib.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/origin-trial-token/lib.rs')
-rw-r--r-- | third_party/rust/origin-trial-token/lib.rs | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/third_party/rust/origin-trial-token/lib.rs b/third_party/rust/origin-trial-token/lib.rs new file mode 100644 index 0000000000..8872095a1d --- /dev/null +++ b/third_party/rust/origin-trial-token/lib.rs @@ -0,0 +1,268 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ + +//! Implements a simple processor for +//! https://github.com/chromium/chromium/blob/d7da0240cae77824d1eda25745c4022757499131/third_party/blink/public/common/origin_trials/origin_trials_token_structure.md +//! +//! This crate intentionally leaves the cryptography to the caller. See the +//! tools/ directory for example usages. + + +/// Latest version as documented. +pub const LATEST_VERSION: u8 = 3; + +#[repr(C)] +pub struct RawToken { + version: u8, + signature: [u8; 64], + payload_length: [u8; 4], + /// Payload is an slice of payload_length bytes, and has to be verified + /// before returning it to the caller. + payload: [u8; 0], +} + +#[derive(Debug)] +pub enum TokenValidationError { + BufferTooSmall, + MismatchedPayloadSize { expected: usize, actual: usize }, + InvalidSignature, + UnknownVersion, + UnsupportedThirdPartyToken, + UnexpectedUsageInNonThirdPartyToken, + MalformedPayload(serde_json::Error), +} + +impl RawToken { + const HEADER_SIZE: usize = std::mem::size_of::<Self>(); + + #[inline] + pub fn version(&self) -> u8 { + self.version + } + + #[inline] + pub fn signature(&self) -> &[u8; 64] { + &self.signature + } + + #[inline] + pub fn payload_length(&self) -> usize { + u32::from_be_bytes(self.payload_length) as usize + } + + #[inline] + pub fn as_buffer(&self) -> &[u8] { + let buffer_size = Self::HEADER_SIZE + self.payload_length(); + unsafe { std::slice::from_raw_parts(self as *const _ as *const u8, buffer_size) } + } + + #[inline] + pub fn payload(&self) -> &[u8] { + let len = self.payload_length(); + unsafe { std::slice::from_raw_parts(self.payload.as_ptr(), len) } + } + + /// Returns a RawToken from a raw buffer. + pub fn from_buffer<'a>(buffer: &'a [u8]) -> Result<&'a Self, TokenValidationError> { + if buffer.len() <= Self::HEADER_SIZE { + return Err(TokenValidationError::BufferTooSmall); + } + assert_eq!( + std::mem::align_of::<Self>(), + 1, + "RawToken is a view over the buffer" + ); + let raw_token = unsafe { &*(buffer.as_ptr() as *const Self) }; + let payload = &buffer[Self::HEADER_SIZE..]; + let expected = raw_token.payload_length(); + let actual = payload.len(); + if expected != actual { + return Err(TokenValidationError::MismatchedPayloadSize { expected, actual }); + } + Ok(raw_token) + } + + /// The data to verify the signature in this raw token. + fn signature_data(&self) -> Vec<u8> { + Self::raw_signature_data(self.version, self.payload()) + } + + /// The data to sign or verify given a payload and a version. + fn raw_signature_data(version: u8, payload: &[u8]) -> Vec<u8> { + let mut data = Vec::with_capacity(payload.len() + 5); + data.push(version); + data.extend((payload.len() as u32).to_be_bytes()); + data.extend(payload); + data + } + + /// Verify the signature of this raw token. + pub fn verify(&self, verify_signature: impl FnOnce(&[u8; 64], &[u8]) -> bool) -> bool { + let signature_data = self.signature_data(); + verify_signature(&self.signature, &signature_data) + } +} + +#[derive(serde::Deserialize, serde::Serialize, Debug, Eq, PartialEq)] +#[serde(rename_all = "camelCase")] +pub enum Usage { + #[serde(rename = "")] + None, + Subset, +} + +impl Usage { + fn is_none(&self) -> bool { + *self == Self::None + } +} + +impl Default for Usage { + fn default() -> Self { + Self::None + } +} + +fn is_false(t: &bool) -> bool { + *t == false +} + +/// An already decoded and maybe-verified token. +#[derive(serde::Deserialize, serde::Serialize, Debug, Eq, PartialEq)] +#[serde(rename_all = "camelCase")] +pub struct Token { + pub origin: String, + pub feature: String, + pub expiry: u64, // Timestamp. Seconds since epoch. + #[serde(default, skip_serializing_if = "is_false")] + pub is_subdomain: bool, + #[serde(default, skip_serializing_if = "is_false")] + pub is_third_party: bool, + #[serde(default, skip_serializing_if = "Usage::is_none")] + pub usage: Usage, +} + +impl Token { + #[inline] + pub fn origin(&self) -> &str { + &self.origin + } + + #[inline] + pub fn feature(&self) -> &str { + &self.feature + } + + #[inline] + pub fn expiry_since_unix_epoch(&self) -> std::time::Duration { + std::time::Duration::from_secs(self.expiry) + } + + #[inline] + pub fn expiry_time(&self) -> Option<std::time::SystemTime> { + std::time::UNIX_EPOCH.checked_add(self.expiry_since_unix_epoch()) + } + + #[inline] + pub fn is_expired(&self) -> bool { + let now_duration = std::time::SystemTime::now() + .duration_since(std::time::UNIX_EPOCH) + .expect("System time before epoch?"); + now_duration >= self.expiry_since_unix_epoch() + } + + /// Most high-level function: For a given buffer, tries to parse it and + /// verify it as a token. + pub fn from_buffer( + buffer: &[u8], + verify_signature: impl FnOnce(&[u8; 64], &[u8]) -> bool, + ) -> Result<Self, TokenValidationError> { + Self::from_raw_token(RawToken::from_buffer(buffer)?, verify_signature) + } + + /// Validates a RawToken's signature and converts the token if valid. + pub fn from_raw_token( + token: &RawToken, + verify_signature: impl FnOnce(&[u8; 64], &[u8]) -> bool, + ) -> Result<Self, TokenValidationError> { + if !token.verify(verify_signature) { + return Err(TokenValidationError::InvalidSignature); + } + Self::from_raw_token_unverified(token) + } + + /// Converts the token from a raw token, without verifying first. + pub fn from_raw_token_unverified(token: &RawToken) -> Result<Self, TokenValidationError> { + Self::from_payload(token.version, token.payload()) + } + + /// Converts the token from a raw payload, version pair. + pub fn from_payload(version: u8, payload: &[u8]) -> Result<Self, TokenValidationError> { + if version != 2 && version != 3 { + assert_ne!(version, LATEST_VERSION); + return Err(TokenValidationError::UnknownVersion); + } + + let token: Token = match serde_json::from_slice(payload) { + Ok(t) => t, + Err(e) => return Err(TokenValidationError::MalformedPayload(e)), + }; + + // Third-party tokens are not supported in version 2. + if token.is_third_party { + if version == 2 { + return Err(TokenValidationError::UnsupportedThirdPartyToken); + } + } else if !token.usage.is_none() { + return Err(TokenValidationError::UnexpectedUsageInNonThirdPartyToken); + } + + Ok(token) + } + + /// Converts the token to a raw payload. + pub fn to_payload(&self) -> Vec<u8> { + serde_json::to_string(self) + .expect("Should always be able to turn a token into a payload") + .into_bytes() + } + + /// Converts the token to the data that should be signed. + pub fn to_signature_data(&self) -> Vec<u8> { + RawToken::raw_signature_data(LATEST_VERSION, &self.to_payload()) + } + + /// Turns the token into a fully signed token. + pub fn to_signed_token(&self, sign: impl FnOnce(&[u8]) -> [u8; 64]) -> Vec<u8> { + self.to_signed_token_with_payload(sign, &self.to_payload()) + } + + /// DO NOT EXPOSE: This is intended for testing only. We need to test with + /// the original payload so that the tokens match, but we assert + /// that self.to_payload() and payload are equivalent. + fn to_signed_token_with_payload( + &self, + sign: impl FnOnce(&[u8]) -> [u8; 64], + payload: &[u8], + ) -> Vec<u8> { + let signature_data_with_payload = RawToken::raw_signature_data(LATEST_VERSION, &payload); + let signature = sign(&signature_data_with_payload); + + let mut buffer = Vec::with_capacity(1 + signature.len() + 4 + payload.len()); + buffer.push(LATEST_VERSION); + buffer.extend(signature); + buffer.extend((payload.len() as u32).to_be_bytes()); + buffer.extend(payload); + + if cfg!(debug_assertions) { + let token = Self::from_buffer(&buffer, |_, _| true).expect("Creating malformed token?"); + assert_eq!(self, &token, "Token differs after deserialization?"); + } + + buffer + } +} + +#[cfg(test)] +mod tests; |