1 files changed, 118 insertions, 0 deletions
diff --git a/src/api/common/signature/mod.rs b/src/api/common/signature/mod.rs
new file mode 100644
index 00000000..50fbd304
--- /dev/null
+++ b/src/api/common/signature/mod.rs
@@ -0,0 +1,118 @@
+use chrono::{DateTime, Utc};
+use hmac::{Hmac, Mac};
+use sha2::Sha256;
+
+use hyper::header::HeaderName;
+use hyper::{body::Incoming as IncomingBody, Request};
+
+use garage_model::garage::Garage;
+use garage_model::key_table::Key;
+use garage_util::data::{sha256sum, Hash};
+
+use error::*;
+
+pub mod body;
+pub mod checksum;
+pub mod error;
+pub mod payload;
+pub mod streaming;
+
+pub const SHORT_DATE: &str = "%Y%m%d";
+pub const LONG_DATETIME: &str = "%Y%m%dT%H%M%SZ";
+
+// ---- Constants used in AWSv4 signatures ----
+
+pub const X_AMZ_ALGORITHM: HeaderName = HeaderName::from_static("x-amz-algorithm");
+pub const X_AMZ_CREDENTIAL: HeaderName = HeaderName::from_static("x-amz-credential");
+pub const X_AMZ_DATE: HeaderName = HeaderName::from_static("x-amz-date");
+pub const X_AMZ_EXPIRES: HeaderName = HeaderName::from_static("x-amz-expires");
+pub const X_AMZ_SIGNEDHEADERS: HeaderName = HeaderName::from_static("x-amz-signedheaders");
+pub const X_AMZ_SIGNATURE: HeaderName = HeaderName::from_static("x-amz-signature");
+pub const X_AMZ_CONTENT_SHA256: HeaderName = HeaderName::from_static("x-amz-content-sha256");
+pub const X_AMZ_TRAILER: HeaderName = HeaderName::from_static("x-amz-trailer");
+
+/// Result of `sha256("")`
+pub(crate) const EMPTY_STRING_HEX_DIGEST: &str =
+	"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855";
+
+// Signature calculation algorithm
+pub const AWS4_HMAC_SHA256: &str = "AWS4-HMAC-SHA256";
+type HmacSha256 = Hmac<Sha256>;
+
+// Possible values for x-amz-content-sha256, in addition to the actual sha256
+pub const UNSIGNED_PAYLOAD: &str = "UNSIGNED-PAYLOAD";
+pub const STREAMING_UNSIGNED_PAYLOAD_TRAILER: &str = "STREAMING-UNSIGNED-PAYLOAD-TRAILER";
+pub const STREAMING_AWS4_HMAC_SHA256_PAYLOAD: &str = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD";
+
+// Used in the computation of StringToSign
+pub const AWS4_HMAC_SHA256_PAYLOAD: &str = "AWS4-HMAC-SHA256-PAYLOAD";
+
+// ---- enums to describe stuff going on in signature calculation ----
+
+#[derive(Debug)]
+pub enum ContentSha256Header {
+	UnsignedPayload,
+	Sha256Checksum(Hash),
+	StreamingPayload { trailer: bool, signed: bool },
+}
+
+// ---- top-level functions ----
+
+pub struct VerifiedRequest {
+	pub request: Request<streaming::ReqBody>,
+	pub access_key: Key,
+	pub content_sha256_header: ContentSha256Header,
+}
+
+pub async fn verify_request(
+	garage: &Garage,
+	mut req: Request<IncomingBody>,
+	service: &'static str,
+) -> Result<VerifiedRequest, Error> {
+	let checked_signature = payload::check_payload_signature(&garage, &mut req, service).await?;
+
+	let request = streaming::parse_streaming_body(
+		req,
+		&checked_signature,
+		&garage.config.s3_api.s3_region,
+		service,
+	)?;
+
+	let access_key = checked_signature
+		.key
+		.ok_or_else(|| Error::forbidden("Garage does not support anonymous access yet"))?;
+
+	Ok(VerifiedRequest {
+		request,
+		access_key,
+		content_sha256_header: checked_signature.content_sha256_header,
+	})
+}
+
+pub fn signing_hmac(
+	datetime: &DateTime<Utc>,
+	secret_key: &str,
+	region: &str,
+	service: &str,
+) -> Result<HmacSha256, crypto_common::InvalidLength> {
+	let secret = String::from("AWS4") + secret_key;
+	let mut date_hmac = HmacSha256::new_from_slice(secret.as_bytes())?;
+	date_hmac.update(datetime.format(SHORT_DATE).to_string().as_bytes());
+	let mut region_hmac = HmacSha256::new_from_slice(&date_hmac.finalize().into_bytes())?;
+	region_hmac.update(region.as_bytes());
+	let mut service_hmac = HmacSha256::new_from_slice(&region_hmac.finalize().into_bytes())?;
+	service_hmac.update(service.as_bytes());
+	let mut signing_hmac = HmacSha256::new_from_slice(&service_hmac.finalize().into_bytes())?;
+	signing_hmac.update(b"aws4_request");
+	let hmac = HmacSha256::new_from_slice(&signing_hmac.finalize().into_bytes())?;
+	Ok(hmac)
+}
+
+pub fn compute_scope(datetime: &DateTime<Utc>, region: &str, service: &str) -> String {
+	format!(
+		"{}/{}/{}/aws4_request",
+		datetime.format(SHORT_DATE),
+		region,
+		service
+	)
+}