Revamp errors for aws-sigv4 (#1937)

aws/rust-runtime/aws-sig-auth/external-types.toml

@@ -1,5 +1,6 @@
 allowed_external_types = [
     "aws_sigv4::http_request::sign::SignableBody",
+    "aws_sigv4::http_request::error::SigningError",
     "aws_smithy_http::*",
     "aws_types::*",
     "http::request::Request",

aws/rust-runtime/aws-sig-auth/src/middleware.rs

@@ -103,7 +103,7 @@ impl From<SigningError> for SigningStageError {
 impl Error for SigningStageError {
     fn source(&self) -> Option<&(dyn Error + 'static)> {
         match &self {
-            SigningStageError::SigningFailure(err) => Some(err.as_ref()),
+            SigningStageError::SigningFailure(err) => Some(err),
             _ => None,
         }
     }
@@ -160,7 +160,7 @@ impl MapRequest for SigV4SigningStage {
             let signature = self
                 .signer
                 .sign(operation_config, &request_config, &creds, &mut req)
-                .map_err(|err| SigningStageError::SigningFailure(err))?;
+                .map_err(SigningStageError::SigningFailure)?;
             config.insert(signature);
             Ok(req)
         })

aws/rust-runtime/aws-sig-auth/src/signer.rs

@@ -12,11 +12,11 @@ use aws_smithy_http::body::SdkBody;
 use aws_types::region::SigningRegion;
 use aws_types::Credentials;
 use aws_types::SigningService;
-use std::error::Error;
 use std::fmt;
 use std::time::{Duration, SystemTime};
 
 pub use aws_sigv4::http_request::SignableBody;
+pub type SigningError = aws_sigv4::http_request::SigningError;
 
 const EXPIRATION_WARNING: &str = "Presigned request will expire before the given \
     `expires_in` duration because the credentials used to sign it will expire first.";
@@ -121,8 +121,6 @@ impl fmt::Debug for SigV4Signer {
     }
 }
 
-pub type SigningError = Box<dyn Error + Send + Sync>;
-
 impl SigV4Signer {
     pub fn new() -> Self {
         SigV4Signer { _private: () }

aws/rust-runtime/aws-sigv4/src/http_request/canonical_request.rs

@@ -3,12 +3,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-use super::query_writer::QueryWriter;
-use super::{Error, PayloadChecksumKind, SignableBody, SignatureLocation, SigningParams};
 use crate::date_time::{format_date, format_date_time};
+use crate::http_request::error::CanonicalRequestError;
+use crate::http_request::query_writer::QueryWriter;
 use crate::http_request::sign::SignableRequest;
 use crate::http_request::url_escape::percent_encode_path;
 use crate::http_request::PercentEncodingMode;
+use crate::http_request::{PayloadChecksumKind, SignableBody, SignatureLocation, SigningParams};
 use crate::sign::sha256_hex_string;
 use http::header::{HeaderName, HOST};
 use http::{HeaderMap, HeaderValue, Method, Uri};
@@ -124,7 +125,7 @@ impl<'a> CanonicalRequest<'a> {
     pub(super) fn from<'b>(
         req: &'b SignableRequest<'b>,
         params: &'b SigningParams<'b>,
-    ) -> Result<CanonicalRequest<'b>, Error> {
+    ) -> Result<CanonicalRequest<'b>, CanonicalRequestError> {
         // Path encoding: if specified, re-encode % as %25
         // Set method and path into CanonicalRequest
         let path = req.uri().path();
@@ -182,7 +183,7 @@ impl<'a> CanonicalRequest<'a> {
         params: &SigningParams<'_>,
         payload_hash: &str,
         date_time: &str,
-    ) -> Result<(Vec<CanonicalHeaderName>, HeaderMap), Error> {
+    ) -> Result<(Vec<CanonicalHeaderName>, HeaderMap), CanonicalRequestError> {
         // Header computation:
         // The canonical request will include headers not present in the input. We need to clone and
         // normalize the headers from the original request and add:
@@ -375,9 +376,15 @@ fn trim_spaces_from_byte_string(bytes: &[u8]) -> &[u8] {
 
 /// Works just like [trim_all] but acts on HeaderValues instead of bytes.
 /// Will ensure that the underlying bytes are valid UTF-8.
-fn normalize_header_value(header_value: &HeaderValue) -> Result<HeaderValue, Error> {
+fn normalize_header_value(
+    header_value: &HeaderValue,
+) -> Result<HeaderValue, CanonicalRequestError> {
     let trimmed_value = trim_all(header_value.as_bytes());
-    HeaderValue::from_str(std::str::from_utf8(&trimmed_value)?).map_err(Error::from)
+    HeaderValue::from_str(
+        std::str::from_utf8(&trimmed_value)
+            .map_err(CanonicalRequestError::invalid_utf8_in_header_value)?,
+    )
+    .map_err(CanonicalRequestError::from)
 }
 
 #[derive(Debug, PartialEq, Default)]

aws/rust-runtime/aws-sigv4/src/http_request/error.rs

@@ -0,0 +1,104 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+use http::header::{InvalidHeaderName, InvalidHeaderValue};
+use std::error::Error;
+use std::fmt;
+use std::str::Utf8Error;
+
+#[derive(Debug)]
+enum SigningErrorKind {
+    FailedToCreateCanonicalRequest { source: CanonicalRequestError },
+}
+
+/// Error signing request
+#[derive(Debug)]
+pub struct SigningError {
+    kind: SigningErrorKind,
+}
+
+impl fmt::Display for SigningError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.kind {
+            SigningErrorKind::FailedToCreateCanonicalRequest { .. } => {
+                write!(f, "failed to create canonical request")
+            }
+        }
+    }
+}
+
+impl Error for SigningError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        match &self.kind {
+            SigningErrorKind::FailedToCreateCanonicalRequest { source } => Some(source),
+        }
+    }
+}
+
+impl From<CanonicalRequestError> for SigningError {
+    fn from(source: CanonicalRequestError) -> Self {
+        Self {
+            kind: SigningErrorKind::FailedToCreateCanonicalRequest { source },
+        }
+    }
+}
+
+#[derive(Debug)]
+enum CanonicalRequestErrorKind {
+    InvalidHeaderName { source: InvalidHeaderName },
+    InvalidHeaderValue { source: InvalidHeaderValue },
+    InvalidUtf8InHeaderValue { source: Utf8Error },
+}
+
+#[derive(Debug)]
+pub(crate) struct CanonicalRequestError {
+    kind: CanonicalRequestErrorKind,
+}
+
+impl fmt::Display for CanonicalRequestError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use CanonicalRequestErrorKind::*;
+        match self.kind {
+            InvalidHeaderName { .. } => write!(f, "invalid header name"),
+            InvalidHeaderValue { .. } => write!(f, "invalid header value"),
+            InvalidUtf8InHeaderValue { .. } => write!(f, "invalid UTF-8 in header value"),
+        }
+    }
+}
+
+impl Error for CanonicalRequestError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        use CanonicalRequestErrorKind::*;
+        match &self.kind {
+            InvalidHeaderName { source } => Some(source),
+            InvalidHeaderValue { source } => Some(source),
+            InvalidUtf8InHeaderValue { source } => Some(source),
+        }
+    }
+}
+
+impl CanonicalRequestError {
+    pub(crate) fn invalid_utf8_in_header_value(source: Utf8Error) -> Self {
+        Self {
+            kind: CanonicalRequestErrorKind::InvalidUtf8InHeaderValue { source },
+        }
+    }
+}
+
+impl From<InvalidHeaderName> for CanonicalRequestError {
+    fn from(source: InvalidHeaderName) -> Self {
+        Self {
+            kind: CanonicalRequestErrorKind::InvalidHeaderName { source },
+        }
+    }
+}
+
+impl From<InvalidHeaderValue> for CanonicalRequestError {
+    fn from(source: InvalidHeaderValue) -> Self {
+        Self {
+            kind: CanonicalRequestErrorKind::InvalidHeaderValue { source },
+        }
+    }
+}

aws/rust-runtime/aws-sigv4/src/http_request/mod.rs

@@ -8,7 +8,7 @@
 //! # Example: Signing an HTTP request
 //!
 //! ```rust
-//! # fn test() -> Result<(), aws_sigv4::http_request::Error> {
+//! # fn test() -> Result<(), aws_sigv4::http_request::SigningError> {
 //! use aws_sigv4::http_request::{sign, SigningSettings, SigningParams, SignableRequest};
 //! use http;
 //! use std::time::SystemTime;
@@ -42,6 +42,7 @@
 //!
 
 mod canonical_request;
+mod error;
 mod query_writer;
 mod settings;
 mod sign;
@@ -50,7 +51,8 @@ mod url_escape;
 #[cfg(test)]
 pub(crate) mod test;
 
+pub use error::SigningError;
 pub use settings::{
     PayloadChecksumKind, PercentEncodingMode, SignatureLocation, SigningParams, SigningSettings,
 };
-pub use sign::{sign, Error, SignableBody, SignableRequest};
+pub use sign::{sign, SignableBody, SignableRequest};

aws/rust-runtime/aws-sigv4/src/http_request/sign.rs

@@ -3,6 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+use super::error::SigningError;
 use super::{PayloadChecksumKind, SignatureLocation};
 use crate::http_request::canonical_request::header;
 use crate::http_request::canonical_request::param;
@@ -15,12 +16,8 @@ use http::header::HeaderValue;
 use http::{HeaderMap, Method, Uri};
 use std::borrow::Cow;
 use std::convert::TryFrom;
-use std::error::Error as StdError;
 use std::str;
 
-/// Signing error type
-pub type Error = Box<dyn StdError + Send + Sync + 'static>;
-
 /// Represents all of the information necessary to sign an HTTP request.
 #[derive(Debug)]
 #[non_exhaustive]
@@ -155,7 +152,7 @@ impl SigningInstructions {
 pub fn sign<'a>(
     request: SignableRequest<'a>,
     params: &'a SigningParams<'a>,
-) -> Result<SigningOutput<SigningInstructions>, Error> {
+) -> Result<SigningOutput<SigningInstructions>, SigningError> {
     tracing::trace!(request = ?request, params = ?params, "signing request");
     match params.settings.signature_location {
         SignatureLocation::Headers => {
@@ -181,7 +178,7 @@ type CalculatedParams = Vec<(&'static str, Cow<'static, str>)>;
 fn calculate_signing_params<'a>(
     request: &'a SignableRequest<'a>,
     params: &'a SigningParams<'a>,
-) -> Result<(CalculatedParams, String), Error> {
+) -> Result<(CalculatedParams, String), SigningError> {
     let creq = CanonicalRequest::from(request, params)?;
     tracing::trace!(canonical_request = %creq);
 
@@ -230,7 +227,7 @@ fn calculate_signing_params<'a>(
 fn calculate_signing_headers<'a>(
     request: &'a SignableRequest<'a>,
     params: &'a SigningParams<'a>,
-) -> Result<SigningOutput<HeaderMap<HeaderValue>>, Error> {
+) -> Result<SigningOutput<HeaderMap<HeaderValue>>, SigningError> {
     // Step 1: https://docs.aws.amazon.com/en_pv/general/latest/gr/sigv4-create-canonical-request.html.
     let creq = CanonicalRequest::from(request, params)?;
     tracing::trace!(canonical_request = %creq);