Decode query paramters for ALB event source (#545)

* decode ALB query strings
awslabs · Oct 11, 2022 · 2201109 · 2201109
1 parent 45211b0
commit 2201109
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Showing 5 changed files with 127 additions and 5 deletions.
diff --git a/lambda-http/Cargo.toml b/lambda-http/Cargo.toml
@@ -36,6 +36,7 @@ query_map = { version = "0.5", features = ["url-query"] }
 mime = "0.3.16"
 encoding_rs = "0.8.31"
 url = "2.2.2"
+percent-encoding = "2.2.0"
 
 [dependencies.aws_lambda_events]
 version = "^0.6.3"

diff --git a/lambda-http/src/request.rs b/lambda-http/src/request.rs
@@ -20,6 +20,7 @@ use serde::Deserialize;
 use serde_json::error::Error as JsonError;
 use std::future::Future;
 use std::pin::Pin;
+use std::str::FromStr;
 use std::{io::Read, mem};
 use url::Url;
 
@@ -201,22 +202,25 @@ fn into_alb_request(alb: AlbTargetGroupRequest) -> http::Request<Body> {
     let host = alb.headers.get(http::header::HOST).and_then(|s| s.to_str().ok());
     let raw_path = alb.path.unwrap_or_default();
 
+    let query_string_parameters = decode_query_map(alb.query_string_parameters);
+    let multi_value_query_string_parameters = decode_query_map(alb.multi_value_query_string_parameters);
+
     let builder = http::Request::builder()
         .uri(build_request_uri(
             &raw_path,
             &alb.headers,
             host,
-            Some((&alb.multi_value_query_string_parameters, &alb.query_string_parameters)),
+            Some((&multi_value_query_string_parameters, &query_string_parameters)),
         ))
         .extension(RawHttpPath(raw_path))
         // multi valued query string parameters are always a super
         // set of singly valued query string parameters,
         // when present, multi-valued query string parameters are preferred
         .extension(QueryStringParameters(
-            if alb.multi_value_query_string_parameters.is_empty() {
-                alb.query_string_parameters
+            if multi_value_query_string_parameters.is_empty() {
+                query_string_parameters
             } else {
-                alb.multi_value_query_string_parameters
+                multi_value_query_string_parameters
             },
         ))
         .extension(RequestContext::Alb(alb.request_context));
@@ -243,6 +247,12 @@ fn into_alb_request(alb: AlbTargetGroupRequest) -> http::Request<Body> {
     req
 }
 
+fn decode_query_map(query_map: QueryMap) -> QueryMap {
+    let query_string = query_map.to_query_string();
+    let decoded = percent_encoding::percent_decode(query_string.as_bytes()).decode_utf8_lossy();
+    QueryMap::from_str(&decoded).unwrap_or_default()
+}
+
 #[cfg(feature = "apigw_websockets")]
 fn into_websocket_request(ag: ApiGatewayWebsocketProxyRequest) -> http::Request<Body> {
     let http_method = ag.http_method;
@@ -548,6 +558,34 @@ mod tests {
         );
     }
 
+    #[test]
+    fn deserializes_alb_request_encoded_query_parameters_events() {
+        // from the docs
+        // https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html#multi-value-headers
+        let input = include_str!("../tests/data/alb_request_encoded_query_parameters.json");
+        let result = from_str(input);
+        assert!(
+            result.is_ok(),
+            "event was not parsed as expected {:?} given {}",
+            result,
+            input
+        );
+        let req = result.expect("failed to parse request");
+        assert_eq!(req.method(), "GET");
+        assert_eq!(
+            req.uri(),
+            "https://lambda-846800462-us-east-2.elb.amazonaws.com/?myKey=%3FshowAll%3Dtrue"
+        );
+
+        // Ensure this is an ALB request
+        let req_context = req.request_context();
+        assert!(
+            matches!(req_context, RequestContext::Alb(_)),
+            "expected Alb context, got {:?}",
+            req_context
+        );
+    }
+
     #[test]
     fn deserializes_apigw_multi_value_request_events() {
         // from docs
@@ -593,6 +631,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn deserializes_alb_multi_value_request_encoded_query_parameters_events() {
+        // from docs
+        // https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-input-format
+        let input = include_str!("../tests/data/alb_multi_value_request_encoded_query_parameters.json");
+        let result = from_str(input);
+        assert!(
+            result.is_ok(),
+            "event is was not parsed as expected {:?} given {}",
+            result,
+            input
+        );
+        let request = result.expect("failed to parse request");
+        assert!(!request.query_string_parameters().is_empty());
+
+        // test RequestExt#query_string_parameters does the right thing
+        assert_eq!(
+            request.query_string_parameters().all("myKey"),
+            Some(vec!["?showAll=true", "?showAll=false"])
+        );
+    }
+
     #[test]
     fn deserialize_apigw_http_sam_local() {
         // manually generated from AWS SAM CLI

diff --git a/lambda-http/tests/data/alb_multi_value_request_encoded_query_parameters.json b/lambda-http/tests/data/alb_multi_value_request_encoded_query_parameters.json
@@ -0,0 +1,37 @@
+{
+  "requestContext": {
+      "elb": {
+          "targetGroupArn": "arn:aws:elasticloadbalancing:region:123456789012:targetgroup/my-target-group/6d0ecf831eec9f09"
+      }
+  },
+  "httpMethod": "GET",
+  "path": "/",
+  "queryStringParameters": { "myKey": "%3FshowAll%3Dtrue" },
+  "multiValueQueryStringParameters": { "myKey": ["%3FshowAll%3Dtrue", "%3FshowAll%3Dfalse"] },
+  "headers": {
+      "accept": "text/html,application/xhtml+xml",
+      "accept-language": "en-US,en;q=0.8",
+      "content-type": "text/plain",
+      "cookie": "name1=value1",
+      "host": "lambda-846800462-us-east-2.elb.amazonaws.com",
+      "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6)",
+      "x-amzn-trace-id": "Root=1-5bdb40ca-556d8b0c50dc66f0511bf520",
+      "x-forwarded-for": "72.21.198.66",
+      "x-forwarded-port": "443",
+      "x-forwarded-proto": "https"
+  },
+  "multiValueHeaders": {
+      "accept": ["text/html,application/xhtml+xml"],
+      "accept-language": ["en-US,en;q=0.8"],
+      "content-type": ["text/plain"],
+      "cookie":  ["name1=value1", "name2=value2"],
+      "host": ["lambda-846800462-us-east-2.elb.amazonaws.com"],
+      "user-agent": ["Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6)"],
+      "x-amzn-trace-id": ["Root=1-5bdb40ca-556d8b0c50dc66f0511bf520"],
+      "x-forwarded-for": ["72.21.198.66"],
+      "x-forwarded-port": ["443"],
+      "x-forwarded-proto": ["https"]
+  },
+  "isBase64Encoded": false,
+  "body": "request_body"
+}
diff --git a/lambda-http/tests/data/alb_request_encoded_query_parameters.json b/lambda-http/tests/data/alb_request_encoded_query_parameters.json
@@ -0,0 +1,24 @@
+{
+  "requestContext": {
+      "elb": {
+          "targetGroupArn": "arn:aws:elasticloadbalancing:region:123456789012:targetgroup/my-target-group/6d0ecf831eec9f09"
+      }
+  },
+  "httpMethod": "GET",
+  "path": "/",
+  "queryStringParameters": { "myKey": "%3FshowAll%3Dtrue"},
+  "headers": {
+      "accept": "text/html,application/xhtml+xml",
+      "accept-language": "en-US,en;q=0.8",
+      "content-type": "text/plain",
+      "cookie": "cookies",
+      "host": "lambda-846800462-us-east-2.elb.amazonaws.com",
+      "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6)",
+      "x-amzn-trace-id": "Root=1-5bdb40ca-556d8b0c50dc66f0511bf520",
+      "x-forwarded-for": "72.21.198.66",
+      "x-forwarded-port": "443",
+      "x-forwarded-proto": "https"
+  },
+  "isBase64Encoded": false,
+  "body": "request_body"
+}
diff --git a/lambda-runtime-api-client/README.md b/lambda-runtime-api-client/README.md
@@ -32,4 +32,4 @@ async fn main() -> Result<(), Error> {
 
     client.call(request).await
 }
-```
+```