@@ -37,7 +37,7 @@ sha256 = "1.6"
 tokio = { version = "1", features = ["macros", "rt"] }
 tokio-tar = { package = "astral-tokio-tar", version = "0.6.2" }
 tokio-util = "0.7.18"
-md5 = "0.8"
+crc-fast = { version = "1.9.0", default-features = false, features = ["std"] }
 base64 = "0.22.1"
 async-compression = { version = "0.4.42", features = ["tokio", "gzip"] }
 schemars = "1.2.1"
@@ -77,6 +77,7 @@ uuid = { version = "1.23.1", features = ["v4"] }
 which = "8.0.2"
 crc32fast = "1.5.0"
 samply = { path = "crates/samply-codspeed/samply" }
+bytes = "1"
 
 # Memory profiling (memtrack) and the capability handling around it are Linux-only.
 [target.'cfg(target_os = "linux")'.dependencies]
 
@@ -136,8 +136,7 @@ pub trait RunEnvironmentProvider {
             tokenless: api_client.token().is_none(),
             repository_provider: self.get_repository_provider(),
             run_environment_metadata,
-            profile_md5: profile_archive.hash.clone(),
-            profile_encoding: profile_archive.content.encoding(),
+            profile_archive_metadata: profile_archive.metadata.clone(),
             commit_hash,
             allow_empty: config.allow_empty,
             runner: Runner {
 
@@ -1,20 +1,21 @@
+use std::collections::BTreeMap;
+
 use serde::{Deserialize, Serialize};
 
 use crate::executor::ExecutorName;
 use crate::instruments::InstrumentName;
 use crate::run_environment::{RepositoryProvider, RunEnvironment, RunEnvironmentMetadata, RunPart};
 use crate::system::SystemInfo;
 
-pub const LATEST_UPLOAD_METADATA_VERSION: u32 = 11;
+pub const LATEST_UPLOAD_METADATA_VERSION: u32 = 12;
 
 #[derive(Serialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct UploadMetadata {
     pub repository_provider: RepositoryProvider,
     pub version: Option<u32>,
     pub tokenless: bool,
-    pub profile_md5: String,
-    pub profile_encoding: Option<String>,
+    pub profile_archive_metadata: ProfileArchiveMetadata,
     pub runner: Runner,
     pub run_environment: RunEnvironment,
     pub run_part: Option<RunPart>,
@@ -24,6 +25,22 @@ pub struct UploadMetadata {
     pub run_environment_metadata: RunEnvironmentMetadata,
 }
 
+/// Metadata of the profile archive, uploaded as an S3 multipart upload in consecutive
+/// `part_size` chunks, the last one holding the remainder. S3 requires parts of 5 MiB to 5 GiB
+/// (the last one excepted from the minimum), and at most 10,000 of them.
+#[derive(Serialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct ProfileArchiveMetadata {
+    /// `Content-Encoding` of the archive, such as `gzip`
+    pub encoding: Option<String>,
+    pub size: u64,
+    /// Base64 big-endian CRC64NVME of the whole archive
+    pub crc64nvme: String,
+    pub part_size: u64,
+    /// Base64 big-endian CRC64NVME of each part, in upload order
+    pub part_crc64nvmes: Vec<String>,
+}
+
 #[derive(Serialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct Runner {
@@ -46,12 +63,69 @@ pub struct Runner {
 #[serde(rename_all = "camelCase")]
 pub struct UploadData {
     pub status: String,
-    pub upload_url: String,
+    pub multipart_upload: MultipartUpload,
     pub run_id: String,
 }
 
+#[derive(Deserialize, Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct MultipartUpload {
+    /// Presigned S3 `UploadPart` requests, one per part, in upload order
+    pub parts: Vec<PresignedRequest>,
+    /// Presigned S3 `CompleteMultipartUpload` request
+    pub complete: PresignedRequest,
+}
+
+/// Request presigned by the API, to send to `url` with `headers` as is: they are
+/// part of the signature
+#[derive(Deserialize, Serialize, Debug)]
+pub struct PresignedRequest {
+    pub url: String,
+    pub headers: BTreeMap<String, String>,
+}
+
 #[derive(Deserialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct UploadError {
     pub error: String,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_multipart_upload_response() {
+        let upload_data: UploadData = serde_json::from_str(
+            r#"{
+                "status": "success",
+                "runId": "run-id",
+                "multipartUpload": {
+                    "parts": [
+                        { "url": "https://part/1", "headers": { "x-amz-checksum-crc64nvme": "nq48tdaL2no=" } },
+                        { "url": "https://part/2", "headers": { "x-amz-checksum-crc64nvme": "XMXoclwBfLo=" } }
+                    ],
+                    "complete": {
+                        "url": "https://complete",
+                        "headers": { "x-amz-checksum-type": "FULL_OBJECT" }
+                    }
+                }
+            }"#,
+        )
+        .unwrap();
+
+        assert_eq!(upload_data.run_id, "run-id");
+        let upload = upload_data.multipart_upload;
+        let part_urls: Vec<_> = upload.parts.iter().map(|part| part.url.as_str()).collect();
+        assert_eq!(part_urls, ["https://part/1", "https://part/2"]);
+        assert_eq!(
+            upload.parts[1].headers,
+            BTreeMap::from([("x-amz-checksum-crc64nvme".into(), "XMXoclwBfLo=".into())])
+        );
+        assert_eq!(upload.complete.url, "https://complete");
+        assert_eq!(
+            upload.complete.headers,
+            BTreeMap::from([("x-amz-checksum-type".into(), "FULL_OBJECT".into())])
+        );
+    }
+}
@@ -3,6 +3,7 @@ mod interfaces;
 pub mod poll_results;
 mod profile_archive;
 mod run_index_state;
+mod s3;
 mod upload_metadata;
 mod uploader;