Range header not signable about aws4fetch

[mhart]

@robtimmer @kyranb @alukach Apologies for leaving it so long, but if you're still using this library (or can remember), can you tell me what errors you're encountering?

In the testing I've tried for S3, there's no error if the range header is included but isn't signed. Is it some other tool that's expecting this?

It was removed back in #5 to support CDN use cases.

I'll be publishing a new v1.1 version that allows ppl to specify their own unsignable headers – and I'm considering a v2 that actually removes the range header from the default list of unsignable headers (ie, it would be signed by default again) – but I need to know what problems it's actually causing because so far I'm unable to reproduce.

[kyranb]

Also running into this error

[robtimmer]

Hi @kyranb @drappier-charles, have a look at my fork. I've committed a fix if you are interested. https://github.com/robtimmer/aws4fetch/commits/master

[alukach]

I'm a bit late to this discussion, but can one of you help me understand the basis of the issue?

I am currently successfully making requests to S3 in a manner similar to:

new AwsClient(creds).fetch(
  "https://my-bucket.s3.amazonaws.com/a-file.json",
  {
    method: "GET",
    body: null,
    headers: {
      range: "bytes=16777216-",
    }
  }
)

Would you expect that to work?

The reason that I wound up on this ticket is because my signatures started to fail when I added a accept-encoding header:

new AwsClient(creds).fetch(
  "https://my-bucket.s3.amazonaws.com/a-file.json",
  {
    method: "GET",
    body: null,
    headers: {
      range: "bytes=16777216-",
      "accept-encoding": "gzip",
    }
  }
)

I'm struggling to make sense of why.

[robtimmer]

@mhart For default S3 it should work. Only when doing multipart upload/ downloads it needs a Range-header to be present (files downloaded in parts, e.g. bytes 0-342423 after that 342423-574884), if I remember correctly.

[mhart]

@robtimmer I actually meant it worked when I included the range header (and didn't sign it). I can do multipart downloads no problem.

What platform were you using this lib on when it errored, do you remember?

[alukach]

@mhart I'm pretty confused about what is going on with my issue. It may be a part of this issue, or it may be something entirely different.

I have a HonoJS API with some test endpoints:

const app = new Hono<{ Bindings: Env }>();

const app = new Hono<{ Bindings: Env }>();

app.get("/test1", async (c) => {
  return new AwsClient({
    accessKeyId: c.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: c.env.AWS_SECRET_ACCESS_KEY,
    region: "us-west-2",
  }).fetch("https://s3-event-bucket-test.s3.amazonaws.com/user_data.json", {
    method: "GET",
    body: null,
    headers: {
      range: "bytes=0-5",
    },
  });
});

app.get("/test2", async (c) => {
  return new AwsClient({
    accessKeyId: c.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: c.env.AWS_SECRET_ACCESS_KEY,
    region: "us-west-2",
  }).fetch("https://s3-event-bucket-test.s3.amazonaws.com/user_data.json", {
    method: "GET",
    body: null,
    headers: {
      "accept-encoding": "gzip",
      range: "bytes=0-5",
    },
  });
});

app.get("/test3", async (c) => {
  return new AwsClient({
    accessKeyId: c.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: c.env.AWS_SECRET_ACCESS_KEY,
    region: "us-west-2",
  }).fetch("https://aws4fetch-err-example.s3.amazonaws.com/data");
});

I wrote my original comment after noticing that a range request (eg /test1) would function but as soon as I added the accept-encoding, it failed (eg /test2

➤ curl http://localhost:8787/test1
{
  "A%

➤ curl http://localhost:8787/test2
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>AKIAOBSCURED</AWSAccessKeyId><StringToSign>AWS4-HMAC-SHA256
20221009T053354Z
20221009/us-west-2/s3/aws4_request
42b48badfba9efdfd095e2f0531b2216bb4cf350eb3be2e719b37c13c6c36518</StringToSign><SignatureProvided>62838b16df14856b7cd38e20fc654ae479327fb5819dbfc04713197ae662aec5</SignatureProvided><StringToSignBytes>41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 0a 32 30 32 32 31 30 30 39 54 30 35 33 33 35 34 5a 0a 32 30 32 32 31 30 30 39 2f 75 73 2d 77 65 73 74 2d 32 2f 73 33 2f 61 77 73 34 5f 72 65 71 75 65 73 74 0a 34 32 62 34 38 62 61 64 66 62 61 39 65 66 64 66 64 30 39 35 65 32 66 30 35 33 31 62 32 32 31 36 62 62 34 63 66 33 35 30 65 62 33 62 65 32 65 37 31 39 62 33 37 63 31 33 63 36 63 33 36 35 31 38</StringToSignBytes><CanonicalRequest>GET
/user_data.json

accept-encoding:gzip, identity
host:s3-event-bucket-test.s3.amazonaws.com
x-amz-content-sha256:UNSIGNED-PAYLOAD
x-amz-date:20221009T053354Z

accept-encoding;host;x-amz-content-sha256;x-amz-date
UNSIGNED-PAYLOAD</CanonicalRequest><CanonicalRequestBytes>47 45 54 0a 2f 75 73 65 72 5f 64 61 74 61 2e 6a 73 6f 6e 0a 0a 61 63 63 65 70 74 2d 65 6e 63 6f 64 69 6e 67 3a 67 7a 69 70 2c 20 69 64 65 6e 74 69 74 79 0a 68 6f 73 74 3a 73 33 2d 65 76 65 6e 74 2d 62 75 63 6b 65 74 2d 74 65 73 74 2e 73 33 2e 61 6d 61 7a 6f 6e 61 77 73 2e 63 6f 6d 0a 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44 0a 78 2d 61 6d 7a 2d 64 61 74 65 3a 32 30 32 32 31 30 30 39 54 30 35 33 33 35 34 5a 0a 0a 61 63 63 65 70 74 2d 65 6e 63 6f 64 69 6e 67 3b 68 6f 73 74 3b 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3b 78 2d 61 6d 7a 2d 64 61 74 65 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes><RequestId>NBJWGEJ2QZ51TC9V</RequestId><HostId>Wch/vGpPh5S6lnj8GwThlziDlkaNlIonpEloNajiEv/tu6L908Hamhd3ijKkkFrWj+oRSvFzT40=</HostId></Error>%         

However, in writing this comment, I'm left really scratching my head as I'm somehow hitting these SignatureDoesNotMatch errors even with the most basic request on a recently created bucket with a public file:

➤ aws s3 mb s3://aws4fetch-err-example
➤ echo 🚀 | aws s3 cp - s3://aws4fetch-err-example/data --acl public-read
➤ curl http://localhost:8787/test3
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>AKIA5Q2DAUVI6BFTMLF2</AWSAccessKeyId><StringToSign>AWS4-HMAC-SHA256
20221009T141218Z
20221009/us-west-2/s3/aws4_request
9d5aed65d4ee4f6ce55f3204713339d8b3b0ea90975622f3f868034022602e61</StringToSign><SignatureProvided>ddc72979e1941802cbad093ed3f19693bcd9b22d54611cc95d5a23f847c553a3</SignatureProvided><StringToSignBytes>41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 0a 32 30 32 32 31 30 30 39 54 31 34 31 32 31 38 5a 0a 32 30 32 32 31 30 30 39 2f 75 73 2d 77 65 73 74 2d 32 2f 73 33 2f 61 77 73 34 5f 72 65 71 75 65 73 74 0a 39 64 35 61 65 64 36 35 64 34 65 65 34 66 36 63 65 35 35 66 33 32 30 34 37 31 33 33 33 39 64 38 62 33 62 30 65 61 39 30 39 37 35 36 32 32 66 33 66 38 36 38 30 33 34 30 32 32 36 30 32 65 36 31</StringToSignBytes><CanonicalRequest>GET
/data

host:aws4fetch-err-example.s3-us-west-2.amazonaws.com
x-amz-content-sha256:UNSIGNED-PAYLOAD
x-amz-date:20221009T141218Z

host;x-amz-content-sha256;x-amz-date
UNSIGNED-PAYLOAD</CanonicalRequest><CanonicalRequestBytes>47 45 54 0a 2f 64 61 74 61 0a 0a 68 6f 73 74 3a 61 77 73 34 66 65 74 63 68 2d 65 72 72 2d 65 78 61 6d 70 6c 65 2e 73 33 2d 75 73 2d 77 65 73 74 2d 32 2e 61 6d 61 7a 6f 6e 61 77 73 2e 63 6f 6d 0a 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44 0a 78 2d 61 6d 7a 2d 64 61 74 65 3a 32 30 32 32 31 30 30 39 54 31 34 31 32 31 38 5a 0a 0a 68 6f 73 74 3b 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3b 78 2d 61 6d 7a 2d 64 61 74 65 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes><RequestId>NAMGPE8R9MR455ES</RequestId><HostId>DQeMWIjkIikUEfYMYhQ+wLNoffBz0GTCD+CzEQ/IXBU/2j7c5pLDxS9nIDeW+9CPBZOyUK0c8xk=</HostId></Error>%

So I really have no idea what is going on. It's feeling like I'm doing something wrong, but /test3 makes me totally unsure as to what that could be. All buckets and objects were created using the same AWS account.

[mhart]

@alukach interesting – I notice that S3 is telling you the header needs to match accept-encoding:gzip, identity – I wonder if that's Cloudflare (or whatever provider you're using) adding the extra header on the fetch.

Maybe try:

    headers: {
      "accept-encoding": "gzip, identity",
      range: "bytes=0-5",
    },

Also, you only need to create AwsClient once – you don't need to create it per request (you could hold it in a global variable, or perhaps Hono has a way to store objects beyond a single request)

[mhart]

@alukach also I think the <CanonicalRequest> details from the error message were truncated in the last part of your message (for /test3) – not sure exactly what's going on there

[alukach]

I notice that S3 is telling you the header needs to match accept-encoding:gzip, identity – I wonder if that's Cloudflare (or whatever provider you're using) adding the extra header on the fetch.

Yes, I think that there may be something to this idea. When I do add the identity header myself, it appears that it gets double-added:

app.get("/test2", async (c) => {
  return new AwsClient({
    accessKeyId: c.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: c.env.AWS_SECRET_ACCESS_KEY,
    region: "us-west-2",
  }).fetch("https://s3-event-bucket-test.s3.amazonaws.com/user_data.json", {
    method: "GET",
    body: null,
    headers: {
      "accept-encoding": "gzip, identity",
      range: "bytes=0-5",
    },
  });
});

➤ curl http://localhost:8787/test2
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>AKIAOBSCURED</AWSAccessKeyId><StringToSign>AWS4-HMAC-SHA256
20221009T141522Z
20221009/us-west-2/s3/aws4_request
5e3bc4735e22db6bc1889ad0d52c779950181eeb5896e1be6485350b80c539ad</StringToSign><SignatureProvided>b3eaad4ac4e882ff22fb283b1202d380f6d96aaf992d8af013c652e8a7c6f06d</SignatureProvided><StringToSignBytes>41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 0a 32 30 32 32 31 30 30 39 54 31 34 31 35 32 32 5a 0a 32 30 32 32 31 30 30 39 2f 75 73 2d 77 65 73 74 2d 32 2f 73 33 2f 61 77 73 34 5f 72 65 71 75 65 73 74 0a 35 65 33 62 63 34 37 33 35 65 32 32 64 62 36 62 63 31 38 38 39 61 64 30 64 35 32 63 37 37 39 39 35 30 31 38 31 65 65 62 35 38 39 36 65 31 62 65 36 34 38 35 33 35 30 62 38 30 63 35 33 39 61 64</StringToSignBytes><CanonicalRequest>GET
/user_data.json

accept-encoding:gzip, identity, identity
host:s3-event-bucket-test.s3.amazonaws.com
x-amz-content-sha256:UNSIGNED-PAYLOAD
x-amz-date:20221009T141522Z

accept-encoding;host;x-amz-content-sha256;x-amz-date
UNSIGNED-PAYLOAD</CanonicalRequest><CanonicalRequestBytes>47 45 54 0a 2f 75 73 65 72 5f 64 61 74 61 2e 6a 73 6f 6e 0a 0a 61 63 63 65 70 74 2d 65 6e 63 6f 64 69 6e 67 3a 67 7a 69 70 2c 20 69 64 65 6e 74 69 74 79 2c 20 69 64 65 6e 74 69 74 79 0a 68 6f 73 74 3a 73 33 2d 65 76 65 6e 74 2d 62 75 63 6b 65 74 2d 74 65 73 74 2e 73 33 2e 61 6d 61 7a 6f 6e 61 77 73 2e 63 6f 6d 0a 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44 0a 78 2d 61 6d 7a 2d 64 61 74 65 3a 32 30 32 32 31 30 30 39 54 31 34 31 35 32 32 5a 0a 0a 61 63 63 65 70 74 2d 65 6e 63 6f 64 69 6e 67 3b 68 6f 73 74 3b 78 2d 61 6d 7a 2d 63 6f 6e 74 65 6e 74 2d 73 68 61 32 35 36 3b 78 2d 61 6d 7a 2d 64 61 74 65 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes><RequestId>6HASSH6RFKNK6N61</RequestId><HostId>nlZbinSJ/a6c0PefnmJNuAnJ6w8V0Xk/JxD1MO/3074rhZ8CFOLlbOYmAJOkJL46aRoYPB5mVdU=</HostId></Error>%   

How do you typically test this library? I'm happy to run some tests to remove Cloudflare from the equation but I'm not sure of the simplest path to do that. Do you typically run it in the browser? I struggled calling the lib directly from node.js (which seems to be outside the target of this package).

Also, you only need to create AwsClient once

Thanks, my code makes more sense in my actual use-case (using unique credentials per-request).

also I think the details from the error message were truncated in the last part of your message (for /test3) – not sure exactly what's going on there

Confirmed, I think that was a copy/paste issue on my side. Fixed now.

[mhart]

@alukach I can see you're using different hosts. If your bucket is in the us-west-2 region, shouldn't your host be aws4fetch-err-example.s3.us-west-2.amazonaws.com?

[mhart]

See: https://docs.aws.amazon.com/AmazonS3/latest/userguide/VirtualHosting.html#virtual-hosted-style-access

[mhart]

Actually, if you're using Cloudflare, it will always be accept-encoding: gzip – regardless of if you specify it or not.

https://github.com/cloudflare/miniflare/blob/9265fa4d53262ce66278b91f2001b090e10696e8/packages/http-server/src/index.ts#L117-L123

I'd just remove the header altogether and try again. I'm not sure what's appending the identity though

[kyranb]

@mhart I ran into the issue while using aws4fetch in a cloudflare worker, connecting to Backblaze B2's S3 compatible API.

[mhart]

@kyranb ah ok, thanks. I guess Backblaze must require that the range header is signed.

[alukach]

Actually, if you're using Cloudflare, it will always be accept-encoding: gzip – regardless of if you specify it or not.

So are you saying that Cloudflare will alter the outgoing requests made by the fetch API?

[mhart]

Actually, if you're using Cloudflare, it will always be accept-encoding: gzip – regardless of if you specify it or not.

So are you saying that Cloudflare will alter the outgoing requests made by the fetch API?

Correct

[robtimmer]

@robtimmer I actually meant it worked when I included the range header (and didn't sign it). I can do multipart downloads no problem.

What platform were you using this lib on when it errored, do you remember?

I was using CloudFlare workers (without any framework like HonoJS)