I would like to generate a pre signed PUT URL in order to upload images to my S3-Bucket.
This works great with files of type text where the Content-Type:text/plain
.
Now I’m facing an issue, when I try the same with images (e.g. dummy.png).
My input parameters
const bucketParameter: PutObjectCommandInput = {
Bucket: "myBucket",
Key: "dummy.png",
Body: Buffer.from("BODY", "utf-8"),
ContentType: "image/png",
};
My code
import { GetObjectCommand, PutObjectCommand, PutObjectCommandInput, S3Client } from "@aws-sdk/client-s3";
import { getSignedUrl } from "@aws-sdk/s3-request-presigner";
const AWS = require("aws-sdk");
AWS.config.update({
accessKeyId: "myAccessKey",
secretAccessKey: "mySecretKey",
region: "myRegion",
});
export async function getPresignedPutURL(bucketParameter: PutObjectCommandInput, region: string) {
const s3Client = new S3Client({ region: region });
try {
const command = new PutObjectCommand(bucketParameter);
const signedUrl = await getSignedUrl(s3Client, command, {
expiresIn: 3600,
});
return signedUrl;
} catch (err) {
throw new Error("Error creating presigned PUT URL" + err.message);
}
}
It generates the pre signed URL and I try to execute PUT with the content of an png.
My request header
Accept: */*
User-Agent: Thunder Client (https://www.thunderclient.com)
Content-Type: image/png
My request body is a binary from a png file.
Error message
<?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>AKIATFE5YPEBOFPZJYRN</AWSAccessKeyId>
<StringToSign>AWS4-HMAC-SHA256
20220818T085341Z
20220818/us-east-1/s3/aws4_request
8fcfeba678fa30bdf6ce03595ecb6e80b5aa5429aa0b5b0c7820489113871295</StringToSign>
<SignatureProvided>606187f7b354fc07df7e7cb0967a71f701c7df32c50393613e4124d95bce950f</SignatureProvided>
<StringToSignBytes>41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 0a 32 30 32 32 30 38 31 38 54 30 38 35 33 34 31 5a 0a 32 30 32 32 30 38 31 38 2f 75 73 2d 65 61 73 74 2d 31 2f 73 33 2f 61 77 73 34 5f 72 65 71 75 65 73 74 0a 38 66 63 66 65 62 61 36 37 38 66 61 33 30 62 64 66 36 63 65 30 33 35 39 35 65 63 62 36 65 38 30 62 35 61 61 35 34 32 39 61 61 30 62 35 62 30 63 37 38 32 30 34 38 39 31 31 33 38 37 31 32 39 35</StringToSignBytes>
<CanonicalRequest>PUT
/dummy.png
X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIATFE5YPEBOFPZJYRN%2F20220818%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20220818T085341Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=content-length%3Bhost&x-id=PutObject
content-length:17663
host:eu-central-1-radix-iflair.s3.us-east-1.amazonaws.com
content-length;host
UNSIGNED-PAYLOAD</CanonicalRequest>
<CanonicalRequestBytes>50 55 54 0a 2f 64 75 6d 6d 79 2e 70 6e 67 0a 58 2d 41 6d 7a 2d 41 6c 67 6f 72 69 74 68 6d 3d 41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 26 58 2d 41 6d 7a 2d 43 6f 6e 74 65 6e 74 2d 53 68 61 32 35 36 3d 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44 26 58 2d 41 6d 7a 2d 43 72 65 64 65 6e 74 69 61 6c 3d 41 4b 49 41 54 46 45 35 59 50 45 42 4f 46 50 5a 4a 59 52 4e 25 32 46 32 30 32 32 30 38 31 38 25 32 46 75 73 2d 65 61 73 74 2d 31 25 32 46 73 33 25 32 46 61 77 73 34 5f 72 65 71 75 65 73 74 26 58 2d 41 6d 7a 2d 44 61 74 65 3d 32 30 32 32 30 38 31 38 54 30 38 35 33 34 31 5a 26 58 2d 41 6d 7a 2d 45 78 70 69 72 65 73 3d 33 36 30 30 26 58 2d 41 6d 7a 2d 53 69 67 6e 65 64 48 65 61 64 65 72 73 3d 63 6f 6e 74 65 6e 74 2d 6c 65 6e 67 74 68 25 33 42 68 6f 73 74 26 78 2d 69 64 3d 50 75 74 4f 62 6a 65 63 74 0a 63 6f 6e 74 65 6e 74 2d 6c 65 6e 67 74 68 3a 31 37 36 36 33 0a 68 6f 73 74 3a 65 75 2d 63 65 6e 74 72 61 6c 2d 31 2d 72 61 64 69 78 2d 69 66 6c 61 69 72 2e 73 33 2e 75 73 2d 65 61 73 74 2d 31 2e 61 6d 61 7a 6f 6e 61 77 73 2e 63 6f 6d 0a 0a 63 6f 6e 74 65 6e 74 2d 6c 65 6e 67 74 68 3b 68 6f 73 74 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes>
<RequestId>TP7WQ2EVDH41F2V3</RequestId>
<HostId>brjgBeKuLLcc7pzrrBMPRNtVp2jO/irnMRTyXPwDm9tKUi2aa/FuIG5AJcYVvcbQs7y3jyAIpJ4=</HostId>
</Error>
Why does it work with text files but not with images?
3
Answers
I‘ve found out that the issue was that I‘ve passed the body parameter to the getSignedUrl function.
Therefore the URL is only valid for a content with the same content-length and type, but if I do not set the Body Parameter my generated URL works.
Your problem seems to be with Body property of the bucketParameter. You are providing the value of a Buffer with the string "BODY"(https://nodejs.org/api/buffer.html#static-method-bufferfromstring-encoding). This is not an image.
Change your code like this:
I am making the request using Postman.
Try making the request again and let’s see if it works for you.
This is the full code that I use. Try it exactly like this to see if it works for you.
index.mjs:
package.json
While this doesn’t directly answer the question, I thought I’d add my experience here as it may help some people. I kept getting this error for my presigned PUT url:
After spending absolutely aaages trying to work out what the problem was with the code, it turned out that the problem was that my lambda didn’t have the
"s3:PutObject"
permission! Once I added that permission to my cloudformation template and redeployed, it started working. Major face palm moment!Anyway, for anyone curious, here is my code for generating the signed URL for uploading a file to S3 (when you have the
s3:PutObject
permission!):