Encountering SignatureDoesNotMatch Error When Accessing Amazon SP API (/feeds/2021-06-30/documents)

Question

How can I resolve the signature issue I'm facing when trying to access a feed document link from the Amazon SP API?

I have been utilizing the API mentioned below to create feed documents successfully:

API: https://sellingpartnerapi-na.amazon.com/feeds/2021-06-30/documents

However, when attempting to open the document link generated by the API, I am encountering a signature issue.

This is the Error I am getting

<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>ID</AWSAccessKeyId>
<StringToSign>AWS4-HMAC-SHA256 20230808T124615Z 20230808/us-east-1/s3/aws4_request 61c729c2ca5fb09dd58a387ef1d3ace2133e80b84604aceebc7126e1f574adc9</StringToSign>
<SignatureProvided>60c4b5671d3a97f085e0e306a1458935b4b73e77e34d29184677424ed5bae5aa</SignatureProvided>
<StringToSignBytes>41 57 53 34 2d 48 4d 41 43 2d 53 48 41 32 35 36 0a 32 30 32 33 30 38 30 38 54 31 32 34 36 31 35 5a 0a 32 30 32 33 30 38 30 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 36 31 63 37 32 39 63 32 63 61 35 66 62 30 39 64 64 35 38 61 33 38 37 65 66 31 64 33 61 63 65 32 31 33 33 65 38 30 62 38 34 36 30 34 61 63 65 65 62 63 37 31 32 36 65 31 66 35 37 34 61 64 63 39</StringToSignBytes>
<CanonicalRequest>GET //NinetyDays/amzn1.tortuga.4.na.15401127-ae1a-4f28-a919-591f7b836d65.T2CN4ZABFR7TJ7 X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA5U6MO6RANIQBJIW5%2F20230808%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20230808T124615Z&X-Amz-Expires=300&X-Amz-SignedHeaders=content-type%3Bhost content-type: host:tortuga-prod-na.s3-external-1.amazonaws.com content-type;host UNSIGNED-PAYLOAD</CanonicalRequest>
<CanonicalRequestBytes>47 45 54 0a 2f 2f 4e 69 6e 65 74 79 44 61 79 73 2f 61 6d 7a 6e 31 2e 74 6f 72 74 75 67 61 2e 34 2e 6e 61 2e 31 35 34 30 31 31 32 37 2d 61 65 31 61 2d 34 66 32 38 2d 61 39 31 39 2d 35 39 31 66 37 62 38 33 36 64 36 35 2e 54 32 43 4e 34 5a 41 42 46 52 37 54 4a 37 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 72 65 64 65 6e 74 69 61 6c 3d 41 4b 49 41 35 55 36 4d 4f 36 52 41 4e 49 51 42 4a 49 57 35 25 32 46 32 30 32 33 30 38 30 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 33 30 38 30 38 54 31 32 34 36 31 35 5a 26 58 2d 41 6d 7a 2d 45 78 70 69 72 65 73 3d 33 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 74 79 70 65 25 33 42 68 6f 73 74 0a 63 6f 6e 74 65 6e 74 2d 74 79 70 65 3a 0a 68 6f 73 74 3a 74 6f 72 74 75 67 61 2d 70 72 6f 64 2d 6e 61 2e 73 33 2d 65 78 74 65 72 6e 61 6c 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 74 79 70 65 3b 68 6f 73 74 0a 55 4e 53 49 47 4e 45 44 2d 50 41 59 4c 4f 41 44</CanonicalRequestBytes>
<RequestId>6ZT96W3BYGNWY38D</RequestId>
<HostId>F3JHNt5H3NanKm6rJOG1vbzRhSHuDeNpr4tLIPasUTr64KI6HvpUQdwErURNYRK4Z5wYyWif7io=</HostId>
</Error>

I am calling this API (https://sellingpartnerapi-na.amazon.com/feeds/2021-06-30/documents) with a POST request with "contentType":"text/xml; charset=utf-8" in the body with the token set in the header.

This is the Postmen collection (Amazon sp API collection)

https://elements.getpostman.com/redirect?entityId=28629677-e578d4aa-a0ab-44c5-addf-506e8cb18102&entityType=collection

you can find the API call in feeds documents API POST request.

Any guidance or expertise would be greatly appreciated.

Answer 1

I finally found what was the issue

key is to

• have Content-Type header which has to be exactly the same for both requests
• provide correct json data to upload

I will provide full example with JSON_LISTINGS_FEED content

1. create feed document

curl --location 'https://sellingpartnerapi-eu.amazon.com/feeds/2021-06-30/documents' \
--header 'Content-Type: application/json' \
--header 'x-amz-access-token: Atza|xxxxx' \
--data '{
  "contentType":"application/json"
}'

response:

{
  "feedDocumentId":"amzn1.tortuga.4.eu.AAAAAA",
  "url": "https://tortuga-prod-eu.s3-eu-west-1.amazonaws.com/xxxxx.amzn1.tortuga.4.eu.TBQCUC81FDX8P?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20241015T192701Z&X-Amz-SignedHeaders=content-type%3Bhost&X-Amz-Expires=300&X-Amz-Credential=xxxxxxxxxx"
}

2. upload of JSON feed

curl --location --request PUT 'https://tortuga-prod-eu.s3-eu-west-1.amazonaws.com/xxxxx.amzn1.tortuga.4.eu.TBQCUC81FDX8P?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20241015T192701Z&X-Amz-SignedHeaders=content-type%3Bhost&X-Amz-Expires=300&X-Amz-Credential=xxxxxxxxxx' \
--header 'Content-Type: application/json' \
--data '{
  "header": {
    "sellerId": "A3XXXXXXXXXX",
    "version": "2.0",
    "issueLocale": "de_DE"
  },
  "messages": [
    {
      "messageId": 1,
      "sku": "12345",
      "operationType": "PARTIAL_UPDATE",
      "productType": "PRODUCT",
      "attributes": {
        "fulfillment_availability": [
          {
            "fulfillment_channel_code": "DEFAULT",
            "quantity": 1
          }
        ]
      }
    },
  ]
}'

3. create feed

curl --location 'https://sellingpartnerapi-eu.amazon.com/feeds/2021-06-30/feeds' \
--header 'Content-Type: application/json' \
--header 'x-amz-access-token: Atza|xxxxx' \
--data '{
    "inputFeedDocumentId": "amzn1.tortuga.4.eu.AAAAAA",
    "feedType": "JSON_LISTINGS_FEED",
    "marketplaceIds": [
        "A1XXXXXXXXXXX"
    ],
    "feedOptions": {}
}'

Answer 2

i think might be a PUT request, not a POST