# S3 Multipart Upload failed with SignatureDoesNotMatch error

**URL:** <https://discourse.julialang.org/t/s3-multipart-upload-failed-with-signaturedoesnotmatch-error/113363>\
**Category:** Specific Domains\
**Tags:** question, hash, aws\
**Created:** [April 22, 2024, 11:14pm UTC](https://discourse.julialang.org/t/s3-multipart-upload-failed-with-signaturedoesnotmatch-error/113363 "2024-04-22T23:14:24Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Chamika\_Kasun](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chamika_kasun/32/202926_2.png) [@Chamika\_Kasun](https://discourse.julialang.org/u/Chamika_Kasun)\
**Post date:** [April 22, 2024, 11:14pm UTC](https://discourse.julialang.org/t/s3-multipart-upload-failed-with-signaturedoesnotmatch-error/113363/1 "2024-04-22T23:14:24Z")

</div>

I tried to do the multipart upload with the S3 methods as follows using [AWS.ji](https://github.com/JuliaCloud/AWS.jl) library, but every time it gives me the following error, appreciate if someone can point out the mistake that I’ve made.

```julia
<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>AKIAWMRX3SPXW54A3657</AWSAccessKeyId><StringToSign>AWS4-HMAC-SHA256

```

And following is the Code:

NOTE: I’ve used (-------) to show the different parts of the code

```julia
using AWS
@service S3 use_response_type = true

using Base64
using MD5

---------
""
const GLOBAL_AWS_CONFIG = Ref{AWS.AWSConfig}()

"""
    set_global_config(aws_secret_key_id::String, aws_secret_access_key::String, aws_region::String, aws_profile::String)

Sets the `GLOBAL_AWS_CONFIG[]` reference object with the credentials provided.

This extends the AWS Credential chain sequencing. Order of auth options:

1. Use the profile name if provided 
2. Usage of the access and secret keys
2a. If credentials are not provided explicitly, `GLOBAL_AWS_CONFIG[]` is set with the environment variables:
- `AWS_ACCESS_KEY_ID`
- `AWS_SECRET_ACCESS_KEY`
- `AWS_DEFAULT_REGION`
3. empty inputs resolve to the AWS credential chain, including machine roles

"""
function set_global_config(aws_secret_key_id::String=get(ENV, "AWS_ACCESS_KEY_ID", ""),
                           aws_secret_access_key::String=get(ENV, "AWS_SECRET_ACCESS_KEY", ""),
                           aws_region::String=get(ENV, "AWS_DEFAULT_REGION", "ap-southeast-2"),
                           aws_profile::String="")
    if !isempty(aws_profile)
        GLOBAL_AWS_CONFIG[] = global_aws_config(profile = aws_profile)
    elseif !isempty(aws_secret_access_key)
        creds = AWSCredentials(aws_secret_key_id, aws_secret_access_key)
        GLOBAL_AWS_CONFIG[] = global_aws_config(region=aws_region, creds=creds)
    else
        GLOBAL_AWS_CONFIG[] = global_aws_config(region=aws_region)
    end
end
set_global_config(aws_credentials::AWSCredentials, aws_region::String=get(ENV, "AWS_DEFAULT_REGION", "ap-southeast-2")) = set_global_config(aws_credentials.access_key_id, aws_credentials.secret_key, aws_region)

"""
    get_global_config()

Returns the `GLOBAL_AWS_CONFIG[]` reference object.
"""
get_global_config() = isassigned(GLOBAL_AWS_CONFIG) ? GLOBAL_AWS_CONFIG[] : set_global_config()

----------
function s3_multipart_upload(
  bucket,
    key,
    data::IO;
    aws=global_aws_config(),
    part_size_mb=50,
    parse_response::Bool=true,
    tags::AbstractDict=Dict(),
    metadata::AbstractDict=Dict(),
)
  @info "========== Starting S3 Multi-part Upload"
    part_size = part_size_mb * 1024 * 1024
 
    headers = Dict{String,Any}()
 
    if !isempty(tags)
        headers["x-amz-tagging"] = escapeuri(tags)
        headers["x-amz-tagging-directive"] = "REPLACE"
    end
 
    if !isempty(metadata)
        merge!(headers, Dict("x-amz-meta-$k" => v for (k, v) in metadata))
        headers["x-amz-metadata-directive"] = "REPLACE"
    end
  
  headers["Content-Type"] = "application/json"

  @info "+++ Creating Multipart Upload"
  upload = S3.create_multipart_upload(bucket, key, headers; aws_config=aws)
  upload_id = upload["UploadId"]

  @info "upload : $(upload)"
  @info "bucket", upload["Bucket"]
  @info "upload_id", upload["UploadId"]

    tags = Vector{String}()
    buf = Vector{UInt8}(undef, part_size)
 
    i = 0
    while (n = readbytes!(data, buf, part_size)) > 0
        if n < part_size
            resize!(buf, n)
        end
 
    @info "+++ Uploading Part $(i)"

    part = S3.upload_part(
      bucket,
      key,
      (i += 1),
      upload_id,
      Dict{String,Any}(
        "Body" => buf,
        "Content-MD5" => generate_content_md5(data, part_size),
        "Content-Type" => "application/json"
      ),
      aws_config=aws,
    )
    @info "Part response $(part)"

        # push!(tags, s3_upload_part(aws, upload, (i += 1), buf))
        push!(tags, part)
    end

  @info "All tags : $(tags)"

  @info "+++ Completing Multipart Upload"
    return s3_complete_multipart_upload(aws, upload, tags; parse_response)
end

------

function generate_content_md5(data, part_size)
    # Calculate the MD5 digest of the data
    md5_digest = md5(data, part_size)
    @info "md5_digest : $(md5_digest)"
    
    # Encode the MD5 digest in base64 format
    base64_md5_digest = base64encode(md5_digest)
    @info "base64_md5_digest : $(base64_md5_digest)"
    
    return base64_md5_digest
end

----------
Usage of the above function:

function test_s3_upload()

    set_global_config("KEY", "SECRET", "ap-southeast-2")
    

    tags = Dict(
        "version" => "0.0.0"
    )
    metadata = Dict(
        "version" => "0.0.0"
    )

    open("./small.json", "r") do file_io::IO
        S3Interface.s3_multipart_upload(
            App.AWS_S3_MM_BUCKET[],
            "map_exporter/osm_export/latest/new.json",
            file_io;
            tags=tags,
            metadata=metadata,
        );
    end
end

-----

Following is the above small.json context

{
  "version": "2.2",
  "changeset_id": "15cdde2b-0a19-428e-9ebe-5c3518d3cf63",
  "source_ingestion_date": "O2023-12-05T23:27:21.722"
}

```