AWS S3 Upload using signature v4

s3-upload-aws4.sh

#!/bin/sh -u

# To the extent possible under law, Viktor Szakats (vszakats.net)
# has waived all copyright and related or neighboring rights to this
# script.
# CC0 - https://creativecommons.org/publicdomain/zero/1.0/

# Upload a file to Amazon AWS S3 using Signature Version 4
#
# docs:
#    https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
#
# requires:
#    curl, openssl 1.x, GNU sed, LF EOLs in this file

fileLocal="${1:-example-local-file.ext}"
bucket="${2:-example-bucket}"
remotePath="${3:-remote-path}"
region="${4:-}"
storageClass="${5:-STANDARD}"  # or 'REDUCED_REDUNDANCY'
awsAccess="${6:-YOUR_AWS_ACCESS_KEY}"
awsSecret="${7:-YOUR_AWS_SECRET_KEY}"

m_openssl() {
  if [ -f /usr/local/opt/openssl@1.1/bin/openssl ]; then
    /usr/local/opt/openssl@1.1/bin/openssl "$@"
  elif [ -f /usr/local/opt/openssl/bin/openssl ]; then
    /usr/local/opt/openssl/bin/openssl "$@"
  else
    openssl "$@"
  fi
}

m_sed() {
  if which gsed > /dev/null 2>&1; then
    gsed "$@"
  else
    sed "$@"
  fi
}

awsStringSign4() {
  kSecret="AWS4$1"
  kDate=$(printf         '%s' "$2" | m_openssl dgst -sha256 -hex -mac HMAC -macopt "key:${kSecret}"     2>/dev/null | m_sed 's/^.* //')
  kRegion=$(printf       '%s' "$3" | m_openssl dgst -sha256 -hex -mac HMAC -macopt "hexkey:${kDate}"    2>/dev/null | m_sed 's/^.* //')
  kService=$(printf      '%s' "$4" | m_openssl dgst -sha256 -hex -mac HMAC -macopt "hexkey:${kRegion}"  2>/dev/null | m_sed 's/^.* //')
  kSigning=$(printf 'aws4_request' | m_openssl dgst -sha256 -hex -mac HMAC -macopt "hexkey:${kService}" 2>/dev/null | m_sed 's/^.* //')
  signedString=$(printf  '%s' "$5" | m_openssl dgst -sha256 -hex -mac HMAC -macopt "hexkey:${kSigning}" 2>/dev/null | m_sed 's/^.* //')
  printf '%s' "${signedString}"
}

iniGet() {
  # based on: https://stackoverflow.com/questions/22550265/read-certain-key-from-certain-section-of-ini-file-sed-awk#comment34321563_22550640
  printf '%s' "$(m_sed -n -E "/\[$2\]/,/\[.*\]/{/$3/s/(.*)=[ \\t]*(.*)/\2/p}" "$1")"
}


# Initialize defaults

fileRemote="${remotePath}/${fileLocal}"


echo "Uploading" "${fileLocal}" "->" "${bucket}" "${region}" "${storageClass}"
echo "| $(uname) | $(m_openssl version) "

# Initialize helper variables

httpReq='PUT'
authType='AWS4-HMAC-SHA256'
service="s3"
baseUrl=".${service}.amazonaws.com"
dateValueS=$(date -u +'%Y%m%d')
dateValueL=$(date -u +'%Y%m%dT%H%M%SZ')
if hash file 2>/dev/null; then
  contentType="$(file -b --mime-type "${fileLocal}")"
else
  contentType='application/octet-stream'
fi

# 0. Hash the file to be uploaded

if [ -f "${fileLocal}" ]; then
  payloadHash=$(m_openssl dgst -sha256 -hex < "${fileLocal}" 2>/dev/null | m_sed 's/^.* //')
else
  echo "File not found: '${fileLocal}'"
  exit 1
fi

# 1. Create canonical request

# NOTE: order significant in ${headerList} and ${canonicalRequest}

headerList='content-type;host;x-amz-content-sha256;x-amz-date;x-amz-server-side-encryption;x-amz-storage-class'

canonicalRequest="\
${httpReq}
/${fileRemote}

content-type:${contentType}
host:${bucket}${baseUrl}
x-amz-content-sha256:${payloadHash}
x-amz-date:${dateValueL}
x-amz-server-side-encryption:AES256
x-amz-storage-class:${storageClass}

${headerList}
${payloadHash}"

# Hash it

canonicalRequestHash=$(printf '%s' "${canonicalRequest}" | m_openssl dgst -sha256 -hex 2>/dev/null | m_sed 's/^.* //')

# 2. Create string to sign

stringToSign="\
${authType}
${dateValueL}
${dateValueS}/${region}/${service}/aws4_request
${canonicalRequestHash}"

# 3. Sign the string

signature=$(awsStringSign4 "${awsSecret}" "${dateValueS}" "${region}" "${service}" "${stringToSign}")

# Upload
curl -s -L --proto-redir =https -X "${httpReq}" -T "${fileLocal}" \
  -H "Content-Type: ${contentType}" \
  -H "Host: ${bucket}${baseUrl}" \
  -H "X-Amz-Content-SHA256: ${payloadHash}" \
  -H "X-Amz-Date: ${dateValueL}" \
  -H "X-Amz-Server-Side-Encryption: AES256" \
  -H "X-Amz-Storage-Class: ${storageClass}" \
  -H "Authorization: ${authType} Credential=${awsAccess}/${dateValueS}/${region}/${service}/aws4_request, SignedHeaders=${headerList}, Signature=${signature}" \
  "https://${bucket}${baseUrl}/${fileRemote}"

echo "https://${bucket}${baseUrl}/${fileRemote}"

updated to accept subfolders in the destination bucket

run by issuing:

. s3-upload-aws4.sh "myfile.ext" "my_bucket_name" "folder_name_in_bucket" "region" "REDUCED_REDUNDANCY" "MY_AWS_ACCESS_KEY" "MY_AWS_SECRET_KEY"

Hi, I keep getting the error:
The request signature we calculated does not match the signature you provided. Check your key and signing method.

Are you able to help?

Sounds like an error in your credentials. Be sure to use the right aws access key and secret.

Thanks, I've managed to get it all working now. Thanks for the script