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@danielpradilla
Last active December 12, 2018 15:49
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#!/bin/sh -u
fileLocal="${1:-example-local-file.ext}"
bucket="${2:-example-bucket}"
remotePath="${3:-remote-path}"
region="${4:-}"
awsAccess="${5:-YOUR_AWS_ACCESS_KEY}"
awsSecret="${6:-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}/${fileLocal}"
echo "Downloading" "${fileLocal}" "->" "${bucket}" "${region}"
echo "| $(uname) | $(m_openssl version) "
# Initialize helper variables
httpReq='GET'
authType='AWS4-HMAC-SHA256'
service="s3"
baseUrl=".${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 empty string
payloadHash=$(printf "" | m_openssl dgst -sha256 -hex 2>/dev/null | m_sed 's/^.* //')
# 1. Create canonical request
# NOTE: order significant in ${headerList} and ${canonicalRequest}
headerList='content-type;host;x-amz-content-sha256;x-amz-date'
canonicalRequest="\
${httpReq}
/${fileRemote}
content-type:${contentType}
host:${bucket}${baseUrl}
x-amz-content-sha256:${payloadHash}
x-amz-date:${dateValueL}
${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}" \
-H "Content-Type: ${contentType}" \
-H "Host: ${bucket}${baseUrl}" \
-H "X-Amz-Content-SHA256: ${payloadHash}" \
-H "X-Amz-Date: ${dateValueL}" \
-H "Authorization: ${authType} Credential=${awsAccess}/${dateValueS}/${region}/${service}/aws4_request, SignedHeaders=${headerList}, Signature=${signature}" \
"https://${bucket}${baseUrl}/${fileRemote}" -o "${fileLocal}"
echo "https://${bucket}${baseUrl}/${fileRemote}"
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