Function generatePresignedUrl

apps/sim/tools/s3/utils.ts:96–121

(params: any, expiresIn = 3600)

}

export function generatePresignedUrl(params: any, expiresIn = 3600): string {
  const date = new Date()
  const amzDate = date.toISOString().replace(/[:-]|\.\d{3}/g, '')
  const dateStamp = amzDate.slice(0, 8)
  const encodedPath = encodeS3PathComponent(params.objectKey)

  const _expires = Math.floor(Date.now() / 1000) + expiresIn

  const method = 'GET'
  const canonicalUri = `/${encodedPath}`
  const canonicalQueryString = `X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=${encodeURIComponent(`${params.accessKeyId}/${dateStamp}/${params.region}/s3/aws4_request`)}&X-Amz-Date=${amzDate}&X-Amz-Expires=${expiresIn}&X-Amz-SignedHeaders=host`
  const canonicalHeaders = `host:${params.bucketName}.s3.${params.region}.amazonaws.com\n`
  const signedHeaders = 'host'
  const payloadHash = 'UNSIGNED-PAYLOAD'

  const canonicalRequest = `${method}\n${canonicalUri}\n${canonicalQueryString}\n${canonicalHeaders}\n${signedHeaders}\n${payloadHash}`

  const algorithm = 'AWS4-HMAC-SHA256'
  const credentialScope = `${dateStamp}/${params.region}/s3/aws4_request`
  const stringToSign = `${algorithm}\n${amzDate}\n${credentialScope}\n${crypto.createHash('sha256').update(canonicalRequest).digest('hex')}`

  const signingKey = getSignatureKey(params.secretAccessKey, dateStamp, params.region, 's3')
  const signature = crypto.createHmac('sha256', signingKey).update(stringToSign).digest('hex')

  return `https://${params.bucketName}.s3.${params.region}.amazonaws.com/${encodedPath}?${canonicalQueryString}&X-Amz-Signature=${signature}`
}