signature_v4_auth: Signature Version 4

Description

AWS Signature Version 4 for use in query or header authorization

Usage

signature_v4_auth(datetime = format(Sys.time(), "%Y%M%dT%H%M%SZ", tz = "UTC"),  region = Sys.getenv("AWS_DEFAULT_REGION"),  service, verb, action, query_args = list(), canonical_headers, request_body,  key = Sys.getenv("AWS_ACCESS_KEY_ID"),  secret = Sys.getenv("AWS_SECRET_ACCESS_KEY"),  session_token = Sys.getenv("AWS_SESSION_TOKEN"), query = FALSE, algorithm = "AWS4-HMAC-SHA256")

Arguments

datetime

A character string containing a datetime in the form of “YYYYMMDDTHHMMSSZ”. If missing, it is generated automatically using Sys.time.

region

A character string containing the AWS region for the request. If missing, “us-east-1” is assumed.

service

A character string containing the AWS service (e.g., “iam”, “host”, “ec2”).

verb

A character string containing the HTTP verb being used in the request.

action

A character string containing the API endpoint used in the request.

query_args

A named list of character strings containing the query string values (if any) used in the API request, passed to canonical_request.

canonical_headers

A named list of character strings containing the headers used in the request.

request_body

The body of the HTTP request.

key

An AWS Access Key ID. If missing, it is retrieved using Sys.getenv("AWS_ACCESS_KEY_ID")

secret

An AWS Secret Access Key. If missing, it is retrieved using Sys.getenv("AWS_SECRET_ACCESS_KEY")

session_token

Optionally, an AWS Security Token Service (STS) temporary Session Token. This is added automatically as a header to canonical_headers.

query

A logical. Currently ignored.

algorithm

A character string containing the hashing algorithm used in the request. Should only be “SHA256”.

Value

“aws_signature_v4”, containing the information needed to sign an AWS API request using either query string authentication or request header authentication. Specifically, the list contains:These values can either be used as query parameters in a REST-style API request, or as request headers. If authentication is supplied via query string parameters, the query string should include the following:Action=action &X-Amz-Algorithm=Algorithm &X-Amz-Credential=URLencode(Credentials) &X-Amz-Date=Date &X-Amz-Expires=timeout &X-Amz-SignedHeaders=SignedHeaderswhere action is the API endpoint being called and timeout is a numeric value indicating when the request should expire.If signing a request using header-based authentication, the “Authorization” header in the request should be included with the request that looks as follows:Authorization: Algorithm Credential=Credential, SignedHeaders=SignedHeaders, Signature=SignatureThis is the value printed by default for all objects of class “aws_signature_v4”.

Details

This function generates an AWS Signature Version 4 for authorizing API requests.

References

AWS General Reference: Signature Version 4 Signing Process

Amazon S3 API Reference: Authenticating Requests (AWS Signature Version 4)