# `AWSAuth`
[🔗](https://github.com/neilberkman/ex_aws_auth/blob/v1.4.1/lib/aws_auth.ex#L1)

Signs urls or authentication headers for use with AWS requests.

## New in 1.2.0

This version adds convenient new APIs while maintaining 100% backward compatibility:

- `AWSAuth.Credentials` struct for cleaner credential management
- Credential struct overloads for `sign_url` and `sign_authorization_header`
- Optional `return_format` option (`:list`, `:map`, `:req`) for flexible header formats
- `AWSAuth.Req` plugin for seamless Req integration

## Migration Guide

### Old API (still fully supported)
```elixir
AWSAuth.sign_authorization_header(
  access_key,
  secret_key,
  "POST",
  url,
  "us-east-1",
  "bedrock",
  headers,
  body,
  NaiveDateTime.utc_now(),
  session_token
)
```

### New credential struct API
```elixir
creds = %AWSAuth.Credentials{
  access_key_id: access_key,
  secret_access_key: secret_key,
  session_token: session_token,
  region: "us-east-1"
}

# Or load from environment
creds = AWSAuth.Credentials.from_env()

# Simpler function call
AWSAuth.sign_authorization_header(
  creds,
  "POST",
  url,
  "bedrock",
  headers,
  body
)
```

### With Req plugin
```elixir
creds = AWSAuth.Credentials.from_env()

Req.new(url: url, method: :post, body: body)
|> AWSAuth.Req.attach(credentials: creds, service: "bedrock")
|> Req.request()
```

# `sign_authorization_header`

Signs request headers using AWS Signature V4 with a Credentials struct.

This is a convenience overload that accepts an `AWSAuth.Credentials` struct.

## Parameters

  * `credentials` - `AWSAuth.Credentials` struct with AWS credentials
  * `http_method` - HTTP method as string ("GET", "POST", etc)
  * `url` - The AWS URL to sign
  * `service` - AWS service name (e.g., "s3", "bedrock"). Can be `nil` to auto-detect from URL.
  * `opts` - Keyword list of options:
    * `:headers` - Request headers as map (default: `%{}`)
    * `:payload` - Request body (default: `""`), `:unsigned` for streaming
      uploads, or `:streaming_events` to seed an event-stream request
      (`x-amz-content-sha256: STREAMING-AWS4-HMAC-SHA256-EVENTS`; see `AWSAuth.EventStream`)
    * `:timestamp` - `NaiveDateTime` for signing (default: current time)
    * `:region` - Override region from credentials (auto-detected from URL if not provided)
    * `:return_format` - Return format (`:list`, `:map`, `:req`) (default: `:list`)
    * `:unsigned_headers` - List of header names to exclude from signing (default: `[]`)
    * `:uri_escape_path` - Enable/disable URI path escaping (default: `true`)
    * `:apply_checksum_header` - Include x-amz-content-sha256 header (default: `true`)

## Return Formats

  * `:list` - (default) Returns list of tuples `[{"header", "value"}]`
  * `:map` - Returns map `%{"header" => "value"}`
  * `:req` - Returns Req-compatible map `%{"header" => ["value"]}`

## Examples

    creds = AWSAuth.Credentials.from_env()

    # Returns list of tuples (default)
    headers = AWSAuth.sign_authorization_header(creds, "POST", url, "bedrock", headers: %{}, payload: body)
    # => [{"authorization", "AWS4-HMAC-SHA256 ..."}, {"x-amz-date", "..."}]

    # Auto-detect service and region
    headers = AWSAuth.sign_authorization_header(creds, "POST", "https://bedrock-runtime.us-east-1.amazonaws.com/...", nil, payload: body)

    # Unsigned payload for streaming
    headers = AWSAuth.sign_authorization_header(creds, "PUT", url, "s3", payload: :unsigned)

    # Return as map
    headers = AWSAuth.sign_authorization_header(
      creds,
      "POST",
      url,
      "bedrock",
      headers: %{"content-type" => "application/json"},
      payload: body,
      return_format: :map
    )
    # => %{"authorization" => "AWS4-HMAC-SHA256 ...", "x-amz-date" => "..."}

# `sign_authorization_header`

`AWSAuth.sign_authorization_header(access_key, secret_key, http_method, url, region, service, headers, payload, request_time, session_token)`

`access_key`: Your AWS Access key

`secret_key`: Your AWS secret key

`http_method`: "GET","POST","PUT","DELETE", etc

`url`: The AWS url you want to sign

`region`: The AWS name for the region you want to access (i.e. us-east-1). Check [here](http://docs.aws.amazon.com/general/latest/gr/rande.html) for the region names

`service`: The AWS service you are trying to access (i.e. s3). Check the url above for names as well.

`headers` (optional. defaults to `Map.new`): The headers that will be used in the request. Used for signing the request.
For signing, host is the only one required unless using any other x-amx-* headers.
If host is present here, it will override using the host in the url to attempt signing.
Same goes for the x-amz-content-sha256 headers
If only the host and x-amz-content-sha256 headers are needed, then you don't have to supply it and the host from the url will be used and
the payload will be hashed to get the x-amz-content-sha256 header.

`payload` (optional. defaults to `""`): The contents of the payload if there is one.

`request_time` (optional): NaiveDateTime for the request timestamp. Defaults to current time.

`session_token` (optional. defaults to `nil`): AWS session token for temporary credentials (from STS).
When provided, adds the X-Amz-Security-Token header to the signed request.

# `sign_authorization_header`

# `sign_authorization_header`

# `sign_authorization_header`

# `sign_authorization_header`

# `sign_authorization_header`

# `sign_url`

Signs a URL using AWS Signature V4 with a Credentials struct.

This is a convenience overload that accepts an `AWSAuth.Credentials` struct.

## Parameters

  * `credentials` - `AWSAuth.Credentials` struct with AWS credentials
  * `http_method` - HTTP method as string ("GET", "POST", etc)
  * `url` - The AWS URL to sign
  * `service` - AWS service name (e.g., "s3", "bedrock"). Can be `nil` to auto-detect from URL.
  * `opts` - Keyword list of options:
    * `:headers` - Request headers (default: `%{}`)
    * `:payload` - Request body (default: `""`) or `:unsigned` for streaming
    * `:timestamp` - `NaiveDateTime` for signing (default: current time)
    * `:region` - Override region from credentials (auto-detected from URL if not provided)
    * `:expires_in` - Expiration time in seconds for presigned URLs (default: 900, max: 604800)
    * `:uri_escape_path` - Enable/disable URI path escaping (default: `true`)
    * `:unsigned_headers` - List of header names to exclude from signing (default: `[]`)

## Examples

    creds = AWSAuth.Credentials.from_env()
    signed_url = AWSAuth.sign_url(creds, "GET", url, "s3")

    # Auto-detect service and region from URL
    signed_url = AWSAuth.sign_url(creds, "GET", "https://s3.us-west-2.amazonaws.com/bucket/key", nil)

    # Custom expiration (1 hour)
    signed_url = AWSAuth.sign_url(creds, "GET", url, "s3", expires_in: 3600)

# `sign_url`

`AWSAuth.sign_url(access_key, secret_key, http_method, url, region, service, headers, request_time, payload, session_token)`

`access_key`: Your AWS Access key

`secret_key`: Your AWS secret key

`http_method`: "GET","POST","PUT","DELETE", etc

`url`: The AWS url you want to sign

`region`: The AWS name for the region you want to access (i.e. us-east-1). Check [here](http://docs.aws.amazon.com/general/latest/gr/rande.html) for the region names

`service`: The AWS service you are trying to access (i.e. s3). Check the url above for names as well.

`headers` (optional. defaults to `Map.new`): The headers that will be used in the request. Used for signing the request.
For signing, host is the only one required unless using any other x-amx-* headers.
If host is present here, it will override using the host in the url to attempt signing.
If only the host is needed, then you don't have to supply it and the host from the url will be used.

`request_time` (optional): NaiveDateTime for the request timestamp. Defaults to current time.

`payload` (optional. defaults to `""`): The contents of the payload if there is one.

`session_token` (optional. defaults to `nil`): AWS session token for temporary credentials (from STS).
When provided, adds the X-Amz-Security-Token header to the signed request.

# `sign_url`

# `sign_url`

# `sign_url`

# `sign_url`

# `sign_url`

---

*Consult [api-reference.md](api-reference.md) for complete listing*
