Class: TOS::Signer

Inherits:
Object
  • Object
show all
Defined in:
lib/tos/signer.rb

Overview

Signs HTTP requests for the TOS object service using the TOS4-HMAC-SHA256 scheme (analogous to AWS SigV4, but with the “tos” service name and a slightly different signed-header policy: by default only ‘content-type` and any `x-tos-*` headers are signed).

Reference: github.com/volcengine/ve-tos-golang-sdk/blob/master/tos/sign_v4.go

Constant Summary collapse

ALGORITHM = 
"TOS4-HMAC-SHA256"
SERVICE = 
"tos"
REQUEST = 
"request"
EMPTY_SHA256 = 
"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
UNSIGNED_PAYLOAD = 
"UNSIGNED-PAYLOAD"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(credentials:, region:) ⇒ Signer

Returns a new instance of Signer.

Raises:



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# File 'lib/tos/signer.rb', line 24

def initialize(credentials:, region:)
  @credentials = Credentials.from(credentials)
  raise ConfigError, "TOS credentials are missing access_key_id/secret_access_key" unless @credentials.valid?
  raise ConfigError, "TOS region is required" if region.to_s.empty?

  @region = region.to_s
end

Instance Attribute Details

#credentials ⇒ Object (readonly)

Returns the value of attribute credentials.



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# File 'lib/tos/signer.rb', line 22

def credentials
  @credentials
end

#region ⇒ Object (readonly)

Returns the value of attribute region.



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# File 'lib/tos/signer.rb', line 22

def region
  @region
end

Instance Method Details

#presign(method:, host:, path:, query: {}, expires_in: 3600, now: Time.now.utc) ⇒ Object

Build a presigned URL with all signing material in the query string. Returns a fully-qualified URL.



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# File 'lib/tos/signer.rb', line 76

def presign(method:, host:, path:, query: {}, expires_in: 3600, now: Time.now.utc)
  datetime = now.strftime("%Y%m%dT%H%M%SZ")
  date = datetime[0, 8]
  credential_scope = "#{date}/#{@region}/#{SERVICE}/#{REQUEST}"

  query_with_sig = query.dup
  query_with_sig["X-Tos-Algorithm"] = ALGORITHM
  query_with_sig["X-Tos-Credential"] = "#{@credentials.access_key_id}/#{credential_scope}"
  query_with_sig["X-Tos-Date"] = datetime
  query_with_sig["X-Tos-Expires"] = expires_in.to_s
  query_with_sig["X-Tos-SignedHeaders"] = ""
  query_with_sig["X-Tos-Security-Token"] = @credentials.security_token if @credentials.security_token

  canonical_request = build_canonical_request(
    method: method.to_s.upcase,
    path: path,
    query: query_with_sig,
    signed_headers: [],
    content_sha: UNSIGNED_PAYLOAD
  )

  string_to_sign = [ALGORITHM, datetime, credential_scope, sha256_hex(canonical_request)].join("\n")
  signing_key = derive_signing_key(date)
  query_with_sig["X-Tos-Signature"] = hmac_hex(signing_key, string_to_sign)

  "https://#{host}#{path}?#{encode_query(query_with_sig)}"
end

#sign_headers(method:, path:, query: {}, headers: {}, body: nil, now: Time.now.utc) ⇒ Object

Sign a request and return a Hash of headers to add (Authorization, X-Tos-Date, X-Tos-Content-Sha256, plus X-Tos-Security-Token when STS credentials are used).

Parameters:

  • method (String) —

    HTTP method, uppercased (e.g. “PUT”)

  • path (String) —

    URI path starting with “/” (e.g. “/bucket/key”)

  • query (Hash{String=>String,Array<String>}) (defaults to: {}) —

    query params

  • headers (Hash) (defaults to: {}) —

    existing request headers (case-insensitive keys)

  • body (String, nil) (defaults to: nil) —

    request body — may be nil for GET/HEAD/DELETE

  • now (Time) (defaults to: Time.now.utc) —

    override for testing



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# File 'lib/tos/signer.rb', line 42

def sign_headers(method:, path:, query: {}, headers: {}, body: nil, now: Time.now.utc)
  datetime = now.strftime("%Y%m%dT%H%M%SZ")
  date = datetime[0, 8]
  content_sha = body ? sha256_hex(body) : EMPTY_SHA256

  working_headers = headers.dup
  working_headers["X-Tos-Date"] = datetime
  working_headers["X-Tos-Content-Sha256"] = content_sha
  working_headers["X-Tos-Security-Token"] = @credentials.security_token if @credentials.security_token

  signed_headers = filter_signed_headers(working_headers)

  canonical_request = build_canonical_request(
    method: method.to_s.upcase,
    path: path,
    query: query,
    signed_headers: signed_headers,
    content_sha: content_sha
  )

  credential_scope = "#{date}/#{@region}/#{SERVICE}/#{REQUEST}"
  string_to_sign = [ALGORITHM, datetime, credential_scope, sha256_hex(canonical_request)].join("\n")

  signing_key = derive_signing_key(date)
  signature = hmac_hex(signing_key, string_to_sign)

  authorization = build_authorization_header(signed_headers, credential_scope, signature)
  working_headers["Authorization"] = authorization

  working_headers
end