Class: Aws::Signers::V4 Private

Inherits:
Object
  • Object
show all
Defined in:
lib/aws-sdk-core/signers/v4.rb

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(credentials, service_name, region) ⇒ V4

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of V4.

Parameters:

  • credentials (Credentials)
  • service_name (String)

    The name used by the service in signing signature version 4 requests. This is generally the endpoint prefix.

  • region (String)

    The region (e.g. ‘us-west-1’) the request will be made to.



22
23
24
25
26
# File 'lib/aws-sdk-core/signers/v4.rb', line 22

def initialize(credentials, service_name, region)
  @service_name = service_name
  @credentials = credentials
  @region = region
end

Class Method Details

.sign(context) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



8
9
10
11
12
13
14
# File 'lib/aws-sdk-core/signers/v4.rb', line 8

def self.sign(context)
  new(
    context.config.credentials,
    context.config.sigv4_name,
    context.config.sigv4_region
  ).sign(context.http_request)
end

Instance Method Details

#authorization(request, datetime, body_digest) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



83
84
85
86
87
88
89
# File 'lib/aws-sdk-core/signers/v4.rb', line 83

def authorization(request, datetime, body_digest)
  parts = []
  parts << "AWS4-HMAC-SHA256 Credential=#{credential(datetime)}"
  parts << "SignedHeaders=#{signed_headers(request)}"
  parts << "Signature=#{signature(request, datetime, body_digest)}"
  parts.join(', ')
end

#canonical_header_value(value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



165
166
167
# File 'lib/aws-sdk-core/signers/v4.rb', line 165

def canonical_header_value(value)
  value.match(/^".*"$/) ? value : value.gsub(/\s+/, ' ').strip
end

#canonical_headers(request) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



155
156
157
158
159
160
161
162
163
# File 'lib/aws-sdk-core/signers/v4.rb', line 155

def canonical_headers(request)
  headers = []
  request.headers.each_pair do |k,v|
    k = k.downcase
    headers << [k,v] unless k == 'authorization'
  end
  headers = headers.sort_by(&:first)
  headers.map{|k,v| "#{k}:#{canonical_header_value(v.to_s)}" }.join("\n")
end

#canonical_request(request, body_digest) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



122
123
124
125
126
127
128
129
130
131
# File 'lib/aws-sdk-core/signers/v4.rb', line 122

def canonical_request(request, body_digest)
  [
    request.http_method,
    path(request.endpoint),
    normalized_querystring(request.endpoint.query || ''),
    canonical_headers(request) + "\n",
    signed_headers(request),
    body_digest
  ].join("\n")
end

#credential(datetime) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



91
92
93
# File 'lib/aws-sdk-core/signers/v4.rb', line 91

def credential(datetime)
  "#{credentials.access_key_id}/#{credential_scope(datetime)}"
end

#credential_scope(datetime) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



113
114
115
116
117
118
119
120
# File 'lib/aws-sdk-core/signers/v4.rb', line 113

def credential_scope(datetime)
  parts = []
  parts << datetime[0,8]
  parts << region
  parts << service_name
  parts << 'aws4_request'
  parts.join("/")
end

#hexdigest(value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



169
170
171
172
173
174
175
176
177
178
179
180
# File 'lib/aws-sdk-core/signers/v4.rb', line 169

def hexdigest(value)
  digest = OpenSSL::Digest::SHA256.new
  if value.respond_to?(:read)
    chunk = nil
    chunk_size = 1024 * 1024 # 1 megabyte
    digest.update(chunk) while chunk = value.read(chunk_size)
    value.rewind
  else
    digest.update(value)
  end
  digest.hexdigest
end

#hexhmac(key, value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



186
187
188
# File 'lib/aws-sdk-core/signers/v4.rb', line 186

def hexhmac(key, value)
  OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha256'), key, value)
end

#hmac(key, value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



182
183
184
# File 'lib/aws-sdk-core/signers/v4.rb', line 182

def hmac(key, value)
  OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha256'), key, value)
end

#normalized_querystring(querystring) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



142
143
144
145
146
147
# File 'lib/aws-sdk-core/signers/v4.rb', line 142

def normalized_querystring(querystring)
  params = querystring.split('&')
  params = params.map { |p| p.match(/=/) ? p : p + '=' }
  params = params.sort { |a, b| a.split('=')[0] <=> b.split('=')[0] }
  params.join('&')
end

#path(uri) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



133
134
135
136
137
138
139
140
# File 'lib/aws-sdk-core/signers/v4.rb', line 133

def path(uri)
  path = uri.path == '' ? '/' : uri.path
  if @service_name == 's3'
    path
  else
    path.gsub(/[^\/]+/) { |segment| Seahorse::Util.uri_escape(segment) }
  end
end

#presigned_url(request, options = {}) ⇒ Seahorse::Client::Http::Request

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Generates an returns a presigned URL.

Parameters:

Options Hash (options):

  • :expires_in (required, Integer<Seconds>)
  • :body_digest (optional, String)

    The SHA256 hexdigest of the payload to sign. For S3, this should be the string literal ‘UNSIGNED-PAYLOAD`.

Returns:



50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
# File 'lib/aws-sdk-core/signers/v4.rb', line 50

def presigned_url(request, options = {})
  now = Time.now.utc.strftime("%Y%m%dT%H%M%SZ")
  body_digest = options[:body_digest] || hexdigest(request.body)

  params = Query::ParamList.new

  request.headers['Host'] ||= request.endpoint.host
  request.headers.each do |header_name, header_value|
    if header_name.match(/^x-amz/)
      params.set(header_name, header_value)
    end
    unless %w(host content-md5).include?(header_name)
      request.headers.delete(header_name)
    end
  end

  params.set("X-Amz-Algorithm", "AWS4-HMAC-SHA256")
  params.set("X-Amz-Date", now)
  params.set("X-Amz-SignedHeaders", signed_headers(request))
  params.set("X-Amz-Expires", options[:expires_in].to_s)
  params.set('X-Amz-Security-Token', credentials.session_token) if
    credentials.session_token
  params.set("X-Amz-Credential", credential(now))

  endpoint = request.endpoint
  if endpoint.query
    endpoint.query += '&' + params.to_s
  else
    endpoint.query = params.to_s
  end
  endpoint.to_s + '&X-Amz-Signature=' + signature(request, now, body_digest)
end

#sign(req) ⇒ Seahorse::Client::Http::Request

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the signed request.

Parameters:

Returns:



30
31
32
33
34
35
36
37
38
39
40
# File 'lib/aws-sdk-core/signers/v4.rb', line 30

def sign(req)
  datetime = Time.now.utc.strftime("%Y%m%dT%H%M%SZ")
  body_digest = req.headers['X-Amz-Content-Sha256'] || hexdigest(req.body)
  req.headers['X-Amz-Date'] = datetime
  req.headers['Host'] = req.endpoint.host
  req.headers['X-Amz-Security-Token'] = credentials.session_token if
    credentials.session_token
  req.headers['X-Amz-Content-Sha256'] ||= body_digest
  req.headers['Authorization'] = authorization(req, datetime, body_digest)
  req
end

#signature(request, datetime, body_digest) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



95
96
97
98
99
100
101
102
# File 'lib/aws-sdk-core/signers/v4.rb', line 95

def signature(request, datetime, body_digest)
  k_secret = credentials.secret_access_key
  k_date = hmac("AWS4" + k_secret, datetime[0,8])
  k_region = hmac(k_date, region)
  k_service = hmac(k_region, service_name)
  k_credentials = hmac(k_service, 'aws4_request')
  hexhmac(k_credentials, string_to_sign(request, datetime, body_digest))
end

#signed_headers(request) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



149
150
151
152
153
# File 'lib/aws-sdk-core/signers/v4.rb', line 149

def signed_headers(request)
  headers = request.headers.keys
  headers.delete('authorization')
  headers.sort.join(';')
end

#string_to_sign(request, datetime, body_digest) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.



104
105
106
107
108
109
110
111
# File 'lib/aws-sdk-core/signers/v4.rb', line 104

def string_to_sign(request, datetime, body_digest)
  parts = []
  parts << 'AWS4-HMAC-SHA256'
  parts << datetime
  parts << credential_scope(datetime)
  parts << hexdigest(canonical_request(request, body_digest))
  parts.join("\n")
end