8936: consider blobSigningTtl while generating and verifying signatures.

[arvados.git] / services / api / app / models / blob.rb

diff --git a/services/api/app/models/blob.rb b/services/api/app/models/blob.rb
index 7d16048bf81a29d8a806caa5904e2870a42fbf6e..91007fcc8aad42792a5fbff014965475940393c5 100644 (file)
--- a/services/api/app/models/blob.rb
+++ b/services/api/app/models/blob.rb
@@ -1,4 +1,5 @@
 class Blob
+  extend DbCurrentTime
 
   def initialize locator
     @locator = locator
@@ -27,8 +28,8 @@ class Blob
   # Blob.sign_locator: return a signed and timestamped blob locator.
   #
   # The 'opts' argument should include:
-  #   [required] :key       - the Arvados server-side blobstore key
-  #   [required] :api_token - user's API token
+  #   [required] :api_token - API token (signatures only work for this token)
+  #   [optional] :key       - the Arvados server-side blobstore key
   #   [optional] :ttl       - number of seconds before signature should expire
   #   [optional] :expire    - unix timestamp when signature should expire
   #
@@ -43,14 +44,16 @@ class Blob
       end
       timestamp = opts[:expire]
     else
-      timestamp = Time.now.to_i + (opts[:ttl] || 1209600)
+      timestamp = db_current_time.to_i +
+        (opts[:ttl] || Rails.configuration.blob_signature_ttl)
     end
     timestamp_hex = timestamp.to_s(16)
     # => "53163cb4"
 
     # Generate a signature.
     signature =
-      generate_signature opts[:key], blob_hash, opts[:api_token], timestamp_hex
+      generate_signature((opts[:key] or Rails.configuration.blob_signing_key),
+                         blob_hash, opts[:api_token], timestamp_hex)
 
     blob_locator + '+A' + signature + '@' + timestamp_hex
   end
@@ -87,15 +90,16 @@ class Blob
     if !timestamp
       raise Blob::InvalidSignatureError.new 'No signature provided.'
     end
-    if !timestamp.match /^[\da-f]+$/
+    unless timestamp =~ /^[\da-f]+$/
       raise Blob::InvalidSignatureError.new 'Timestamp is not a base16 number.'
     end
-    if timestamp.to_i(16) < Time.now.to_i
+    if timestamp.to_i(16) < (opts[:now] or db_current_time.to_i)
       raise Blob::InvalidSignatureError.new 'Signature expiry time has passed.'
     end
 
     my_signature =
-      generate_signature opts[:key], blob_hash, opts[:api_token], timestamp
+      generate_signature((opts[:key] or Rails.configuration.blob_signing_key),
+                         blob_hash, opts[:api_token], timestamp)
 
     if my_signature != given_signature
       raise Blob::InvalidSignatureError.new 'Signature is invalid.'
@@ -108,6 +112,7 @@ class Blob
     OpenSSL::HMAC.hexdigest('sha1', key,
                             [blob_hash,
                              api_token,
-                             timestamp].join('@'))
+                             timestamp,
+                             Rails.configuration.blob_signature_ttl].join('@'))
   end
 end