Add poor man’s ASN1 parsing

This commit is contained in:
Nicolas Bouilleaud 2019-05-14 15:19:25 +02:00
parent bef9f9e361
commit e16cb731c5
4 changed files with 45 additions and 1 deletions

View file

@ -10,5 +10,5 @@ indent_size = 2
indent_style = space indent_style = space
trim_trailing_whitespace = true trim_trailing_whitespace = true
[*.{ico,keep,pdf,svg}] [*.{ico,keep,pdf,svg,der}]
insert_final_newline = false insert_final_newline = false

25
app/lib/asn1/timestamp.rb Normal file
View file

@ -0,0 +1,25 @@
class ASN1::Timestamp
## Poor mans rfc3161 timestamp decoding
# This works, as of 2019-05, for timestamps delivered by the universign POST api.
# We should properly access the ASN1 contents using the sequence and tags structure.
# However:
# * Its hard to do right.
# * We currently dont require it for proper operation; timestamps are never exposed to users.
# * Theres an ongoing PR https://github.com/ruby/openssl/pull/204 for proper timestamp decoding in the ruby openssl library; lets use OpenSSL::TS once it exists.
def self.timestampInfo(asn1timestamp)
asn1 = OpenSSL::ASN1.decode(asn1timestamp)
tstInfo = OpenSSL::ASN1.decode(asn1.value[1].value[0].value[2].value[1].value[0].value)
tstInfo
end
def self.signature_time(asn1timestamp)
tstInfo = timestampInfo(asn1timestamp)
tstInfo.value[4].value
end
def self.signed_digest(asn1timestamp)
tstInfo = timestampInfo(asn1timestamp)
tstInfo.value[2].value[1].value.unpack1('H*')
end
end

Binary file not shown.

View file

@ -0,0 +1,19 @@
require 'spec_helper'
describe ASN1::Timestamp do
let(:asn1timestamp) { File.read('spec/fixtures/files/bill_signature/signature.der') }
describe '.timestamp_time' do
subject { described_class.signature_time(asn1timestamp) }
it { is_expected.to eq Time.zone.parse('2019-04-30 15:30:20 UTC') }
end
describe '.timestamp_signed_data' do
subject { described_class.signed_digest(asn1timestamp) }
let(:data) { Digest::SHA256.hexdigest('CECI EST UN BLOB') }
it { is_expected.to eq data }
end
end