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module SSHData
module PublicKey
module SecurityKey
# Defaults to match OpenSSH, user presence is required by verification is not.
DEFAULT_SK_VERIFY_OPTS = {
user_presence_required: true,
user_verification_required: false
}
SK_FLAG_USER_PRESENCE = 0b001
SK_FLAG_USER_VERIFICATION = 0b100
def build_signing_blob(application, signed_data, signature)
read = 0
sig_algo, raw_sig, signature_read = Encoding.decode_signature(signature)
read += signature_read
sk_flags, sk_flags_read = Encoding.decode_uint8(signature, read)
read += sk_flags_read
counter, counter_read = Encoding.decode_uint32(signature, read)
read += counter_read
if read != signature.bytesize
raise DecodeError, "unexpected trailing data"
end
application_hash = OpenSSL::Digest::SHA256.digest(application)
message_hash = OpenSSL::Digest::SHA256.digest(signed_data)
blob =
application_hash +
Encoding.encode_uint8(sk_flags) +
Encoding.encode_uint32(counter) +
message_hash
[sig_algo, raw_sig, sk_flags, blob]
end
end
end
end
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