add config option

src/config.ml

@@ -7,7 +7,287 @@
    - default config: use relevant duration, all set to 1 year for now
    *)
 
-(* ---- *)
+module Global = struct end
+
+(*
+Sections with a name of the form “[currency-$NAME]” (where "$NAME" could
+be any unique string) are used to specify details about how currencies
+should be handled (and in particularly rendered) by the user interface.
+A detailed motivation for this section can be found in DD51.
+Different components can have different rules for the same currency. For
+example, a bank or merchant may decide to render Euros or Dollars with
+always exactly two fractional decimals, while an Exchange for the same
+currency may support additional decimals.  The required options in each
+currency specification section are: *)
+module type Currency = sig
+  (*
+  Set to YES or NO. If set to NO, the currency specification
+  section is ignored. Can be used to disable currencies or
+  select alternative sections for the same CODE with different
+  choices. *)
+  val enabled : [ `YES | `NO ]
+
+  (*
+  Code name for the currency. Can be at most 11 characters,
+  only the letters A-Z are allowed. Primary way to identify
+  the currency in the protocol. *)
+  val code : string
+
+  (*
+  Long human-readable name for the currency. No restrictions,
+  but should match the official name in English. *)
+  val name : string
+
+  (*
+  Number of fractional digits that users are allowed to enter
+  manually in the user interface. *)
+  val fractional_input_digits : int
+
+  (*
+  Number of fractional digits that will be rendered normally
+  (in terms of size and placement).  Digits shown beyond this
+  number will typically be rendered smaller and raised (if
+  possible). *)
+  val fractional_normal_digits : int
+
+  (*
+  Number of fractional digits to pad rendered amounts with
+  even if these digits are all zero. For example, use 2 to
+  render 1 USD as $1.00. *)
+  val fractional_trailing_zero_digits : int
+
+  (*
+  JSON map determining how to encode very large or very tiny
+  amounts in this currency. Maps a base10 logarithm to the
+  respective currency symbol. Must include at least an
+  entry for 0 (currency unit).  For example, use
+  {"0":"€"} for Euros or {"0":"$"} for Dollars. You could
+  additionally use {"0":"€","3":"k€"} to render 3000 EUR
+  as 3k€. For BTC a typical map would be
+  {"0":"BTC","-3":"mBTC"}, informing the UI to render small
+  amounts in milli-Bitcoin (mBTC). *)
+  val alt_unit_names : (int * string) list
+end
+
+(* TODO unikernel *)
+type directory
+
+(* TODO *)
+(* Values that represent a time duration are represented as a series of one or more NUMBER UNIT pairs, e.g. 60 s, 4 weeks 1 day, 5 years 2 minutes. *)
+type duration
+
+(* TODO
+   make it Amount.t *)
+type amount = string
+
+(* TODO
+   still need to parse them and tell that its not supported
+   some maybe are relevant
+   idk *)
+type not_relevant
+type url = string
+type seconds = int
+
+(* The following options are from the “[exchange]” section and used by most
+   exchange tools. *)
+module type Exchange = sig
+  (*
+  Name of the currency, e.g. “EUR” for Euro. *)
+  val currency : string
+
+  (*
+  Smallest amount in this currency that can be transferred using the
+  underlying RTGS. For example: "EUR:0.01" or "JPY:1". *)
+  val currency_round_unit : amount
+
+  (*
+  Plugin to use for the database, e.g. “postgres”. *)
+  val db : string
+
+  (*
+  Attribute encryption key for storing attributes encrypted
+  in the database. Should be a high-entropy nonce. *)
+  val attribute_encryption_key : string
+
+  (*
+  Should the HTTP server listen on a UNIX domain socket (set option to "unix"), or on a TCP socket (set option to "tcp"), or be activated via systemd (set option to "systemd"). *)
+  val serve : not_relevant
+
+  (*
+  Path to listen on if we "SERVE" is set to "unix". *)
+  val unixpath : not_relevant
+
+  (*
+  Access permission mask to use for the "UNIXPATH". *)
+  val unixpath_mode : not_relevant
+
+  (*
+  Port on which the HTTP server listens, e.g. 8080. *)
+  val port : int
+
+  (*
+  Hostname to which the exchange HTTP server should be bound to, e.g. "localhost". *)
+  val bind_to : string
+
+  (*
+  Crockford Base32-encoded master public key, public version of the
+  exchange's long-time offline signing key.  This configuration option
+  is also used by the **auditor** to determine the public key of the
+  exchange which it is auditing. *)
+  val master_public_key : string
+
+  (*
+  Small amount that can be transferred to the exchange for the
+  KYC authentication wire transfers. Should be given as a hint
+  for merchants what amount they need to transfer to begin the
+  KYC transfer. Note that the amount is not enforced by the
+  exchange *and* that this option is optional. However, if it is
+  not given, merchants will have to guess what amount to transfer,
+  so it really should be configured. *)
+  val tiny_amount : amount option
+
+  (*
+  Web URL where users can discover shops that accept digital cash
+  offered by this exchange. Optional, but highly recommended. *)
+  val shopping_url : url option
+
+  (*
+  URL where wallets can find an open banking gateway to
+  initiate wire transfers when withdrawing digital cash
+  from this exchange. Optional (as obviously not every
+  exchange will have an open banking gateway attached). *)
+  val open_banking_gateway_url : url option
+
+  (*
+  Determines the variant of the AML SPA that should be shown. This
+  will determine the set of forms shown to AML staff, statistics to
+  be displayed on the main page, and influence the default set of
+  properties/events the AML forms show when AML staff makes decisions.
+  Possible values for now include "gls", "tops" and "magnet".
+  Optional. The AML SPA will only show certain default forms and
+  generic decisions if this option is not set. *)
+  val aml_spa_dialect : string option
+
+  (*
+  Determines the legal language (and possibly other UI/UX aspects)
+  wallets should use when providing the user interface for this bank.
+  Allows banks to communicate the desired compliance language they
+  want to see used to the wallet. Wallets SHOULD follow the guidance
+  provided by the bank, but some wallets MAY not understand all compliance
+  languages. Optional, if not set wallets will use their default UI/UX. *)
+  val bank_compliance_language : string option
+
+  (*
+  Absolute amount to add as an offset in the STEFAN fee approximation
+  curve (see DD47).  Defaults to CURRENCY:0 if not specified. *)
+  val stefan_abs : amount
+
+  (*
+  Amount to multiply by the base-2 logarithm of the total amount
+  divided by the amount of the smallest denomination
+  in the STEFAN fee approximation curve (see DD47).
+  Defaults to CURRENCY:0 if not specified. *)
+  val stefan_log : amount
+
+  (*
+  Linear floating point factor to be multiplied by the total amount
+  to use in the STEFAN fee approximation curve (see DD47).
+  Defaults to 0.0 if not specified. *)
+  val stefan_lin : float
+
+  (*
+  The base URL under which the exchange can be reached.
+  Added to wire transfers to enable tracking by merchants.
+  Used by the KYC logic when interacting with OAuth 2.0. *)
+  val base_url : url
+
+  (*
+  Where to redirect visitors that access the top-level
+  "/" endpoint of the exchange. Should point users to
+  information about the exchange operator.
+  Optional setting, defaults to "/terms". *)
+  val toplevel_redirect_url : string option
+
+  (*
+  For how long should the taler-exchange-aggregator sleep when it is idle
+  before trying to look for more work? Default is 60 seconds. *)
+  val aggregator_idle_sleep_interval : seconds
+
+  (*
+  For how long should the taler-exchange-closer sleep when it is idle
+  before trying to look for more work? Default is 60 seconds. *)
+  val closer_idle_sleep_interval : seconds
+
+  (*
+  For how long should the taler-exchange-transfer sleep when it is idle
+  before trying to look for more work? Default is 60 seconds. *)
+  val transfer_idle_sleep_interval : seconds
+
+  (*
+  For how long should the taler-exchange-wirewatch sleep when it is idle
+  before trying to look for more work? Default is 60 seconds. *)
+  val wirewatch_idle_sleep_interval : seconds
+
+  (*
+  Which share of the range from [0,..2147483648] should be processed by one of the shards of the aggregator. Useful only for Taler exchanges with ultra high-performance needs. When changing this value, you must stop all aggregators and run "taler-exchange-dbinit -s" before resuming. Default is 2147483648 (no sharding). *)
+  val aggregator_shard_size : int option
+
+  (*
+  For how long are signatures with signing keys legally valid? *)
+  val signkey_legal_duration : duration
+
+  (*
+  For how long should clients cache ``/keys`` responses at most? *)
+  val max_keys_caching : duration
+
+  (*
+  How many requests should the HTTP server process at most before committing suicide? *)
+  val max_requests : int
+
+  (*
+  Directory where the terms of service of the exchange operator can be fund.
+  The directory must contain sub-directories for every supported language,
+  using the two-character language code in lower case, e.g. "en/" or "fr/".
+  Each subdirectory must then contain files with the terms of service in
+  various formats.  The basename of the file of the current policy must be
+  specified under ``TERMS_ETAG``.  The extension defines the mime type.
+  Supported extensions include "html", "htm", "txt", "pdf", "jpg", "jpeg",
+  "png" and "gif".  For example, using a ``TERMS_ETAG`` of "0", the structure
+  could be the following:
+
+  - $TERMS_DIR/en/0.pdf
+  - $TERMS_DIR/en/0.html
+  - $TERMS_DIR/en/0.txt
+  - $TERMS_DIR/fr/0.pdf
+  - $TERMS_DIR/fr/0.html
+  - $TERMS_DIR/de/0.txt *)
+  val terms_dir : directory
+
+  (*
+  Basename of the file(s) in the ``TERMS_DIR`` with the current terms of service.
+  The value is also used for the "Etag" in the HTTP request to control
+  caching.  Whenever the terms of service change, the ``TERMS_ETAG`` MUST also
+  change, and old values MUST NOT be repeated.  For example, the date or
+  version number of the terms of service SHOULD be used for the Etag.  If
+  there are minor (e.g. spelling) fixes to the terms of service, the
+  ``TERMS_ETAG`` probably SHOULD NOT be changed. However, whenever users must
+  approve the new terms, the ``TERMS_ETAG`` MUST change. *)
+  val terms_etag : string
+
+  (*
+  Works the same as ``TERMS_DIR``, just for the privacy policy. *)
+  val privacy_dir : directory
+
+  (*
+  Works the same as ``TERMS_ETAG``, just for the privacy policy. *)
+  val privacy_etag : string
+
+  (*
+  Must be set to ``YES`` to enable AML/KYC rule enforcement. Note that the administrative endpoints will always work, even if the flag is set to ``NO``. *)
+  val enable_kyc : [ `YES | `NO ]
+end
+
+(* -- ********************************** -- *)
 let currency = `Eur
 let currency_to_string = function `Eur -> "EUR"