add taler_config.ml with module sig; put config in assets.ml

include/taler_config_type.ml

@@ -0,0 +1,175 @@
+(* https://docs.taler.net/manpages/taler-exchange.conf.5.html
+   taler-docs/manpages/taler-exchange.conf.5.rst *)
+(* TODO
+   - generate `config.ml` from config file (virtual module)?
+   - parse config file format
+   - no relative path
+   - default config
+   - better types
+   - impl duration
+   *)
+
+(* TODO unikernel *)
+type dir_path
+type file_path
+
+(* 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
+type payto_uri = 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
+
+(* not relevant for mirage *)
+(* this contains path that can be referenced in other with $PATH
+   (unsupported) *)
+module type Global = sig
+  val taler_home : dir_path
+  val taler_data_home : dir_path
+  val taler_config_home : dir_path
+  val taler_cache_home : dir_path
+  val taler_runtime_dir : dir_path
+end
+
+(* sections "[currency-$NAME]"
+   see DD51 *)
+module type Currency = sig
+  val enabled : [ `YES | `NO ]
+  val code : string
+  val name : string
+  val fractional_input_digits : int
+  val fractional_normal_digits : int
+  val fractional_trailing_zero_digits : int
+  val alt_unit_names : (int * string) list
+end
+
+(* section "[exchange]" *)
+module type Exchange = sig
+  val currency : string
+  val currency_round_unit : amount
+  val db : string
+  val attribute_encryption_key : string
+  val serve : [ `Unix | `Tcp | `Systemd ]
+  val unixpath : file_path
+  val unixpath_mode : int
+  val port : int
+  val bind_to : string
+  val master_public_key : string
+  val tiny_amount : amount option
+  val shopping_url : url option
+  val open_banking_gateway_url : url option
+  val aml_spa_dialect : string option
+  val bank_compliance_language : string option
+  val stefan_abs : amount
+  val stefan_log : amount
+  val stefan_lin : float
+  val base_url : url
+  val toplevel_redirect_url : string option
+  val aggregator_idle_sleep_interval : seconds
+  val closer_idle_sleep_interval : seconds
+  val transfer_idle_sleep_interval : seconds
+  val wirewatch_idle_sleep_interval : seconds
+  val aggregator_shard_size : int option
+  val signkey_legal_duration : duration
+  val max_keys_caching : duration
+  val max_requests : int
+  val terms_dir : dir_path
+  val terms_etag : string
+  val privacy_dir : dir_path
+  val privacy_etag : string
+  val enable_kyc : [ `YES | `NO ]
+end
+
+(* section "[taler-exchange-secmod-{rsa|cs|eddsa}]". *)
+module type Secmod = sig
+  val lookahead_sign : duration
+  val overlap_duration : duration
+  val sm_priv_key : file_path
+  val key_dir : dir_path
+  val unixpath : not_relevant
+end
+
+module type Secmod_rsa = Secmod
+module type Secmod_cs = Secmod
+module type Secmod_eddsa = Secmod
+
+(* TODO config
+   what is the time/duration unit used here? *)
+(* section "[exchangedb]". *)
+module type Database = sig
+  val idle_reserve_expiration_time : seconds
+  val legal_reserve_expiration_time : seconds
+  val aggregator_shift : seconds
+  val default_purse_limit : int
+  val max_aml_program_runtime : int option
+
+  module type Postgres_backend = sig
+    val config : string
+  end
+end
+
+(* sections "[coin_XXX]"
+   used by secmods *)
+module type Coin = sig
+  val value : amount
+  val duration_withdraw : duration
+  val duration_spend : duration
+  val duration_legal : duration
+  val fee_withdraw : amount
+  val fee_deposit : amount
+  val fee_refresh : amount
+  val fee_refund : amount
+  val cipher : [ `CS | `RSA ]
+  val rsa_keysize : int option (*only if `RSA *)
+  val age_restricted : [ (*`YES|*) `NO ]
+end
+
+(* sections "[exchange-account-XXX]" *)
+module type Account = sig
+  val payto_uri : payto_uri
+  val enable_debit : [ `YES | `NO ]
+  val enable_credit : [ `YES | `NO ]
+end
+
+(* sections "[exchange-accountcredentials-XXX]"
+   must exists for each "[exchange-account-XXX]" section
+
+   ! credentials to access the bank account
+   should be in a secret configuration file
+   only redable for `taler-exchange-wirewatch` `taler-exchange-transfer` processes *)
+module type Account_secret = sig
+  val wire_gateway_url : url
+  val wire_gateway_auth_method : string
+  val username : string
+  val password : string
+  val token : string
+end
+
+(* section "[exchange-extension-<extensionname>]" *)
+module type Extensions = sig
+  val enabled : [ (*`YES|*) `NO ]
+end
+
+(* section "[exchange-offline]". *)
+module type Offline_signing = sig
+  val master_priv_file : file_path
+
+  (* TODO
+   - we need two different file here
+   - there is three, not two, crypto helper modules
+     is it only two, because the eddsa one is not comptabilized as a "crypto helper" here? *)
+  (* tofu = Trust On First Use *)
+  val secm_tofu_file : file_path
+  val secm_denom_pubkey : string option
+  val secm_esign_pubkey : string option
+end