better config: parse file + crunch

default.config

@@ -1,17 +0,0 @@
-# comment 1
-#   foo
-#   barr
-[currency-EUR]
-enabled = NO
-  # comment 2
-code= "EUR"
-name =euro
-fractional_input_digits = 2
-fractional_normal_digits =2
-fractional_trailing_zero_digits= 2
-  % comment 3
-alt_unit_names = "{"0":"€","3":"k€"}"
-% comment 4
-
-[dummy-section]
-dummy =   "blah"

include/dune

@@ -14,10 +14,10 @@
  (modules gen_eddsa_key)
  (libraries fmt mirage-crypto-rng.unix mirage-crypto-ec b32))
 
-(executable
+(library ; todo: should I have a /lib?
  (name parse_config)
  (modules parse_config)
- (libraries fmt angstrom amount))
+ (libraries mirage-crypto-ec ptime fmt angstrom uri amount b32))
 
 ; we prefer to generate taler_signatures.ml once,
 ; and commit it, for versionning:

include/parse_config.ml

@@ -3,64 +3,33 @@
 
    do not support "$"-path expansion*)
 
-(* TODO
+open Angstrom
-   - integer
-   - duration
-   - YES|NO
-   - alt_unit_names json pair
 
-type duration_element = {
-  number: int;
-  unit_: [ `Year | `Week | `Day | `Hour | `Minute | `Second ];
-}
-
-let integer =
-  take_while1 (function '0' .. '9' -> true | _ -> false) >>= fun s ->
-  match int_of_string_opt s with
-  | None -> fail "not an integer"
-  | Some i -> return i
-
-let duration_value =
-  let number = whitespace *> integer in
-  let unit =
-    whitespace *> take_while1 (fun c -> not (is_whitespace c || is_eol c))
-    >>= function
-    | "year" | "years" -> return `Year
-    | "week" | "weeks" -> return `Week
-    | "day" | "days" -> return `Day
-    | "hour" | "hours" -> return `Hour
-    | "minute" | "minutes" -> return `Minute
-    | "s" -> return `Second
-    | _ -> fail "not a valid duration unit"
-  in
-  many1 (lift2 (fun number unit_ -> { number; unit_ }) number unit)
-*)
-
-let read_file file = In_channel.with_open_bin file In_channel.input_all
-
-module Untyped = struct
 type item = {
   key: string;
   value: string;
 }
 
-  type line =
-    | Blank
-    | Comment of string
-    | Header of string
-    | Item of item
-
 type section = {
   header: string;
   items: item list;
 }
 
-  open Angstrom
+let fail_with msg =
+  Fmt.epr "Configuration failure: %s.@." msg;
+  exit 1
 
 let is_eol = function '\n' | '\r' -> true | _ -> false
 let is_whitespace = function ' ' | '\t' -> true | _ -> false
 let whitespace = skip_while is_whitespace
 
+module Parse_data = struct
+  type line =
+    | Blank
+    | Comment of string
+    | Header of string
+    | Item of item
+
   let id =
     let ident_char = function
       | 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' | '-' -> true
@@ -86,7 +55,7 @@ module Untyped = struct
     let quoted_value =
       char '"' *> take_till is_eol >>= fun s ->
       match String.ends_with ~suffix:"\"" s with
-      | false -> fail "invalid quoted value"
+      | false -> fail_with "invalid quoted value"
       | true ->
           let value = String.sub s 0 (String.length s - 1) in
           return value
@@ -107,7 +76,7 @@ module Untyped = struct
       match l with
       | [] ->
           if List.is_empty item_l then section_l
-          else Fmt.failwith "invalid config structure"
+          else fail_with "invalid configuration structure"
       | Blank :: tl | Comment _ :: tl -> loop section_l item_l tl
       | Item item :: tl -> loop section_l (item :: item_l) tl
       | Header header :: tl ->
@@ -118,8 +87,9 @@ module Untyped = struct
 
   let parse s =
     match parse_string ~consume:All config s with
-    | Error msg -> Fmt.failwith "config parse error: %s" msg
+    | Error msg -> fail_with (Fmt.str "parse error `%s`" msg)
     | Ok v -> fold_sections v
+end
 
 module Pp_debug = struct
   let pp_item ppf { key; value } =
@@ -130,6 +100,7 @@ module Untyped = struct
 
   let pp_line ppf line =
     let open Fmt in
+    let open Parse_data in
     match line with
     | Blank -> Fmt.nop ppf ()
     | Comment s -> pf ppf "#%s" s
@@ -148,13 +119,158 @@ module Untyped = struct
     let open Fmt in
     pf ppf "%a" (list ~sep:(any "\n") pp_section) l
 end
+[@@ocaml.warning "-32"]
+
+module Parse_duration = struct
+  type duration_element = {
+    number: int;
+    dunit: [ `Year | `Week | `Day | `Hour | `Minute | `Second ];
+  }
+
+  let integer =
+    take_while1 (function '0' .. '9' -> true | _ -> false) >>= fun s ->
+    match int_of_string_opt s with
+    | None -> fail_with (Fmt.str "expected integer, got `%s`" s)
+    | Some i -> return i
+
+  let duration_element =
+    let number = whitespace *> integer in
+    let dunit =
+      whitespace *> take_while1 (fun c -> not (is_whitespace c || is_eol c))
+      >>= function
+      | "year" | "years" -> return `Year
+      | "week" | "weeks" -> return `Week
+      | "day" | "days" -> return `Day
+      | "hour" | "hours" -> return `Hour
+      | "minute" | "minutes" -> return `Minute
+      | "second" | "seconds" | "s" -> return `Second
+      | s -> fail_with (Fmt.str "expected a duration unit, got `%s`" s)
+    in
+    lift2 (fun number dunit -> { number; dunit }) number dunit
+
+  let duration = many1 duration_element <* end_of_input
+
+  let dunit_to_seconds u =
+    let rec f = function
+      | `Year -> 365 * f `Day
+      | `Week -> 7 * f `Day
+      | `Day -> 24 * f `Hour
+      | `Hour -> 60 * f `Minute
+      | `Minute -> 60 * f `Second
+      | `Second -> 1
+    in
+    f u
+
+  let ptime_span_of_int64 i =
+    match Ptime.Span.of_float_s (Int64.to_float i) with
+    | None ->
+        fail_with
+          (Fmt.str "ptime_span_of_int64 error: `%Ld` is not a valid ptime span"
+             i)
+    | Some ts -> ts
+
+  let to_ptime_span t =
+    let acc =
+      List.fold_left
+        (fun acc { number; dunit } -> acc + (number * dunit_to_seconds dunit))
+        0 t
+    in
+    let acc = Int64.of_int acc in
+    let ptime = ptime_span_of_int64 acc in
+    ptime
+
+  let parse s : duration_element list =
+    match parse_string ~consume:All duration s with
+    | Error msg -> fail_with (Fmt.str "duration parse error `%s`" msg)
+    | Ok v -> v
 end
 
-let () =
+let unwrap_res = function Error e -> fail_with (Fmt.str "`%s`." e) | Ok v -> v
-  let content = read_file "default.config" in
-  (*Fmt.pr "%s" content;*)
-  let config = Untyped.parse content in
-  (*Fmt.pr "%a@." pp_lines config;*)
-  Fmt.pr "%a@." Untyped.Pp_debug.pp_config config;
 
-  ()
+let get_opt t ~section ~field =
+  match List.find_opt (fun v -> v.header = section) t with
+  | None -> None
+  | Some v -> (
+      match List.find_opt (fun item -> item.key = field) v.items with
+      | None -> None
+      | Some item -> Some item.value)
+
+let get t ~section ~field =
+  match get_opt t ~section ~field with
+  | None -> fail_with (Fmt.str "option `[%s].%s` not found" section field)
+  | Some v -> v
+
+let int s =
+  match int_of_string_opt s with
+  | None -> fail_with (Fmt.str "expected int value, got `%s`" s)
+  | Some v -> v
+
+let float s =
+  match float_of_string_opt s with
+  | None -> fail_with (Fmt.str "expected float value, got `%s`" s)
+  | Some v -> v
+
+let const_value a b =
+  match a = b with
+  | false -> fail_with (Fmt.str "unexpected value `%s`" b)
+  | true -> a
+
+let yes_no = function
+  | "NO" -> `NO
+  | "YES" -> `YES
+  | s -> fail_with (Fmt.str "expected `YES`/`NO` value, got `%s`" s)
+
+let uri s = Uri.of_string s
+let amount s = s |> Amount.of_string |> unwrap_res
+let duration s = Parse_duration.(s |> parse |> to_ptime_span)
+
+let ed25519 s =
+  s
+  |> B32.decode
+  |> unwrap_res
+  |> Mirage_crypto_ec.Ed25519.pub_of_octets
+  |> Result.map_error (fun e -> Fmt.str "%a" Mirage_crypto_ec.pp_error e)
+  |> unwrap_res
+
+module Parse_alt_unit_names = struct
+  let rm_brackets s =
+    let s = String.trim s in
+    match
+      String.starts_with ~prefix:"{" s && String.ends_with ~suffix:"}" s
+    with
+    | false -> fail_with (Fmt.str "expected json, got `%s`" s)
+    | true ->
+        let s = String.sub s 1 (String.length s - 2) in
+        s
+
+  let rm_quotes s =
+    let s = String.trim s in
+    match
+      String.starts_with ~prefix:"\"" s && String.ends_with ~suffix:"\"" s
+    with
+    | false -> fail_with (Fmt.str "expected quoted string, got `%s`" s)
+    | true ->
+        let s = String.sub s 1 (String.length s - 2) in
+        s
+
+  let parse s =
+    let s = rm_brackets s in
+    String.split_on_char ',' s
+    |> List.map (String.split_on_char ':')
+    |> List.map (function
+      | [ k; v ] -> (k, v)
+      | _ -> fail_with "invalid json key-value map")
+    |> List.map (fun (k, v) ->
+        let k = rm_quotes k in
+        let v = rm_quotes v in
+        let k =
+          match int_of_string_opt k with
+          | None ->
+              fail_with
+                (Fmt.str
+                   "invalid json key-value map, expected integer key, got `%s`"
+                   k)
+          | Some k -> k
+        in
+        (k, v))
+end

include/taler_config_type.ml

@@ -1,175 +0,0 @@
-(* 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

src/amount.ml

@@ -35,19 +35,15 @@ let make ~sign ~currency ~value ~fraction =
   in
   Ok { sign; currency; value; fraction }
 
-let to_string =
 let pp =
   let open Fmt in
-    let pp_sign ppf = function
+  let pp_sign ppf = function `Plus -> char ppf '+' | `Minus -> char ppf '-' in
-      | `Plus -> char ppf '+'
-      | `Minus -> char ppf '-'
-    in
   let pp_currency ppf = function `Eur -> string ppf "EUR" in
   fun ppf { sign; currency; value; fraction } ->
-      pf ppf "%a%a:%Ld.%02ld" (Fmt.option pp_sign) sign pp_currency currency
+    pf ppf "%a%a:%Ld.%02ld" (Fmt.option pp_sign) sign pp_currency currency value
-        value fraction
+      fraction
-  in
+
-  Fmt.str "%a" pp
+let to_string = Fmt.str "%a" pp
 
 let of_string =
   let open Angstrom in

src/assets.ml

@@ -51,21 +51,23 @@ module Mimetype = struct
   let pp_mime fmt mime = Fmt.pf fmt "%s/%s" (fst mime) (snd mime)
 end
 
+(* TODO config *)
 type t =
   | Terms
   | Privacy
 
-let etag = function
+let etag k =
-  | Terms -> Config.Exchange.terms_etag
+  Result.get_ok
-  | Privacy -> Config.Exchange.privacy_etag
+  @@ Headers_lib.Etag.of_crockford32
+  @@ match k with Terms -> "0" | Privacy -> "0"
 
 let legal_version = function
   | Terms -> terms_legal_version
   | Privacy -> privacy_legal_version
 
 let base_dir = function
-  | Terms -> Config.Exchange.terms_dir
+  | Terms -> Fpath.v "terms"
-  | Privacy -> Config.Exchange.privacy_dir
+  | Privacy -> Fpath.v "privacy"
 
 (* TODO
    better use of Fmt to have error prefix or smthing

src/assets/default.config

@@ -0,0 +1,73 @@
+[currency-EUR]
+enabled= YES
+code= EUR
+name= euro
+fractional_input_digits= 2
+fractional_normal_digits= 2
+fractional_trailing_zero_digits= 2
+alt_unit_names= "{"0":"€","3":"k€"}"
+
+[exchange]
+currency = EUR
+currency_round_unit = EUR:0.01
+db = postgres
+attribute_encryption_key = "deadbeef"
+port = 3434
+bind_to = localhost
+master_public_key = "8MQF2XPWCKCW4199JFPE08X7Y9XAX21SF2HD8NZKXM3PY3CMCJ90===="
+stefan_abs = EUR:0.00
+stefan_log = EUR:0.00
+stefan_lin = 0.00
+aggregator_idle_sleep_interval = "1 hour"
+closer_idle_sleep_interval = "1 hour"
+transfer_idle_sleep_interval = "1 hour"
+wirewatch_idle_sleep_interval = "1 hour"
+signkey_legal_duration = "1 year"
+max_keys_caching = "4 weeks"
+enable_kyc = NO
+terms_etag = "0"
+privacy_etag = "0"
+
+[exchangedb]
+idle_reserve_expiration_time = "1 year 2 weeks 3 hours 4 minutes 5 seconds"
+legal_reserve_expiration_time = "1 year"
+aggregator_shift = "1 year"
+max_aml_program_runtime = "1 year"
+default_purse_limit = 9999
+
+[exchangedb-postgres]
+config = "pgx://mte:hunter2@localhost:5432/taler-exchange"
+
+[taler-exchange-secmod-rsa]
+lookahead_sign = "1 year"
+overlap_duration = "1 year"
+
+[taler-exchange-secmod-eddsa]
+lookahead_sign = "1 year"
+overlap_duration = "1 year"
+
+[coin_kudo_1]
+value= EUR:0.01
+duration_withdraw= "1 year"
+duration_spend= "1 year"
+duration_legal= "1 year"
+fee_withdraw= EUR:0.00
+fee_deposit= EUR:0.00
+fee_refresh= EUR:0.00
+fee_refund= EUR:0.00
+cipher= RSA
+rsa_keysize= 2048
+age_restricted= NO
+
+[coin_kudo_2]
+value= EUR:0.02
+duration_withdraw= "1 year"
+duration_spend= "1 year"
+duration_legal= "1 year"
+fee_withdraw= EUR:0.00
+fee_deposit= EUR:0.00
+fee_refresh= EUR:0.00
+fee_refund= EUR:0.00
+cipher= RSA
+rsa_keysize= 2048
+age_restricted= NO

src/config.ml

@@ -1,100 +1,208 @@
-(* hardcoded config for now *)
+open Parse_config
 
-let amount s = Amount.of_string s |> Result.get_ok
+let config_data =
-let zero_eur = amount "EUR:0.00"
+  let path = Fpath.to_string (Fpath.v "default.config") in
-let dummy_duration = Ptime.Span.of_int_s 99999999
+  match Assets_crunch.read path with
+  | None -> Fmt.failwith "static file not found: `%s`" path
+  | Some data ->
+      let v = Parse_data.parse data in
+      (*Fmt.epr "config file:@\n%a@." Pp_debug.pp_config v;*)
+      v
 
 module Exchange = struct
-  let currency = "EUR"
+  let get_opt field = get_opt config_data ~section:"exchange" ~field
-  let currency_round_unit = amount "EUR:0.01"
+  let get field = get config_data ~section:"exchange" ~field
-  let db = `Pgx (* plugin to use for the database *)
-  let attribute_encryption_key = "uhuhg" (* high-entropy nonce. *)
-  let port = 3434
 
-  let master_public_key =
+  (* - *)
-    "8MQF2XPWCKCW4199JFPE08X7Y9XAX21SF2HD8NZKXM3PY3CMCJ90===="
+  let currency = (* todo: constraint on currency string *) get "currency"
-    |> B32.decode
+  let currency_round_unit = get "currency_round_unit" |> amount
-    |> Result.get_ok
+  let db = get "db" |> const_value "postgres"
-    |> Mirage_crypto_ec.Ed25519.pub_of_octets
+  let attribute_encryption_key = get "attribute_encryption_key"
-    |> Result.get_ok
+  let port = get "port" |> int
+  let bind_to = get "bind_to"
+  let master_public_key = get "master_public_key" |> ed25519
+  let stefan_abs = get "stefan_abs" |> amount
+  let stefan_log = get "stefan_log" |> amount
+  let stefan_lin = get_opt "stefan_lin" |> Option.map float
 
-  let stefan_abs = zero_eur
+  let aggregator_idle_sleep_interval =
-  let stefan_log = zero_eur
+    get "aggregator_idle_sleep_interval" |> duration
-  let stefan_lin = 0.0
-  let signkey_legal_duration = dummy_duration
-  let max_keys_caching = 9999999
-  let max_requests = 99999999
-  let terms_dir = Fpath.(v "terms")
-  let terms_etag = "0" |> Headers_lib.Etag.of_crockford32 |> Result.get_ok
-  let privacy_dir = Fpath.(v "privacy")
-  let privacy_etag = "0" |> Headers_lib.Etag.of_crockford32 |> Result.get_ok
-  let enable_kyc = `NO
-end
 
-let currency_eur =
+  let closer_idle_sleep_interval = get "closer_idle_sleep_interval" |> duration
-  Types.Config_types.Currency.
-    {
-      enabled= `NO;
-      code= "EUR";
-      name= "euro";
-      fractional_input_digits= 2;
-      fractional_normal_digits= 2;
-      fractional_trailing_zero_digits= 2;
-      alt_unit_names= [ (0, "E"); (3, "kE") ];
-    }
 
-module Secmod_rsa = struct
+  let transfer_idle_sleep_interval =
-  let lookahead_sign = dummy_duration
+    get "transfer_idle_sleep_interval" |> duration
-  let overlap_duration = dummy_duration
-  let sm_priv_key = Fpath.(v "rsa_key.priv")
-  let key_dir = Fpath.(v "rsa")
-end
 
-module Secmod_eddsa = struct
+  let wirewatch_idle_sleep_interval =
-  let lookahead_sign = dummy_duration
+    get "wirewatch_idle_sleep_interval" |> duration
-  let overlap_duration = dummy_duration
+
-  let sm_priv_key = Fpath.(v "eddsa_key.priv")
+  let signkey_legal_duration = get "signkey_legal_duration" |> duration
-  let key_dir = Fpath.(v "eddsa")
+  let max_keys_caching = get "max_keys_caching" |> duration
+  let enable_kyc = get "enable_kyc" |> yes_no
+  let terms_etag = get "terms_etag"
+  let privacy_etag = get "privacy_etag"
+
+  (* optional:
+       tiny_amount
+       shopping_url
+       open_banking_gateway_url
+       aml_spa_dialect
+       bank_compliance_language
+       toplevel_redirect_url *)
+  (* not implemented or not relevant to MTE:
+       let max_requests = get "max_requests" |> int
+       base_url
+       aggregator_shard_size
+       serve
+       unixpath
+       unixpath_mode
+       terms_dir
+       privacy_dir *)
 end
 
 module Exchangedb = struct
-  let idle_reserve_expiration_time = dummy_duration
+  let get field = get config_data ~section:"exchangedb" ~field
-  let legal_reserve_expiration_time = dummy_duration
+
-  let aggregator_shift = dummy_duration
+  (* - *)
-  let default_purse_limit = 9999
+  let idle_reserve_expiration_time =
-  let max_aml_program_runtime = dummy_duration
+    get "idle_reserve_expiration_time" |> duration
+
+  let legal_reserve_expiration_time =
+    get "legal_reserve_expiration_time" |> duration
+
+  let aggregator_shift = get "aggregator_shift" |> duration
+  let max_aml_program_runtime = get "max_aml_program_runtime" |> duration
+  let default_purse_limit = get "default_purse_limit" |> int
 end
 
 module Exchangedb_postgres = struct
-  (* pgx://<user>:<password>@<host-or-directory>:<port>/<database> *)
   let config =
-    let user = "mte" in
+    get config_data ~section:"exchangedb-postgres" ~field:"config" |> uri
-    let password = "hunter2" in
-    let host = "localhost" in
-    let port = 5432 in
-    let database = "taler-exchange" in
-    Uri.of_string
-    @@ Fmt.str "pgx://%s:%s@%s:%d/%s" user password host port database
 end
 
-let coin_kudo_1 =
+module Currency = struct
-  Types.Config_types.Coin.
+  type t = {
-    {
+    enabled: [ `YES | `NO ];
-      section_name= "kudo_1";
+    code: string;
-      value= amount "EUR:0.01";
+    name: string;
-      duration_withdraw= dummy_duration;
+    fractional_input_digits: int;
-      duration_spend= dummy_duration;
+    fractional_normal_digits: int;
-      duration_legal= dummy_duration;
+    fractional_trailing_zero_digits: int;
-      fee_withdraw= zero_eur;
+    alt_unit_names: (int * string) list;
-      fee_deposit= zero_eur;
-      fee_refresh= zero_eur;
-      fee_refund= zero_eur;
-      cipher= `RSA;
-      rsa_keysize= 2048;
-      age_restricted= `NO;
   }
 
-let coin_kudo_2 =
+  let currency_sections =
-  { coin_kudo_1 with section_name= "kudo_2"; value= amount "EUR:0.02" }
+    List.filter
+      (fun v -> String.starts_with ~prefix:"currency-" v.header)
+      config_data
 
-let coins = [ coin_kudo_1; coin_kudo_2 ]
+  let parse_currency section =
+    let get field = get config_data ~section:section.header ~field in
+    {
+      enabled= get "enabled" |> yes_no;
+      code= get "code";
+      name= get "name";
+      fractional_input_digits= get "fractional_input_digits" |> int;
+      fractional_normal_digits= get "fractional_normal_digits" |> int;
+      fractional_trailing_zero_digits=
+        get "fractional_trailing_zero_digits" |> int;
+      alt_unit_names= get "alt_unit_names" |> Parse_alt_unit_names.parse;
+    }
+
+  let all_currencies = List.map parse_currency currency_sections
+
+  (* I think the exchange only handle one currency *)
+  let v =
+    match
+      List.find_opt (fun v -> v.code = Exchange.currency) all_currencies
+    with
+    | None ->
+        fail_with
+          (Fmt.str
+             "section `[currency-%s]` not found, currency `%s` is not defined"
+             Exchange.currency Exchange.currency)
+    | Some v -> (
+        match v.enabled = `YES with
+        | false ->
+            fail_with (Fmt.str "currency `%s` is not enabled" Exchange.currency)
+        | true -> v)
+end
+
+module Coin = struct
+  type t = {
+    section_name: string;
+    value: Amount.t;
+    duration_withdraw: Ptime.Span.t;
+    duration_spend: Ptime.Span.t;
+    duration_legal: Ptime.Span.t;
+    fee_withdraw: Amount.t;
+    fee_deposit: Amount.t;
+    fee_refresh: Amount.t;
+    fee_refund: Amount.t;
+    cipher: [ (* `CS |*) `RSA ];
+    rsa_keysize: int; (* : int option (only if `RSA) *)
+    age_restricted: [ (*`YES|*) `NO ];
+  }
+
+  let coin_sections =
+    List.filter
+      (fun v ->
+        (* note: here its a '_' not '-' *)
+        String.starts_with ~prefix:"coin_" v.header)
+      config_data
+
+  let parse_coin section =
+    let get field = get config_data ~section:section.header ~field in
+    let section_name =
+      String.sub section.header 5 (String.length section.header - 5)
+    in
+    {
+      section_name;
+      value= get "value" |> amount;
+      duration_withdraw= get "duration_withdraw" |> duration;
+      duration_spend= get "duration_spend" |> duration;
+      duration_legal= get "duration_legal" |> duration;
+      fee_withdraw= get "fee_withdraw" |> amount;
+      fee_deposit= get "fee_deposit" |> amount;
+      fee_refresh= get "fee_refresh" |> amount;
+      fee_refund= get "fee_refund" |> amount;
+      cipher= (get "cipher" |> const_value "RSA" |> fun _s -> `RSA);
+      rsa_keysize= get "rsa_keysize" |> int;
+      age_restricted=
+        ( get "age_restricted" |> yes_no |> function
+          | `NO -> `NO
+          | `YES -> fail_with "`age_restricted = YES` is not supported" );
+    }
+
+  let all_coins = List.map parse_coin coin_sections
+
+  let get_coin name =
+    match List.find_opt (fun v -> v.section_name = name) all_coins with
+    | None ->
+        fail_with
+          (Fmt.str "section `[coin_%s]` not found, coin `%s` is not defined"
+             name name)
+    | Some v -> v
+
+  let kudo_1 = get_coin "kudo_1"
+  let kudo_2 = get_coin "kudo_2"
+end
+
+module Exchange_secmod_rsa = struct
+  let get field =
+    let section = "taler-exchange-secmod-" ^ "rsa" in
+    get config_data ~section ~field
+
+  let lookahead_sign = get "lookahead_sign" |> duration
+  let overlap_duration = get "overlap_duration" |> duration
+  (* not relevant: sm_priv_key key_dir unixpath *)
+end
+
+module Exchange_secmod_eddsa = struct
+  let get field =
+    let section = "taler-exchange-secmod-" ^ "eddsa" in
+    get config_data ~section ~field
+
+  let lookahead_sign = get "lookahead_sign" |> duration
+  let overlap_duration = get "overlap_duration" |> duration
+end

src/denomination.ml

@@ -36,7 +36,7 @@ let make
        rsa_keysize;
        age_restricted= _;
      } :
-      Config_types.Coin.t) =
+      Config.Coin.t) =
   assert (cipher = `RSA);
 
   let stamp_start = Ptime_clock.now () in

src/devices.ml

@@ -29,7 +29,7 @@ module Secmod_denom = struct
     let finally _key = () in
     Vif.Device.v ~name:"secmod_denom" ~finally [] @@ fun (_env : env) ->
     let sm_key = Signkey.generate () in
-    let keys = List.map Denomination.make Config.coins in
+    let keys = List.map Denomination.make Config.Coin.all_coins in
     { sm_key; keys }
 end
 

src/dune

@@ -13,6 +13,7 @@
   b32
   ;
   include
+  parse_config
   ;
   caqti
   caqti-miou

src/types.ml

@@ -1,35 +1,3 @@
-module Config_types = struct
-  module Currency = struct
-    type t = {
-      enabled: [ `YES | `NO ];
-      code: string;
-      name: string;
-      fractional_input_digits: int;
-      fractional_normal_digits: int;
-      fractional_trailing_zero_digits: int;
-      alt_unit_names: (int * string) list;
-    }
-  end
-
-  module Coin = struct
-    type t = {
-      (* section_name: Name in the configuration file that defines this denomination *)
-      section_name: string;
-      value: Amount.t;
-      duration_withdraw: Ptime.Span.t;
-      duration_spend: Ptime.Span.t;
-      duration_legal: Ptime.Span.t;
-      fee_withdraw: Amount.t;
-      fee_deposit: Amount.t;
-      fee_refresh: Amount.t;
-      fee_refund: Amount.t;
-      cipher: [ (* `CS |*) `RSA ];
-      rsa_keysize: int; (* : int option (only if `RSA) *)
-      age_restricted: [ (*`YES|*) `NO ];
-    }
-  end
-end
-
 module Amount = struct
   include Amount