PuTTYgen: option to control Argon2 flavour.

I left this out of yesterday's collection of cmdgen CLI options and
GUI PuTTYgen dialog box, but only because I forgot about it. I don't
know off the top of my head why someone would particularly want to
configure this detail, but given that it _is_ configurable, it seems
like no extra trouble to expose it along with the rest of the
parameters, just in case.

cmdgen.c

@@ -155,11 +155,13 @@ void help(void)
            "format:\n"
            "            version       PPK format version (min 2, max 3, "
            "default 3)\n"
+           "            kdf           key derivation function (argon2id, "
+           "argon2i, argon2d)\n"
            "            memory        Kb of memory to use in password hash "
            "(default 8192)\n"
            "            time          approx milliseconds to hash for "
            "(default 100)\n"
-           "            passes        exact number of hash passes to run "
+           "            passes        number of hash passes to run "
            "(alternative to 'time')\n"
            "            parallelism   number of parallelisable threads in the "
            "hash function\n"
@@ -403,8 +405,27 @@ int main(int argc, char **argv)
                                             "'%s' expected a value\n", val);
                                     continue;
                                 }
-
                                 *optvalue++ = '\0';
+
+                                /* Non-numeric options */
+                                if (!strcmp(val, "kdf")) {
+                                    if (!strcmp(optvalue, "Argon2id") ||
+                                        !strcmp(optvalue, "argon2id")) {
+                                        params.argon2_flavour = Argon2id;
+                                    } else if (!strcmp(optvalue, "Argon2i") ||
+                                               !strcmp(optvalue, "argon2i")) {
+                                        params.argon2_flavour = Argon2i;
+                                    } else if (!strcmp(optvalue, "Argon2d") ||
+                                               !strcmp(optvalue, "argon2d")) {
+                                        params.argon2_flavour = Argon2d;
+                                    } else {
+                                        errs = true;
+                                        fprintf(stderr, "puttygen: unrecognise"
+                                                "d kdf '%s'\n", optvalue);
+                                    }
+                                    continue;
+                                }
+
                                 char *end;
                                 unsigned long n = strtoul(optvalue, &end, 0);
                                 if (!*optvalue || *end) {

windows/puttygen-rc.h

@@ -1,13 +1,17 @@
 #define IDC_PPKVER_STATIC               100
 #define IDC_PPKVER_2                    101
 #define IDC_PPKVER_3                    102
-#define IDC_ARGON2_MEM_STATIC           103
+#define IDC_KDF_STATIC                  103
-#define IDC_ARGON2_MEM                  104
+#define IDC_KDF_ARGON2ID                104
-#define IDC_ARGON2_MEM_STATIC2          105
+#define IDC_KDF_ARGON2I                 105
-#define IDC_PPK_AUTO_STATIC             106
+#define IDC_KDF_ARGON2D                 106
-#define IDC_PPK_AUTO_YES                107
+#define IDC_ARGON2_MEM_STATIC           107
-#define IDC_PPK_AUTO_NO                 108
+#define IDC_ARGON2_MEM                  108
-#define IDC_ARGON2_TIME_STATIC          109
+#define IDC_ARGON2_MEM_STATIC2          109
-#define IDC_ARGON2_TIME                 110
+#define IDC_PPK_AUTO_STATIC             110
-#define IDC_ARGON2_PARALLEL_STATIC      111
+#define IDC_PPK_AUTO_YES                111
-#define IDC_ARGON2_PARALLEL             112
+#define IDC_PPK_AUTO_NO                 112
+#define IDC_ARGON2_TIME_STATIC          113
+#define IDC_ARGON2_TIME                 114
+#define IDC_ARGON2_PARALLEL_STATIC      115
+#define IDC_ARGON2_PARALLEL             116

windows/puttygen.rc

@@ -54,7 +54,7 @@ BEGIN
     EDITTEXT 1000, 10, 10, 306, 200, ES_READONLY | ES_MULTILINE | ES_LEFT, WS_EX_STATICEDGE
 END
 
-215 DIALOG DISCARDABLE 0, 0, 240, 84
+215 DIALOG DISCARDABLE 0, 0, 255, 98
 STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "PuTTYgen: Private Key File Parameters"
 FONT 8, "MS Shell Dlg"
@@ -62,21 +62,24 @@ BEGIN
     LTEXT "PPK file version:", IDC_PPKVER_STATIC, 5, 6, 115, 8
     AUTORADIOBUTTON "2", IDC_PPKVER_2, 120, 5, 30, 10, WS_GROUP
     AUTORADIOBUTTON "3", IDC_PPKVER_3, 150, 5, 30, 10
+    LTEXT "Key derivation function:", IDC_KDF_STATIC, 5, 22, 115, 8
+    AUTORADIOBUTTON "Argon2id", IDC_KDF_ARGON2ID, 120, 21, 45, 10, WS_GROUP
+    AUTORADIOBUTTON "Argon2i", IDC_KDF_ARGON2I, 165, 21, 45, 10, WS_GROUP
+    AUTORADIOBUTTON "Argon2d", IDC_KDF_ARGON2D, 210, 21, 45, 10
     LTEXT "Memory to use for password hash:", IDC_ARGON2_MEM_STATIC,
-        5, 22, 115, 8
-    EDITTEXT IDC_ARGON2_MEM, 120, 20, 40, 12
-    LTEXT "Kb", IDC_ARGON2_MEM_STATIC2,
-        170, 22, 20, 8
-    LTEXT "Time to use for password hash:", IDC_ARGON2_TIME_STATIC,
         5, 36, 115, 8
-    EDITTEXT IDC_ARGON2_TIME, 120, 34, 40, 12
+    EDITTEXT IDC_ARGON2_MEM, 120, 34, 40, 12
-    AUTORADIOBUTTON "ms", IDC_PPK_AUTO_YES, 170, 35, 20, 10, WS_GROUP
+    LTEXT "Kb", IDC_ARGON2_MEM_STATIC2, 170, 36, 34, 8
-    AUTORADIOBUTTON "passes", IDC_PPK_AUTO_NO, 200, 35, 40, 10
+    LTEXT "Time to use for password hash:", IDC_ARGON2_TIME_STATIC,
-    LTEXT "Parallelism for password hash:", IDC_ARGON2_PARALLEL_STATIC,
         5, 50, 115, 8
-    EDITTEXT IDC_ARGON2_PARALLEL, 120, 48, 60, 12
+    EDITTEXT IDC_ARGON2_TIME, 120, 48, 40, 12
-    DEFPUSHBUTTON "O&K", IDOK, 70, 66, 40, 14
+    AUTORADIOBUTTON "ms", IDC_PPK_AUTO_YES, 170, 49, 20, 10, WS_GROUP
-    PUSHBUTTON "&Cancel", IDCANCEL, 130, 66, 40, 14
+    AUTORADIOBUTTON "passes", IDC_PPK_AUTO_NO, 200, 49, 40, 10
+    LTEXT "Parallelism for password hash:", IDC_ARGON2_PARALLEL_STATIC,
+        5, 64, 115, 8
+    EDITTEXT IDC_ARGON2_PARALLEL, 120, 62, 60, 12
+    DEFPUSHBUTTON "O&K", IDOK, 70, 80, 40, 14
+    PUSHBUTTON "&Cancel", IDCANCEL, 130, 80, 40, 14
 END
 
 #include "version.rc2"

windows/winpgen.c

@@ -328,6 +328,12 @@ static INT_PTR CALLBACK PPKParamsProc(HWND hwnd, UINT msg,
         CheckRadioButton(hwnd, IDC_PPKVER_2, IDC_PPKVER_3,
                          IDC_PPKVER_2 + (pp->params.fmt_version - 2));
 
+        CheckRadioButton(
+            hwnd, IDC_KDF_ARGON2ID, IDC_KDF_ARGON2D,
+            (pp->params.argon2_flavour == Argon2id ?    IDC_KDF_ARGON2ID :
+             pp->params.argon2_flavour == Argon2i  ?    IDC_KDF_ARGON2I  :
+          /* pp->params.argon2_flavour == Argon2d  ? */ IDC_KDF_ARGON2D));
+
         buf = dupprintf("%"PRIu32, pp->params.argon2_mem);
         SetDlgItemText(hwnd, IDC_ARGON2_MEM, buf);
         sfree(buf);
@@ -365,6 +371,15 @@ static INT_PTR CALLBACK PPKParamsProc(HWND hwnd, UINT msg,
           case IDC_PPKVER_3:
             pp->params.fmt_version = 3;
             return 0;
+          case IDC_KDF_ARGON2ID:
+            pp->params.argon2_flavour = Argon2id;
+            return 0;
+          case IDC_KDF_ARGON2I:
+            pp->params.argon2_flavour = Argon2i;
+            return 0;
+          case IDC_KDF_ARGON2D:
+            pp->params.argon2_flavour = Argon2d;
+            return 0;
           case IDC_ARGON2_MEM:
             try_get_dlg_item_uint32(hwnd, IDC_ARGON2_MEM,
                                     &pp->params.argon2_mem);