🛡️ Sentinel: [MEDIUM] Fix integer coercion DoS vulnerability

.Rbuildignore

@@ -22,3 +22,4 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^.semgrepignore$

.jules/sentinel.md

@@ -2,3 +2,8 @@
 **Vulnerability:** Unvalidated inputs passed to `if()` statements can cause process crashes (`condition has length > 1`) or unexpected coercion vulnerabilities.
 **Learning:** In R, optional boolean parameters that default to `NULL` should be validated using explicit runtime type validation (e.g., `if (!is.null(flag) && (!is.logical(flag) || length(flag) != 1 || is.na(flag)))`).
 **Prevention:** Always implement explicit runtime type validation for optional boolean parameters.
+
+## 2024-07-20 - Integer Coercion DoS Vulnerability in `readline()` Parsing
+**Vulnerability:** Weak regex `grepl("^[0-9]+$", n)` was used to validate integer inputs from interactive `readline()` prompts before passing them to `as.integer()`.
+**Learning:** Large numbers provided by users can pass the `^[0-9]+$` regex but fail to coerce properly via `as.integer()`, resulting in `NA`. This causes unhandled exceptions when evaluating the `if` conditions, leading to Denial of Service (DoS) in automated or interactive contexts.
+**Prevention:** Always use strictly bounded exact-match regex (e.g., `^[12]$`) for constrained numeric choices to prevent `NA` coercion crashes.

R/aFIPC.R

@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +171,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +390,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }