Add Black Belt alternate no-save launcher binary source

Author: mearvk

bin/blackbelt-2.c

@@ -0,0 +1,55 @@
+/* Black Belt Ethical Auditor - alternate no-save launcher. */
+#define _POSIX_C_SOURCE 200809L
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+
+static int copy_argument(char **dst, int *outc, int max, const char *arg) {
+    if (*outc >= max) return 0;
+    dst[(*outc)++] = (char *)arg;
+    return 1;
+}
+
+int main(int argc, char **argv) {
+    char executable[PATH_MAX];
+    ssize_t n = readlink("/proc/self/exe", executable, sizeof(executable) - 1);
+    if (n < 0 || (size_t)n >= sizeof(executable) - 1) {
+        perror("blackbelt-2: cannot locate executable");
+        return 127;
+    }
+    executable[n] = '\0';
+    char *slash = strrchr(executable, '/');
+    if (!slash) {
+        fprintf(stderr, "blackbelt-2: invalid executable path\n");
+        return 127;
+    }
+    *slash = '\0';
+    char blackbelt_c[PATH_MAX];
+    if (snprintf(blackbelt_c, sizeof(blackbelt_c), "%s/blackbelt-c", executable) >= (int)sizeof(blackbelt_c)) {
+        fprintf(stderr, "blackbelt-2: executable path is too long\n");
+        return 127;
+    }
+
+    setenv("BBEA_NO_SAVE", "1", 1);
+
+    /* This alternate binary is deliberately no-save: reject --save FILE rather
+       than allowing the underlying standard binary to write a response file. */
+    char *child_argv[argc + 2];
+    int child_argc = 0;
+    copy_argument(child_argv, &child_argc, argc + 1, blackbelt_c);
+    for (int i = 1; i < argc; ++i) {
+        if (!strcmp(argv[i], "--save")) {
+            if (i + 1 < argc) ++i;
+            fprintf(stderr, "blackbelt-2: --save is disabled; output will not be saved\n");
+            continue;
+        }
+        if (!copy_argument(child_argv, &child_argc, argc + 1, argv[i])) return 2;
+    }
+    child_argv[child_argc] = NULL;
+
+    execv(blackbelt_c, child_argv);
+    perror("blackbelt-2: exec blackbelt-c");
+    return 127;
+}