support checkra1n clones being passed into -i

include/kerninfo.h

@@ -59,6 +59,7 @@
 #define palerain_option_setup_rootful        (1 << 2) /* create fakefs */
 #define palerain_option_setup_rootful_forced (1 << 3) /* create fakefs over an existing one */
 #define palerain_option_setup_partial_root   (1 << 4) /* fakefs creating should be partial */
+#define palerain_option_checkrain_is_clone   (1 << 5) /* supplied checkra1n is checkra1n clone */
 
 #ifdef DEV_BUILD
 #define palerain_option_test1               (1 << 29)

include/palerain.h

@@ -198,6 +198,9 @@ int exitrecv_cmd(const uint64_t ecid);
 int exec_checkra1n(void);
 int override_file(override_file_t *finfo, niarelap_file_t** orig, unsigned int *orig_len, char *filename);
 void* pongo_helper(void* ptr);
+const unsigned char *
+boyermoore_horspool_memmem(const unsigned char* haystack, size_t hlen,
+                           const unsigned char* needle,   size_t nlen);
 
 
 extern void* pongo_usb_callback(void* arg);

src/Makefile

@@ -3,6 +3,7 @@ all: palera1n
 OBJECTS  = main.o dfuhelper.o devhelper.o lockdown_helper.o
 OBJECTS += optparse.o override_file.o log.o lock_vars.o credits.o
 OBJECTS += fake_embedded.o exec_checkra1n.o pongo_helper.o
+OBJECTS += boyermoore_memmem.o
 
 ifeq (,$(findstring macosx, $(CFLAGS)))
 ifneq (,$(findstring version-min=, $(CFLAGS)))

src/boyermoore_memmem.c

@@ -0,0 +1,59 @@
+#include <limits.h>
+#include <stdlib.h>
+
+const unsigned char *
+boyermoore_horspool_memmem(const unsigned char* haystack, size_t hlen,
+                           const unsigned char* needle,   size_t nlen)
+{
+    size_t scan = 0;
+    size_t bad_char_skip[UCHAR_MAX + 1]; /* Officially called:
+                                          * bad character shift */
+ 
+    /* Sanity checks on the parameters */
+    if (nlen <= 0 || !haystack || !needle)
+        return NULL;
+ 
+    /* ---- Preprocess ---- */
+    /* Initialize the table to default value */
+    /* When a character is encountered that does not occur
+     * in the needle, we can safely skip ahead for the whole
+     * length of the needle.
+     */
+    for (scan = 0; scan <= UCHAR_MAX; scan = scan + 1)
+        bad_char_skip[scan] = nlen;
+ 
+    /* C arrays have the first byte at [0], therefore:
+     * [nlen - 1] is the last byte of the array. */
+    size_t last = nlen - 1;
+ 
+    /* Then populate it with the analysis of the needle */
+    for (scan = 0; scan < last; scan = scan + 1)
+        bad_char_skip[needle[scan]] = last - scan;
+ 
+    /* ---- Do the matching ---- */
+ 
+    /* Search the haystack, while the needle can still be within it. */
+    while (hlen >= nlen)
+    {
+        /* scan from the end of the needle */
+        for (scan = last; haystack[scan] == needle[scan]; scan = scan - 1)
+            if (scan == 0) /* If the first byte matches, we've found it. */
+            {
+                return haystack;
+            }
+ 
+        /* otherwise, we need to skip some bytes and start again.
+           Note that here we are getting the skip value based on the last byte
+           of needle, no matter where we didn't match. So if needle is: "abcd"
+           then we are skipping based on 'd' and that value will be 4, and
+           for "abcdd" we again skip on 'd' but the value will be only 1.
+           The alternative of pretending that the mismatched character was
+           the last character is slower in the normal case (E.g. finding
+           "abcd" in "...azcd..." gives 4 by using 'd' but only
+           4-2==2 using 'z'. */
+        hlen     -= bad_char_skip[haystack[last]];
+        haystack += bad_char_skip[haystack[last]];
+    }
+ 
+    return NULL;
+}

src/exec_checkra1n.c

@@ -97,9 +97,14 @@ int exec_checkra1n(void) {
 	}
 #endif
 checkra1n_exec: {};
-	char args[0x10] = "-pE";
+	char args[0x10] = "-E";
 	if (checkrain_option_enabled(host_flags, host_option_demote)) strncat(args, "d", 0xf);
-	if (verbose >= 2) strncat(args, "v", 0xf);
+	if (!checkrain_option_enabled(host_flags, palerain_option_checkrain_is_clone)) {
+		strncat(args, "p", 0xf);
+		if (verbose >= 2) strncat(args, "v", 0xf);
+	} else {
+		strncat(args, "R", 0xf);
+	}
 	if (pongo_path != NULL) strncat(args, "k", 0xf); // keep this at last
 	pid_t pid;
 	char* checkra1n_argv[] = {

src/main.c

@@ -7,6 +7,7 @@
 #include <unistd.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <limits.h>
 #include <assert.h>
 
 #include <sys/select.h>
@@ -56,8 +57,8 @@ void thr_cleanup(void* ptr) {
 }
 
 int build_checks(void) {
-#if defined(__APPLE__)
 #ifndef NO_CHECKRAIN
+#if defined(__APPLE__)
 	struct mach_header_64* c1_header = (struct mach_header_64*)&checkra1n[0];
 	if (c1_header->magic != MH_MAGIC_64 && c1_header->magic != MH_CIGAM_64) {
 		LOG(LOG_FATAL, "Broken build: checkra1n is not a thin Mach-O");
@@ -68,6 +69,13 @@ int build_checks(void) {
 		return -1;
 	}
 #endif
+	if (checkra1n_len <= (UCHAR_MAX + 1)) {
+		LOG(LOG_FATAL, "checkra1n too small");
+	}
+	if (boyermoore_horspool_memmem(&checkra1n[0], checkra1n_len, (const unsigned char*)"[ra1npoc15-part] thanks to", strlen("[ra1npoc15-part] thanks to")) != NULL) {
+		host_flags |= palerain_option_checkrain_is_clone;
+		LOG(LOG_WARNING, "Do not distribute!");
+	}
 #endif
 #ifndef NO_KPF
 	struct mach_header_64 *kpf_hdr = (struct mach_header_64 *)checkra1n_kpf_pongo;

src/optparse.c

@@ -9,8 +9,10 @@
 #include <ctype.h>
 #include <assert.h>
 #include <getopt.h>
+#include <limits.h>
 #include <errno.h>
 #include <palerain.h>
+#include <sys/mman.h>
 
 checkrain_option_t host_flags = 0;
 checkrain_option_p host_flags_p = &host_flags;
@@ -211,7 +213,36 @@ int optparse(int argc, char* argv[]) {
 			} else if (!(st.st_mode & S_IXUSR) && !(st.st_mode & S_IXGRP) && !(st.st_mode & S_IXOTH)) {
 				LOG(LOG_FATAL, "%s is not executable", optarg);
 				return -1;
-			};
+			} else if (!(st.st_mode & S_IFREG)) {
+				LOG(LOG_FATAL, "%s is not a regular file", optarg);
+				return -1;
+			}
+			if (st.st_size < (UCHAR_MAX+1)) {
+				LOG(LOG_FATAL, "%s too small", optarg);
+				return -1;
+			}
+			int checkra1n_fd = open(optarg, O_RDONLY);
+			if (checkra1n_fd == -1) {
+				LOG(LOG_FATAL, "Cannot open %s: %d (%s)", optarg, errno, strerror(errno));
+				return -1;
+			}
+			void* addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, checkra1n_fd, 0);
+			if (addr == MAP_FAILED) {
+				LOG(LOG_ERROR, "Failed to map file %s: %d (%s)", optarg, errno, strerror(errno));
+				return -1;
+			}
+			if (boyermoore_horspool_memmem(addr, st.st_size, (const unsigned char*)"[ra1npoc15-part] thanks to", strlen("[ra1npoc15-part] thanks to")) != NULL) 
+				{
+					host_flags |= palerain_option_checkrain_is_clone;
+					LOG(LOG_VERBOSE3, "%s is checkra1n clone", optarg);
+				}
+			else
+			{
+				host_flags &= ~palerain_option_checkrain_is_clone;
+				LOG(LOG_VERBOSE3, "%s is checkra1n", optarg);
+			}
+			munmap(addr, st.st_size);
+			close(checkra1n_fd);
 			ext_checkra1n = calloc(1, strlen(optarg) + 1);
 			snprintf(ext_checkra1n, strlen(optarg) + 1, "%s", optarg);
 			break;