1 files changed, 126 insertions, 0 deletions

diff --git a/apps/plugins/puzzles/obfusc.c b/apps/plugins/puzzles/obfusc.c
new file mode 100644
index 0000000000..e95fa3f397
--- /dev/null
+++ b/apps/plugins/puzzles/obfusc.c
@@ -0,0 +1,126 @@
+/*
+ * Stand-alone tool to access the Puzzles obfuscation algorithm.
+ * 
+ * To deobfuscate, use "obfusc -d":
+ * 
+ *   obfusc -d                 reads binary data from stdin, writes to stdout
+ *   obfusc -d <hex string>    works on the given hex string instead of stdin
+ *   obfusc -d -h              writes a hex string instead of binary to stdout
+ *
+ * To obfuscate, "obfusc -e":
+ * 
+ *   obfusc -e                 reads binary from stdin, writes hex to stdout
+ *   obfusc -e <hex string>    works on the given hex string instead of stdin
+ *   obfusc -e -b              writes binary instead of text to stdout
+ *
+ * The default output format is hex for -e and binary for -d
+ * because that's the way obfuscation is generally used in
+ * Puzzles. Either of -b and -h can always be specified to set it
+ * explicitly.
+ *
+ * Data read from standard input is assumed always to be binary;
+ * data provided on the command line is taken to be hex.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+
+#include "puzzles.h"
+
+int main(int argc, char **argv)
+{
+    enum { BINARY, DEFAULT, HEX } outputmode = DEFAULT;
+    char *inhex = NULL;
+    unsigned char *data;
+    int datalen;
+    int decode = -1;
+    int doing_opts = TRUE;
+
+    while (--argc > 0) {
+        char *p = *++argv;
+
+        if (doing_opts && *p == '-') {
+            if (!strcmp(p, "--")) {
+                doing_opts = 0;
+                continue;
+            }
+            p++;
+            while (*p) {
+                switch (*p) {
+                  case 'e':
+                    decode = 0;
+                    break;
+                  case 'd':
+                    decode = 1;
+                    break;
+                  case 'b':
+                    outputmode = BINARY;
+                    break;
+                  case 'h':
+                    outputmode = HEX;
+                    break;
+                  default:
+                    return 1;
+                }
+                p++;
+            }
+        } else {
+            if (!inhex) {
+                inhex = p;
+            } else {
+                return 1;
+            }
+        }
+    }
+
+    if (decode < 0) {
+        return 0;
+    }
+
+    if (outputmode == DEFAULT)
+        outputmode = (decode ? BINARY : HEX);
+
+    if (inhex) {
+        datalen = strlen(inhex) / 2;
+        data = hex2bin(inhex, datalen);
+    } else {
+        int datasize = 4096;
+        datalen = 0;
+        data = snewn(datasize, unsigned char);
+        while (1) {
+            int ret = fread(data + datalen, 1, datasize - datalen, stdin);
+            if (ret < 0) {
+                fprintf(stderr, "obfusc: read: %s\n", strerror(errno));
+                return 1;
+            } else if (ret == 0) {
+                break;
+            } else {
+                datalen += ret;
+                if (datasize - datalen < 4096) {
+                    datasize = datalen * 5 / 4 + 4096;
+                    data = sresize(data, datasize, unsigned char);
+                }
+            }
+        }
+    }
+
+    obfuscate_bitmap(data, datalen * 8, decode);
+
+    if (outputmode == BINARY) {
+        int ret = fwrite(data, 1, datalen, stdout);
+        if (ret < 0) {
+            fprintf(stderr, "obfusc: write: %s\n", strerror(errno));
+            return 1;
+        }
+    } else {
+        int i;
+        for (i = 0; i < datalen; i++)
+            printf("%02x", data[i]);
+        printf("\n");
+    }
+
+    return 0;
+}