diff --git a/src/config.c b/src/config.c
index e5a5afe..95548be 100644
--- a/src/config.c
+++ b/src/config.c
@@ -1,3 +1,5 @@
+#include <ctype.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -6,9 +8,9 @@
 
 #define PMSG(t, x) fprintf(stderr, t ":%s:%d: " x "\n", path, line)
 
-#define BUF_STORE(name) { \
-    if (i >= 10) { \
-        PMSG("error", name " is too big"); \
+#define BUF_STORE(name, len) { \
+    if (i >= len) { \
+        PMSG("error", name " is too long"); \
         err = 1; \
     } else { \
         ibuf[i] = ch; \
@@ -16,6 +18,8 @@
     } \
 }
 
+static int parse_conf_opts(struct conf_opts_t *, char *);
+
 config_t *
 parse_config(char *path)
 {
@@ -29,7 +33,7 @@ parse_config(char *path)
 #define ST_SKIP_B       5
 #define ST_OPTS         6
     char ch;
-    char ibuf[11];
+    char ibuf[32];
     config_t *conf, *cur;
 
     fd = fopen(path, "r");
@@ -56,27 +60,33 @@ parse_config(char *path)
             if (comment)
                 continue;
 
+            /* only run on the first whitespace */
             if (!ws) {
                 i = 0;
                 ws = 1;
                 state++;
-                /* convert offsets to uint32_t (or close enough) */
                 switch (state) {
+                /* convert offsets to uint32_t (or close enough) */
                 case ST_START:
-                    cur->start = strtoul(ibuf, ibuf+strlen(ibuf), 10);
+                    cur->start = strtoul(ibuf, NULL, 10);
                     break;
                 case ST_END:
-                    cur->end = strtoul(ibuf, ibuf+strlen(ibuf), 10);
+                    cur->end = strtoul(ibuf, NULL, 10);
                     break;
                 case ST_SKIP_A:
-                    cur->skip_a = strtoul(ibuf, ibuf+strlen(ibuf), 10);
+                    cur->skip_a = strtoul(ibuf, NULL, 10);
                     break;
                 case ST_SKIP_B:
-                    cur->skip_b = strtoul(ibuf, ibuf+strlen(ibuf), 10);
+                    cur->skip_b = strtoul(ibuf, NULL, 10);
                     break;
-                /* TODO: probably handle ST_OPTS here? */
+                /* parse options */
+                case ST_OPTS:
+                    if (parse_conf_opts(&cur->opts, ibuf) != 0) {
+                        PMSG("error", "unable to parse opts (see above)");
+                        err = 1;
+                    }
                 }
-                memset(ibuf, 0, 11);
+                memset(ibuf, 0, 32);
             }
             break;
         case '\r': /* dos line end */
@@ -91,7 +101,7 @@ parse_config(char *path)
             }
 
             if (state != ST_OPTS) {
-                PMSG("warn", "line ends early")
+                PMSG("warn", "line ends early");
             }
 
             /* reset state for next line */
@@ -117,7 +127,7 @@ parse_config(char *path)
                     PMSG("error", "filename must be less than eight characters");
                     err = 1;
                 } else {
-                    cur->filename[i] = ch;
+                    cur->filename[i] = toupper(ch);
                     i++;
                 }
                 break;
@@ -126,20 +136,20 @@ parse_config(char *path)
                     PMSG("error", "ext must be less than three characters");
                     err = 1;
                 } else {
-                    cur->ext[i] = ch;
+                    cur->ext[i] = toupper(ch);
                     i++;
                 }
                 break;
             case ST_START:
-                BUF_STORE("start byte")
+                BUF_STORE("start byte", 10);
             case ST_END:
-                BUF_STORE("end byte")
+                BUF_STORE("end byte", 10);
             case ST_SKIP_A:
-                BUF_STORE("first byte skip")
+                BUF_STORE("first byte skip", 10);
             case ST_SKIP_B:
-                BUF_STORE("second byte skip")
+                BUF_STORE("second byte skip", 10);
             case ST_OPTS:
-                /* TODO */
+                BUF_STORE("option string", 31);
             default:
                 PMSG("error", "too many columns");
                 err = 1;
@@ -160,6 +170,42 @@ parse_config(char *path)
     return conf;
 }
 
+#define STORE_VAL(name, var, lim) { \
+    val = strtoul(cur+4, NULL, 10); \
+    if (val > lim) { \
+        fprintf(stderr, "err: " name " value out of bounds\n"); \
+        return 1; \
+    } else { \
+        var = val; \
+    } \
+}
+
+/*
+ * Parses the options column of the config, ex.
+ * "xor=10,add=5,shl=2"
+ */
+static int
+parse_conf_opts(struct conf_opts_t *opts, char *parse)
+{
+    char *cur, *last;
+    unsigned int val;
+
+    for ((cur = strtok_r(parse, ",", &last)); cur;
+        (cur = strtok_r(NULL, ",", &last))) {
+        if (!strncmp(cur, "xor=", 4)) {
+            STORE_VAL("xor", opts->bit_xor, 0xff);
+        } else if (!strncmp(cur, "add=", 4)) {
+            STORE_VAL("add", opts->add, 0xff);
+        } else if (!strncmp(cur, "shr=", 4)) {
+            STORE_VAL("shr", opts->shr, 8);
+        } else if (!strncmp(cur, "shl=", 4)) {
+            STORE_VAL("shl", opts->shl, 8);
+        }
+    }
+
+    return 0;
+}
+
 void
 free_config(config_t *conf)
 {