From 7f0383dc6d58498d501d4c1f6dd6ff7196d716e0 Mon Sep 17 00:00:00 2001
From: Zachary Vance <za3k@za3k.com>
Date: Sun, 14 May 2017 00:13:27 -0700
Subject: [PATCH] Solve Set 1, Problem 2

---
 Makefile      | 12 ++++++++----
 set1p2.test.c | 29 +++++++++++++++++++++++++++++
 xor.c         |  5 +++++
 xor.h         |  1 +
 4 files changed, 43 insertions(+), 4 deletions(-)
 create mode 100644 set1p2.test.c
 create mode 100644 xor.c
 create mode 100644 xor.h

diff --git a/Makefile b/Makefile
index f11b138..5bbfa62 100644
--- a/Makefile
+++ b/Makefile
@@ -2,11 +2,15 @@ CC=gcc
 ODIR=obj
 CFLAGS=
 
-all: io.o io.test.o
-%.test: %.o %.test.c
+all: libs
+libs: io.o xor.o
+set1p1.test: set1p1.test.c io.o
 	$(CC) -o $@ $? $(CFLAGS)
-test: set1p2.test
-	./set1p2.test
+set1p2.test: set1p2.test.c io.o xor.o
+	$(CC) -o $@ $? $(CFLAGS)
+test: set1p1.test set1p2.test
+	./set1p1.test >/dev/null || echo "Set 1, Problem 1: Failed"
+	./set1p2.test >/dev/null || echo "Set 1, Problem 2: Failed"
 clean:
 	rm -f *.o a.out *.test
 %.o: %.c
diff --git a/set1p2.test.c b/set1p2.test.c
new file mode 100644
index 0000000..1097a80
--- /dev/null
+++ b/set1p2.test.c
@@ -0,0 +1,29 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "io.h"
+#include "xor.h"
+
+int main() {
+  char a[] = "1c0111001f010100061a024b53535009181c";
+  char b[] = "686974207468652062756c6c277320657965";
+  char expected_a_xor_b[] = "746865206b696420646f6e277420706c6179";
+
+  char a_xor_b[37];
+  char a_bytes[18], b_bytes[18], ab_bytes[18];
+  int a_bytes_len, b_bytes_len;
+  decode_hex(a, a_bytes, &a_bytes_len);
+  decode_hex(b, b_bytes, &b_bytes_len);
+  if (a_bytes_len != 18 || b_bytes_len != 18) {
+    printf("Wrong length."); exit(1);
+  }
+  xor(a_bytes, b_bytes, ab_bytes, a_bytes_len);
+  encode_hex(ab_bytes, a_bytes_len, a_xor_b);
+  if (strcmp(a_xor_b, expected_a_xor_b)==0) {
+    printf("Xor succeeded.\n");
+  } else {
+    printf("Xor failed.\nExpected: %s\n     Got: %s\n", expected_a_xor_b, a_xor_b);
+    exit(1);
+  }
+  exit(0);
+}
diff --git a/xor.c b/xor.c
new file mode 100644
index 0000000..ad84b89
--- /dev/null
+++ b/xor.c
@@ -0,0 +1,5 @@
+xor(char* buf1, char* buf2, char* buf3, int length) {
+  int i;
+  for(i=0; i<length; i++)
+    buf3[i] = buf1[i] ^ buf2[i];
+}
diff --git a/xor.h b/xor.h
new file mode 100644
index 0000000..b4c7ba4
--- /dev/null
+++ b/xor.h
@@ -0,0 +1 @@
+void xor(char* buf1, char* buf2, char* buf3, int length);
-- 
2.47.3