CTFs and solutions

openssl-rand/openssl-rand.c

@@ -0,0 +1,21 @@
+#include <stdio.h>
+#define MAX 64
+int main(){
+    unsigned char rand1[MAX]="\xed\x8a\x3b\xe8\x17\x68\x38\x78\xf6\xb1\x77\x3e\x73\xb3\xf7\x97\xf3\x00\x47\x76\x54\xee\x8d\x51\x0a\x2f\x10\x79\x17\xf8\xea\xd8\x81\x83\x6e\x0f\x0c\xb8\x49\x5a\x77\xef\x2d\x62\xb6\x5e\xe2\x10\x69\xd6\xcc\xd6\xa0\x77\xa2\x0a\xd3\xf7\x9f\xa7\x9e\xa7\xc9\x08";
+    unsigned char rand2[MAX]="\x4c\x75\x82\xca\x02\x07\xbd\x1d\x8d\x52\xf0\x6c\x7a\xd6\xb7\x87\x83\x95\x06\x2f\xe0\xf7\xd4\x24\xf8\x03\x68\x97\x41\x4c\x85\x29\xe5\x0d\xb0\xe4\x3c\xee\x74\xdc\x18\x8a\xaa\x26\xf0\x46\x94\xe8\x52\x91\x4a\x43\x8f\xdd\xea\xbb\xa8\xcf\x51\x14\x79\xec\x17\xc2";
+
+    unsigned char k1[MAX];
+    unsigned char k2[MAX];
+    unsigned char key[MAX];
+    for(int i=0; i<64; i++){
+        k1[i]=rand1[i]|rand2[i];
+        k2[i]=rand1[i]&rand2[i];
+        key[i]=k1[i]^k2[i];
+    }
+    printf("CRYPTO25{");
+    for(int i=0; i < MAX; i++)
+		printf("%02x-", key[i]);
+    printf("}");
+	printf("\n");
+    return 0;
+}