Remove inappropriate sodium_memzero() calls

demos/auth.c

@@ -32,7 +32,7 @@ auth(void)
      * function which reads exactly n bytes into a buffer to
      * prevent buffer overflows.
      */
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
     puts("Your key that you entered");
     print_hex(k, sizeof k);

demos/box.c

@@ -104,11 +104,8 @@ box(void)
     if (r == 0)
         printf("Plaintext: %s\n\n", m);
 
-    sodium_memzero(bob_pk, sizeof bob_pk); /* wipe sensitive data */
-    sodium_memzero(bob_sk, sizeof bob_sk);
-    sodium_memzero(alice_pk, sizeof alice_pk);
+    sodium_memzero(bob_sk, sizeof bob_sk); /* wipe sensitive data */
     sodium_memzero(alice_sk, sizeof alice_sk);
-    sodium_memzero(n, sizeof n);
     sodium_memzero(m, sizeof m);
     sodium_memzero(c, sizeof c);
     return r;

demos/generichash.c

@@ -28,7 +28,7 @@ generichash(void)
 
     puts("Example: crypto_generichash\n");
 
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
 
     mlen = prompt_input("Input your message > ", (char*)m, sizeof m);

demos/generichashstream.c

@@ -26,7 +26,7 @@ generichashstream(void)
 
     puts("Example: crypto_generichashstream\n");
 
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
     putchar('\n');
 

demos/onetimeauth.c

@@ -26,8 +26,6 @@ onetimeauth(void)
     size_t mlen;                                  /* message length */
     int r;
 
-    sodium_memzero(k, sizeof k); /* must zero the key */
-
     puts("Example: crypto_onetimeauth\n");
 
     /*
@@ -36,7 +34,7 @@ onetimeauth(void)
      * function which reads exactly n bytes into a buffer to
      * prevent buffer overflows.
      */
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
     puts("Your key that you entered");
     print_hex(k, sizeof k);

demos/shorthash.c

@@ -25,7 +25,7 @@ shorthash(void)
 
     puts("Example: crypto_shorthash\n");
 
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
 
     mlen = prompt_input("Input your message > ", (char*)m, sizeof m);

demos/sign.c

@@ -74,8 +74,7 @@ sign(void)
     if (r == 0)
         printf("Message: %s\n\n", m);
 
-    sodium_memzero(pk, sizeof pk); /* wipe sensitive data */
-    sodium_memzero(sk, sizeof sk);
+    sodium_memzero(sk, sizeof sk); /* wipe sensitive data */
     sodium_memzero(m, sizeof m);
     sodium_memzero(sm, sizeof sm);
     return r;

demos/stream.c

@@ -32,7 +32,7 @@ stream(void)
 
     puts("Example: crypto_stream\n");
 
-    sodium_memzero(k, sizeof k);
+    memset(k, 0, sizeof k);
     prompt_input("Input your key > ", (char*)k, sizeof k);
     putchar('\n');
 
@@ -68,7 +68,6 @@ stream(void)
         printf("Plaintext: %s\n\n", m);
 
     sodium_memzero(k, sizeof k); /* wipe sensitive data */
-    sodium_memzero(n, sizeof n);
     sodium_memzero(m, sizeof m);
     sodium_memzero(c, sizeof c);
     return r;