Fix warnings on 32-bit builds.

When size_t is the most memory you can have, make sure that things
referring to real parts of memory are size_t, not uint64_t or off_t.

But not on any released Tor.

src/common/crypto_curve25519.c

@@ -181,6 +181,7 @@ crypto_read_tagged_contents_from_file(const char *fname,
   char *content = NULL;
   struct stat st;
   ssize_t r = -1;
+  size_t st_size;
 
   *tag_out = NULL;
   st.st_size = 0;
@@ -189,6 +190,7 @@ crypto_read_tagged_contents_from_file(const char *fname,
     goto end;
   if (st.st_size < 32 || st.st_size > 32 + data_out_len)
     goto end;
+  st_size = (size_t)st.st_size;
 
   memcpy(prefix, content, 32);
   prefix[32] = 0;
@@ -205,12 +207,12 @@ crypto_read_tagged_contents_from_file(const char *fname,
   *tag_out = tor_strndup(prefix+5+strlen(typestring),
                          strlen(prefix)-8-strlen(typestring));
 
-  memcpy(data_out, content+32, st.st_size-32);
-  r = st.st_size - 32;
+  memcpy(data_out, content+32, st_size-32);
+  r = st_size - 32;
 
  end:
   if (content)
-    memwipe(content, 0, st.st_size);
+    memwipe(content, 0, st_size);
   tor_free(content);
   return r;
 }

src/ext/ed25519/ref10/ed25519_ref10.h

@@ -9,11 +9,11 @@ int ed25519_ref10_pubkey(unsigned char *pk,const unsigned char *sk);
 int ed25519_ref10_keygen(unsigned char *pk,unsigned char *sk);
 int ed25519_ref10_open(
   const unsigned char *signature,
-  const unsigned char *m,uint64_t mlen,
+  const unsigned char *m, size_t mlen,
   const unsigned char *pk);
 int ed25519_ref10_sign(
   unsigned char *sig,
-  const unsigned char *m,uint64_t mlen,
+  const unsigned char *m, size_t mlen,
   const unsigned char *sk, const unsigned char *pk);
 
 /* Added in Tor */

src/ext/ed25519/ref10/open.c

@@ -9,7 +9,7 @@
 /* 'signature' must be 64-bytes long. */
 int crypto_sign_open(
   const unsigned char *signature,
-  const unsigned char *m,uint64_t mlen,
+  const unsigned char *m, size_t mlen,
   const unsigned char *pk
 )
 {

src/ext/ed25519/ref10/sign.c

@@ -7,7 +7,7 @@
 
 int crypto_sign(
   unsigned char *sig,
-  const unsigned char *m,uint64_t mlen,
+  const unsigned char *m, size_t mlen,
   const unsigned char *sk,const unsigned char *pk
 )
 {