Merge commit 'nickm/fix_security_bug_022' into maint-0.2.2

28 files changed, 166 insertions, 122 deletions

diff --git a/changes/security_bug b/changes/security_bug
new file mode 100644
index 0000000000..990beee506
--- /dev/null
+++ b/changes/security_bug
@@ -0,0 +1,5 @@
+  o Major bugfixes:
+    - Fix a remotely exploitable bug that could be used to crash instances
+      of Tor remotely by overflowing on the heap.  Remove-code execution
+      hasn't been confirmed, but can't be ruled out.  Obviously, everyone
+      should upgrade.  Bugfix on the 0.1.1 series and later.
diff --git a/src/common/compat.c b/src/common/compat.c
index 4d556a85e6..8ec4221b22 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -126,6 +126,7 @@ tor_mmap_file(const char *filename)
     return NULL;
   }
 
+  /* XXXX why not just do fstat here? */
   size = filesize = (size_t) lseek(fd, 0, SEEK_END);
   lseek(fd, 0, SEEK_SET);
   /* ensure page alignment */
@@ -299,7 +300,7 @@ tor_vsnprintf(char *str, size_t size, const char *format, va_list args)
   int r;
   if (size == 0)
     return -1; /* no place for the NUL */
-  if (size > SSIZE_T_MAX-16)
+  if (size > SIZE_T_CEILING)
     return -1;
 #ifdef MS_WINDOWS
   r = _vsnprintf(str, size, format, args);
@@ -560,7 +561,7 @@ tor_fix_source_file(const char *fname)
  * unaligned memory access.
  */
 uint16_t
-get_uint16(const char *cp)
+get_uint16(const void *cp)
 {
   uint16_t v;
   memcpy(&v,cp,2);
@@ -572,7 +573,7 @@ get_uint16(const char *cp)
  * unaligned memory access.
  */
 uint32_t
-get_uint32(const char *cp)
+get_uint32(const void *cp)
 {
   uint32_t v;
   memcpy(&v,cp,4);
@@ -584,7 +585,7 @@ get_uint32(const char *cp)
  * unaligned memory access.
  */
 uint64_t
-get_uint64(const char *cp)
+get_uint64(const void *cp)
 {
   uint64_t v;
   memcpy(&v,cp,8);
@@ -596,7 +597,7 @@ get_uint64(const char *cp)
  * *(uint16_t*)(cp) = v, but will not cause segfaults on platforms that forbid
  * unaligned memory access. */
 void
-set_uint16(char *cp, uint16_t v)
+set_uint16(void *cp, uint16_t v)
 {
   memcpy(cp,&v,2);
 }
@@ -605,7 +606,7 @@ set_uint16(char *cp, uint16_t v)
  * *(uint32_t*)(cp) = v, but will not cause segfaults on platforms that forbid
  * unaligned memory access. */
 void
-set_uint32(char *cp, uint32_t v)
+set_uint32(void *cp, uint32_t v)
 {
   memcpy(cp,&v,4);
 }
@@ -614,7 +615,7 @@ set_uint32(char *cp, uint32_t v)
  * *(uint64_t*)(cp) = v, but will not cause segfaults on platforms that forbid
  * unaligned memory access. */
 void
-set_uint64(char *cp, uint64_t v)
+set_uint64(void *cp, uint64_t v)
 {
   memcpy(cp,&v,8);
 }
diff --git a/src/common/compat.h b/src/common/compat.h
index 449bf748f4..03e0686e8d 100644
--- a/src/common/compat.h
+++ b/src/common/compat.h
@@ -488,18 +488,18 @@ long tor_weak_random(void);
 /* ===== OS compatibility */
 const char *get_uname(void);
 
-uint16_t get_uint16(const char *cp) ATTR_PURE ATTR_NONNULL((1));
-uint32_t get_uint32(const char *cp) ATTR_PURE ATTR_NONNULL((1));
-uint64_t get_uint64(const char *cp) ATTR_PURE ATTR_NONNULL((1));
-void set_uint16(char *cp, uint16_t v) ATTR_NONNULL((1));
-void set_uint32(char *cp, uint32_t v) ATTR_NONNULL((1));
-void set_uint64(char *cp, uint64_t v) ATTR_NONNULL((1));
+uint16_t get_uint16(const void *cp) ATTR_PURE ATTR_NONNULL((1));
+uint32_t get_uint32(const void *cp) ATTR_PURE ATTR_NONNULL((1));
+uint64_t get_uint64(const void *cp) ATTR_PURE ATTR_NONNULL((1));
+void set_uint16(void *cp, uint16_t v) ATTR_NONNULL((1));
+void set_uint32(void *cp, uint32_t v) ATTR_NONNULL((1));
+void set_uint64(void *cp, uint64_t v) ATTR_NONNULL((1));
 
 /* These uint8 variants are defined to make the code more uniform. */
 #define get_uint8(cp) (*(const uint8_t*)(cp))
-static void set_uint8(char *cp, uint8_t v);
+static void set_uint8(void *cp, uint8_t v);
 static INLINE void
-set_uint8(char *cp, uint8_t v)
+set_uint8(void *cp, uint8_t v)
 {
   *(uint8_t*)cp = v;
 }
diff --git a/src/common/crypto.c b/src/common/crypto.c
index 81a432d8d4..e030c56064 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -901,6 +901,8 @@ crypto_pk_public_checksig_digest(crypto_pk_env_t *env, const char *data,
   tor_assert(env);
   tor_assert(data);
   tor_assert(sig);
+  tor_assert(datalen < SIZE_T_CEILING);
+  tor_assert(siglen < SIZE_T_CEILING);
 
   if (crypto_digest(digest,data,datalen)<0) {
     log_warn(LD_BUG, "couldn't compute digest");
@@ -1001,6 +1003,7 @@ crypto_pk_public_hybrid_encrypt(crypto_pk_env_t *env,
   tor_assert(env);
   tor_assert(from);
   tor_assert(to);
+  tor_assert(fromlen < SIZE_T_CEILING);
 
   overhead = crypto_get_rsa_padding_overhead(crypto_get_rsa_padding(padding));
   pkeylen = crypto_pk_keysize(env);
@@ -1068,6 +1071,7 @@ crypto_pk_private_hybrid_decrypt(crypto_pk_env_t *env,
   crypto_cipher_env_t *cipher = NULL;
   char *buf = NULL;
 
+  tor_assert(fromlen < SIZE_T_CEILING);
   pkeylen = crypto_pk_keysize(env);
 
   if (fromlen <= pkeylen) {
@@ -1117,7 +1121,7 @@ crypto_pk_asn1_encode(crypto_pk_env_t *pk, char *dest, size_t dest_len)
   int len;
   unsigned char *buf, *cp;
   len = i2d_RSAPublicKey(pk->key, NULL);
-  if (len < 0 || (size_t)len > dest_len)
+  if (len < 0 || (size_t)len > dest_len || dest_len > SIZE_T_CEILING)
     return -1;
   cp = buf = tor_malloc(len+1);
   len = i2d_RSAPublicKey(pk->key, &cp);
@@ -1192,6 +1196,8 @@ add_spaces_to_fp(char *out, size_t outlen, const char *in)
 {
   int n = 0;
   char *end = out+outlen;
+  tor_assert(outlen < SIZE_T_CEILING);
+
   while (*in && out<end) {
     *out++ = *in++;
     if (++n == 4 && *in && out<end) {
@@ -1337,6 +1343,7 @@ crypto_cipher_encrypt(crypto_cipher_env_t *env, char *to,
   tor_assert(from);
   tor_assert(fromlen);
   tor_assert(to);
+  tor_assert(fromlen < SIZE_T_CEILING);
 
   aes_crypt(env->cipher, from, fromlen, to);
   return 0;
@@ -1353,6 +1360,7 @@ crypto_cipher_decrypt(crypto_cipher_env_t *env, char *to,
   tor_assert(env);
   tor_assert(from);
   tor_assert(to);
+  tor_assert(fromlen < SIZE_T_CEILING);
 
   aes_crypt(env->cipher, from, fromlen, to);
   return 0;
@@ -1364,6 +1372,7 @@ crypto_cipher_decrypt(crypto_cipher_env_t *env, char *to,
 int
 crypto_cipher_crypt_inplace(crypto_cipher_env_t *env, char *buf, size_t len)
 {
+  tor_assert(len < SIZE_T_CEILING);
   aes_crypt_inplace(env->cipher, buf, len);
   return 0;
 }
diff --git a/src/common/memarea.c b/src/common/memarea.c
index 77579e63be..dac15434c0 100644
--- a/src/common/memarea.c
+++ b/src/common/memarea.c
@@ -95,6 +95,7 @@ static memarea_chunk_t *freelist = NULL;
 static memarea_chunk_t *
 alloc_chunk(size_t sz, int freelist_ok)
 {
+  tor_assert(sz < SIZE_T_CEILING);
   if (freelist && freelist_ok) {
     memarea_chunk_t *res = freelist;
     freelist = res->next_chunk;
@@ -211,6 +212,7 @@ memarea_alloc(memarea_t *area, size_t sz)
   char *result;
   tor_assert(chunk);
   CHECK_SENTINEL(chunk);
+  tor_assert(sz < SIZE_T_CEILING);
   if (sz == 0)
     sz = 1;
   if (chunk->next_mem+sz > chunk->u.mem+chunk->mem_size) {
@@ -269,6 +271,7 @@ memarea_strndup(memarea_t *area, const char *s, size_t n)
   size_t ln;
   char *result;
   const char *cp, *end = s+n;
+  tor_assert(n < SIZE_T_CEILING);
   for (cp = s; cp < end && *cp; ++cp)
     ;
   /* cp now points to s+n, or to the 0 in the string. */
diff --git a/src/common/mempool.c b/src/common/mempool.c
index c795d83f0c..9d019d618e 100644
--- a/src/common/mempool.c
+++ b/src/common/mempool.c
@@ -357,6 +357,10 @@ mp_pool_new(size_t item_size, size_t chunk_capacity)
   mp_pool_t *pool;
   size_t alloc_size, new_chunk_cap;
 
+  tor_assert(item_size < SIZE_T_CEILING);
+  tor_assert(chunk_capacity < SIZE_T_CEILING);
+  tor_assert(SIZE_T_CEILING / item_size > chunk_capacity);
+
   pool = ALLOC(sizeof(mp_pool_t));
   CHECK_ALLOC(pool);
   memset(pool, 0, sizeof(mp_pool_t));
diff --git a/src/common/torint.h b/src/common/torint.h
index 57f18212ad..a57d501002 100644
--- a/src/common/torint.h
+++ b/src/common/torint.h
@@ -330,7 +330,7 @@ typedef uint32_t uintptr_t;
 #endif
 
 /* Any size_t larger than this amount is likely to be an underflow. */
-#define SIZE_T_CEILING (sizeof(char)<<(sizeof(size_t)*8 - 1))
+#define SIZE_T_CEILING (SSIZE_T_MAX-16)
 
 #endif /* __TORINT_H */
 
diff --git a/src/common/util.c b/src/common/util.c
index dafe12071f..d511872964 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -122,6 +122,8 @@ _tor_malloc(size_t size DMALLOC_PARAMS)
 {
   void *result;
 
+  tor_assert(size < SIZE_T_CEILING);
+
 #ifndef MALLOC_ZERO_WORKS
   /* Some libc mallocs don't work when size==0. Override them. */
   if (size==0) {
@@ -218,6 +220,7 @@ _tor_strndup(const char *s, size_t n DMALLOC_PARAMS)
 {
   char *dup;
   tor_assert(s);
+  tor_assert(n < SIZE_T_CEILING);
   dup = _tor_malloc((n+1) DMALLOC_FN_ARGS);
   /* Performance note: Ordinarily we prefer strlcpy to strncpy.  But
    * this function gets called a whole lot, and platform strncpy is
@@ -234,6 +237,7 @@ void *
 _tor_memdup(const void *mem, size_t len DMALLOC_PARAMS)
 {
   char *dup;
+  tor_assert(len < SIZE_T_CEILING);
   tor_assert(mem);
   dup = _tor_malloc(len DMALLOC_FN_ARGS);
   memcpy(dup, mem, len);
@@ -263,12 +267,15 @@ void *
 _tor_malloc_roundup(size_t *sizep DMALLOC_PARAMS)
 {
 #ifdef HAVE_MALLOC_GOOD_SIZE
+  tor_assert(*sizep < SIZE_T_CEILING);
   *sizep = malloc_good_size(*sizep);
   return _tor_malloc(*sizep DMALLOC_FN_ARGS);
 #elif 0 && defined(HAVE_MALLOC_USABLE_SIZE) && !defined(USE_DMALLOC)
   /* Never use malloc_usable_size(); it makes valgrind really unhappy,
    * and doesn't win much in terms of usable space where it exists. */
-  void *result = _tor_malloc(*sizep DMALLOC_FN_ARGS);
+  void *result;
+  tor_assert(*sizep < SIZE_T_CEILING);
+  result = _tor_malloc(*sizep DMALLOC_FN_ARGS);
   *sizep = malloc_usable_size(result);
   return result;
 #else
@@ -2131,7 +2138,7 @@ read_file_to_str(const char *filename, int flags, struct stat *stat_out)
     return NULL;
   }
 
-  if ((uint64_t)(statbuf.st_size)+1 > SIZE_T_MAX)
+  if ((uint64_t)(statbuf.st_size)+1 > SIZE_T_CEILING)
     return NULL;
 
   string = tor_malloc((size_t)(statbuf.st_size+1));
diff --git a/src/or/buffers.c b/src/or/buffers.c
index 658a924cef..f84fb45c64 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -1048,7 +1048,7 @@ fetch_var_cell_from_buf(buf_t *buf, var_cell_t **out, int linkproto)
   result->circ_id = ntohs(get_uint16(hdr));
 
   buf_remove_from_front(buf, VAR_CELL_HEADER_SIZE);
-  peek_from_buf(result->payload, length, buf);
+  peek_from_buf((char*) result->payload, length, buf);
   buf_remove_from_front(buf, length);
   check();
 
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 473b28e872..2fe750ea5b 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1902,7 +1902,7 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
        * and a DH operation. */
       cell_type = CELL_CREATE_FAST;
       memset(payload, 0, sizeof(payload));
-      crypto_rand(circ->cpath->fast_handshake_state,
+      crypto_rand((char*) circ->cpath->fast_handshake_state,
                   sizeof(circ->cpath->fast_handshake_state));
       memcpy(payload, circ->cpath->fast_handshake_state,
              sizeof(circ->cpath->fast_handshake_state));
@@ -2081,8 +2081,8 @@ circuit_extend(cell_t *cell, circuit_t *circ)
 
   n_addr32 = ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE));
   n_port = ntohs(get_uint16(cell->payload+RELAY_HEADER_SIZE+4));
-  onionskin = cell->payload+RELAY_HEADER_SIZE+4+2;
-  id_digest = cell->payload+RELAY_HEADER_SIZE+4+2+ONIONSKIN_CHALLENGE_LEN;
+  onionskin = (char*) cell->payload+RELAY_HEADER_SIZE+4+2;
+  id_digest = (char*) cell->payload+RELAY_HEADER_SIZE+4+2+ONIONSKIN_CHALLENGE_LEN;
   tor_addr_from_ipv4h(&n_addr, n_addr32);
 
   if (!n_port || !n_addr32) {
@@ -2220,7 +2220,7 @@ circuit_init_cpath_crypto(crypt_path_t *cpath, const char *key_data,
  */
 int
 circuit_finish_handshake(origin_circuit_t *circ, uint8_t reply_type,
-                         const char *reply)
+                         const uint8_t *reply)
 {
   char keys[CPATH_KEY_MATERIAL_LEN];
   crypt_path_t *hop;
@@ -2237,7 +2237,7 @@ circuit_finish_handshake(origin_circuit_t *circ, uint8_t reply_type,
   tor_assert(hop->state == CPATH_STATE_AWAITING_KEYS);
 
   if (reply_type == CELL_CREATED && hop->dh_handshake_state) {
-    if (onion_skin_client_handshake(hop->dh_handshake_state, reply, keys,
+    if (onion_skin_client_handshake(hop->dh_handshake_state, (char*)reply, keys,
                                     DIGEST_LEN*2+CIPHER_KEY_LEN*2) < 0) {
       log_warn(LD_CIRC,"onion_skin_client_handshake failed.");
       return -END_CIRC_REASON_TORPROTOCOL;
@@ -2245,7 +2245,8 @@ circuit_finish_handshake(origin_circuit_t *circ, uint8_t reply_type,
     /* Remember hash of g^xy */
     memcpy(hop->handshake_digest, reply+DH_KEY_LEN, DIGEST_LEN);
   } else if (reply_type == CELL_CREATED_FAST && !hop->dh_handshake_state) {
-    if (fast_client_handshake(hop->fast_handshake_state, reply, keys,
+    if (fast_client_handshake(hop->fast_handshake_state, reply,
+                              (uint8_t*)keys,
                               DIGEST_LEN*2+CIPHER_KEY_LEN*2) < 0) {
       log_warn(LD_CIRC,"fast_client_handshake failed.");
       return -END_CIRC_REASON_TORPROTOCOL;
diff --git a/src/or/circuitbuild.h b/src/or/circuitbuild.h
index 888bf9d255..a85c410133 100644
--- a/src/or/circuitbuild.h
+++ b/src/or/circuitbuild.h
@@ -31,7 +31,7 @@ int circuit_extend(cell_t *cell, circuit_t *circ);
 int circuit_init_cpath_crypto(crypt_path_t *cpath, const char *key_data,
                               int reverse);
 int circuit_finish_handshake(origin_circuit_t *circ, uint8_t cell_type,
-                             const char *reply);
+                             const uint8_t *reply);
 int circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer);
 int onionskin_answer(or_circuit_t *circ, uint8_t cell_type,
                      const char *payload, const char *keys);
diff --git a/src/or/command.c b/src/or/command.c
index ea0bbea1e5..beb5d09a9d 100644
--- a/src/or/command.c
+++ b/src/or/command.c
@@ -306,7 +306,8 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn)
     char keys[CPATH_KEY_MATERIAL_LEN];
     char reply[DIGEST_LEN*2];
     tor_assert(cell->command == CELL_CREATE_FAST);
-    if (fast_server_handshake(cell->payload, reply, keys, sizeof(keys))<0) {
+    if (fast_server_handshake(cell->payload, (uint8_t*)reply,
+                              (uint8_t*)keys, sizeof(keys))<0) {
       log_warn(LD_OR,"Failed to generate key material. Closing.");
       circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
       return;
@@ -353,7 +354,7 @@ command_process_created_cell(cell_t *cell, or_connection_t *conn)
     int err_reason = 0;
     log_debug(LD_OR,"at OP. Finishing handshake.");
     if ((err_reason = circuit_finish_handshake(origin_circ, cell->command,
-                                 cell->payload)) < 0) {
+                                               cell->payload)) < 0) {
       log_warn(LD_OR,"circuit_finish_handshake failed.");
       circuit_mark_for_close(circ, -err_reason);
       return;
@@ -369,7 +370,7 @@ command_process_created_cell(cell_t *cell, or_connection_t *conn)
     log_debug(LD_OR,
               "Converting created cell to extended relay cell, sending.");
     relay_send_command_from_edge(0, circ, RELAY_COMMAND_EXTENDED,
-                                 cell->payload, ONIONSKIN_REPLY_LEN,
+                                 (char*)cell->payload, ONIONSKIN_REPLY_LEN,
                                  NULL);
   }
 }
@@ -499,7 +500,7 @@ static void
 command_process_versions_cell(var_cell_t *cell, or_connection_t *conn)
 {
   int highest_supported_version = 0;
-  const char *cp, *end;
+  const uint8_t *cp, *end;
   if (conn->link_proto != 0 ||
       conn->_base.state != OR_CONN_STATE_OR_HANDSHAKING ||
       (conn->handshake_state && conn->handshake_state->received_versions)) {
@@ -553,8 +554,8 @@ command_process_netinfo_cell(cell_t *cell, or_connection_t *conn)
   time_t timestamp;
   uint8_t my_addr_type;
   uint8_t my_addr_len;
-  const char *my_addr_ptr;
-  const char *cp, *end;
+  const uint8_t *my_addr_ptr;
+  const uint8_t *cp, *end;
   uint8_t n_other_addrs;
   time_t now = time(NULL);
 
@@ -582,7 +583,7 @@ command_process_netinfo_cell(cell_t *cell, or_connection_t *conn)
 
   my_addr_type = (uint8_t) cell->payload[4];
   my_addr_len = (uint8_t) cell->payload[5];
-  my_addr_ptr = cell->payload + 6;
+  my_addr_ptr = (uint8_t*) cell->payload + 6;
   end = cell->payload + CELL_PAYLOAD_SIZE;
   cp = cell->payload + 6 + my_addr_len;
   if (cp >= end) {
@@ -599,7 +600,7 @@ command_process_netinfo_cell(cell_t *cell, or_connection_t *conn)
     /* Consider all the other addresses; if any matches, this connection is
      * "canonical." */
     tor_addr_t addr;
-    const char *next = decode_address_from_payload(&addr, cp, (int)(end-cp));
+    const uint8_t *next = decode_address_from_payload(&addr, cp, (int)(end-cp));
     if (next == NULL) {
       log_fn(LOG_PROTOCOL_WARN,  LD_OR,
              "Bad address in netinfo cell; closing connection.");
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index cc040b1780..2bfa88e6a9 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -1492,7 +1492,8 @@ connection_ap_handshake_rewrite_and_attach(edge_connection_t *conn,
       tor_snprintf(socks->address, sizeof(socks->address), "REVERSE[%s]",
                   orig_address);
       connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_HOSTNAME,
-                                             strlen(result), result, -1,
+                                             strlen(result), (uint8_t*)result,
+                                             -1,
                                              map_expires);
       connection_mark_unattached_ap(conn,
                                 END_STREAM_REASON_DONE |
@@ -1613,7 +1614,8 @@ connection_ap_handshake_rewrite_and_attach(edge_connection_t *conn,
         /* remember _what_ is supposed to have been resolved. */
         strlcpy(socks->address, orig_address, sizeof(socks->address));
         connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
-                                               (char*)&answer,-1,map_expires);
+                                               (uint8_t*)&answer,
+                                               -1,map_expires);
         connection_mark_unattached_ap(conn,
                                 END_STREAM_REASON_DONE |
                                 END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
@@ -2318,7 +2320,7 @@ void
 connection_ap_handshake_socks_resolved(edge_connection_t *conn,
                                        int answer_type,
                                        size_t answer_len,
-                                       const char *answer,
+                                       const uint8_t *answer,
                                        int ttl,
                                        time_t expires)
 {
@@ -2332,7 +2334,7 @@ connection_ap_handshake_socks_resolved(edge_connection_t *conn,
         client_dns_set_addressmap(conn->socks_request->address, a,
                                   conn->chosen_exit_name, ttl);
     } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
-      char *cp = tor_strndup(answer, answer_len);
+      char *cp = tor_strndup((char*)answer, answer_len);
       client_dns_set_reverse_addressmap(conn->socks_request->address,
                                         cp,
                                         conn->chosen_exit_name, ttl);
@@ -2343,14 +2345,14 @@ connection_ap_handshake_socks_resolved(edge_connection_t *conn,
   if (conn->is_dns_request) {
     if (conn->dns_server_request) {
       /* We had a request on our DNS port: answer it. */
-      dnsserv_resolved(conn, answer_type, answer_len, answer, ttl);
+      dnsserv_resolved(conn, answer_type, answer_len, (char*)answer, ttl);
       conn->socks_request->has_finished = 1;
       return;
     } else {
       /* This must be a request from the controller. We already sent
        * a mapaddress if there's a ttl. */
       tell_controller_about_resolved_result(conn, answer_type, answer_len,
-                                            answer, ttl, expires);
+                                            (char*)answer, ttl, expires);
       conn->socks_request->has_finished = 1;
       return;
     }
@@ -2495,6 +2497,8 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
     or_circ = TO_OR_CIRCUIT(circ);
 
   relay_header_unpack(&rh, cell->payload);
+  if (rh.length > RELAY_PAYLOAD_SIZE)
+    return -1;
 
   /* Note: we have to use relay_send_command_from_edge here, not
    * connection_edge_end or connection_edge_send_command, since those require
@@ -2518,7 +2522,8 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
                                     END_STREAM_REASON_TORPROTOCOL, NULL);
       return 0;
     }
-    if (parse_addr_port(LOG_PROTOCOL_WARN, cell->payload+RELAY_HEADER_SIZE,
+    if (parse_addr_port(LOG_PROTOCOL_WARN,
+                        (char*)(cell->payload+RELAY_HEADER_SIZE),
                         &address,NULL,&port)<0) {
       log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
              "Unable to parse addr:port in relay begin cell. Closing.");
@@ -2683,6 +2688,8 @@ connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ)
 
   assert_circuit_ok(TO_CIRCUIT(circ));
   relay_header_unpack(&rh, cell->payload);
+  if (rh.length > RELAY_PAYLOAD_SIZE)
+    return -1;
 
   /* This 'dummy_conn' only exists to remember the stream ID
    * associated with the resolve request; and to make the
@@ -2693,8 +2700,9 @@ connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ)
    */
   dummy_conn = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
   dummy_conn->stream_id = rh.stream_id;
-  dummy_conn->_base.address = tor_strndup(cell->payload+RELAY_HEADER_SIZE,
-                                          rh.length);
+  dummy_conn->_base.address = tor_strndup(
+                                       (char*)cell->payload+RELAY_HEADER_SIZE,
+                                       rh.length);
   dummy_conn->_base.port = 0;
   dummy_conn->_base.state = EXIT_CONN_STATE_RESOLVEFAILED;
   dummy_conn->_base.purpose = EXIT_PURPOSE_RESOLVE;
diff --git a/src/or/connection_edge.h b/src/or/connection_edge.h
index 762af5172e..cca82022c3 100644
--- a/src/or/connection_edge.h
+++ b/src/or/connection_edge.h
@@ -38,7 +38,7 @@ void connection_ap_handshake_socks_reply(edge_connection_t *conn, char *reply,
 void connection_ap_handshake_socks_resolved(edge_connection_t *conn,
                                             int answer_type,
                                             size_t answer_len,
-                                            const char *answer,
+                                            const uint8_t *answer,
                                             int ttl,
                                             time_t expires);
 
diff --git a/src/or/connection_or.c b/src/or/connection_or.c
index 415a48dca3..45266a99b1 100644
--- a/src/or/connection_or.c
+++ b/src/or/connection_or.c
@@ -1259,7 +1259,8 @@ connection_or_write_var_cell_to_buf(const var_cell_t *cell,
   tor_assert(conn);
   var_cell_pack_header(cell, hdr);
   connection_write_to_buf(hdr, sizeof(hdr), TO_CONN(conn));
-  connection_write_to_buf(cell->payload, cell->payload_len, TO_CONN(conn));
+  connection_write_to_buf((char*)cell->payload,
+                          cell->payload_len, TO_CONN(conn));
   if (cell->command != CELL_PADDING)
     conn->timestamp_last_added_nonpadding = approx_time();
 }
@@ -1388,7 +1389,7 @@ connection_or_send_netinfo(or_connection_t *conn)
   time_t now = time(NULL);
   routerinfo_t *me;
   int len;
-  char *out;
+  uint8_t *out;
 
   memset(&cell, 0, sizeof(cell_t));
   cell.command = CELL_NETINFO;
diff --git a/src/or/onion.c b/src/or/onion.c
index fa001656e6..4d14f9095b 100644
--- a/src/or/onion.c
+++ b/src/or/onion.c
@@ -349,9 +349,9 @@ onion_skin_client_handshake(crypto_dh_env_t *handshake_state,
  * Return 0 on success, &lt;0 on failure.
  **/
 int
-fast_server_handshake(const char *key_in, /* DIGEST_LEN bytes */
-                      char *handshake_reply_out, /* DIGEST_LEN*2 bytes */
-                      char *key_out,
+fast_server_handshake(const uint8_t *key_in, /* DIGEST_LEN bytes */
+                      uint8_t *handshake_reply_out, /* DIGEST_LEN*2 bytes */
+                      uint8_t *key_out,
                       size_t key_out_len)
 {
   char tmp[DIGEST_LEN+DIGEST_LEN];
@@ -359,7 +359,7 @@ fast_server_handshake(const char *key_in, /* DIGEST_LEN bytes */
   size_t out_len;
   int r = -1;
 
-  if (crypto_rand(handshake_reply_out, DIGEST_LEN)<0)
+  if (crypto_rand((char*)handshake_reply_out, DIGEST_LEN)<0)
     return -1;
 
   memcpy(tmp, key_in, DIGEST_LEN);
@@ -392,9 +392,9 @@ fast_server_handshake(const char *key_in, /* DIGEST_LEN bytes */
  * and protected by TLS).
  */
 int
-fast_client_handshake(const char *handshake_state, /* DIGEST_LEN bytes */
-                      const char *handshake_reply_out, /* DIGEST_LEN*2 bytes */
-                      char *key_out,
+fast_client_handshake(const uint8_t *handshake_state, /* DIGEST_LEN bytes */
+                      const uint8_t *handshake_reply_out, /* DIGEST_LEN*2 bytes */
+                      uint8_t *key_out,
                       size_t key_out_len)
 {
   char tmp[DIGEST_LEN+DIGEST_LEN];
diff --git a/src/or/onion.h b/src/or/onion.h
index e84dbb47be..e097dcdbb3 100644
--- a/src/or/onion.h
+++ b/src/or/onion.h
@@ -32,14 +32,14 @@ int onion_skin_client_handshake(crypto_dh_env_t *handshake_state,
                                 char *key_out,
                                 size_t key_out_len);
 
-int fast_server_handshake(const char *key_in,
-                          char *handshake_reply_out,
-                          char *key_out,
+int fast_server_handshake(const uint8_t *key_in,
+                          uint8_t *handshake_reply_out,
+                          uint8_t *key_out,
                           size_t key_out_len);
 
-int fast_client_handshake(const char *handshake_state,
-                          const char *handshake_reply_out,
-                          char *key_out,
+int fast_client_handshake(const uint8_t *handshake_state,
+                          const uint8_t *handshake_reply_out,
+                          uint8_t *key_out,
                           size_t key_out_len);
 
 void clear_pending_onions(void);
diff --git a/src/or/or.h b/src/or/or.h
index a2cefe2b4a..07b73ec9b7 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -838,7 +838,7 @@ typedef struct cell_t {
   circid_t circ_id; /**< Circuit which received the cell. */
   uint8_t command; /**< Type of the cell: one of CELL_PADDING, CELL_CREATE,
                     * CELL_DESTROY, etc */
-  char payload[CELL_PAYLOAD_SIZE]; /**< Cell body. */
+  uint8_t payload[CELL_PAYLOAD_SIZE]; /**< Cell body. */
 } cell_t;
 
 /** Parsed variable-length onion routing cell. */
@@ -846,7 +846,7 @@ typedef struct var_cell_t {
   uint8_t command;
   circid_t circ_id;
   uint16_t payload_len;
-  char payload[1];
+  uint8_t payload[1];
 } var_cell_t;
 
 /** A cell as packed for writing to the network. */
@@ -1958,7 +1958,7 @@ typedef struct crypt_path_t {
    * authentication, secrecy, and integrity we need, and we're already
    * distinguishable from an OR.
    */
-  char fast_handshake_state[DIGEST_LEN];
+  uint8_t fast_handshake_state[DIGEST_LEN];
   /** Negotiated key material shared with the OR at this step. */
   char handshake_digest[DIGEST_LEN];/* KH in tor-spec.txt */
 
diff --git a/src/or/relay.c b/src/or/relay.c
index a65280e2a3..c951cab560 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -97,7 +97,7 @@ relay_set_digest(crypto_digest_env_t *digest, cell_t *cell)
   char integrity[4];
   relay_header_t rh;
 
-  crypto_digest_add_bytes(digest, cell->payload, CELL_PAYLOAD_SIZE);
+  crypto_digest_add_bytes(digest, (char*)cell->payload, CELL_PAYLOAD_SIZE);
   crypto_digest_get_digest(digest, integrity, 4);
 //  log_fn(LOG_DEBUG,"Putting digest of %u %u %u %u into relay cell.",
 //    integrity[0], integrity[1], integrity[2], integrity[3]);
@@ -130,7 +130,7 @@ relay_digest_matches(crypto_digest_env_t *digest, cell_t *cell)
 //    received_integrity[0], received_integrity[1],
 //    received_integrity[2], received_integrity[3]);
 
-  crypto_digest_add_bytes(digest, cell->payload, CELL_PAYLOAD_SIZE);
+  crypto_digest_add_bytes(digest, (char*) cell->payload, CELL_PAYLOAD_SIZE);
   crypto_digest_get_digest(digest, calculated_integrity, 4);
 
   if (memcmp(received_integrity, calculated_integrity, 4)) {
@@ -156,12 +156,12 @@ relay_digest_matches(crypto_digest_env_t *digest, cell_t *cell)
  * Return -1 if the crypto fails, else return 0.
  */
 static int
-relay_crypt_one_payload(crypto_cipher_env_t *cipher, char *in,
+relay_crypt_one_payload(crypto_cipher_env_t *cipher, uint8_t *in,
                         int encrypt_mode)
 {
   int r;
   (void)encrypt_mode;
-  r = crypto_cipher_crypt_inplace(cipher, in, CELL_PAYLOAD_SIZE);
+  r = crypto_cipher_crypt_inplace(cipher, (char*) in, CELL_PAYLOAD_SIZE);
 
   if (r) {
     log_warn(LD_BUG,"Error during relay encryption");
@@ -476,10 +476,9 @@ relay_lookup_conn(circuit_t *circ, cell_t *cell,
  * about the wire format.
  */
 void
-relay_header_pack(char *dest, const relay_header_t *src)
+relay_header_pack(uint8_t *dest, const relay_header_t *src)
 {
-  *(uint8_t*)(dest) = src->command;
-
+  set_uint8(dest, src->command);
   set_uint16(dest+1, htons(src->recognized));
   set_uint16(dest+3, htons(src->stream_id));
   memcpy(dest+5, src->integrity, 4);
@@ -490,10 +489,9 @@ relay_header_pack(char *dest, const relay_header_t *src)
  * relay_header_t structure <b>dest</b>.
  */
 void
-relay_header_unpack(relay_header_t *dest, const char *src)
+relay_header_unpack(relay_header_t *dest, const uint8_t *src)
 {
-  dest->command = *(uint8_t*)(src);
-
+  dest->command = get_uint8(src);
   dest->recognized = ntohs(get_uint16(src+1));
   dest->stream_id = ntohs(get_uint16(src+3));
   memcpy(dest->integrity, src+5, 4);
@@ -1124,13 +1122,13 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
       }
 
       stats_n_data_bytes_received += rh.length;
-      connection_write_to_buf(cell->payload + RELAY_HEADER_SIZE,
+      connection_write_to_buf((char*)(cell->payload + RELAY_HEADER_SIZE),
                               rh.length, TO_CONN(conn));
       connection_edge_consider_sending_sendme(conn);
       return 0;
     case RELAY_COMMAND_END:
       reason = rh.length > 0 ?
-        *(uint8_t *)(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
+        get_uint8(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
       if (!conn) {
         log_info(domain,"end cell (%s) dropped, unknown stream.",
                  stream_end_reason_to_string(reason));
@@ -2463,7 +2461,7 @@ append_cell_to_circuit_queue(circuit_t *circ, or_connection_t *orconn,
  *   ADDRESS                                   [length bytes]
  * Return the number of bytes added, or -1 on error */
 int
-append_address_to_payload(char *payload_out, const tor_addr_t *addr)
+append_address_to_payload(uint8_t *payload_out, const tor_addr_t *addr)
 {
   uint32_t a;
   switch (tor_addr_family(addr)) {
@@ -2488,13 +2486,13 @@ append_address_to_payload(char *payload_out, const tor_addr_t *addr)
  * encoded as by append_address_to_payload(), try to decode the address into
  * *<b>addr_out</b>.  Return the next byte in the payload after the address on
  * success, or NULL on failure. */
-const char *
-decode_address_from_payload(tor_addr_t *addr_out, const char *payload,
+const uint8_t *
+decode_address_from_payload(tor_addr_t *addr_out, const uint8_t *payload,
                             int payload_len)
 {
   if (payload_len < 2)
     return NULL;
-  if (payload_len < 2+(uint8_t)payload[1])
+  if (payload_len < 2+payload[1])
     return NULL;
 
   switch (payload[0]) {
@@ -2506,13 +2504,13 @@ decode_address_from_payload(tor_addr_t *addr_out, const char *payload,
   case RESOLVED_TYPE_IPV6:
     if (payload[1] != 16)
       return NULL;
-    tor_addr_from_ipv6_bytes(addr_out, payload+2);
+    tor_addr_from_ipv6_bytes(addr_out, (char*)(payload+2));
     break;
   default:
     tor_addr_make_unspec(addr_out);
     break;
   }
-  return payload + 2 + (uint8_t)payload[1];
+  return payload + 2 + payload[1];
 }
 
 /** Remove all the cells queued on <b>circ</b> for <b>orconn</b>. */
diff --git a/src/or/relay.h b/src/or/relay.h
index 08a1ffe789..8ccf0e2b30 100644
--- a/src/or/relay.h
+++ b/src/or/relay.h
@@ -18,8 +18,8 @@ extern uint64_t stats_n_relay_cells_delivered;
 int circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
                                cell_direction_t cell_direction);
 
-void relay_header_pack(char *dest, const relay_header_t *src);
-void relay_header_unpack(relay_header_t *dest, const char *src);
+void relay_header_pack(uint8_t *dest, const relay_header_t *src);
+void relay_header_unpack(relay_header_t *dest, const uint8_t *src);
 int relay_send_command_from_edge(streamid_t stream_id, circuit_t *circ,
                                uint8_t relay_command, const char *payload,
                                size_t payload_len, crypt_path_t *cpath_layer);
@@ -55,9 +55,9 @@ void assert_active_circuits_ok(or_connection_t *orconn);
 void make_circuit_inactive_on_conn(circuit_t *circ, or_connection_t *conn);
 void make_circuit_active_on_conn(circuit_t *circ, or_connection_t *conn);
 
-int append_address_to_payload(char *payload_out, const tor_addr_t *addr);
-const char *decode_address_from_payload(tor_addr_t *addr_out,
-                                        const char *payload,
+int append_address_to_payload(uint8_t *payload_out, const tor_addr_t *addr);
+const uint8_t *decode_address_from_payload(tor_addr_t *addr_out,
+                                        const uint8_t *payload,
                                         int payload_len);
 unsigned cell_ewma_get_tick(void);
 void cell_ewma_set_scale_factor(or_options_t *options,
diff --git a/src/or/rendclient.c b/src/or/rendclient.c
index 3e1083f694..ab968078e8 100644
--- a/src/or/rendclient.c
+++ b/src/or/rendclient.c
@@ -234,7 +234,7 @@ rend_client_rendcirc_has_opened(origin_circuit_t *circ)
  */
 int
 rend_client_introduction_acked(origin_circuit_t *circ,
-                               const char *request, size_t request_len)
+                               const uint8_t *request, size_t request_len)
 {
   origin_circuit_t *rendcirc;
   (void) request; // XXXX Use this.
@@ -583,7 +583,7 @@ rend_client_remove_intro_point(extend_info_t *failed_intro,
  * the circuit to C_REND_READY.
  */
 int
-rend_client_rendezvous_acked(origin_circuit_t *circ, const char *request,
+rend_client_rendezvous_acked(origin_circuit_t *circ, const uint8_t *request,
                              size_t request_len)
 {
   (void) request;
@@ -609,7 +609,7 @@ rend_client_rendezvous_acked(origin_circuit_t *circ, const char *request,
 
 /** Bob sent us a rendezvous cell; join the circuits. */
 int
-rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
+rend_client_receive_rendezvous(origin_circuit_t *circ, const uint8_t *request,
                                size_t request_len)
 {
   crypt_path_t *hop;
@@ -637,9 +637,10 @@ rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
   tor_assert(circ->build_state->pending_final_cpath);
   hop = circ->build_state->pending_final_cpath;
   tor_assert(hop->dh_handshake_state);
-  if (crypto_dh_compute_secret(LOG_PROTOCOL_WARN, hop->dh_handshake_state,
-                               request, DH_KEY_LEN, keys,
-                               DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
+  if (crypto_dh_compute_secret(LOG_PROTOCOL_WARN,
+                               hop->dh_handshake_state, (char*)request,
+                               DH_KEY_LEN,
+                               keys, DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
     log_warn(LD_GENERAL, "Couldn't complete DH handshake.");
     goto err;
   }
diff --git a/src/or/rendclient.h b/src/or/rendclient.h
index 842fe0b8ce..79d37b2a58 100644
--- a/src/or/rendclient.h
+++ b/src/or/rendclient.h
@@ -14,14 +14,17 @@
 
 void rend_client_introcirc_has_opened(origin_circuit_t *circ);
 void rend_client_rendcirc_has_opened(origin_circuit_t *circ);
-int rend_client_introduction_acked(origin_circuit_t *circ, const char *request,
+int rend_client_introduction_acked(origin_circuit_t *circ,
+                                   const uint8_t *request,
                                    size_t request_len);
 void rend_client_refetch_v2_renddesc(const rend_data_t *rend_query);
 int rend_client_remove_intro_point(extend_info_t *failed_intro,
                                    const rend_data_t *rend_query);
-int rend_client_rendezvous_acked(origin_circuit_t *circ, const char *request,
+int rend_client_rendezvous_acked(origin_circuit_t *circ,
+                                 const uint8_t *request,
                                  size_t request_len);
-int rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
+int rend_client_receive_rendezvous(origin_circuit_t *circ,
+                                   const uint8_t *request,
                                    size_t request_len);
 void rend_client_desc_trynow(const char *query);
 
diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c
index ec6680b1e6..85d97e0253 100644
--- a/src/or/rendcommon.c
+++ b/src/or/rendcommon.c
@@ -1358,7 +1358,7 @@ rend_cache_store_v2_desc_as_client(const char *desc,
 void
 rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint,
                         int command, size_t length,
-                        const char *payload)
+                        const uint8_t *payload)
 {
   or_circuit_t *or_circ = NULL;
   origin_circuit_t *origin_circ = NULL;
diff --git a/src/or/rendcommon.h b/src/or/rendcommon.h
index 00705022a2..d3313faf5a 100644
--- a/src/or/rendcommon.h
+++ b/src/or/rendcommon.h
@@ -22,7 +22,8 @@ rend_data_free(rend_data_t *data)
 int rend_cmp_service_ids(const char *one, const char *two);
 
 void rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint,
-                             int command, size_t length, const char *payload);
+                             int command, size_t length,
+                             const uint8_t *payload);
 
 void rend_service_descriptor_free(rend_service_descriptor_t *desc);
 rend_service_descriptor_t *rend_parse_service_descriptor(const char *str,
diff --git a/src/or/rendmid.c b/src/or/rendmid.c
index d392f8e53a..bc36a4e117 100644
--- a/src/or/rendmid.c
+++ b/src/or/rendmid.c
@@ -18,7 +18,7 @@
  * setting the circuit's purpose and service pk digest.
  */
 int
-rend_mid_establish_intro(or_circuit_t *circ, const char *request,
+rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
                          size_t request_len)
 {
   crypto_pk_env_t *pk = NULL;
@@ -48,7 +48,7 @@ rend_mid_establish_intro(or_circuit_t *circ, const char *request,
   /* Next asn1len bytes: asn1-encoded key. */
   if (request_len < 2+DIGEST_LEN+asn1len)
     goto truncated;
-  pk = crypto_pk_asn1_decode(request+2, asn1len);
+  pk = crypto_pk_asn1_decode((char*)(request+2), asn1len);
   if (!pk) {
     reason = END_CIRC_REASON_TORPROTOCOL;
     log_warn(LD_PROTOCOL, "Couldn't decode public key.");
@@ -69,8 +69,8 @@ rend_mid_establish_intro(or_circuit_t *circ, const char *request,
   }
   /* Rest of body: signature of previous data */
   note_crypto_pk_op(REND_MID);
-  if (crypto_pk_public_checksig_digest(pk, request, 2+asn1len+DIGEST_LEN,
-                                       request+2+DIGEST_LEN+asn1len,
+  if (crypto_pk_public_checksig_digest(pk, (char*)request, 2+asn1len+DIGEST_LEN,
+                                       (char*)(request+2+DIGEST_LEN+asn1len),
                                        request_len-(2+DIGEST_LEN+asn1len))<0) {
     log_warn(LD_PROTOCOL,
              "Incorrect signature on ESTABLISH_INTRO cell; rejecting.");
@@ -130,7 +130,7 @@ rend_mid_establish_intro(or_circuit_t *circ, const char *request,
  * INTRODUCE2 cell.
  */
 int
-rend_mid_introduce(or_circuit_t *circ, const char *request, size_t request_len)
+rend_mid_introduce(or_circuit_t *circ, const uint8_t *request, size_t request_len)
 {
   or_circuit_t *intro_circ;
   char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
@@ -159,10 +159,10 @@ rend_mid_introduce(or_circuit_t *circ, const char *request, size_t request_len)
   }
 
   base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
-                request, REND_SERVICE_ID_LEN);
+                (char*)request, REND_SERVICE_ID_LEN);
 
   /* The first 20 bytes are all we look at: they have a hash of Bob's PK. */
-  intro_circ = circuit_get_intro_point(request);
+  intro_circ = circuit_get_intro_point((char*)request);
   if (!intro_circ) {
     log_info(LD_REND,
              "No intro circ found for INTRODUCE1 cell (%s) from circuit %d; "
@@ -180,7 +180,7 @@ rend_mid_introduce(or_circuit_t *circ, const char *request, size_t request_len)
   /* Great.  Now we just relay the cell down the circuit. */
   if (relay_send_command_from_edge(0, TO_CIRCUIT(intro_circ),
                                    RELAY_COMMAND_INTRODUCE2,
-                                   request, request_len, NULL)) {
+                                   (char*)request, request_len, NULL)) {
     log_warn(LD_GENERAL,
              "Unable to send INTRODUCE2 cell to Tor client.");
     goto err;
@@ -212,7 +212,7 @@ rend_mid_introduce(or_circuit_t *circ, const char *request, size_t request_len)
  * rendezvous cookie.
  */
 int
-rend_mid_establish_rendezvous(or_circuit_t *circ, const char *request,
+rend_mid_establish_rendezvous(or_circuit_t *circ, const uint8_t *request,
                               size_t request_len)
 {
   char hexid[9];
@@ -232,7 +232,7 @@ rend_mid_establish_rendezvous(or_circuit_t *circ, const char *request,
     goto err;
   }
 
-  if (circuit_get_rendezvous(request)) {
+  if (circuit_get_rendezvous((char*)request)) {
     log_warn(LD_PROTOCOL,
              "Duplicate rendezvous cookie in ESTABLISH_RENDEZVOUS.");
     goto err;
@@ -250,7 +250,7 @@ rend_mid_establish_rendezvous(or_circuit_t *circ, const char *request,
   circ->_base.purpose = CIRCUIT_PURPOSE_REND_POINT_WAITING;
   memcpy(circ->rend_token, request, REND_COOKIE_LEN);
 
-  base16_encode(hexid,9,request,4);
+  base16_encode(hexid,9,(char*)request,4);
 
   log_info(LD_REND,
            "Established rendezvous point on circuit %d for cookie %s",
@@ -267,13 +267,13 @@ rend_mid_establish_rendezvous(or_circuit_t *circ, const char *request,
  * connecting the two circuits.
  */
 int
-rend_mid_rendezvous(or_circuit_t *circ, const char *request,
+rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request,
                     size_t request_len)
 {
   or_circuit_t *rend_circ;
   char hexid[9];
   int reason = END_CIRC_REASON_INTERNAL;
-  base16_encode(hexid,9,request,request_len<4?request_len:4);
+  base16_encode(hexid,9,(char*)request,request_len<4?request_len:4);
 
   if (request_len>=4) {
     log_info(LD_REND,
@@ -297,7 +297,7 @@ rend_mid_rendezvous(or_circuit_t *circ, const char *request,
     goto err;
   }
 
-  rend_circ = circuit_get_rendezvous(request);
+  rend_circ = circuit_get_rendezvous((char*)request);
   if (!rend_circ) {
     log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
          "Rejecting RENDEZVOUS1 cell with unrecognized rendezvous cookie %s.",
@@ -309,7 +309,7 @@ rend_mid_rendezvous(or_circuit_t *circ, const char *request,
   /* Send the RENDEZVOUS2 cell to Alice. */
   if (relay_send_command_from_edge(0, TO_CIRCUIT(rend_circ),
                                    RELAY_COMMAND_RENDEZVOUS2,
-                                   request+REND_COOKIE_LEN,
+                                   (char*)(request+REND_COOKIE_LEN),
                                    request_len-REND_COOKIE_LEN, NULL)) {
     log_warn(LD_GENERAL,
              "Unable to send RENDEZVOUS2 cell to client on circuit %d.",
diff --git a/src/or/rendmid.h b/src/or/rendmid.h
index 4d08d4c8b9..f06dd3d85e 100644
--- a/src/or/rendmid.h
+++ b/src/or/rendmid.h
@@ -12,13 +12,13 @@
 #ifndef _TOR_RENDMID_H
 #define _TOR_RENDMID_H
 
-int rend_mid_establish_intro(or_circuit_t *circ, const char *request,
+int rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
                              size_t request_len);
-int rend_mid_introduce(or_circuit_t *circ, const char *request,
+int rend_mid_introduce(or_circuit_t *circ, const uint8_t *request,
                        size_t request_len);
-int rend_mid_establish_rendezvous(or_circuit_t *circ, const char *request,
+int rend_mid_establish_rendezvous(or_circuit_t *circ, const uint8_t *request,
                                   size_t request_len);
-int rend_mid_rendezvous(or_circuit_t *circ, const char *request,
+int rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request,
                         size_t request_len);
 
 #endif
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index b0d791529b..f06c98337a 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -849,7 +849,7 @@ clean_accepted_intros(rend_service_t *service, time_t now)
  * rendezvous point.
  */
 int
-rend_service_introduce(origin_circuit_t *circuit, const char *request,
+rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
                        size_t request_len)
 {
   char *ptr, *r_cookie;
@@ -913,7 +913,7 @@ rend_service_introduce(origin_circuit_t *circuit, const char *request,
   crypto_pk_get_digest(intro_key, intro_key_digest);
   if (memcmp(intro_key_digest, request, DIGEST_LEN)) {
     base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
-                  request, REND_SERVICE_ID_LEN);
+                  (char*)request, REND_SERVICE_ID_LEN);
     log_warn(LD_REND, "Got an INTRODUCE2 cell for the wrong service (%s).",
              escaped(serviceid));
     return -1;
@@ -928,7 +928,7 @@ rend_service_introduce(origin_circuit_t *circuit, const char *request,
   /* Next N bytes is encrypted with service key */
   note_crypto_pk_op(REND_SERVER);
   r = crypto_pk_private_hybrid_decrypt(
-       intro_key,buf,request+DIGEST_LEN,request_len-DIGEST_LEN,
+       intro_key,buf,(char*)(request+DIGEST_LEN),request_len-DIGEST_LEN,
        PK_PKCS1_OAEP_PADDING,1);
   if (r<0) {
     log_warn(LD_PROTOCOL, "Couldn't decrypt INTRODUCE2 cell.");
@@ -1392,7 +1392,8 @@ rend_service_intro_has_opened(origin_circuit_t *circuit)
  * live introduction point, and note that the service descriptor is
  * now out-of-date.*/
 int
-rend_service_intro_established(origin_circuit_t *circuit, const char *request,
+rend_service_intro_established(origin_circuit_t *circuit,
+                               const uint8_t *request,
                                size_t request_len)
 {
   rend_service_t *service;
diff --git a/src/or/rendservice.h b/src/or/rendservice.h
index 1767714c60..722cec1561 100644
--- a/src/or/rendservice.h
+++ b/src/or/rendservice.h
@@ -22,10 +22,10 @@ void rend_consider_descriptor_republication(void);
 
 void rend_service_intro_has_opened(origin_circuit_t *circuit);
 int rend_service_intro_established(origin_circuit_t *circuit,
-                                   const char *request,
+                                   const uint8_t *request,
                                    size_t request_len);
 void rend_service_rendezvous_has_opened(origin_circuit_t *circuit);
-int rend_service_introduce(origin_circuit_t *circuit, const char *request,
+int rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
                            size_t request_len);
 void rend_service_relaunch_rendezvous(origin_circuit_t *oldcirc);
 int rend_service_set_connection_addr_port(edge_connection_t *conn,