[tor-commits] [tor/master] Add a BASE32_DIGEST_LEN define

[nickm at torproject.org]

commit 5dea4b565f7295bae8c48790cc7d00a6e237fff0
Author: David Goulet <dgoulet at torproject.org>
Date:   Tue Sep 19 12:33:04 2017 -0400

    Add a BASE32_DIGEST_LEN define
    
    Use this value instead of hardcoded values of 32 everywhere. This also
    addresses the use of REND_DESC_ID_V2_LEN_BASE32 in
    hs_lookup_last_hid_serv_request() for the HSDir encoded identity digest length
    which is accurate but semantically wrong.
    
    Fixes #23305.
    
    Signed-off-by: David Goulet <dgoulet at torproject.org>
---
 src/common/crypto.h | 3 +++
 src/or/hs_common.c  | 2 +-
 src/or/or.h         | 6 +++---
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/common/crypto.h b/src/common/crypto.h
index 6f5e13a8d..f9aeeee2c 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -73,6 +73,9 @@
 /** Length of our DH keys. */
 #define DH_BYTES (1024/8)
 
+/** Length of a sha1 message digest when encoded in base32 with trailing =
+ * signs removed. */
+#define BASE32_DIGEST_LEN 32
 /** Length of a sha1 message digest when encoded in base64 with trailing =
  * signs removed. */
 #define BASE64_DIGEST_LEN 27
diff --git a/src/or/hs_common.c b/src/or/hs_common.c
index 2cdfe57cd..42c15c80d 100644
--- a/src/or/hs_common.c
+++ b/src/or/hs_common.c
@@ -1453,7 +1453,7 @@ hs_lookup_last_hid_serv_request(routerstatus_t *hs_dir,
                                 const char *req_key_str,
                                 time_t now, int set)
 {
-  char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+  char hsdir_id_base32[BASE32_DIGEST_LEN + 1];
   char *hsdir_desc_comb_id = NULL;
   time_t *last_request_ptr;
   strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
diff --git a/src/or/or.h b/src/or/or.h
index 4fc0e788a..c23054c3b 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -747,15 +747,15 @@ typedef enum {
 #define REND_NUMBER_OF_CONSECUTIVE_REPLICAS 3
 
 /** Length of v2 descriptor ID (32 base32 chars = 160 bits). */
-#define REND_DESC_ID_V2_LEN_BASE32 32
+#define REND_DESC_ID_V2_LEN_BASE32 BASE32_DIGEST_LEN
 
 /** Length of the base32-encoded secret ID part of versioned hidden service
  * descriptors. */
-#define REND_SECRET_ID_PART_LEN_BASE32 32
+#define REND_SECRET_ID_PART_LEN_BASE32 BASE32_DIGEST_LEN
 
 /** Length of the base32-encoded hash of an introduction point's
  * identity key. */
-#define REND_INTRO_POINT_ID_LEN_BASE32 32
+#define REND_INTRO_POINT_ID_LEN_BASE32 BASE32_DIGEST_LEN
 
 /** Length of the descriptor cookie that is used for client authorization
  * to hidden services. */