[tor-commits] [tor/master] Allow checkpointing of non-sha1 digests.

[nickm at torproject.org]

commit a34fc1dad2ba2be5af4c04a9c46c9ef5e248c81f
Author: Nick Mathewson <nickm at torproject.org>
Date:   Fri Feb 16 09:25:50 2018 -0500

    Allow checkpointing of non-sha1 digests.
    
    This is necessary because apparently v3 rendezvous cpath hops use
    sha3, which I had forgotten.
    
    Bugfix on master; bug not in any released Tor.
---
 src/common/crypto.c | 8 ++------
 src/common/crypto.h | 2 +-
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 69faa0f63..ade8b0191 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -1163,10 +1163,7 @@ void
 crypto_digest_checkpoint(crypto_digest_checkpoint_t *checkpoint,
                          const crypto_digest_t *digest)
 {
-  tor_assert(digest->algorithm == DIGEST_SHA1);
-  /* The optimizer should turn this into a constant... */
-  const size_t bytes = crypto_digest_alloc_bytes(DIGEST_SHA1);
-  /* ... and remove this assertion entirely. */
+  const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm);
   tor_assert(bytes <= sizeof(checkpoint->mem));
   memcpy(checkpoint->mem, digest, bytes);
 }
@@ -1178,8 +1175,7 @@ void
 crypto_digest_restore(crypto_digest_t *digest,
                       const crypto_digest_checkpoint_t *checkpoint)
 {
-  tor_assert(digest->algorithm == DIGEST_SHA1);
-  const size_t bytes = crypto_digest_alloc_bytes(DIGEST_SHA1);
+  const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm);
   memcpy(digest, checkpoint->mem, bytes);
 }
 
diff --git a/src/common/crypto.h b/src/common/crypto.h
index f8a392dff..792533642 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -90,7 +90,7 @@ typedef struct crypto_digest_t crypto_digest_t;
 typedef struct crypto_xof_t crypto_xof_t;
 typedef struct crypto_dh_t crypto_dh_t;
 
-#define DIGEST_CHECKPOINT_BYTES (SIZEOF_VOID_P + SIZEOF_SHA_CTX)
+#define DIGEST_CHECKPOINT_BYTES (SIZEOF_VOID_P + 256)
 /** Structure used to temporarily save the a digest object. Only implemented
  * for SHA1 digest for now. */
 typedef struct crypto_digest_checkpoint_t {