Restrict the meaning of digests_t to sha1+sha256.

This saves CPU and RAM when handling consensuses and x509 certs.

Closes ticket 17795; bug not in any released tor.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/common/crypto.h b/src/common/crypto.h
index fa2ed610c7..73b94b77db 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -100,8 +100,10 @@ typedef enum {
   DIGEST_SHA3_512 = 4,
 } digest_algorithm_t;
 #define  N_DIGEST_ALGORITHMS (DIGEST_SHA3_512+1)
+#define  N_COMMON_DIGEST_ALGORITHMS (DIGEST_SHA256+1)
 
-/** A set of all the digests we know how to compute, taken on a single
+
+/** A set of all the digests we commonly compute, taken on a single
  * string.  Any digests that are shorter than 512 bits are right-padded
  * with 0 bits.
  *
@@ -110,7 +112,7 @@ typedef enum {
  * once.
  **/
 typedef struct {
-  char d[N_DIGEST_ALGORITHMS][DIGEST512_LEN];
+  char d[N_COMMON_DIGEST_ALGORITHMS][DIGEST256_LEN];
 } digests_t;
 
 typedef struct crypto_pk_t crypto_pk_t;