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authorDavid Goulet <dgoulet@torproject.org>2022-03-15 14:00:00 -0400
committerDavid Goulet <dgoulet@torproject.org>2022-03-15 14:00:00 -0400
commitcf93d352095d252baf4cba07e51cb9a84ef8d9de (patch)
tree1c9d28477c84da27efe7bc4f3ec5de16a64e8aff
parent9841e7173d7bad5aca0ceb529d31000e8a852089 (diff)
downloadtor-cf93d352095d252baf4cba07e51cb9a84ef8d9de.tar.gz
tor-cf93d352095d252baf4cba07e51cb9a84ef8d9de.zip
crypto: Clarifying comment for the random hostname calculation
Closes #40520 Signed-off-by: David Goulet <dgoulet@torproject.org>
-rw-r--r--src/lib/crypt_ops/crypto_rand.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/src/lib/crypt_ops/crypto_rand.c b/src/lib/crypt_ops/crypto_rand.c
index 5bf3a65b3b..f39ee6c24f 100644
--- a/src/lib/crypt_ops/crypto_rand.c
+++ b/src/lib/crypt_ops/crypto_rand.c
@@ -568,6 +568,8 @@ crypto_random_hostname(int min_rand_len, int max_rand_len, const char *prefix,
prefixlen = strlen(prefix);
resultlen = prefixlen + strlen(suffix) + randlen + 16;
+ /* (x+(n-1))/n is an idiom for dividing x by n, rounding up to the nearest
+ * integer and thus why this construction. */
rand_bytes_len = ((randlen*5)+7)/8;
if (rand_bytes_len % 5)
rand_bytes_len += 5 - (rand_bytes_len%5);