Simplify the crypto_cipher_t interface and structure

Previously, the IV and key were stored in the structure, even though
they mostly weren't needed.  The only purpose they had was to
support a seldom-used API where you could pass NULL when creating
a cipher in order to get a random key/IV, and then pull that key/IV
back out.

This saves 32 bytes per AES instance, and makes it easier to support
different key lengths.

2 files changed, 16 insertions, 9 deletions

diff --git a/src/test/bench.c b/src/test/bench.c
index f373019b95..30984fda70 100644
--- a/src/test/bench.c
+++ b/src/test/bench.c
@@ -90,7 +90,9 @@ bench_aes(void)
   uint64_t start, end;
   const int bytes_per_iter = (1<<24);
   reset_perftime();
-  c = crypto_cipher_new(NULL);
+  char key[CIPHER_KEY_LEN];
+  crypto_rand(key, sizeof(key));
+  c = crypto_cipher_new(key);
 
   for (len = 1; len <= 8192; len *= 2) {
     int iters = bytes_per_iter / len;
@@ -328,8 +330,9 @@ bench_cell_aes(void)
   char *b = tor_malloc(len+max_misalign);
   crypto_cipher_t *c;
   int i, misalign;
-
-  c = crypto_cipher_new(NULL);
+  char key[CIPHER_KEY_LEN];
+  crypto_rand(key, sizeof(key));
+  c = crypto_cipher_new(key);
 
   reset_perftime();
   for (misalign = 0; misalign <= max_misalign; ++misalign) {
@@ -501,8 +504,11 @@ bench_cell_ops(void)
   or_circ->base_.purpose = CIRCUIT_PURPOSE_OR;
 
   /* Initialize crypto */
-  or_circ->p_crypto = crypto_cipher_new(NULL);
-  or_circ->n_crypto = crypto_cipher_new(NULL);
+  char key1[CIPHER_KEY_LEN], key2[CIPHER_KEY_LEN];
+  crypto_rand(key1, sizeof(key1));
+  crypto_rand(key2, sizeof(key2));
+  or_circ->p_crypto = crypto_cipher_new(key1);
+  or_circ->n_crypto = crypto_cipher_new(key2);
   or_circ->p_digest = crypto_digest_new();
   or_circ->n_digest = crypto_digest_new();
 
diff --git a/src/test/test_crypto.c b/src/test/test_crypto.c
index d83b93be58..6586c06209 100644
--- a/src/test/test_crypto.c
+++ b/src/test/test_crypto.c
@@ -371,7 +371,7 @@ test_crypto_aes(void *arg)
   crypto_cipher_t *env1 = NULL, *env2 = NULL;
   int i, j;
   char *mem_op_hex_tmp=NULL;
-
+  char key[CIPHER_KEY_LEN];
   int use_evp = !strcmp(arg,"evp");
   evaluate_evp_for_aes(use_evp);
   evaluate_ctr_for_aes();
@@ -387,9 +387,10 @@ test_crypto_aes(void *arg)
 
   memset(data2, 0, 1024);
   memset(data3, 0, 1024);
-  env1 = crypto_cipher_new(NULL);
+  crypto_rand(key, sizeof(key));
+  env1 = crypto_cipher_new(key);
   tt_ptr_op(env1, OP_NE, NULL);
-  env2 = crypto_cipher_new(crypto_cipher_get_key(env1));
+  env2 = crypto_cipher_new(key);
   tt_ptr_op(env2, OP_NE, NULL);
 
   /* Try encrypting 512 chars. */
@@ -420,7 +421,7 @@ test_crypto_aes(void *arg)
   env2 = NULL;
 
   memset(data3, 0, 1024);
-  env2 = crypto_cipher_new(crypto_cipher_get_key(env1));
+  env2 = crypto_cipher_new(key);
   tt_ptr_op(env2, OP_NE, NULL);
   for (j = 0; j < 1024-16; j += 17) {
     crypto_cipher_encrypt(env2, data3+j, data1+j, 17);