From cb75519bbf6d89ddaf6a6bb40a01a2dba09ad530 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 22 Feb 2013 12:53:45 -0500
Subject: Refactor dirobj signature generation

Now we can compute the hash and signature of a dirobj before
concatenating the smartlist, and we don't need to play silly games
with sigbuf and realloc any more.
---
 src/common/crypto.c | 23 +++++++++++++++++++++++
 src/common/crypto.h |  4 ++++
 2 files changed, 27 insertions(+)

(limited to 'src/common')

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 22d57c7c8..aeef1e3c6 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -1631,6 +1631,29 @@ crypto_digest_assign(crypto_digest_t *into,
   memcpy(into,from,sizeof(crypto_digest_t));
 }
 
+
+/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest
+ * at <b>digest_out</b> to the hash of the concatenation of those strings,
+ * plus the optional string <b>append</b>, computed with the algorithm
+ * <b>alg</b>. */
+void
+crypto_digest_smartlist(char *digest_out, size_t len_out,
+                        const smartlist_t *lst, const char *append,
+                        digest_algorithm_t alg)
+{
+  crypto_digest_t *d;
+  if (alg == DIGEST_SHA1)
+    d = crypto_digest_new();
+  else
+    d = crypto_digest256_new(alg);
+  SMARTLIST_FOREACH(lst, const char *, cp,
+                    crypto_digest_add_bytes(d, cp, strlen(cp)));
+  if (append)
+    crypto_digest_add_bytes(d, append, strlen(append));
+  crypto_digest_get_digest(d, digest_out, len_out);
+  crypto_digest_free(d);
+}
+
 /** Compute the HMAC-SHA-1 of the <b>msg_len</b> bytes in <b>msg</b>, using
  * the <b>key</b> of length <b>key_len</b>.  Store the DIGEST_LEN-byte result
  * in <b>hmac_out</b>.
diff --git a/src/common/crypto.h b/src/common/crypto.h
index 12fcfae27..e8f6eace1 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -206,6 +206,10 @@ int crypto_digest(char *digest, const char *m, size_t len);
 int crypto_digest256(char *digest, const char *m, size_t len,
                      digest_algorithm_t algorithm);
 int crypto_digest_all(digests_t *ds_out, const char *m, size_t len);
+struct smartlist_t;
+void crypto_digest_smartlist(char *digest_out, size_t len_out,
+                             const struct smartlist_t *lst, const char *append,
+                             digest_algorithm_t alg);
 const char *crypto_digest_algorithm_get_name(digest_algorithm_t alg);
 int crypto_digest_algorithm_parse_name(const char *name);
 crypto_digest_t *crypto_digest_new(void);
-- 
cgit v1.2.3