receive-pack: use find_commit_header() in check_nonce()

Use the public function find_commit_header() and remove find_header(),
as it becomes unused.  This is safe and appropriate because we pass the
NUL-terminated payload buffer to check_nonce() instead of its start and
length.  The underlying strbuf push_cert cannot contain NULs, as it is
built using strbuf_addstr(), only.

We no longer need to call strlen(), as find_commit_header() returns the
length of nonce already.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 8ebb3a872f1ca65135bed5b85e177ef25ac1a22e..db656074857e765c8b5d5c91ab1b872de0bad66d 100644 (file)
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -593,21 +593,6 @@ static char *prepare_push_cert_nonce(const char *path, timestamp_t stamp)
        return strbuf_detach(&buf, NULL);
 }
 
-static char *find_header(const char *msg, size_t len, const char *key,
-                        const char **next_line)
-{
-       size_t out_len;
-       const char *val = find_header_mem(msg, len, key, &out_len);
-
-       if (!val)
-               return NULL;
-
-       if (next_line)
-               *next_line = val + out_len + 1;
-
-       return xmemdupz(val, out_len);
-}
-
 /*
  * Return zero if a and b are equal up to n bytes and nonzero if they are not.
  * This operation is guaranteed to run in constant time to avoid leaking data.
@@ -622,13 +607,14 @@ static int constant_memequal(const char *a, const char *b, size_t n)
        return res;
 }
 
-static const char *check_nonce(const char *buf, size_t len)
+static const char *check_nonce(const char *buf)
 {
-       char *nonce = find_header(buf, len, "nonce", NULL);
+       size_t noncelen;
+       const char *found = find_commit_header(buf, "nonce", &noncelen);
+       char *nonce = found ? xmemdupz(found, noncelen) : NULL;
        timestamp_t stamp, ostamp;
        char *bohmac, *expect = NULL;
        const char *retval = NONCE_BAD;
-       size_t noncelen;
 
        if (!nonce) {
                retval = NONCE_MISSING;
@@ -670,7 +656,6 @@ static const char *check_nonce(const char *buf, size_t len)
                goto leave;
        }
 
-       noncelen = strlen(nonce);
        expect = prepare_push_cert_nonce(service_dir, stamp);
        if (noncelen != strlen(expect)) {
                /* This is not even the right size. */
@@ -732,9 +717,8 @@ static int check_cert_push_options(const struct string_list *push_options)
                buf = option + optionlen + 1;
                options_seen++;
                if (options_seen > push_options->nr
-                   || strncmp(push_options->items[options_seen - 1].string,
-                              option, optionlen)
-                   || push_options->items[options_seen - 1].string[optionlen])
+                   || xstrncmpz(push_options->items[options_seen - 1].string,
+                                option, optionlen))
                        return 0;
        }
 
@@ -767,7 +751,7 @@ static void prepare_push_cert_sha1(struct child_process *proc)
                check_signature(&sigcheck, push_cert.buf + bogs,
                                push_cert.len - bogs);
 
-               nonce_status = check_nonce(push_cert.buf, bogs);
+               nonce_status = check_nonce(sigcheck.payload);
        }
        if (!is_null_oid(&push_cert_oid)) {
                strvec_pushf(&proc->env, "GIT_PUSH_CERT=%s",