From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 8 Dec 2019 13:13:34 +0000 (+0000)
Subject: dh: move write_mpbin in to dh.c
X-Git-Tag: v0.6.0~21
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=secnet.git;a=commitdiff_plain;h=ed2b0c2a90657c4f5f1e38ec5bca9d05aef1864a

dh: move write_mpbin in to dh.c

This function has a hazardous API.  In fact, the one call site misuses
it, as we shall see in a moment.

If we wanted a thing like this with a less hazardous API we probably
wouldn't base it on mpz_get_str nowadays.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/dh.c b/dh.c
index 0616a43..f94665c 100644
--- a/dh.c
+++ b/dh.c
@@ -61,6 +61,16 @@ static string_t dh_makepublic(void *sst, uint8_t *secret, int32_t secretlen)
     return r;
 }
 
+static int32_t write_mpbin(MP_INT *a, uint8_t *buffer,
+				     int32_t buflen)
+{
+    char *hb = write_mpstring(a);
+    int32_t len;
+    hex_decode(buffer, buflen, &len, hb, True);
+    free(hb);
+    return len;
+}
+
 static dh_makeshared_fn dh_makeshared;
 static void dh_makeshared(void *sst, uint8_t *secret, int32_t secretlen,
 			  cstring_t rempublic, uint8_t *sharedsecret,
diff --git a/util.c b/util.c
index cc2f9fa..3e8d56e 100644
--- a/util.c
+++ b/util.c
@@ -183,15 +183,6 @@ char *write_mpstring(MP_INT *a)
     return buff;
 }
 
-int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen)
-{
-    char *hb = write_mpstring(a);
-    int32_t len;
-    hex_decode(buffer, buflen, &len, hb, True);
-    free(hb);
-    return len;
-}
-
 #define DEFINE_SETFDFLAG(fn,FL,FLAG)					\
 void fn(int fd) {							\
     int r=fcntl(fd, F_GET##FL);						\
diff --git a/util.h b/util.h
index 3929abe..f28a00d 100644
--- a/util.h
+++ b/util.h
@@ -148,9 +148,6 @@ extern void read_mpbin(MP_INT *a, uint8_t *bin, int binsize);
 extern char *write_mpstring(MP_INT *a);
   /* Convert a MP_INT into a hex string */
 
-extern int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen);
-  /* Convert a MP_INT into a buffer; return length; truncate if necessary */
-
 extern struct log_if *init_log(list_t *loglist);
 
 extern void send_nak(const struct comm_addr *dest, uint32_t our_index,