# HG changeset patch
# User Mikael Berthe <mikael@lilotux.net>
# Date 1444663159 -7200
# Node ID 170597f5365bd5e62168b151511796f7a63df8b6
# Parent  ff18feb75a6d7e0801cb8322fc150b38caee812c
Use more generic routines to convert fingerprints to/from hexadecimal
This is a first step towards non-MD5 fingerprints; now we need Loudmouth
support...

diff -r ff18feb75a6d -r 170597f5365b mcabber/mcabber/utils.c
--- a/mcabber/mcabber/utils.c	Mon Oct 12 11:41:34 2015 +0200
+++ b/mcabber/mcabber/utils.c	Mon Oct 12 17:19:19 2015 +0200
@@ -155,36 +155,48 @@
   return g_strdup(fname);
 }
 
-void fingerprint_to_hex(const char *fprstr, char hex[48])
+//  fingerprint_to_hex(fprstr, hex, fpr_len)
+// Convert the binary fingerprint fprstr (which is fpr_len bytes long)
+// to a NULL-terminated hexadecimal string hex.
+// The destination array hex should have been preallocated by the caller,
+// and should be big enough (i.e. >= 3*fpr_len bytes).
+void fingerprint_to_hex(const char *fprstr, char *hex, size_t fpr_len)
 {
-  int i;
+  unsigned int i;
   const unsigned char *fpr = (const unsigned char *)fprstr;
   char *p;
 
   hex[0] = 0;
-  if (!fpr) return;
+  if (!fpr || fpr_len < 16) return;
 
-  for (p = hex, i = 0; i < 15; i++, p+=3)
+  for (p = hex, i = 0; i < fpr_len - 1; i++, p+=3)
     g_snprintf(p, 4, "%02X:", fpr[i]);
   g_snprintf(p, 3, "%02X", fpr[i]);
 }
 
-gboolean hex_to_fingerprint(const char *hex, char fpr[17])
+//  hex_to_fingerprint(hex, fpr, fpr_len)
+// Convert the hexadecimal fingerprint hex to a byte array fpr[].
+// The fpr array should have been preallocated  with a size >= fpr_len.
+gboolean hex_to_fingerprint(const char *hex, char *fpr, size_t fpr_len)
 {
-  int i;
+  unsigned int i;
   const char *p;
 
+  if (fpr_len < 16) return FALSE;
+
   fpr[0] = 0;
-  if (strlen(hex) != 47)
+
+  if (strlen(hex) != fpr_len*3 - 1)
     return FALSE;
-  for (i = 0, p = hex; *p && *(p+1); i++, p += 3) {
-    if (*(p+2) && (*(p+2) != ':')) {
-      fpr[i] = 0;
+
+  for (i = 0, p = hex; i < fpr_len && *p && *(p+1); i++, p += 3) {
+    // Check we have two hex digits followed by a colon (or end of string)
+    if (!isxdigit(*p) || !isxdigit(*(p+1)))
       return FALSE;
-    }
+    if (*(p+2) && (*(p+2) != ':'))
+      return FALSE;
     fpr[i] = (char)g_ascii_strtoull(p, NULL, 16);
   }
-  fpr[i] = 0;
   return TRUE;
 }
 
diff -r ff18feb75a6d -r 170597f5365b mcabber/mcabber/utils.h
--- a/mcabber/mcabber/utils.h	Mon Oct 12 11:41:34 2015 +0200
+++ b/mcabber/mcabber/utils.h	Mon Oct 12 17:19:19 2015 +0200
@@ -21,8 +21,8 @@
                   const char *resource);
 gboolean jid_equal(const char *jid1, const char *jid2);
 
-void fingerprint_to_hex(const char *fpr, char hex[48]);
-gboolean hex_to_fingerprint(const char *hex, char fpr[17]);
+void fingerprint_to_hex(const char *fpr,     char *hex, size_t fpr_len);
+gboolean hex_to_fingerprint(const char *hex, char *fpr, size_t fpr_len);
 
 void ut_init_debug(void);
 void ut_write_log(unsigned int flag, const char *data);
diff -r ff18feb75a6d -r 170597f5365b mcabber/mcabber/xmpp.c
--- a/mcabber/mcabber/xmpp.c	Mon Oct 12 11:41:34 2015 +0200
+++ b/mcabber/mcabber/xmpp.c	Mon Oct 12 17:19:19 2015 +0200
@@ -44,6 +44,8 @@
 
 #define RECONNECTION_TIMEOUT    60L
 
+#define FINGERPRINT_LENGTH      16  //  Currently Loudmouth only supports MD5
+
 LmConnection* lconnection = NULL;
 static guint AutoConnection;
 
@@ -714,8 +716,8 @@
                  "Certificate hostname does not match expected hostname!");
     break;
   case LM_SSL_STATUS_CERT_FINGERPRINT_MISMATCH: {
-      char fpr[49] = {0};
-      fingerprint_to_hex(lm_ssl_get_fingerprint(ssl), fpr);
+      char fpr[3*FINGERPRINT_LENGTH] = {0};
+      fingerprint_to_hex(lm_ssl_get_fingerprint(ssl), fpr, FINGERPRINT_LENGTH);
       scr_LogPrint(LPRINT_LOGNORM,
                 "Certificate fingerprint does not match expected fingerprint!");
       scr_LogPrint(LPRINT_LOGNORM, "Remote fingerprint: %s", fpr);
@@ -743,8 +745,8 @@
 {
   LmSSL *lssl;
   if ((lssl = lm_connection_get_ssl(connection)) != NULL) {
-    char fpr[49] = {0};
-    fingerprint_to_hex(lm_ssl_get_fingerprint(lssl), fpr);
+    char fpr[3*FINGERPRINT_LENGTH] = {0};
+    fingerprint_to_hex(lm_ssl_get_fingerprint(lssl), fpr, FINGERPRINT_LENGTH);
     scr_LogPrint(LPRINT_LOGNORM, "Connection established.\n"
                  "Remote fingerprint: %s", fpr);
   }
@@ -1738,7 +1740,7 @@
 {
   const char *userjid, *password, *resource, *servername, *ssl_fpr;
   char *dynresource = NULL;
-  char fpr[17] = {0};
+  char fpr[FINGERPRINT_LENGTH] = {0};
   const char *proxy_host;
   const char *resource_prefix = PACKAGE_NAME;
   char *fjid;
@@ -1883,7 +1885,7 @@
     port = (ssl ? LM_CONNECTION_DEFAULT_PORT_SSL : LM_CONNECTION_DEFAULT_PORT);
   lm_connection_set_port(lconnection, port);
 
-  if (ssl_fpr && (!hex_to_fingerprint(ssl_fpr, fpr))) {
+  if (ssl_fpr && (!hex_to_fingerprint(ssl_fpr, fpr, FINGERPRINT_LENGTH))) {
     scr_LogPrint(LPRINT_LOGNORM, "** Please set the fingerprint in the format "
                  "97:5C:00:3F:1D:77:45:25:E2:C5:70:EC:83:C8:87:EE");
     return -1;