[PATCH setup 1/4] Various improvements to debug output from crypto.cc

[Jon Turney]

Build an adaptor for log output from gcrypt (unfortunately complex as it
needs to gather/split lines on '\n')

Don't really need a hard breakpoint for ERRKIND, so it's the same,
irrespective of CRYPTODEBUGGING being defined.

Always debug log the pk type and hash alg in use.

Allow CRYPTODEBUGGING to be set by CPPFLAGS etc.
---
 crypto.cc | 67 +++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 58 insertions(+), 9 deletions(-)

diff --git a/crypto.cc b/crypto.cc
index 0974c6a..364ef82 100644
--- a/crypto.cc
+++ b/crypto.cc
@@ -30,15 +30,16 @@
 #include "gpg-packet.h"
 #include "geturl.h"
 
+#ifndef CRYPTODEBUGGING
 #define CRYPTODEBUGGING         (0)
+#endif
 
+#define ERRKIND note
 #if CRYPTODEBUGGING
-#define ERRKIND __asm__ __volatile__ (".byte 0xcc"); note
 #define MESSAGE LogBabblePrintf
-#else  /* !CRYPTODEBUGGING */
-#define ERRKIND note
+#else
 #define MESSAGE while (0) LogBabblePrintf
-#endif /* CRYPTODEBUGGING */
+#endif
 
 /*  Command-line options for specifying and controlling extra keys.  */
 static StringArrayOption ExtraKeyOption ('K', "pubkey",
@@ -334,8 +335,8 @@ pkt_cb_resp sig_file_walker (struct packet_walker *wlk, unsigned char tag,
       sigdat->hash_alg = pkt_getch (wlk->pfile);
     }
 
-  MESSAGE ("sig type %d, pk_alg %d, hash_alg %d\n", sigdat->sig_type,
-						sigdat->pk_alg, sigdat->hash_alg);
+  LogBabblePrintf("signature: sig_type %d, pk_alg %d, hash_alg %d\n",
+                  sigdat->sig_type, sigdat->pk_alg, sigdat->hash_alg);
 
   // We only handle binary file signatures
   if (sigdat->sig_type != RFC4880_ST_BINARY)
@@ -392,8 +393,7 @@ pkt_cb_resp sig_file_walker (struct packet_walker *wlk, unsigned char tag,
   // Both formats now have 16 bits of the hash value.
   int hash_first = pkt_getword (wlk->pfile);
 
-  MESSAGE ("sig type %d, pk_alg %d, hash_alg %d - first $%04x\n", sigdat->sig_type,
-			sigdat->pk_alg, sigdat->hash_alg, hash_first);
+  MESSAGE ("signature: hash leftmost 2 bytes 0x%04x\n", hash_first);
 
   /*  Algorithm-Specific Fields for signatures:
 
@@ -471,6 +471,46 @@ add_key_from_sexpr (gcry_sexp_t key)
   delete [] sexprbuf;
 }
 
+#if CRYPTODEBUGGING
+static void
+gcrypt_log_adaptor(void *priv, int level, const char *fmt, va_list args)
+{
+  static std::string collected;
+
+  char buf[GPG_KEY_SEXPR_BUF_SIZE];
+  vsnprintf (buf, GPG_KEY_SEXPR_BUF_SIZE, fmt, args);
+
+  char *start = buf;
+  char *end;
+
+  do
+    {
+      if (collected.length() == 0)
+        {
+          collected = "gcrypt: ";
+        }
+
+      end = strchr(start, '\n');
+      if (end)
+        *end = '\0';
+
+      collected += start;
+
+      if (end)
+        {
+          if (level == GCRY_LOG_DEBUG)
+            Log (LOG_BABBLE) << collected << endLog;
+          else
+            Log (LOG_PLAIN) << collected << endLog;
+
+          collected.clear();
+          start = end + 1;
+        }
+    }
+  while (end);
+}
+#endif
+
 /*  Verify the signature on an ini file.  Takes care of all key-handling.  */
 bool
 verify_ini_file_sig (io_stream *ini_file, io_stream *ini_sig_file, HWND owner)
@@ -501,7 +541,16 @@ verify_ini_file_sig (io_stream *ini_file, io_stream *ini_sig_file, HWND owner)
   size_t n;
 
   /* Initialise the library.  */
-  gcry_check_version (NULL);
+  static bool gcrypt_init = false;
+  if (!gcrypt_init)
+    {
+#if CRYPTODEBUGGING
+      gcry_set_log_handler (gcrypt_log_adaptor, NULL);
+      gcry_control (GCRYCTL_SET_DEBUG_FLAGS, 1);
+#endif
+      gcry_check_version (NULL);
+      gcrypt_init = true;
+    }
 
   /* So first build the built-in key.  */
   gcry_sexp_t dsa_key;
-- 
2.21.0