From 439c9b5cb55044f13d4af6563f4e791093d510b0 Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Fri, 8 May 2020 15:21:51 +0200
Subject: [PATCH] sm: Print algorithm infos in data decryption mode.

* common/sexputil.c (cipher_mode_to_string): New.
* sm/decrypt.c (prepare_decryption): Show cipher algo and mode.
(gpgsm_decrypt): Show key algo and fingerprint

Signed-off-by: Werner Koch <wk@gnupg.org>
---
 common/sexputil.c | 16 ++++++++++++++++
 common/util.h     |  1 +
 sm/decrypt.c      | 13 +++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/common/sexputil.c b/common/sexputil.c
index 66cd9f60e..7a67f2b7c 100644
--- a/common/sexputil.c
+++ b/common/sexputil.c
@@ -698,3 +698,19 @@ hash_algo_to_string (int algo)
       return hashnames[i].name;
   return "?";
 }
+
+
+/* Map cipher modes to a string.  */
+const char *
+cipher_mode_to_string (int mode)
+{
+  switch (mode)
+    {
+    case GCRY_CIPHER_MODE_CFB: return "CFB";
+    case GCRY_CIPHER_MODE_CBC: return "CBC";
+    case GCRY_CIPHER_MODE_GCM: return "GCM";
+    case GCRY_CIPHER_MODE_OCB: return "OCB";
+    case 14:                   return "EAX";  /* Only in gcrypt 1.9 */
+    default: return "[?]";
+    }
+}
diff --git a/common/util.h b/common/util.h
index f2b4306c3..b5bdd0385 100644
--- a/common/util.h
+++ b/common/util.h
@@ -204,6 +204,7 @@ int get_pk_algo_from_canon_sexp (const unsigned char *keydata,
 char *pubkey_algo_string (gcry_sexp_t s_pkey, enum gcry_pk_algos *r_algoid);
 const char *pubkey_algo_to_string (int algo);
 const char *hash_algo_to_string (int algo);
+const char *cipher_mode_to_string (int mode);
 
 /*-- convert.c --*/
 int hex2bin (const char *string, void *buffer, size_t length);
diff --git a/sm/decrypt.c b/sm/decrypt.c
index d64c6091b..3689ed388 100644
--- a/sm/decrypt.c
+++ b/sm/decrypt.c
@@ -455,6 +455,11 @@ prepare_decryption (ctrl_t ctrl, const char *hexkeygrip,
   if (DBG_CRYPTO)
     log_printhex (seskey+n, seskeylen-n, "CEK .....:");
 
+  if (opt.verbose)
+    log_info (_("%s.%s encrypted data\n"),
+              gcry_cipher_algo_name (parm->algo),
+              cipher_mode_to_string (parm->mode));
+
   rc = gcry_cipher_open (&parm->hd, parm->algo, parm->mode, 0);
   if (rc)
     {
@@ -733,6 +738,8 @@ gpgsm_decrypt (ctrl_t ctrl, int in_fd, estream_t out_fp)
               ksba_sexp_t serial;
               ksba_sexp_t enc_val;
               char *hexkeygrip = NULL;
+              char *pkalgostr = NULL;
+              char *pkfpr = NULL;
               char *desc = NULL;
               char kidbuf[16+1];
               int tmp_rc;
@@ -819,7 +826,11 @@ gpgsm_decrypt (ctrl_t ctrl, int in_fd, estream_t out_fp)
                   hexkeygrip = gpgsm_get_keygrip_hexstring (cert);
                   desc = gpgsm_format_keydesc (cert);
 
+                  pkfpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
+                  pkalgostr = gpgsm_pubkey_algo_string (cert, NULL);
                   pk_algo = gpgsm_get_key_algo_info (cert, &nbits);
+                  if (!opt.quiet)
+                    log_info (_("encrypted to %s key %s\n"), pkalgostr, pkfpr);
 
                   /* Check compliance.  */
                   if (!gnupg_pk_is_allowed (opt.compliance,
@@ -886,6 +897,8 @@ gpgsm_decrypt (ctrl_t ctrl, int in_fd, estream_t out_fp)
                     }
                   audit_log_ok (ctrl->audit, AUDIT_RECP_RESULT, rc);
                 }
+              xfree (pkalgostr);
+              xfree (pkfpr);
               xfree (hexkeygrip);
               xfree (desc);
             }