diff --git a/etc/init.lisp b/etc/init.lisp
index 405938d..c9cd1d4 100644
--- a/etc/init.lisp
+++ b/etc/init.lisp
@@ -506,7 +506,9 @@
 
 (define-key "q"         #'gemini-close-certificate-window            *gemini-certificates-keymap*)
 
-(define-key "C-J"       #'gemini-delete-certificate                  *gemini-certificates-keymap*)
+(define-key "d"         #'gemini-delete-certificate                  *gemini-certificates-keymap*)
+
+(define-key "C-J"       #'gemini-certificate-information             *gemini-certificates-keymap*)
 
 ;; gemini subscription window
 
diff --git a/po/it.po b/po/it.po
index 787705b..8eead34 100644
--- a/po/it.po
+++ b/po/it.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: tinmop 0.0.1\n"
 "Report-Msgid-Bugs-To: https://notabug.org/cage/tinmop/\n"
-"POT-Creation-Date: 2022-04-16 12:19+0200\n"
+"POT-Creation-Date: 2022-04-22 11:33+0200\n"
 "PO-Revision-Date: 2022-04-16 12:19+0200\n"
 "Last-Translator: cage <cage@invalid.org>\n"
 "Language-Team: Italian\n"
@@ -169,11 +169,11 @@ msgstr "Carica un modulo"
 msgid "MODULE-FILE"
 msgstr "FILE-DEL-MODULO"
 
-#: src/command-line.lisp:130
+#: src/command-line.lisp:129
 msgid "Usage"
 msgstr "Uso"
 
-#: src/command-line.lisp:131
+#: src/command-line.lisp:130
 msgid "Available options"
 msgstr "Opzioni diponibili"
 
@@ -306,6 +306,7 @@ msgid "Redirects to ~s, follows redirect? [y/N] "
 msgstr "Seguire la redirezione a ~s? [s/N] "
 
 #: src/gemini-viewer.lisp:744 src/tui-utils.lisp:504 src/tui-utils.lisp:514
+#: src/ui-goodies.lisp:2702 src/ui-goodies.lisp:2708
 #, lisp-format
 msgid "Error: ~a"
 msgstr "Errore: ~a"
@@ -361,7 +362,7 @@ msgstr "Biblioteca dei gempub"
 msgid "No address found"
 msgstr "nessun indirizzo trovato"
 
-#: src/kami/client.lisp:175
+#: src/kami/client.lisp:197
 #, lisp-format
 msgid "User: ~a Group: ~a Others ~a"
 msgstr "\"Utente: ~a Gruppo: ~a Altri: ~a\""
@@ -479,7 +480,7 @@ msgstr "Aiuto rapido"
 msgid "invalid regular expression ~s ~a"
 msgstr "Espressione regolare non valida ~s ~a"
 
-#: src/line-oriented-window.lisp:473
+#: src/line-oriented-window.lisp:474
 #, lisp-format
 msgid "line ~a of ~a"
 msgstr "linea ~a di ~a"
@@ -1509,154 +1510,154 @@ msgstr "eval: "
 msgid "load file: "
 msgstr "Carica il file: "
 
-#: src/ui-goodies.lisp:2722
+#: src/ui-goodies.lisp:2736
 #, lisp-format
 msgid "~s is not a valid kami address"
 msgstr "~s non è un indirizzo kami valido"
 
-#: src/ui-goodies.lisp:2746
+#: src/ui-goodies.lisp:2760
 #, lisp-format
 msgid "deleting ~a"
 msgstr "cancell ~a"
 
-#: src/ui-goodies.lisp:2752
+#: src/ui-goodies.lisp:2766
 #, lisp-format
 msgid "Delete ~a? [y/N] "
 msgstr "Cancella ~a? [s/N] "
 
-#: src/ui-goodies.lisp:2766
+#: src/ui-goodies.lisp:2780
 #, lisp-format
 msgid "Rename ~a to: "
 msgstr "Rinomina ~a a: "
 
-#: src/ui-goodies.lisp:2784
+#: src/ui-goodies.lisp:2798
 #, lisp-format
 msgid "Starting download of ~a"
 msgstr "Avvio il download di ~a"
 
-#: src/ui-goodies.lisp:2785
+#: src/ui-goodies.lisp:2799
 #, lisp-format
 msgid "Download completed in ~a"
 msgstr "Scaricamento di ~a completato"
 
-#: src/ui-goodies.lisp:2792
+#: src/ui-goodies.lisp:2806
 #, lisp-format
 msgid "Download ~a to: "
 msgstr "Scarica ~a in: "
 
-#: src/ui-goodies.lisp:2809
+#: src/ui-goodies.lisp:2823
 msgid "Download: "
 msgstr "Scarica: "
 
-#: src/ui-goodies.lisp:2829 src/ui-goodies.lisp:2879 src/ui-goodies.lisp:3124
+#: src/ui-goodies.lisp:2843 src/ui-goodies.lisp:2893 src/ui-goodies.lisp:3138
 #, lisp-format
 msgid "downloading ~a → ~a"
 msgstr "Scaricamento di ~a → ~a"
 
-#: src/ui-goodies.lisp:2838 src/ui-goodies.lisp:3133
+#: src/ui-goodies.lisp:2852 src/ui-goodies.lisp:3147
 msgid "Downloading completed."
 msgstr "Scaricamento completato."
 
-#: src/ui-goodies.lisp:2843
+#: src/ui-goodies.lisp:2857
 msgid "Save downloaded files in directory: "
 msgstr "Salva i file scaricati nella directory: "
 
-#: src/ui-goodies.lisp:2888 src/ui-goodies.lisp:3096
+#: src/ui-goodies.lisp:2902 src/ui-goodies.lisp:3110
 msgid "Uploading completed."
 msgstr "Caricamento completato."
 
-#: src/ui-goodies.lisp:2891 src/ui-goodies.lisp:3098
+#: src/ui-goodies.lisp:2905 src/ui-goodies.lisp:3112
 msgid "Upload: "
 msgstr "Carica: "
 
-#: src/ui-goodies.lisp:2906
+#: src/ui-goodies.lisp:2920
 msgid "Create: "
 msgstr "Crea: "
 
-#: src/ui-goodies.lisp:2928
+#: src/ui-goodies.lisp:2942
 msgid "Search for: "
 msgstr "Criterio di ricerca: "
 
-#: src/ui-goodies.lisp:2956
+#: src/ui-goodies.lisp:2970
 #, lisp-format
 msgid "Invalid regular expression ~a"
 msgstr "Espressione regolare non valida ~a"
 
-#: src/ui-goodies.lisp:2961
+#: src/ui-goodies.lisp:2975
 #, lisp-format
 msgid "Marked ~a item"
 msgid_plural "Marked ~a items"
 msgstr[0] "Selezionato ~a elemento"
 msgstr[1] "Selezionati ~a elementi"
 
-#: src/ui-goodies.lisp:2966
+#: src/ui-goodies.lisp:2980
 msgid "Mark items matching: "
 msgstr "Seleziona elementi che soddisfano la seguente espressione regolare:"
 
-#: src/ui-goodies.lisp:2974
+#: src/ui-goodies.lisp:2988
 #, lisp-format
 msgid "deleting ~a (~a of ~a)"
 msgstr "cancellazione di ~a (~a di ~a)"
 
-#: src/ui-goodies.lisp:2981
+#: src/ui-goodies.lisp:2995
 #, lisp-format
 msgid "Preparing to delete ~a"
 msgstr "Preparazione alla cancellazione di ~a"
 
-#: src/ui-goodies.lisp:2991
+#: src/ui-goodies.lisp:3005
 msgid "Completed"
 msgstr "Compito completato"
 
-#: src/ui-goodies.lisp:2994
+#: src/ui-goodies.lisp:3008
 #, lisp-format
 msgid "Delete ~a? "
 msgstr "Cancella ~a? "
 
-#: src/ui-goodies.lisp:3011
+#: src/ui-goodies.lisp:3025
 msgid "Delete marked items? "
 msgstr "Cancella gli elementi selezionati? "
 
-#: src/ui-goodies.lisp:3045
+#: src/ui-goodies.lisp:3059
 #, lisp-format
 msgid "Details of: ~a"
 msgstr "Dettagli di: ~a"
 
-#: src/ui-goodies.lisp:3046
+#: src/ui-goodies.lisp:3060
 msgid "Type"
 msgstr "Tipo"
 
-#: src/ui-goodies.lisp:3048
+#: src/ui-goodies.lisp:3062
 msgid "Size"
 msgstr "Dimensione"
 
-#: src/ui-goodies.lisp:3050
+#: src/ui-goodies.lisp:3064
 msgid "Permissions"
 msgstr "Permessi"
 
-#: src/ui-goodies.lisp:3061
+#: src/ui-goodies.lisp:3075
 #, lisp-format
 msgid "File ~s was modified on server"
 msgstr "Il file ~s è stato modificato sul server"
 
-#: src/ui-goodies.lisp:3088
+#: src/ui-goodies.lisp:3102
 #, lisp-format
 msgid "Uploading ~a"
 msgstr "Caricamento di ~a"
 
-#: src/ui-goodies.lisp:3111
+#: src/ui-goodies.lisp:3125
 msgid "Preparing for download…"
 msgstr "Preparazione allo scaricamento…"
 
-#: src/ui-goodies.lisp:3136
+#: src/ui-goodies.lisp:3150
 msgid "Download in: "
 msgstr "Scarica in: "
 
-#: src/ui-goodies.lisp:3155
+#: src/ui-goodies.lisp:3169
 #, lisp-format
 msgid "Deleting cache directory ~a"
 msgstr "Cancello la cache ~a"
 
-#: src/ui-goodies.lisp:3162
+#: src/ui-goodies.lisp:3176
 msgid "Delete cache? [y/N] "
 msgstr "Cancella la cache? [s/N] "
 
diff --git a/po/tinmop.pot b/po/tinmop.pot
index 7dbe948..7d52e40 100644
--- a/po/tinmop.pot
+++ b/po/tinmop.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: tinmop 0.9.5\n"
 "Report-Msgid-Bugs-To: https://notabug.org/cage/tinmop/\n"
-"POT-Creation-Date: 2022-04-16 12:19+0200\n"
+"POT-Creation-Date: 2022-04-22 11:33+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -163,11 +163,11 @@ msgstr ""
 msgid "MODULE-FILE"
 msgstr ""
 
-#: src/command-line.lisp:130
+#: src/command-line.lisp:129
 msgid "Usage"
 msgstr ""
 
-#: src/command-line.lisp:131
+#: src/command-line.lisp:130
 msgid "Available options"
 msgstr ""
 
@@ -297,6 +297,7 @@ msgid "Redirects to ~s, follows redirect? [y/N] "
 msgstr ""
 
 #: src/gemini-viewer.lisp:744 src/tui-utils.lisp:504 src/tui-utils.lisp:514
+#: src/ui-goodies.lisp:2702 src/ui-goodies.lisp:2708
 #, lisp-format
 msgid "Error: ~a"
 msgstr ""
@@ -352,7 +353,7 @@ msgstr ""
 msgid "No address found"
 msgstr ""
 
-#: src/kami/client.lisp:175
+#: src/kami/client.lisp:197
 #, lisp-format
 msgid "User: ~a Group: ~a Others ~a"
 msgstr ""
@@ -470,7 +471,7 @@ msgstr ""
 msgid "invalid regular expression ~s ~a"
 msgstr ""
 
-#: src/line-oriented-window.lisp:473
+#: src/line-oriented-window.lisp:474
 #, lisp-format
 msgid "line ~a of ~a"
 msgstr ""
@@ -1485,154 +1486,154 @@ msgstr ""
 msgid "load file: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2722
+#: src/ui-goodies.lisp:2736
 #, lisp-format
 msgid "~s is not a valid kami address"
 msgstr ""
 
-#: src/ui-goodies.lisp:2746
+#: src/ui-goodies.lisp:2760
 #, lisp-format
 msgid "deleting ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2752
+#: src/ui-goodies.lisp:2766
 #, lisp-format
 msgid "Delete ~a? [y/N] "
 msgstr ""
 
-#: src/ui-goodies.lisp:2766
+#: src/ui-goodies.lisp:2780
 #, lisp-format
 msgid "Rename ~a to: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2784
+#: src/ui-goodies.lisp:2798
 #, lisp-format
 msgid "Starting download of ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2785
+#: src/ui-goodies.lisp:2799
 #, lisp-format
 msgid "Download completed in ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2792
+#: src/ui-goodies.lisp:2806
 #, lisp-format
 msgid "Download ~a to: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2809
+#: src/ui-goodies.lisp:2823
 msgid "Download: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2829 src/ui-goodies.lisp:2879 src/ui-goodies.lisp:3124
+#: src/ui-goodies.lisp:2843 src/ui-goodies.lisp:2893 src/ui-goodies.lisp:3138
 #, lisp-format
 msgid "downloading ~a → ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2838 src/ui-goodies.lisp:3133
+#: src/ui-goodies.lisp:2852 src/ui-goodies.lisp:3147
 msgid "Downloading completed."
 msgstr ""
 
-#: src/ui-goodies.lisp:2843
+#: src/ui-goodies.lisp:2857
 msgid "Save downloaded files in directory: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2888 src/ui-goodies.lisp:3096
+#: src/ui-goodies.lisp:2902 src/ui-goodies.lisp:3110
 msgid "Uploading completed."
 msgstr ""
 
-#: src/ui-goodies.lisp:2891 src/ui-goodies.lisp:3098
+#: src/ui-goodies.lisp:2905 src/ui-goodies.lisp:3112
 msgid "Upload: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2906
+#: src/ui-goodies.lisp:2920
 msgid "Create: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2928
+#: src/ui-goodies.lisp:2942
 msgid "Search for: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2956
+#: src/ui-goodies.lisp:2970
 #, lisp-format
 msgid "Invalid regular expression ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2961
+#: src/ui-goodies.lisp:2975
 #, lisp-format
 msgid "Marked ~a item"
 msgid_plural "Marked ~a items"
 msgstr[0] ""
 msgstr[1] ""
 
-#: src/ui-goodies.lisp:2966
+#: src/ui-goodies.lisp:2980
 msgid "Mark items matching: "
 msgstr ""
 
-#: src/ui-goodies.lisp:2974
+#: src/ui-goodies.lisp:2988
 #, lisp-format
 msgid "deleting ~a (~a of ~a)"
 msgstr ""
 
-#: src/ui-goodies.lisp:2981
+#: src/ui-goodies.lisp:2995
 #, lisp-format
 msgid "Preparing to delete ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:2991
+#: src/ui-goodies.lisp:3005
 msgid "Completed"
 msgstr ""
 
-#: src/ui-goodies.lisp:2994
+#: src/ui-goodies.lisp:3008
 #, lisp-format
 msgid "Delete ~a? "
 msgstr ""
 
-#: src/ui-goodies.lisp:3011
+#: src/ui-goodies.lisp:3025
 msgid "Delete marked items? "
 msgstr ""
 
-#: src/ui-goodies.lisp:3045
+#: src/ui-goodies.lisp:3059
 #, lisp-format
 msgid "Details of: ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:3046
+#: src/ui-goodies.lisp:3060
 msgid "Type"
 msgstr ""
 
-#: src/ui-goodies.lisp:3048
+#: src/ui-goodies.lisp:3062
 msgid "Size"
 msgstr ""
 
-#: src/ui-goodies.lisp:3050
+#: src/ui-goodies.lisp:3064
 msgid "Permissions"
 msgstr ""
 
-#: src/ui-goodies.lisp:3061
+#: src/ui-goodies.lisp:3075
 #, lisp-format
 msgid "File ~s was modified on server"
 msgstr ""
 
-#: src/ui-goodies.lisp:3088
+#: src/ui-goodies.lisp:3102
 #, lisp-format
 msgid "Uploading ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:3111
+#: src/ui-goodies.lisp:3125
 msgid "Preparing for download…"
 msgstr ""
 
-#: src/ui-goodies.lisp:3136
+#: src/ui-goodies.lisp:3150
 msgid "Download in: "
 msgstr ""
 
-#: src/ui-goodies.lisp:3155
+#: src/ui-goodies.lisp:3169
 #, lisp-format
 msgid "Deleting cache directory ~a"
 msgstr ""
 
-#: src/ui-goodies.lisp:3162
+#: src/ui-goodies.lisp:3176
 msgid "Delete cache? [y/N] "
 msgstr ""
 
diff --git a/src/filesystem-utils.lisp b/src/filesystem-utils.lisp
index 0b25df5..f7069b0 100644
--- a/src/filesystem-utils.lisp
+++ b/src/filesystem-utils.lisp
@@ -390,8 +390,8 @@
   (dolist (temporary-file *temporary-files-created*)
     (delete-file-if-exists temporary-file)))
 
-(defmacro with-anaphoric-temp-file ((stream &key (prefix nil) (unlink nil)) &body body)
-  `(let ((temp-file (temporary-file ,prefix))) ; anaphora
+(defmacro with-anaphoric-temp-file ((stream &key  (unlink nil)) &body body)
+  `(let ((temp-file (temporary-file))) ; anaphora
        (unwind-protect
             (with-open-file (,stream temp-file
                                      :element-type      '(unsigned-byte 8)
diff --git a/src/package.lisp b/src/package.lisp
index 992fccb..4e715f6 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -751,7 +751,8 @@
    :cl
    :alexandria)
   (:export
-   :dump-certificate))
+   :dump-certificate
+   :certificate-fingerprint))
 
 (defpackage :db-utils
   (:use
@@ -2821,6 +2822,7 @@
    :gemini-streams-window-open-stream
    :gemini-refresh-page
    :gemini-subscribe-gemlog
+   :gemini-certificate-information
    :gemini-open-gemlog-window
    :gemlogs-subscription-go-up
    :gemlogs-subscription-go-down
diff --git a/src/ui-goodies.lisp b/src/ui-goodies.lisp
index dd81825..f5b0abc 100644
--- a/src/ui-goodies.lisp
+++ b/src/ui-goodies.lisp
@@ -1563,6 +1563,21 @@ certificate).
                       :prompt      (_ "Delete this certificate? [Y/n] ")
                       :complete-fn #'complete:complete-always-empty)))
 
+(defun gemini-certificate-information ()
+  (when-let* ((selected-row (line-oriented-window:selected-row-fields
+                             *gemini-certificates-window*))
+              (cache-key    (db:row-cache-key selected-row))
+              (pem-file     (gemini-client::tls-cert-find cache-key)))
+    (with-enqueued-process ()
+      (let ((fingerprint (x509:certificate-fingerprint pem-file)))
+        (windows:make-blocking-message-dialog specials:*main-window*
+                                              nil
+                                              (_ "Certificate information")
+                                              (list (_ "Certificate fingerprint (Kami ID):")
+                                                    fingerprint)
+                                              (swconf:win-bg swconf:+key-help-dialog+)
+                                              (swconf:win-fg swconf:+key-help-dialog+))))))
+
 (defun gemini-open-gemlog-window ()
   "Open a window with all the  gemlog subscribed."
   (gemini-subscription-window:open-gemini-subscription-window)
diff --git a/src/x509.lisp b/src/x509.lisp
index c392c60..b88df7a 100644
--- a/src/x509.lisp
+++ b/src/x509.lisp
@@ -27,9 +27,40 @@
                (cffi:with-foreign-object (buf** :pointer)
                  (setf (cffi:mem-ref buf** :pointer) buf*)
                  (i2d-x509 cert buf**)
-                 (let* ((data (loop for i from 0 below certificate-length collect
-                                                                          (cffi:mem-aref buf* :unsigned-char i)))
+                 (let* ((data (loop for i from 0 below certificate-length
+                                    collect
+                                    (cffi:mem-aref buf* :unsigned-char i)))
                         (res  (misc:make-fresh-array certificate-length 0 '(unsigned-byte 8) t)))
                    (misc:copy-list-into-array data res)
                    res))))
-      (cl+ssl::x509-free cert))))
+      (cl+ssl:x509-free cert))))
+
+
+(defun pem->der (pem-file)
+  (handler-case
+      (let* ((raw     (fs:slurp-file pem-file))
+             (encoded (cl-ppcre:regex-replace-all "-----(BEGIN|END) CERTIFICATE-----" raw ""))
+             (decoded (base64:base64-string-to-usb8-array encoded)))
+        (fs:with-anaphoric-temp-file (stream)
+          (write-sequence decoded stream)
+          filesystem-utils::temp-file))
+   (error () pem-file)))
+
+(defgeneric certificate-fingerprint (object &key hash-algorithm))
+
+(defmacro decode-fingerprint (cert hash-algorithm)
+  (alexandria:with-gensyms (hash hash-string algo-string)
+    `(unwind-protect
+          (let* ((,hash        (cl+ssl:certificate-fingerprint ,cert ,hash-algorithm))
+                 (,hash-string (format nil "~{~2,'0x~}" (map 'list #'identity ,hash)))
+                 (,algo-string (format nil "~:@(~a~)" ,hash-algorithm)))
+            (text-utils:strcat ,algo-string ":" (string-downcase ,hash-string)))
+       (cl+ssl:x509-free ,cert))))
+
+(defmethod certificate-fingerprint ((object cl+ssl::ssl-stream) &key (hash-algorithm :sha256))
+  (let* ((cert (cl+ssl:ssl-stream-x509-certificate object)))
+    (decode-fingerprint cert hash-algorithm)))
+
+(defmethod certificate-fingerprint ((object string) &key (hash-algorithm :sha256))
+  (let* ((cert (cl+ssl:decode-certificate-from-file (pem->der object) :format :der)))
+    (decode-fingerprint cert hash-algorithm)))