fix bug 4143, 'fingerprint in SSL/TLS certificates for ... (regress error)'

patch by Andrej

diff --git a/src/gtk/sslcertwindow.c b/src/gtk/sslcertwindow.c
index cb3ce4c460d9a9fca425e098b7efefc48e1bc4fc..c2748d8641fc9b28d96d6d9048974393f2cc3666 100644 (file)
--- a/src/gtk/sslcertwindow.c
+++ b/src/gtk/sslcertwindow.c
@@ -1,6 +1,6 @@
 /*
  * Claws Mail -- a GTK+ based, lightweight, and fast e-mail client
- * Copyright (C) 1999-2016 Colin Leroy <colin@colino.net>
+ * Copyright (C) 1999-2019 Colin Leroy <colin@colino.net>
  * and the Claws Mail team
  *
  * This program is free software; you can redistribute it and/or modify
@@ -70,6 +70,7 @@ static GtkWidget *cert_presenter(SSLCertificate *cert)
        char *tmp;
        time_t exp_time_t;
        struct tm lt;
+       guint ret;
 
        /* issuer */    
        issuer_commonname = g_malloc(BUFFSIZE);
@@ -142,12 +143,28 @@ static GtkWidget *cert_presenter(SSLCertificate *cert)
        } else
                exp_date = g_strdup("");
 
-       /* fingerprint */
-       n = 128;
-       gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA1, md, &n);
-       sha1_fingerprint = readable_fingerprint(md, (int)n);
-       gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA256, md, &n);
-       sha256_fingerprint = readable_fingerprint(md, (int)n);
+       /* fingerprints */
+       n = 0;
+       memset(md, 0, sizeof(md));
+       if ((ret = gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA1, md, &n)) == GNUTLS_E_SHORT_MEMORY_BUFFER) {
+               if (n <= sizeof(md))
+                       ret = gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA1, md, &n);
+       }
+
+       if (ret != 0)
+               g_warning("failed to obtain SHA1 fingerprint: %d", ret);
+       sha1_fingerprint = readable_fingerprint(md, (int)n); /* all zeroes */
+
+       n = 0;
+       memset(md, 0, sizeof(md));
+       if ((ret = gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA256, md, &n)) == GNUTLS_E_SHORT_MEMORY_BUFFER) {
+               if (n <= sizeof(md))
+                       ret = gnutls_x509_crt_get_fingerprint(cert->x509_cert, GNUTLS_DIG_SHA256, md, &n);
+       }
+
+       if (ret != 0)
+               g_warning("failed to obtain SHA256 fingerprint: %d", ret);
+       sha256_fingerprint = readable_fingerprint(md, (int)n); /* all zeroes */
 
 
        /* signature */