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-rw-r--r--NEWS8
-rw-r--r--socket.c55
2 files changed, 50 insertions, 13 deletions
diff --git a/NEWS b/NEWS
index 22af11f7..f44944b3 100644
--- a/NEWS
+++ b/NEWS
@@ -58,6 +58,14 @@ removed from a 6.4.0 or newer release.)
fetchmail-6.3.25 (not yet released):
+# CHANGES
+* Improved reporting when SSL/TLS X.509 certificate validation has failed,
+ working around a not-so-recent swapping of two OpenSSL error codes, and
+ a practical impossibility to distinguish broken certification chains from
+ missing trust anchors (root certificates).
+* OpenSSL decoded errors are now reported through report(), rather than dumped
+ to stderr, so that they should show up in logfiles and/or syslog.
+
# WORKAROUNDS
* Older systems that provide the older RFC-2553 implementation of getaddrinfo,
rather than the current RFC-3493, and systems that do not provide this
diff --git a/socket.c b/socket.c
index 3e4a3acd..48201d38 100644
--- a/socket.c
+++ b/socket.c
@@ -375,6 +375,20 @@ va_dcl {
#include <openssl/x509v3.h>
#include <openssl/rand.h>
+static void report_SSL_errors(FILE *stream)
+{
+ unsigned long err;
+
+ while (0ul != (err = ERR_get_error())) {
+ char *errstr = ERR_error_string(err, NULL);
+ report(stream, GT_("OpenSSL reported: %s\n"), errstr);
+ }
+}
+
+/* override ERR_print_errors_fp to our own implementation */
+#undef ERR_print_errors_fp
+#define ERR_print_errors_fp(stream) report_SSL_errors((stream))
+
static SSL_CTX *_ctx[FD_SETSIZE];
static SSL *_ssl_context[FD_SETSIZE];
@@ -755,29 +769,44 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
} /* if (depth == 0 && !_depth0ck) */
if (err != X509_V_OK && err != _prev_err && !(_check_fp != 0 && _check_digest && !strict)) {
+ char *tmp;
+ int did_rep_err = 0;
_prev_err = err;
-
+
report(stderr, GT_("Server certificate verification error: %s\n"), X509_verify_cert_error_string(err));
/* We gave the error code, but maybe we can add some more details for debugging */
switch (err) {
+ /* actually we do not want to lump these together, but
+ * since OpenSSL flipped the meaning of these error
+ * codes in the past, and they do hardly make a
+ * practical difference because servers need not provide
+ * the root signing certificate, we don't bother telling
+ * users the difference:
+ */
+ case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
X509_NAME_oneline(issuer, buf, sizeof(buf));
buf[sizeof(buf) - 1] = '\0';
- report(stderr, GT_("unknown issuer (first %d characters): %s\n"), (int)(sizeof(buf)-1), buf);
- report(stderr, GT_("This error usually happens when the server provides an incomplete certificate "
- "chain, which is nothing fetchmail could do anything about. For details, "
- "please see the README.SSL-SERVER document that comes with fetchmail.\n"));
- break;
+ report(stderr, GT_("Broken certification chain at: %s\n"), (tmp = sdump(buf, strlen(buf))));
+ xfree(tmp);
+ report(stderr, GT_( "This could mean that the server did not provide the intermediate CA's certificate(s), "
+ "which is nothing fetchmail could do anything about. For details, "
+ "please see the README.SSL-SERVER document that ships with fetchmail.\n"));
+ did_rep_err = 1;
+ /* FALLTHROUGH */
case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
- case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
- X509_NAME_oneline(subj, buf, sizeof(buf));
- buf[sizeof(buf) - 1] = '\0';
- report(stderr, GT_("This means that the root signing certificate (issued for %s) is not in the "
- "trusted CA certificate locations, or that c_rehash needs to be run "
+ if (!did_rep_err) {
+ X509_NAME_oneline(issuer, buf, sizeof(buf));
+ buf[sizeof(buf) - 1] = '\0';
+ report(stderr, GT_("Missing trust anchor certificate: %s\n"), (tmp = sdump(buf, strlen(buf))));
+ xfree(tmp);
+ }
+ report(stderr, GT_( "This could mean that the root CA's signing certificate is not in the "
+ "trusted CA certificate location, or that c_rehash needs to be run "
"on the certificate directory. For details, please "
- "see the documentation of --sslcertpath and --sslcertfile in the manual page.\n"), buf);
+ "see the documentation of --sslcertpath and --sslcertfile in the manual page.\n"));
break;
default:
break;
@@ -888,7 +917,7 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck
} else if (!strcasecmp("ssl23",myproto)) {
myproto = NULL;
} else {
- fprintf(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
+ report(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
myproto = NULL;
}
}