]> Pileus Git - ~andy/fetchmail/blobdiff - socket.c
Note Earl's regression fix for SSL_CTX_clear_options() on older OpenSSL.
[~andy/fetchmail] / socket.c
index 7a62ffc19df867853d228498ea6c4c9852d446d7..634b4760b87d0ffa106620e62a436967a50d1ea8 100644 (file)
--- a/socket.c
+++ b/socket.c
@@ -52,6 +52,7 @@
 #include "fetchmail.h"
 #include "getaddrinfo.h"
 #include "i18n.h"
+#include "sdump.h"
 
 /* Defines to allow BeOS and Cygwin to play nice... */
 #ifdef __BEOS__
@@ -74,20 +75,15 @@ static ssize_t cygwin_read(int sock, void *buf, size_t count);
 
 /* We need to define h_errno only if it is not already */
 #ifndef h_errno
-
-#ifdef HAVE_RES_SEARCH
-/* some versions of FreeBSD should declare this but don't */
+# if !HAVE_DECL_H_ERRNO
 extern int h_errno;
-#else
-/* pretend we have h_errno to avoid some #ifdef's later */
-static int h_errno;
-#endif
-
+# endif
 #endif /* ndef h_errno */
 
 #ifdef HAVE_SOCKETPAIR
 static char *const *parse_plugin(const char *plugin, const char *host, const char *service)
-{      const char **argvec;
+{
+       char **argvec;
        const char *c, *p;
        char *cp, *plugin_copy;
        unsigned int plugin_copy_len;
@@ -108,7 +104,7 @@ static char *const *parse_plugin(const char *plugin, const char *host, const cha
        }
 
        plugin_copy_len = plugin_len + host_len * host_count + service_len * service_count;
-       plugin_copy = malloc(plugin_copy_len + 1);
+       plugin_copy = (char *)malloc(plugin_copy_len + 1);
        if (!plugin_copy)
        {
                report(stderr, GT_("fetchmail: malloc failed\n"));
@@ -134,25 +130,25 @@ static char *const *parse_plugin(const char *plugin, const char *host, const cha
        }
        plugin_copy[plugin_copy_len] = 0;
 
-       argvec = malloc(s);
+       argvec = (char **)malloc(s);
        if (!argvec)
        {
                report(stderr, GT_("fetchmail: malloc failed\n"));
                return NULL;
        }
        memset(argvec, 0, s);
-       for (c = p = plugin_copy, i = 0; *c; c++)
-       {       if ((!isspace((unsigned char)*c)) && (c == p ? 1 : isspace((unsigned char)*p))) {
-                       argvec[i] = c;
+       for (p = cp = plugin_copy, i = 0; *cp; cp++)
+       {       if ((!isspace((unsigned char)*cp)) && (cp == p ? 1 : isspace((unsigned char)*p))) {
+                       argvec[i] = cp;
                        i++;
                }
-               p = c;
+               p = cp;
        }
        for (cp = plugin_copy; *cp; cp++)
        {       if (isspace((unsigned char)*cp))
                        *cp = 0;
        }
-       return (char *const*)argvec;
+       return argvec;
 }
 
 static int handle_plugin(const char *host,
@@ -183,7 +179,7 @@ static int handle_plugin(const char *host,
                (void) close(fds[1]);
                if ( (dup2(fds[0],0) == -1) || (dup2(fds[0],1) == -1) ) {
                        report(stderr, GT_("dup2 failed\n"));
-                       exit(1);
+                       _exit(EXIT_FAILURE);
                }
                /* fds[0] is now connected to 0 and 1; close it */
                (void) close(fds[0]);
@@ -192,7 +188,7 @@ static int handle_plugin(const char *host,
                argvec = parse_plugin(plugin,host,service);
                execvp(*argvec, argvec);
                report(stderr, GT_("execvp(%s) failed\n"), *argvec);
-               exit(0);
+               _exit(EXIT_FAILURE);
                break;
        default:        /* parent */
                /* NOP */
@@ -204,29 +200,11 @@ static int handle_plugin(const char *host,
 }
 #endif /* HAVE_SOCKETPAIR */
 
-#ifdef __UNUSED__
-
-int SockCheckOpen(int fd)
-/* poll given socket; is it selectable? */
-{
-    fd_set r, w, e;
-    int rt;
-    struct timeval tv;
-  
-    for (;;) 
-    {
-       FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
-       FD_SET(fd, &e);
-    
-       tv.tv_sec = 0; tv.tv_usec = 0;
-       rt = select(fd+1, &r, &w, &e, &tv);
-       if (rt == -1 && (errno != EAGAIN && errno != EINTR))
-           return 0;
-       if (rt != -1)
-           return 1;
-    }
+/** Set socket to SO_KEEPALIVE. \return 0 for success. */
+int SockKeepalive(int sock) {
+    int keepalive = 1;
+    return setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, &keepalive, sizeof keepalive);
 }
-#endif /* __UNUSED__ */
 
 int UnixOpen(const char *path)
 {
@@ -243,12 +221,12 @@ int UnixOpen(const char *path)
        return -1;
     }
 
-       /* Socket opened saved. Usefull if connect timeout 
-        * because it can be closed.
-        */
-       mailserver_socket_temp = sock;
-    
-       if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
+    /* Socket opened saved. Usefull if connect timeout 
+     * because it can be closed.
+     */
+    mailserver_socket_temp = sock;
+
+    if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
     {
        int olderr = errno;
        fm_close(sock); /* don't use SockClose, no traffic yet */
@@ -256,27 +234,33 @@ int UnixOpen(const char *path)
        errno = olderr;
        sock = -1;
     }
-       
-       /* No connect timeout, then no need to set mailserver_socket_temp */
-       mailserver_socket_temp = -1;
+
+    /* No connect timeout, then no need to set mailserver_socket_temp */
+    mailserver_socket_temp = -1;
 
     return sock;
 }
 
 int SockOpen(const char *host, const char *service,
-            const char *plugin)
+            const char *plugin, struct addrinfo **ai0)
 {
-    struct addrinfo *ai, *ai0, req;
-    int i;
+    struct addrinfo *ai, req;
+    int i, acterr = 0;
+    int ord;
+    char errbuf[8192] = "";
 
 #ifdef HAVE_SOCKETPAIR
     if (plugin)
        return handle_plugin(host,service,plugin);
 #endif /* HAVE_SOCKETPAIR */
+
     memset(&req, 0, sizeof(struct addrinfo));
     req.ai_socktype = SOCK_STREAM;
+#ifdef AI_ADDRCONFIG
+    req.ai_flags = AI_ADDRCONFIG;
+#endif
 
-    i = getaddrinfo(host, service, &req, &ai0);
+    i = fm_getaddrinfo(host, service, &req, ai0);
     if (i) {
        report(stderr, GT_("getaddrinfo(\"%s\",\"%s\") error: %s\n"),
                host, service, gai_strerror(i));
@@ -285,30 +269,76 @@ int SockOpen(const char *host, const char *service,
        return -1;
     }
 
+    /* NOTE a Linux bug here - getaddrinfo will happily return 127.0.0.1
+     * twice if no IPv6 is configured */
     i = -1;
-    for (ai = ai0; ai; ai = ai->ai_next) {
-       i = socket(ai->ai_family, ai->ai_socktype, 0);
-       if (i < 0)
+    for (ord = 0, ai = *ai0; ai; ord++, ai = ai->ai_next) {
+       char buf[256]; /* hostname */
+       char pb[256];  /* service name */
+       int gnie;      /* getnameinfo result code */
+
+       gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof(buf), NULL, 0, NI_NUMERICHOST);
+       if (gnie)
+           snprintf(buf, sizeof(buf), GT_("unknown (%s)"), gai_strerror(gnie));
+       gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, NULL, 0, pb, sizeof(pb), NI_NUMERICSERV);
+       if (gnie)
+           snprintf(pb, sizeof(pb), GT_("unknown (%s)"), gai_strerror(gnie));
+
+       if (outlevel >= O_VERBOSE)
+           report_build(stdout, GT_("Trying to connect to %s/%s..."), buf, pb);
+       i = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+       if (i < 0) {
+           int e = errno;
+           /* mask EAFNOSUPPORT errors, they confuse users for
+            * multihomed hosts */
+           if (errno != EAFNOSUPPORT)
+               acterr = errno;
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("cannot create socket: %s\n"), strerror(e));
+           snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf),\
+                    GT_("name %d: cannot create socket family %d type %d: %s\n"), ord, ai->ai_family, ai->ai_socktype, strerror(e));
            continue;
+       }
 
-       /* Socket opened saved. Usefull if connect timeout 
-        * because it can be closed.
-        */
+       SockKeepalive(i);
+
+       /* Save socket descriptor.
+        * Used to close the socket after connect timeout. */
        mailserver_socket_temp = i;
 
        if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) {
+           int e = errno;
+
+           /* additionally, suppress IPv4 network unreach errors */
+           if (e != EAFNOSUPPORT)
+               acterr = errno;
+
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("connection failed.\n"));
+           if (outlevel >= O_VERBOSE)
+               report(stderr, GT_("connection to %s:%s [%s/%s] failed: %s.\n"), host, service, buf, pb, strerror(e));
+           snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf), GT_("name %d: connection to %s:%s [%s/%s] failed: %s.\n"), ord, host, service, buf, pb, strerror(e));
            fm_close(i);
            i = -1;
            continue;
+       } else {
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("connected.\n"));
        }
-       
+
        /* No connect timeout, then no need to set mailserver_socket_temp */
        mailserver_socket_temp = -1;
-       
+
        break;
     }
 
-    freeaddrinfo(ai0);
+    fm_freeaddrinfo(*ai0);
+    *ai0 = NULL;
+
+    if (i == -1) {
+       report(stderr, GT_("Connection errors for this poll:\n%s"), errbuf);
+       errno = acterr;
+    }
 
     return i;
 }
@@ -345,13 +375,13 @@ va_dcl {
 #include <openssl/x509v3.h>
 #include <openssl/rand.h>
 
-static SSL_CTX *_ctx = NULL;
+static SSL_CTX *_ctx[FD_SETSIZE];
 static SSL *_ssl_context[FD_SETSIZE];
 
 static SSL     *SSLGetContext( int );
 #endif /* SSL_ENABLE */
 
-int SockWrite(int sock, char *buf, int len)
+int SockWrite(int sock, const char *buf, int len)
 {
     int n, wrlen = 0;
 #ifdef SSL_ENABLE
@@ -379,9 +409,6 @@ int SockRead(int sock, char *buf, int len)
 {
     char *newline, *bp = buf;
     int n;
-#ifdef FORCE_STUFFING
-    int maxavailable = 0;
-#endif
 #ifdef SSL_ENABLE
     SSL *ssl;
 #endif
@@ -409,7 +436,7 @@ int SockRead(int sock, char *buf, int len)
                /* OK...  SSL_peek works a little different from MSG_PEEK
                        Problem is that SSL_peek can return 0 if there
                        is no data currently available.  If, on the other
-                       hand, we loose the socket, we also get a zero, but
+                       hand, we lose the socket, we also get a zero, but
                        the SSL_read then SEGFAULTS!  To deal with this,
                        we'll check the error code any time we get a return
                        of zero from SSL_peek.  If we have an error, we bail.
@@ -421,14 +448,11 @@ int SockRead(int sock, char *buf, int len)
                        (void)SSL_get_error(ssl, n);
                        return(-1);
                }
-#ifdef FORCE_STUFFING
-               maxavailable = n;
-#endif
                if( 0 == n ) {
                        /* SSL_peek says no data...  Does he mean no data
                        or did the connection blow up?  If we got an error
                        then bail! */
-                       if( 0 != ( n = SSL_get_error(ssl, n) ) ) {
+                       if (0 != SSL_get_error(ssl, n)) {
                                return -1;
                        }
                        /* We didn't get an error so read at least one
@@ -438,10 +462,10 @@ int SockRead(int sock, char *buf, int len)
                         * We don't have a string to pass through
                         * the strchr at this point yet */
                        newline = NULL;
-               } else if ((newline = memchr(bp, '\n', n)) != NULL)
+               } else if ((newline = (char *)memchr(bp, '\n', n)) != NULL)
                        n = newline - bp + 1;
                /* Matthias Andree: SSL_read can return 0, in that case
-                * we must cal SSL_get_error to figure if there was
+                * we must call SSL_get_error to figure if there was
                 * an error or just a "no data" condition */
                if ((n = SSL_read(ssl, bp, n)) <= 0) {
                        if ((n = SSL_get_error(ssl, n))) {
@@ -467,10 +491,7 @@ int SockRead(int sock, char *buf, int len)
            if ((n = fm_peek(sock, bp, len)) <= 0)
 #endif
                return (-1);
-#ifdef FORCE_STUFFING
-           maxavailable = n;
-#endif
-           if ((newline = memchr(bp, '\n', n)) != NULL)
+           if ((newline = (char *)memchr(bp, '\n', n)) != NULL)
                n = newline - bp + 1;
 #ifndef __BEOS__
            if ((n = fm_read(sock, bp, n)) == -1)
@@ -483,46 +504,6 @@ int SockRead(int sock, char *buf, int len)
            (!newline && len);
     *bp = '\0';
 
-#ifdef FORCE_STUFFING          /* too ugly to live -- besides, there's IMAP */
-    /* OK, very weird hack coming up here:
-     * When POP3 servers send us a message, they're supposed to
-     * terminate the message with a line containing only a dot. To protect
-     * against lines in the real message that might contain only a dot,
-     * they're supposed to preface any line that starts with a dot with
-     * an additional dot, which will be removed on the client side. That
-     * process, called byte-stuffing (and unstuffing) is really not the
-     * concern of this low-level routine, ordinarily, but there are some
-     * POP servers (and maybe IMAP servers too, who knows) that fail to
-     * do the byte-stuffing, and this routine is the best place to try to
-     * identify and fix that fault.
-     *
-     * Since the DOT line is supposed to come only at the end of a
-     * message, the implication is that right after we see it, the server
-     * is supposed to go back to waiting for the next command. There
-     * isn't supposed to be any more data to read after we see the dot.
-     * THEREFORE, if we see more data to be read after something that
-     * looks like the dot line, then probably the server is failing to
-     * do byte-stuffing. In that case, we'll byte-pack it for them so
-     * that the higher-level routines see things as hunky-dorey.
-     * This is not a perfect test or fix by any means (it has an
-     * obvious race condition, for one thing), but it should at least
-     * reduce the nastiness that ensues when people don't know how
-     * to write POP servers.
-     */
-    if ((maxavailable > (bp-buf)) &&
-           ((((bp-buf) == 3) &&
-             (buf[0] == '.') &&
-             (buf[1] == '\r') &&
-             (buf[2] == '\n')) ||
-            (((bp-buf) == 2) &&
-             (buf[0] == '.') &&
-             (buf[1] == '\n')))) {
-
-       memmove(buf+1, buf, (bp-buf)+1);
-       buf[0] = '.';
-       bp++;
-    }
-#endif /* FORCE_STUFFING */
     return bp - buf;
 }
 
@@ -551,7 +532,7 @@ int SockPeek(int sock)
                        /* SSL_peek says 0...  Does that mean no data
                        or did the connection blow up?  If we got an error
                        then bail! */
-                       if( 0 != ( n = SSL_get_error(ssl, n) ) ) {
+                       if(0 != SSL_get_error(ssl, n)) {
                                return -1;
                        }
 
@@ -583,33 +564,34 @@ static    int _check_fp;
 static char *_check_digest;
 static         char *_server_label;
 static int _depth0ck;
+static int _firstrun;
 static int _prev_err;
+static int _verify_ok;
 
 SSL *SSLGetContext( int sock )
 {
-       /* If SSLOpen has never initialized - just return NULL */
-       if( NULL == _ctx )
+       if( sock < 0 || (unsigned)sock > FD_SETSIZE )
                return NULL;
-
-       if( sock < 0 || sock > FD_SETSIZE )
+       if( _ctx[sock] == NULL )
                return NULL;
        return _ssl_context[sock];
 }
 
-
 /* ok_return (preverify_ok) is 1 if this stage of certificate verification
    passed, or 0 if it failed. This callback lets us display informative
    errors, and perform additional validation (e.g. CN matches) */
 static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
 {
+#define SSLverbose (((outlevel) >= O_DEBUG) || ((outlevel) >= O_VERBOSE && (depth) == 0)) 
        char buf[257];
        X509 *x509_cert;
-       int err, depth;
+       int err, depth, i;
        unsigned char digest[EVP_MAX_MD_SIZE];
        char text[EVP_MAX_MD_SIZE * 3 + 1], *tp, *te;
        const EVP_MD *digest_tp;
-       unsigned int dsz, i, esz;
+       unsigned int dsz, esz;
        X509_NAME *subj, *issuer;
+       char *tt;
 
        x509_cert = X509_STORE_CTX_get_current_cert(ctx);
        err = X509_STORE_CTX_get_error(ctx);
@@ -618,79 +600,108 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
        subj = X509_get_subject_name(x509_cert);
        issuer = X509_get_issuer_name(x509_cert);
 
-       if (depth == 0 && !_depth0ck) {
-               _depth0ck = 1;
-               
-               if (outlevel >= O_VERBOSE) {
+       if (outlevel >= O_VERBOSE) {
+               if (depth == 0 && SSLverbose)
+                       report(stdout, GT_("Server certificate:\n"));
+               else {
+                       if (_firstrun) {
+                               _firstrun = 0;
+                               if (SSLverbose)
+                                       report(stdout, GT_("Certificate chain, from root to peer, starting at depth %d:\n"), depth);
+                       } else {
+                               if (SSLverbose)
+                                       report(stdout, GT_("Certificate at depth %d:\n"), depth);
+                       }
+               }
+
+               if (SSLverbose) {
                        if ((i = X509_NAME_get_text_by_NID(issuer, NID_organizationName, buf, sizeof(buf))) != -1) {
-                               report(stdout, GT_("Issuer Organization: %s\n"), buf);
-                               if (i >= sizeof(buf) - 1)
+                               report(stdout, GT_("Issuer Organization: %s\n"), (tt = sdump(buf, i)));
+                               xfree(tt);
+                               if ((size_t)i >= sizeof(buf) - 1)
                                        report(stdout, GT_("Warning: Issuer Organization Name too long (possibly truncated).\n"));
                        } else
                                report(stdout, GT_("Unknown Organization\n"));
                        if ((i = X509_NAME_get_text_by_NID(issuer, NID_commonName, buf, sizeof(buf))) != -1) {
-                               report(stdout, GT_("Issuer CommonName: %s\n"), buf);
-                               if (i >= sizeof(buf) - 1)
+                               report(stdout, GT_("Issuer CommonName: %s\n"), (tt = sdump(buf, i)));
+                               xfree(tt);
+                               if ((size_t)i >= sizeof(buf) - 1)
                                        report(stdout, GT_("Warning: Issuer CommonName too long (possibly truncated).\n"));
                        } else
                                report(stdout, GT_("Unknown Issuer CommonName\n"));
                }
+       }
+
+       if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
+               if (SSLverbose) {
+                       report(stdout, GT_("Subject CommonName: %s\n"), (tt = sdump(buf, i)));
+                       xfree(tt);
+               }
+               if ((size_t)i >= sizeof(buf) - 1) {
+                       /* Possible truncation. In this case, this is a DNS name, so this
+                        * is really bad. We do not tolerate this even in the non-strict case. */
+                       report(stderr, GT_("Bad certificate: Subject CommonName too long!\n"));
+                       return (0);
+               }
+               if ((size_t)i > strlen(buf)) {
+                       /* Name contains embedded NUL characters, so we complain. This is likely
+                        * a certificate spoofing attack. */
+                       report(stderr, GT_("Bad certificate: Subject CommonName contains NUL, aborting!\n"));
+                       return 0;
+               }
+       }
+
+       if (depth == 0) { /* peer certificate */
+               if (!_depth0ck) {
+                       _depth0ck = 1;
+               }
+
                if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
-                       if (outlevel >= O_VERBOSE)
-                               report(stdout, GT_("Server CommonName: %s\n"), buf);
-                       if (i >= sizeof(buf) - 1) {
-                               /* Possible truncation. In this case, this is a DNS name, so this
-                                * is really bad. We do not tolerate this even in the non-strict case. */
-                               report(stderr, GT_("Bad certificate: Subject CommonName too long!\n"));
-                               return (0);
-                       }
                        if (_ssl_server_cname != NULL) {
                                char *p1 = buf;
                                char *p2 = _ssl_server_cname;
-                               int n;
                                int matched = 0;
                                STACK_OF(GENERAL_NAME) *gens;
-                               
+
                                /* RFC 2595 section 2.4: find a matching name
                                 * first find a match among alternative names */
-                               gens = X509_get_ext_d2i(x509_cert, NID_subject_alt_name, NULL, NULL);
+                               gens = (STACK_OF(GENERAL_NAME) *)X509_get_ext_d2i(x509_cert, NID_subject_alt_name, NULL, NULL);
                                if (gens) {
-                                       int i, r;
-                                       for (i = 0, r = sk_GENERAL_NAME_num(gens); i < r; ++i) {
-                                               const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, i);
+                                       int j, r;
+                                       for (j = 0, r = sk_GENERAL_NAME_num(gens); j < r; ++j) {
+                                               const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, j);
                                                if (gn->type == GEN_DNS) {
-                                                       char *p1 = (char *)gn->d.ia5->data;
-                                                       char *p2 = _ssl_server_cname;
-                                                       if (outlevel >= O_VERBOSE)
-                                                               report(stderr, "Subject Alternative Name: %s\n", p1);
-                                                       if (*p1 == '*') {
-                                                               ++p1;
-                                                               n = strlen(p2) - strlen(p1);
-                                                               if (n >= 0)
-                                                                       p2 += n;
+                                                       char *pp1 = (char *)gn->d.ia5->data;
+                                                       char *pp2 = _ssl_server_cname;
+                                                       if (outlevel >= O_VERBOSE) {
+                                                               report(stdout, GT_("Subject Alternative Name: %s\n"), (tt = sdump(pp1, (size_t)gn->d.ia5->length)));
+                                                               xfree(tt);
+                                                       }
+                                                       /* Name contains embedded NUL characters, so we complain. This
+                                                        * is likely a certificate spoofing attack. */
+                                                       if ((size_t)gn->d.ia5->length != strlen(pp1)) {
+                                                               report(stderr, GT_("Bad certificate: Subject Alternative Name contains NUL, aborting!\n"));
+                                                               sk_GENERAL_NAME_free(gens);
+                                                               return 0;
                                                        }
-                                                       if (0 == strcasecmp(p1, p2)) {
-                                                               matched = 1;
+                                                       if (name_match(pp1, pp2)) {
+                                                           matched = 1;
                                                        }
                                                }
                                        }
                                        sk_GENERAL_NAME_free(gens);
                                }
-                               if (*p1 == '*') {
-                                       ++p1;
-                                       n = strlen(p2) - strlen(p1);
-                                       if (n >= 0)
-                                               p2 += n;
-                               }       
-                               if (0 == strcasecmp(p1, p2)) {
-                                 matched = 1;
+                               if (name_match(p1, p2)) {
+                                       matched = 1;
                                }
                                if (!matched) {
-                                       report(stderr,
-                                           GT_("Server CommonName mismatch: %s != %s\n"),
-                                           buf, _ssl_server_cname );
-                                       if (ok_return && strict)
-                                               return (0);
+                                       if (strict || SSLverbose) {
+                                               report(stderr,
+                                                               GT_("Server CommonName mismatch: %s != %s\n"),
+                                                               (tt = sdump(buf, i)), _ssl_server_cname );
+                                               xfree(tt);
+                                       }
+                                       ok_return = 0;
                                }
                        } else if (ok_return) {
                                report(stderr, GT_("Server name not set, could not verify certificate!\n"));
@@ -706,8 +717,10 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
                }
                /* Print the finger print. Note that on errors, we might print it more than once
                 * normally; we kluge around that by using a global variable. */
-               if (_check_fp) {
-                       _check_fp = 0;
+               if (_check_fp == 1) {
+                       unsigned dp;
+
+                       _check_fp = -1;
                        digest_tp = EVP_md5();
                        if (digest_tp == NULL) {
                                report(stderr, GT_("EVP_md5() failed!\n"));
@@ -719,9 +732,9 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
                        }
                        tp = text;
                        te = text + sizeof(text);
-                       for (i = 0; i < dsz; i++) {
-                               esz = snprintf(tp, te - tp, i > 0 ? ":%02X" : "%02X", digest[i]);
-                               if (esz >= te - tp) {
+                       for (dp = 0; dp < dsz; dp++) {
+                               esz = snprintf(tp, te - tp, dp > 0 ? ":%02X" : "%02X", digest[dp]);
+                               if (esz >= (size_t)(te - tp)) {
                                        report(stderr, GT_("Digest text buffer too small!\n"));
                                        return (0);
                                }
@@ -730,27 +743,43 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
                        if (outlevel > O_NORMAL)
                            report(stdout, GT_("%s key fingerprint: %s\n"), _server_label, text);
                        if (_check_digest != NULL) {
-                               if (strcmp(text, _check_digest) == 0) {
+                               if (strcasecmp(text, _check_digest) == 0) {
                                    if (outlevel > O_NORMAL)
                                        report(stdout, GT_("%s fingerprints match.\n"), _server_label);
                                } else {
-                                   if (outlevel > O_SILENT)
-                                       report(stderr, GT_("%s fingerprints do not match!\n"), _server_label);
+                                   report(stderr, GT_("%s fingerprints do not match!\n"), _server_label);
                                    return (0);
                                }
-                       }
-               }
-       }
+                       } /* if (_check_digest != NULL) */
+               } /* if (_check_fp) */
+       } /* if (depth == 0 && !_depth0ck) */
+
+       if (err != X509_V_OK && err != _prev_err && !(_check_fp != 0 && _check_digest && !strict)) {
+               _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 */
 
-       if (err != X509_V_OK && err != _prev_err) {
-               _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) {
                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"), sizeof(buf)-1, buf);
+                       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;
+               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 "
+                                               "on the certificate directory. For details, please "
+                                               "see the documentation of --sslcertpath and --sslcertfile in the manual page.\n"), buf);
+                       break;
+               default:
                        break;
                }
        }
@@ -758,6 +787,7 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
         * If not in strict checking mode (--sslcertck), override this
         * and pretend that verification had succeeded.
         */
+       _verify_ok &= ok_return;
        if (!strict)
                ok_return = 1;
        return (ok_return);
@@ -773,20 +803,53 @@ static int SSL_ck_verify_callback( int ok_return, X509_STORE_CTX *ctx )
        return SSL_verify_callback(ok_return, ctx, 1);
 }
 
+
+/* get commonName from certificate set in file.
+ * commonName is stored in buffer namebuffer, limited with namebufferlen
+ */
+static const char *SSLCertGetCN(const char *mycert,
+                                char *namebuffer, size_t namebufferlen)
+{
+       const char *ret       = NULL;
+       BIO        *certBio   = NULL;
+       X509       *x509_cert = NULL;
+       X509_NAME  *certname  = NULL;
+
+       if (namebuffer && namebufferlen > 0) {
+               namebuffer[0] = 0x00;
+               certBio = BIO_new_file(mycert,"r");
+               if (certBio) {
+                       x509_cert = PEM_read_bio_X509(certBio,NULL,NULL,NULL);
+                       BIO_free(certBio);
+               }
+               if (x509_cert) {
+                       certname = X509_get_subject_name(x509_cert);
+                       if (certname &&
+                           X509_NAME_get_text_by_NID(certname, NID_commonName,
+                                                     namebuffer, namebufferlen) > 0)
+                               ret = namebuffer;
+                       X509_free(x509_cert);
+               }
+       }
+       return ret;
+}
+
 /* performs initial SSL handshake over the connected socket
  * uses SSL *ssl global variable, which is currently defined
  * in this file
  */
-int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char *certpath,
-    char *fingerprint, char *servercname, char *label)
+int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck,
+    char *cacertfile, char *certpath,
+    char *fingerprint, char *servercname, char *label, char **remotename)
 {
         struct stat randstat;
         int i;
+       long sslopts = SSL_OP_ALL;
 
        SSL_load_error_strings();
-       SSLeay_add_ssl_algorithms();
-       
-#ifdef SSL_ENABLE
+       SSL_library_init();
+       OpenSSL_add_all_algorithms(); /* see Debian Bug#576430 and manpage */
+
         if (stat("/dev/random", &randstat)  &&
             stat("/dev/urandom", &randstat)) {
           /* Neither /dev/random nor /dev/urandom are present, so add
@@ -802,56 +865,82 @@ int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char
             RAND_add (buf, sizeof buf, 0.1);
           }
         }
-#endif /* SSL_ENABLE */
 
-
-       if( sock < 0 || sock > FD_SETSIZE ) {
+       if( sock < 0 || (unsigned)sock > FD_SETSIZE ) {
                report(stderr, GT_("File descriptor out of range for SSL") );
                return( -1 );
        }
 
-       if( ! _ctx ) {
-               /* Be picky and make sure the memory is cleared */
-               memset( _ssl_context, 0, sizeof( _ssl_context ) );
-               if(myproto) {
-                       if(!strcmp("ssl2",myproto)) {
-                               _ctx = SSL_CTX_new(SSLv2_client_method());
-                       } else if(!strcmp("ssl3",myproto)) {
-                               _ctx = SSL_CTX_new(SSLv3_client_method());
-                       } else if(!strcmp("tls1",myproto)) {
-                               _ctx = SSL_CTX_new(TLSv1_client_method());
-                       } else if (!strcmp("ssl23",myproto)) {
-                               myproto = NULL;
-                       } else {
-                               fprintf(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
-                               myproto = NULL;
-                       }
-               }
-               if(!myproto) {
-                       _ctx = SSL_CTX_new(SSLv23_client_method());
-               }
-               if(_ctx == NULL) {
-                       ERR_print_errors_fp(stderr);
-                       return(-1);
+       /* Make sure a connection referring to an older context is not left */
+       _ssl_context[sock] = NULL;
+       if(myproto) {
+               if(!strcasecmp("ssl2",myproto)) {
+#if HAVE_DECL_SSLV2_CLIENT_METHOD + 0 > 0
+                       _ctx[sock] = SSL_CTX_new(SSLv2_client_method());
+#else
+                       report(stderr, GT_("Your operating system does not support SSLv2.\n"));
+                       return -1;
+#endif
+               } else if(!strcasecmp("ssl3",myproto)) {
+                       _ctx[sock] = SSL_CTX_new(SSLv3_client_method());
+               } else if(!strcasecmp("tls1",myproto)) {
+                       _ctx[sock] = SSL_CTX_new(TLSv1_client_method());
+               } else if (!strcasecmp("ssl23",myproto)) {
+                       myproto = NULL;
+               } else {
+                       fprintf(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
+                       myproto = NULL;
                }
        }
+       if(!myproto) {
+               _ctx[sock] = SSL_CTX_new(SSLv23_client_method());
+       }
+       if(_ctx[sock] == NULL) {
+               ERR_print_errors_fp(stderr);
+               return(-1);
+       }
+
+       {
+           char *tmp = getenv("FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE");
+           if (tmp == NULL || *tmp == '\0' || strspn(tmp, " \t") == strlen(tmp))
+               sslopts &= ~ SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
+       }
+
+       SSL_CTX_set_options(_ctx[sock], sslopts);
 
        if (certck) {
-               SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_ck_verify_callback);
+               SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_ck_verify_callback);
        } else {
                /* In this case, we do not fail if verification fails. However,
-                *  we provide the callback for output and possible fingerprint checks. */
-               SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_nock_verify_callback);
+                * we provide the callback for output and possible fingerprint
+                * checks. */
+               SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_nock_verify_callback);
+       }
+
+       /* Check which trusted X.509 CA certificate store(s) to load */
+       {
+               char *tmp;
+               int want_default_cacerts = 0;
+
+               /* Load user locations if any is given */
+               if (certpath || cacertfile)
+                       SSL_CTX_load_verify_locations(_ctx[sock],
+                                               cacertfile, certpath);
+               else
+                       want_default_cacerts = 1;
+
+               tmp = getenv("FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS");
+               if (want_default_cacerts || (tmp && tmp[0])) {
+                       SSL_CTX_set_default_verify_paths(_ctx[sock]);
+               }
        }
-       if (certpath)
-               SSL_CTX_load_verify_locations(_ctx, NULL, certpath);
-       else
-               SSL_CTX_set_default_verify_paths(_ctx);
        
-       _ssl_context[sock] = SSL_new(_ctx);
+       _ssl_context[sock] = SSL_new(_ctx[sock]);
        
        if(_ssl_context[sock] == NULL) {
                ERR_print_errors_fp(stderr);
+               SSL_CTX_free(_ctx[sock]);
+               _ctx[sock] = NULL;
                return(-1);
        }
        
@@ -861,6 +950,8 @@ int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char
        _check_fp = 1;
        _check_digest = fingerprint;
        _depth0ck = 0;
+       _firstrun = 1;
+       _verify_ok = 1;
        _prev_err = -1;
 
        if( mycert || mykey ) {
@@ -869,18 +960,28 @@ int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char
         * he does NOT have a separate certificate and private key file then
         * assume that it's a combined key and certificate file.
         */
+               char buffer[256];
+               
                if( !mykey )
                        mykey = mycert;
                if( !mycert )
                        mycert = mykey;
+
+               if ((!*remotename || !**remotename) && SSLCertGetCN(mycert, buffer, sizeof(buffer))) {
+                       free(*remotename);
+                       *remotename = xstrdup(buffer);
+               }
                SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
                SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
        }
 
-       SSL_set_fd(_ssl_context[sock], sock);
-       
-       if(SSL_connect(_ssl_context[sock]) < 1) {
+       if (SSL_set_fd(_ssl_context[sock], sock) == 0 
+           || SSL_connect(_ssl_context[sock]) < 1) {
                ERR_print_errors_fp(stderr);
+               SSL_free( _ssl_context[sock] );
+               _ssl_context[sock] = NULL;
+               SSL_CTX_free(_ctx[sock]);
+               _ctx[sock] = NULL;
                return(-1);
        }
 
@@ -894,11 +995,18 @@ int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char
                                SSL_shutdown( _ssl_context[sock] );
                                SSL_free( _ssl_context[sock] );
                                _ssl_context[sock] = NULL;
+                               SSL_CTX_free(_ctx[sock]);
+                               _ctx[sock] = NULL;
                        }
                        return(-1);
                }
        }
 
+       if (!certck && !fingerprint &&
+               (SSL_get_verify_result(_ssl_context[sock]) != X509_V_OK || !_verify_ok)) {
+               report(stderr, GT_("Warning: the connection is insecure, continuing anyways. (Better use --sslcertck!)\n"));
+       }
+
        return(0);
 }
 #endif
@@ -912,33 +1020,11 @@ int SockClose(int sock)
         SSL_shutdown( _ssl_context[sock] );
         SSL_free( _ssl_context[sock] );
         _ssl_context[sock] = NULL;
+       SSL_CTX_free(_ctx[sock]);
+       _ctx[sock] = NULL;
     }
 #endif
 
-#ifdef __UNUSED__
-    /* 
-     * This hangs in RedHat 6.2 after fetchmail runs for a while a
-     * FIN_WAIT2 comes up in netstat and fetchmail never returns from
-     * the recv system call. (Reported from jtnews
-     * <jtnews@bellatlantic.net>, Wed, 24 May 2000 21:26:02.)
-     *
-     * Half-close the connection first so the other end gets notified.
-     *
-     * This stops sends but allows receives (effectively, it sends a
-     * TCP <FIN>).  */
-    if (shutdown(sock, 1) == 0) {
-       char ch;
-       /* If there is any data still waiting in the queue, discard it.
-        * Call recv() until either it returns 0 (meaning we received a FIN)
-        * or any error occurs.  This makes sure all data sent by the other
-        * side is acknowledged at the TCP level.
-        */
-       if (fm_peek(sock, &ch, 1) > 0)
-           while (fm_read(sock, &ch, 1) > 0)
-               continue;
-    }
-#endif /* __UNUSED__ */
-
     /* if there's an error closing at this point, not much we can do */
     return(fm_close(sock));    /* this is guarded */
 }
@@ -951,18 +1037,18 @@ int SockClose(int sock)
  */
 static ssize_t cygwin_read(int sock, void *buf, size_t count)
 {
-    char *bp = buf;
-    int n = 0;
+    char *bp = (char *)buf;
+    size_t n = 0;
 
-    if ((n = read(sock, bp, count)) == -1)
+    if ((n = read(sock, bp, count)) == (size_t)-1)
        return(-1);
 
     if (n != count) {
-       int n2 = 0;
+       size_t n2 = 0;
        if (outlevel >= O_VERBOSE)
            report(stdout, GT_("Cygwin socket read retry\n"));
        n2 = read(sock, bp + n, count - n);
-       if (n2 == -1 || n + n2 != count) {
+       if (n2 == (size_t)-1 || n + n2 != count) {
            report(stderr, GT_("Cygwin socket read retry failed!\n"));
            return(-1);
        }
@@ -971,21 +1057,3 @@ static ssize_t cygwin_read(int sock, void *buf, size_t count)
     return count;
 }
 #endif /* __CYGWIN__ */
-
-#ifdef MAIN
-/*
- * Use the chargen service to test input buffering directly.
- * You may have to uncomment the `chargen' service description in your
- * inetd.conf (and then SIGHUP inetd) for this to work.  */
-main()
-{
-    int                sock = SockOpen("localhost", "chargen", NULL);
-    char       buf[80];
-
-    while (SockRead(sock, buf, sizeof(buf)-1))
-       SockWrite(1, buf, strlen(buf));
-    SockClose(sock);
-}
-#endif /* MAIN */
-
-/* socket.c ends here */