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libtdevnc/x11vnc/sslhelper.c

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/* -- sslhelper.c -- */
#include "x11vnc.h"
#include "inet.h"
#include "cleanup.h"
#include "screen.h"
#include "scan.h"
#include "connections.h"
#include "sslcmds.h"
#include "unixpw.h"
#define OPENSSL_INETD 1
#define OPENSSL_VNC 2
#define OPENSSL_HTTPS 3
#define OPENSSL_REVERSE 4
#define DO_DH 0
#if LIBVNCSERVER_HAVE_FORK
#if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID
#define FORK_OK
#endif
#endif
int openssl_sock = -1;
int openssl_port_num = 0;
int https_sock = -1;
pid_t openssl_last_helper_pid = 0;
char *openssl_last_ip = NULL;
static char *certret = NULL;
static int certret_fd = -1;
static mode_t omode;
char *certret_str = NULL;
static char *dhret = NULL;
static int dhret_fd = -1;
char *dhret_str = NULL;
char *new_dh_params = NULL;
void raw_xfer(int csock, int s_in, int s_out);
#if !LIBVNCSERVER_HAVE_LIBSSL
int openssl_present(void) {return 0;}
static void badnews(void) {
use_openssl = 0;
use_stunnel = 0;
rfbLog("** not compiled with libssl OpenSSL support **\n");
clean_up_exit(1);
}
void openssl_init(int isclient) {badnews();}
void openssl_port(void) {badnews();}
void https_port(void) {badnews();}
void check_openssl(void) {if (use_openssl) badnews();}
void check_https(void) {if (use_openssl) badnews();}
void ssl_helper_pid(pid_t pid, int sock) {badnews(); sock = pid;}
void accept_openssl(int mode, int presock) {mode = 0; presock = 0; badnews();}
char *find_openssl_bin(void) {badnews(); return NULL;}
char *get_saved_pem(char *string, int create) {badnews(); return NULL;}
#else
/*
* This is because on older systems both zlib.h and ssl.h define
* 'free_func' nothing we do below (currently) induces an external
* dependency on 'free_func'.
*/
#define free_func my_jolly_little_free_func
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
int openssl_present(void);
void openssl_init(int isclient);
void openssl_port(void);
void check_openssl(void);
void check_https(void);
void ssl_helper_pid(pid_t pid, int sock);
void accept_openssl(int mode, int presock);
char *find_openssl_bin(void);
char *get_saved_pem(char *string, int create);
static SSL_CTX *ctx = NULL;
static RSA *rsa_512 = NULL;
static RSA *rsa_1024 = NULL;
static SSL *ssl = NULL;
static X509_STORE *revocation_store = NULL;
static void init_prng(void);
static void sslerrexit(void);
static char *get_input(char *tag, char **in);
static char *create_tmp_pem(char *path, int prompt);
static int ssl_init(int s_in, int s_out, int skip_vnc_tls);
static void ssl_xfer(int csock, int s_in, int s_out, int is_https);
#ifndef FORK_OK
void openssl_init(int isclient) {
rfbLog("openssl_init: fork is not supported. cannot create"
" ssl helper process.\n");
clean_up_exit(1);
}
int openssl_present(void) {return 0;}
#else
int openssl_present(void) {return 1;}
static void sslerrexit(void) {
unsigned long err = ERR_get_error();
if (err) {
char str[256];
ERR_error_string(err, str);
fprintf(stderr, "ssl error: %s\n", str);
}
clean_up_exit(1);
}
char *get_saved_pem(char *save, int create) {
char *s = NULL, *path, *cdir, *tmp;
int prompt = 0, len;
struct stat sbuf;
if (! save) {
rfbLog("get_saved_pem: save string is null.\n");
clean_up_exit(1);
}
if (strstr(save, "SAVE_PROMPT") == save) {
prompt = 1;
s = save + strlen("SAVE_PROMPT");
} else if (strstr(save, "SAVE_NOPROMPT") == save) {
set_env("GENCERT_NOPROMPT", "1");
s = save + strlen("SAVE_NOPROMPT");
} else if (strstr(save, "SAVE") == save) {
s = save + strlen("SAVE");
} else {
rfbLog("get_saved_pem: invalid save string: %s\n", save);
clean_up_exit(1);
}
if (strchr(s, '/')) {
rfbLog("get_saved_pem: invalid save string: %s\n", s);
clean_up_exit(1);
}
cdir = get_Cert_dir(NULL, &tmp);
if (! cdir || ! tmp) {
rfbLog("get_saved_pem: could not find Cert dir.\n");
clean_up_exit(1);
}
len = strlen(cdir) + strlen("/server.pem") + strlen(s) + 1;
path = (char *) malloc(len);
sprintf(path, "%s/server%s.pem", cdir, s);
if (stat(path, &sbuf) != 0) {
char *new = NULL;
if (create) {
if (inetd || opts_bg) {
set_env("GENCERT_NOPROMPT", "1");
}
new = create_tmp_pem(path, prompt);
if (!getenv("X11VNC_SSL_NO_PASSPHRASE") && !inetd && !opts_bg) {
sslEncKey(new, 0);
}
}
return new;
}
if (! quiet) {
char line[1024];
int on = 0;
FILE *in = fopen(path, "r");
if (in != NULL) {
rfbLog("\n");
rfbLog("Using SSL Certificate:\n");
fprintf(stderr, "\n");
while (fgets(line, 1024, in) != NULL) {
if (strstr(line, "BEGIN CERTIFICATE")) {
on = 1;
}
if (on) {
fprintf(stderr, "%s", line);
}
if (strstr(line, "END CERTIFICATE")) {
on = 0;
}
if (strstr(line, "PRIVATE KEY")) {
on = 0;
}
}
fprintf(stderr, "\n");
fclose(in);
}
}
return strdup(path);
}
static char *get_input(char *tag, char **in) {
char line[1024], *str;
if (! tag || ! in || ! *in) {
return NULL;
}
fprintf(stderr, "%s:\n [%s] ", tag, *in);
if (fgets(line, 1024, stdin) == NULL) {
rfbLog("could not read stdin!\n");
rfbLogPerror("fgets");
clean_up_exit(1);
}
if ((str = strrchr(line, '\n')) != NULL) {
*str = '\0';
}
str = lblanks(line);
if (!strcmp(str, "")) {
return *in;
} else {
return strdup(line);
}
}
char *find_openssl_bin(void) {
char *path, *exe, *p, *gp;
struct stat sbuf;
int found_openssl = 0;
char extra[] = ":/usr/bin:/bin:/usr/sbin:/usr/local/bin"
":/usr/local/sbin:/usr/sfw/bin";
gp = getenv("PATH");
if (! gp) {
fprintf(stderr, "could not find openssl(1) program in PATH.\n");
return NULL;
}
path = (char *) malloc(strlen(gp) + strlen(extra) + 1);
strcpy(path, gp);
strcat(path, extra);
/* find openssl binary: */
exe = (char *) malloc(strlen(path) + strlen("/openssl") + 1);
p = strtok(path, ":");
while (p) {
sprintf(exe, "%s/openssl", p);
if (stat(exe, &sbuf) == 0) {
if (! S_ISDIR(sbuf.st_mode)) {
found_openssl = 1;
break;
}
}
p = strtok(NULL, ":");
}
free(path);
if (! found_openssl) {
fprintf(stderr, "could not find openssl(1) program in PATH.\n");
fprintf(stderr, "(also checked: %s)\n", extra);
return NULL;
}
return exe;
}
/* uses /usr/bin/openssl to create a tmp cert */
static char *create_tmp_pem(char *pathin, int prompt) {
pid_t pid, pidw;
FILE *in, *out;
char cnf[] = "/tmp/x11vnc-cnf.XXXXXX";
char pem[] = "/tmp/x11vnc-pem.XXXXXX";
char str[8*1024], line[1024], *exe;
int cnf_fd, pem_fd, status, show_cert = 1;
char *days;
char *C, *L, *OU, *O, *CN, *EM;
char tmpl[] =
"[ req ]\n"
"prompt = no\n"
"default_bits = 2048\n"
"encrypt_key = yes\n"
"distinguished_name = req_dn\n"
"x509_extensions = cert_type\n"
"\n"
"[ req_dn ]\n"
"countryName=%s\n"
"localityName=%s\n"
"organizationalUnitName=%s\n"
"organizationName=%s\n"
"commonName=%s\n"
"emailAddress=%s\n"
"\n"
"[ cert_type ]\n"
"nsCertType = server\n"
;
C = strdup("AU");
L = strdup(UT.sysname ? UT.sysname : "unknown-os");
snprintf(line, 1024, "%s-%f", UT.nodename ? UT.nodename :
"unknown-node", dnow());
line[1024-1] = '\0';
OU = strdup(line);
O = strdup("x11vnc");
if (pathin) {
snprintf(line, 1024, "x11vnc-SELF-SIGNED-CERT-%d", getpid());
} else {
snprintf(line, 1024, "x11vnc-SELF-SIGNED-TEMPORARY-CERT-%d",
getpid());
}
line[1024-1] = '\0';
CN = strdup(line);
EM = strdup("x11vnc@server.nowhere");
/* ssl */
if (no_external_cmds || !cmd_ok("ssl")) {
rfbLog("create_tmp_pem: cannot run external commands.\n");
return NULL;
}
rfbLog("\n");
if (pathin) {
rfbLog("Creating a self-signed PEM certificate...\n");
} else {
rfbLog("Creating a temporary, self-signed PEM certificate...\n");
}
rfbLog("\n");
rfbLog("This will NOT prevent Man-In-The-Middle attacks UNLESS you\n");
rfbLog("get the certificate information to the VNC viewers SSL\n");
rfbLog("tunnel configuration or you take the extra steps to sign it\n");
rfbLog("with a CA key. However, it will prevent passive network\n");
rfbLog("sniffing.\n");
rfbLog("\n");
rfbLog("The cert inside -----BEGIN CERTIFICATE-----\n");
rfbLog(" ....\n");
rfbLog(" -----END CERTIFICATE-----\n");
rfbLog("printed below may be used on the VNC viewer-side to\n");
rfbLog("authenticate this server for this session. See the -ssl\n");
rfbLog("help output and the FAQ for how to create a permanent\n");
rfbLog("server certificate.\n");
rfbLog("\n");
exe = find_openssl_bin();
if (! exe) {
return NULL;
}
/* create template file with our made up stuff: */
if (prompt) {
fprintf(stderr, "\nReply to the following prompts to set"
" your Certificate parameters.\n");
fprintf(stderr, "(press Enter to accept the default in [...], "
"or type in the value you want)\n\n");
C = get_input("CountryName", &C);
L = get_input("LocalityName", &L);
OU = get_input("OrganizationalUnitName", &OU);
O = get_input("OrganizationalName", &O);
CN = get_input("CommonName", &CN);
EM = get_input("EmailAddress", &EM);
}
sprintf(str, tmpl, C, L, OU, O, CN, EM);
cnf_fd = mkstemp(cnf);
pem_fd = mkstemp(pem);
if (cnf_fd < 0 || pem_fd < 0) {
return NULL;
}
close(pem_fd);
write(cnf_fd, str, strlen(str));
close(cnf_fd);
if (pathin) {
days = "365";
} else {
days = "30";
}
/* make RSA key */
pid = fork();
if (pid < 0) {
return NULL;
} else if (pid == 0) {
int i;
for (i=0; i<256; i++) {
close(i);
}
execlp(exe, exe, "req", "-new", "-x509", "-nodes",
"-days", days, "-config", cnf, "-out", pem,
"-keyout", pem, (char *)0);
exit(1);
}
pidw = waitpid(pid, &status, 0);
if (pidw != pid) {
return NULL;
}
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
;
} else {
return NULL;
}
#if DO_DH
/* make DH parameters */
pid = fork();
if (pid < 0) {
return NULL;
} else if (pid == 0) {
int i;
for (i=0; i<256; i++) {
close(i);
}
/* rather slow at 1024 */
execlp(exe, exe, "dhparam", "-out", cnf, "512", (char *)0);
exit(1);
}
pidw = waitpid(pid, &status, 0);
if (pidw != pid) {
return NULL;
}
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
;
} else {
return NULL;
}
/* append result: */
in = fopen(cnf, "r");
if (in == NULL) {
return NULL;
}
out = fopen(pem, "a");
if (out == NULL) {
fclose(in);
return NULL;
}
while (fgets(line, 1024, in) != NULL) {
fprintf(out, "%s", line);
}
fclose(in);
fclose(out);
#endif
unlink(cnf);
free(exe);
if (pathin != NULL) {
char *q, *pathcrt = strdup(pathin);
FILE *crt = NULL;
int on = 0;
q = strrchr(pathcrt, '/');
if (q) {
q = strstr(q, ".pem");
if (q) {
*(q+1) = 'c';
*(q+2) = 'r';
*(q+3) = 't';
crt = fopen(pathcrt, "w");
}
}
if (crt == NULL) {
rfbLog("could not open: %s\n", pathcrt);
rfbLogPerror("fopen");
return NULL;
}
out = fopen(pathin, "w");
chmod(pathin, 0600);
if (out == NULL) {
rfbLog("could not open: %s\n", pathin);
rfbLogPerror("fopen");
fclose(crt);
return NULL;
}
in = fopen(pem, "r");
if (in == NULL) {
rfbLog("could not open: %s\n", pem);
rfbLogPerror("fopen");
fclose(out);
fclose(crt);
unlink(pathin);
unlink(pathcrt);
return NULL;
}
while (fgets(line, 1024, in) != NULL) {
if (strstr(line, "BEGIN CERTIFICATE")) {
on = 1;
}
fprintf(out, "%s", line);
if (on) {
fprintf(crt, "%s", line);
if (!quiet) {
fprintf(stderr, "%s", line);
}
}
if (strstr(line, "END CERTIFICATE")) {
on = 0;
}
if (strstr(line, "PRIVATE KEY")) {
on = 0;
}
}
fclose(in);
fclose(out);
fclose(crt);
}
if (show_cert) {
char cmd[100];
if (inetd) {
sprintf(cmd, "openssl x509 -text -in '%s' 1>&2", pem);
} else {
sprintf(cmd, "openssl x509 -text -in '%s'", pem);
}
fprintf(stderr, "\n");
system(cmd);
fprintf(stderr, "\n");
}
if (pathin) {
unlink(pem);
return strdup(pathin);
} else {
return strdup(pem);
}
}
static int pem_passwd_callback(char *buf, int size, int rwflag,
void *userdata) {
char *q, line[1024];
if (! buf) {
exit(1);
}
fprintf(stderr, "\nA passphrase is needed to unlock an OpenSSL "
"private key (PEM file).\n");
fprintf(stderr, "Enter passphrase> ");
system("stty -echo");
if(fgets(line, 1024, stdin) == NULL) {
fprintf(stdout, "\n");
system("stty echo");
exit(1);
}
system("stty echo");
fprintf(stdout, "\n\n");
q = strrchr(line, '\n');
if (q) {
*q = '\0';
}
line[1024 - 1] = '\0';
strncpy(buf, line, size);
buf[size - 1] = '\0';
if (0) rwflag = 0; /* compiler warning. */
if (0) userdata = 0; /* compiler warning. */
return strlen(buf);
}
static int appendfile(FILE *out, char *infile) {
char line[1024];
FILE *in;
if (! infile) {
rfbLog("appendfile: null infile.\n");
return 0;
}
if (! out) {
rfbLog("appendfile: null out handle.\n");
return 0;
}
in = fopen(infile, "r");
if (in == NULL) {
rfbLog("appendfile: %s\n", infile);
rfbLogPerror("fopen");
return 0;
}
while (fgets(line, 1024, in) != NULL) {
fprintf(out, "%s", line);
}
fclose(in);
return 1;
}
static char *get_ssl_verify_file(char *str_in) {
char *p, *str, *cdir, *tmp;
char *tfile, *tfile2;
FILE *file;
struct stat sbuf;
int count = 0, fd;
if (! str_in) {
rfbLog("get_ssl_verify_file: no filename\n");
exit(1);
}
if (stat(str_in, &sbuf) == 0) {
/* assume he knows what he is doing. */
return str_in;
}
cdir = get_Cert_dir(NULL, &tmp);
if (! cdir || ! tmp) {
rfbLog("get_ssl_verify_file: invalid cert-dir.\n");
exit(1);
}
tfile = (char *) malloc(strlen(tmp) + 1024);
tfile2 = (char *) malloc(strlen(tmp) + 1024);
sprintf(tfile, "%s/sslverify-load-%d.crts.XXXXXX", tmp, getpid());
fd = mkstemp(tfile);
if (fd < 0) {
rfbLog("get_ssl_verify_file: %s\n", tfile);
rfbLogPerror("mkstemp");
exit(1);
}
close(fd);
file = fopen(tfile, "w");
chmod(tfile, 0600);
if (file == NULL) {
rfbLog("get_ssl_verify_file: %s\n", tfile);
rfbLogPerror("fopen");
exit(1);
}
str = strdup(str_in);
p = strtok(str, ",");
while (p) {
if (!strcmp(p, "CA")) {
sprintf(tfile2, "%s/CA/cacert.pem", cdir);
if (! appendfile(file, tfile2)) {
unlink(tfile);
exit(1);
}
rfbLog("sslverify: loaded %s\n", tfile2);
count++;
} else if (!strcmp(p, "clients")) {
DIR *dir;
struct dirent *dp;
sprintf(tfile2, "%s/clients", cdir);
dir = opendir(tfile2);
if (! dir) {
rfbLog("get_ssl_verify_file: %s\n", tfile2);
rfbLogPerror("opendir");
unlink(tfile);
exit(1);
}
while ( (dp = readdir(dir)) != NULL) {
char *n = dp->d_name;
char *q = strstr(n, ".crt");
if (! q || strlen(q) != strlen(".crt")) {
continue;
}
if (strlen(n) > 512) {
continue;
}
sprintf(tfile2, "%s/clients/%s", cdir, n);
if (! appendfile(file, tfile2)) {
unlink(tfile);
exit(1);
}
rfbLog("sslverify: loaded %s\n",
tfile2);
count++;
}
closedir(dir);
} else {
if (strlen(p) > 512) {
unlink(tfile);
exit(1);
}
sprintf(tfile2, "%s/clients/%s.crt", cdir, p);
if (stat(tfile2, &sbuf) != 0) {
sprintf(tfile2, "%s/clients/%s", cdir, p);
}
if (! appendfile(file, tfile2)) {
unlink(tfile);
exit(1);
}
rfbLog("sslverify: loaded %s\n", tfile2);
count++;
}
p = strtok(NULL, ",");
}
fclose(file);
free(tfile2);
free(str);
rfbLog("sslverify: using %d client certs in\n", count);
rfbLog("sslverify: %s\n", tfile);
return tfile;
}
/* based on mod_ssl */
static int crl_callback(X509_STORE_CTX *callback_ctx) {
X509_STORE_CTX store_ctx;
X509_OBJECT obj;
X509_NAME *subject;
X509_NAME *issuer;
X509 *xs;
X509_CRL *crl;
X509_REVOKED *revoked;
EVP_PKEY *pubkey;
long serial;
BIO *bio;
int i, n, rc;
char *cp, *cp2;
ASN1_TIME *t;
/* Determine certificate ingredients in advance */
xs = X509_STORE_CTX_get_current_cert(callback_ctx);
subject = X509_get_subject_name(xs);
issuer = X509_get_issuer_name(xs);
/* Try to retrieve a CRL corresponding to the _subject_ of
* the current certificate in order to verify it's integrity. */
memset((char *)&obj, 0, sizeof(obj));
X509_STORE_CTX_init(&store_ctx, revocation_store, NULL, NULL);
rc=X509_STORE_get_by_subject(&store_ctx, X509_LU_CRL, subject, &obj);
X509_STORE_CTX_cleanup(&store_ctx);
crl=obj.data.crl;
if(rc>0 && crl) {
/* Log information about CRL
* (A little bit complicated because of ASN.1 and BIOs...) */
bio=BIO_new(BIO_s_mem());
BIO_printf(bio, "lastUpdate: ");
ASN1_UTCTIME_print(bio, X509_CRL_get_lastUpdate(crl));
BIO_printf(bio, ", nextUpdate: ");
ASN1_UTCTIME_print(bio, X509_CRL_get_nextUpdate(crl));
n=BIO_pending(bio);
cp=malloc(n+1);
n=BIO_read(bio, cp, n);
cp[n]='\0';
BIO_free(bio);
cp2=X509_NAME_oneline(subject, NULL, 0);
rfbLog("CA CRL: Issuer: %s, %s\n", cp2, cp);
OPENSSL_free(cp2);
free(cp);
/* Verify the signature on this CRL */
pubkey=X509_get_pubkey(xs);
if(X509_CRL_verify(crl, pubkey)<=0) {
rfbLog("Invalid signature on CRL\n");
X509_STORE_CTX_set_error(callback_ctx,
X509_V_ERR_CRL_SIGNATURE_FAILURE);
X509_OBJECT_free_contents(&obj);
if(pubkey)
EVP_PKEY_free(pubkey);
return 0; /* Reject connection */
}
if(pubkey)
EVP_PKEY_free(pubkey);
/* Check date of CRL to make sure it's not expired */
t=X509_CRL_get_nextUpdate(crl);
if(!t) {
rfbLog("Found CRL has invalid nextUpdate field\n");
X509_STORE_CTX_set_error(callback_ctx,
X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD);
X509_OBJECT_free_contents(&obj);
return 0; /* Reject connection */
}
if(X509_cmp_current_time(t)<0) {
rfbLog("Found CRL is expired - "
"revoking all certificates until you get updated CRL\n");
X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_CRL_HAS_EXPIRED);
X509_OBJECT_free_contents(&obj);
return 0; /* Reject connection */
}
X509_OBJECT_free_contents(&obj);
}
/* Try to retrieve a CRL corresponding to the _issuer_ of
* the current certificate in order to check for revocation. */
memset((char *)&obj, 0, sizeof(obj));
X509_STORE_CTX_init(&store_ctx, revocation_store, NULL, NULL);
rc=X509_STORE_get_by_subject(&store_ctx, X509_LU_CRL, issuer, &obj);
X509_STORE_CTX_cleanup(&store_ctx);
crl=obj.data.crl;
if(rc>0 && crl) {
/* Check if the current certificate is revoked by this CRL */
n=sk_X509_REVOKED_num(X509_CRL_get_REVOKED(crl));
for(i=0; i<n; i++) {
revoked=sk_X509_REVOKED_value(X509_CRL_get_REVOKED(crl), i);
if(ASN1_INTEGER_cmp(revoked->serialNumber,
X509_get_serialNumber(xs)) == 0) {
serial=ASN1_INTEGER_get(revoked->serialNumber);
cp=X509_NAME_oneline(issuer, NULL, 0);
rfbLog("Certificate with serial %ld (0x%lX) "
"revoked per CRL from issuer %s\n", serial, serial, cp);
OPENSSL_free(cp);
X509_STORE_CTX_set_error(callback_ctx, X509_V_ERR_CERT_REVOKED);
X509_OBJECT_free_contents(&obj);
return 0; /* Reject connection */
}
}
X509_OBJECT_free_contents(&obj);
}
return 1; /* Accept connection */
}
static int verify_callback(int ok, X509_STORE_CTX *callback_ctx) {
if (!ssl_verify) {
rfbLog("CRL_check: skipped.\n");
return ok;
}
if (!ssl_crl) {
rfbLog("CRL_check: skipped.\n");
return ok;
}
if (!ok) {
rfbLog("CRL_check: client cert is already rejected.\n");
return ok;
}
if (revocation_store) {
if (crl_callback(callback_ctx)) {
rfbLog("CRL_check: succeeded.\n");
return 1;
} else {
rfbLog("CRL_check: did not pass.\n");
return 0;
}
}
/* NOTREACHED */
return 1;
}
#define rfbSecTypeAnonTls 18
#define rfbSecTypeVencrypt 19
#define rfbVencryptPlain 256
#define rfbVencryptTlsNone 257
#define rfbVencryptTlsVnc 258
#define rfbVencryptTlsPlain 259
#define rfbVencryptX509None 260
#define rfbVencryptX509Vnc 261
#define rfbVencryptX509Plain 262
static int vencrypt_selected = 0;
static int anontls_selected = 0;
static int ssl_client_mode = 0;
static int switch_to_anon_dh(void);
void openssl_init(int isclient) {
int db = 0, tmp_pem = 0, do_dh;
FILE *in;
double ds;
long mode;
static int first = 1;
do_dh = DO_DH;
if (enc_str != NULL) {
if (first) {
init_prng();
}
first = 0;
return;
}
if (! quiet) {
rfbLog("\n");
rfbLog("Initializing SSL (%s connect mode).\n", isclient ? "client":"server");
}
if (first) {
if (db) fprintf(stderr, "\nSSL_load_error_strings()\n");
SSL_load_error_strings();
if (db) fprintf(stderr, "SSL_library_init()\n");
SSL_library_init();
if (db) fprintf(stderr, "init_prng()\n");
init_prng();
first = 0;
}
if (isclient) {
ssl_client_mode = 1;
} else {
ssl_client_mode = 0;
}
if (ssl_client_mode) {
if (db) fprintf(stderr, "SSLv23_client_method()\n");
ctx = SSL_CTX_new( SSLv23_client_method() );
} else {
if (db) fprintf(stderr, "SSLv23_server_method()\n");
ctx = SSL_CTX_new( SSLv23_server_method() );
}
if (ctx == NULL) {
rfbLog("openssl_init: SSL_CTX_new failed.\n");
sslerrexit();
}
ds = dnow();
rsa_512 = RSA_generate_key(512, RSA_F4, NULL, NULL);
if (rsa_512 == NULL) {
rfbLog("openssl_init: RSA_generate_key(512) failed.\n");
sslerrexit();
}
rfbLog("created 512 bit temporary RSA key: %.3fs\n", dnow() - ds);
ds = dnow();
rsa_1024 = RSA_generate_key(1024, RSA_F4, NULL, NULL);
if (rsa_1024 == NULL) {
rfbLog("openssl_init: RSA_generate_key(1024) failed.\n");
sslerrexit();
}
rfbLog("created 1024 bit temporary RSA key: %.3fs\n", dnow() - ds);
if (db) fprintf(stderr, "SSL_CTX_set_tmp_rsa()\n");
if (! SSL_CTX_set_tmp_rsa(ctx, rsa_1024)) {
rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
sslerrexit();
}
mode = 0;
mode |= SSL_MODE_ENABLE_PARTIAL_WRITE;
mode |= SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
SSL_CTX_set_mode(ctx, mode);
#define ssl_cache 0
#if ssl_cache
SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
SSL_CTX_set_timeout(ctx, 300);
#else
SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
SSL_CTX_set_timeout(ctx, 1);
#endif
ds = dnow();
if (! openssl_pem) {
openssl_pem = create_tmp_pem(NULL, 0);
if (! openssl_pem) {
rfbLog("openssl_init: could not create temporary,"
" self-signed PEM.\n");
clean_up_exit(1);
}
tmp_pem = 1;
} else if (!strcmp(openssl_pem, "ANON")) {
if (ssl_verify) {
rfbLog("openssl_init: Anonymous Diffie-Hellman cannot"
" be used in -sslverify mode.\n");
clean_up_exit(1);
}
if (ssl_crl) {
rfbLog("openssl_init: Anonymous Diffie-Hellman cannot"
" be used in -sslCRL mode.\n");
clean_up_exit(1);
}
/* n.b. new ctx */
if (!switch_to_anon_dh()) {
rfbLog("openssl_init: Anonymous Diffie-Hellman setup"
" failed.\n");
clean_up_exit(1);
}
} else if (strstr(openssl_pem, "SAVE") == openssl_pem) {
openssl_pem = get_saved_pem(openssl_pem, 1);
if (! openssl_pem) {
rfbLog("openssl_init: could not create or open"
" saved PEM: %s\n", openssl_pem);
clean_up_exit(1);
}
tmp_pem = 0;
}
rfbLog("using PEM %s %.3fs\n", openssl_pem, dnow() - ds);
SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_callback);
if (do_dh) {
DH *dh;
BIO *bio;
ds = dnow();
in = fopen(openssl_pem, "r");
if (in == NULL) {
rfbLogPerror("fopen");
clean_up_exit(1);
}
bio = BIO_new_fp(in, BIO_CLOSE|BIO_FP_TEXT);
if (! bio) {
rfbLog("openssl_init: BIO_new_fp() failed.\n");
sslerrexit();
}
dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
if (dh == NULL) {
rfbLog("openssl_init: PEM_read_bio_DHparams() failed.\n");
BIO_free(bio);
sslerrexit();
}
BIO_free(bio);
SSL_CTX_set_tmp_dh(ctx, dh);
rfbLog("loaded Diffie Hellman %d bits, %.3fs\n",
8*DH_size(dh), dnow()-ds);
DH_free(dh);
}
if (strcmp(openssl_pem, "ANON")) {
if (! SSL_CTX_use_certificate_chain_file(ctx, openssl_pem)) {
rfbLog("openssl_init: SSL_CTX_use_certificate_chain_file() failed.\n");
sslerrexit();
}
if (! SSL_CTX_use_RSAPrivateKey_file(ctx, openssl_pem,
SSL_FILETYPE_PEM)) {
rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
sslerrexit();
}
if (! SSL_CTX_check_private_key(ctx)) {
rfbLog("openssl_init: SSL_CTX_set_tmp_rsa(1024) failed.\n");
sslerrexit();
}
}
if (tmp_pem && ! getenv("X11VNC_KEEP_TMP_PEM")) {
if (getenv("X11VNC_SHOW_TMP_PEM")) {
FILE *in = fopen(openssl_pem, "r");
if (in != NULL) {
char line[128];
fprintf(stderr, "\n");
while (fgets(line, 128, in) != NULL) {
fprintf(stderr, "%s", line);
}
fprintf(stderr, "\n");
fclose(in);
}
}
unlink(openssl_pem);
free(openssl_pem);
openssl_pem = NULL;
}
if (ssl_crl) {
struct stat sbuf;
X509_LOOKUP *lookup;
if (stat(ssl_crl, &sbuf) != 0) {
rfbLog("openssl_init: -sslCRL does not exist %s.\n",
ssl_crl ? ssl_crl : "null");
rfbLogPerror("stat");
clean_up_exit(1);
}
revocation_store = X509_STORE_new();
if (!revocation_store) {
rfbLog("openssl_init: X509_STORE_new failed.\n");
sslerrexit();
}
if (! S_ISDIR(sbuf.st_mode)) {
lookup = X509_STORE_add_lookup(revocation_store, X509_LOOKUP_file());
if (!lookup) {
rfbLog("openssl_init: X509_STORE_add_lookup failed.\n");
sslerrexit();
}
if (!X509_LOOKUP_load_file(lookup, ssl_crl, X509_FILETYPE_PEM)) {
rfbLog("openssl_init: X509_LOOKUP_load_file failed.\n");
sslerrexit();
}
} else {
lookup = X509_STORE_add_lookup(revocation_store, X509_LOOKUP_hash_dir());
if (!lookup) {
rfbLog("openssl_init: X509_STORE_add_lookup failed.\n");
sslerrexit();
}
if (!X509_LOOKUP_add_dir(lookup, ssl_crl, X509_FILETYPE_PEM)) {
rfbLog("openssl_init: X509_LOOKUP_add_dir failed.\n");
sslerrexit();
}
}
rfbLog("loaded CRL file: %s\n", ssl_crl);
}
if (ssl_verify) {
struct stat sbuf;
char *file;
int lvl;
file = get_ssl_verify_file(ssl_verify);
if (!file || stat(file, &sbuf) != 0) {
rfbLog("openssl_init: -sslverify does not exist %s.\n",
file ? file : "null");
rfbLogPerror("stat");
clean_up_exit(1);
}
if (! S_ISDIR(sbuf.st_mode)) {
if (! SSL_CTX_load_verify_locations(ctx, file, NULL)) {
rfbLog("openssl_init: SSL_CTX_load_verify_"
"locations() failed.\n");
sslerrexit();
}
} else {
if (! SSL_CTX_load_verify_locations(ctx, NULL, file)) {
rfbLog("openssl_init: SSL_CTX_load_verify_"
"locations() failed.\n");
sslerrexit();
}
}
lvl = SSL_VERIFY_FAIL_IF_NO_PEER_CERT|SSL_VERIFY_PEER;
if (ssl_crl == NULL) {
SSL_CTX_set_verify(ctx, lvl, NULL);
} else {
SSL_CTX_set_verify(ctx, lvl, verify_callback);
}
if (strstr(file, "tmp/sslverify-load-")) {
/* temporary file */
unlink(file);
}
} else {
SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
}
rfbLog("\n");
}
void openssl_port(void) {
int sock, shutdown = 0;
static int port = 0;
static in_addr_t iface = INADDR_ANY;
int db = 0;
if (! screen) {
rfbLog("openssl_port: no screen!\n");
clean_up_exit(1);
}
if (inetd) {
ssl_initialized = 1;
return;
}
if (screen->listenSock > -1 && screen->port > 0) {
port = screen->port;
shutdown = 1;
}
if (screen->listenInterface) {
iface = screen->listenInterface;
}
if (shutdown) {
if (db) fprintf(stderr, "shutting down %d/%d\n",
port, screen->listenSock);
#if LIBVNCSERVER_HAS_SHUTDOWNSOCKETS
rfbShutdownSockets(screen);
#endif
}
sock = rfbListenOnTCPPort(port, iface);
if (sock < 0) {
rfbLog("openssl_port: could not reopen port %d\n", port);
clean_up_exit(1);
}
rfbLog("openssl_port: listen on port/sock %d/%d\n", port, sock);
if (!quiet) {
announce(port, 1, NULL);
}
openssl_sock = sock;
openssl_port_num = port;
ssl_initialized = 1;
}
void https_port(void) {
int sock;
static int port = 0;
static in_addr_t iface = INADDR_ANY;
int db = 0;
/* as openssl_port above: open a listening socket for pure https: */
if (https_port_num < 0) {
return;
}
if (! screen) {
rfbLog("https_port: no screen!\n");
clean_up_exit(1);
}
if (screen->listenInterface) {
iface = screen->listenInterface;
}
if (https_port_num == 0) {
https_port_num = find_free_port(5801, 5851);
}
if (https_port_num <= 0) {
rfbLog("https_port: could not find port %d\n", https_port_num);
clean_up_exit(1);
}
port = https_port_num;
sock = rfbListenOnTCPPort(port, iface);
if (sock < 0) {
rfbLog("https_port: could not open port %d\n", port);
clean_up_exit(1);
}
if (db) fprintf(stderr, "https_port: listen on port/sock %d/%d\n",
port, sock);
https_sock = sock;
}
static void lose_ram(void) {
/*
* for a forked child that will be around for a long time
* without doing exec(). we really should re-exec, but a pain
* to redo all SSL ctx.
*/
free_old_fb();
free_tiles();
}
/* utility to keep track of existing helper processes: */
void ssl_helper_pid(pid_t pid, int sock) {
# define HPSIZE 256
static pid_t helpers[HPSIZE];
static int sockets[HPSIZE], first = 1;
int i, empty, set, status, db = 0;
if (first) {
for (i=0; i < HPSIZE; i++) {
helpers[i] = 0;
sockets[i] = 0;
}
first = 0;
}
if (pid == 0) {
/* killall */
for (i=0; i < HPSIZE; i++) {
if (helpers[i] == 0) {
sockets[i] = -1;
continue;
}
if (kill(helpers[i], 0) == 0) {
int kret = -2;
pid_t wret;
if (sock != -2) {
if (sockets[i] >= 0) {
close(sockets[i]);
}
kret = kill(helpers[i], SIGTERM);
if (kret == 0) {
usleep(20 * 1000);
}
}
#if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID
if (db) fprintf(stderr, "waitpid(%d)\n", helpers[i]);
wret = waitpid(helpers[i], &status, WNOHANG);
if (kret == 0 && wret != helpers[i]) {
int k;
for (k=0; k < 10; k++) {
usleep(100 * 1000);
wret = waitpid(helpers[i], &status, WNOHANG);
if (wret == helpers[i]) {
break;
}
}
}
#endif
if (sock == -2) {
continue;
}
}
helpers[i] = 0;
sockets[i] = -1;
}
return;
}
if (db) fprintf(stderr, "ssl_helper_pid(%d, %d)\n", pid, sock);
/* add (or delete for sock == -1) */
set = 0;
empty = -1;
for (i=0; i < HPSIZE; i++) {
if (helpers[i] == pid) {
if (sock == -1) {
#if LIBVNCSERVER_HAVE_SYS_WAIT_H && LIBVNCSERVER_HAVE_WAITPID
if (db) fprintf(stderr, "waitpid(%d) 2\n", helpers[i]);
waitpid(helpers[i], &status, WNOHANG);
#endif
helpers[i] = 0;
}
sockets[i] = sock;
set = 1;
} else if (empty == -1 && helpers[i] == 0) {
empty = i;
}
}
if (set || sock == -1) {
return; /* done */
}
/* now try to store */
if (empty >= 0) {
helpers[empty] = pid;
sockets[empty] = sock;
return;
}
for (i=0; i < HPSIZE; i++) {
if (helpers[i] == 0) {
continue;
}
/* clear out stale pids: */
if (kill(helpers[i], 0) != 0) {
helpers[i] = 0;
sockets[i] = -1;
if (empty == -1) {
empty = i;
}
}
}
if (empty >= 0) {
helpers[empty] = pid;
sockets[empty] = sock;
}
}
static int is_ssl_readable(int s_in, time_t last_https, char *last_get,
int mode) {
int nfd, db = 0;
struct timeval tv;
fd_set rd;
if (getenv("ACCEPT_OPENSSL_DEBUG")) {
db = atoi(getenv("ACCEPT_OPENSSL_DEBUG"));
}
/*
* we'll do a select() on s_in for reading. this is not an
* absolute proof that SSL_read is ready (XXX use SSL utility).
*/
tv.tv_sec = 2;
tv.tv_usec = 0;
if (mode == OPENSSL_INETD) {
/*
* https via inetd is icky because x11vnc is restarted
* for each socket (and some clients send requests
* rapid fire).
*/
tv.tv_sec = 6;
}
/*
* increase the timeout if we know HTTP traffic has occurred
* recently:
*/
if (time(NULL) < last_https + 30) {
tv.tv_sec = 10;
if (last_get && strstr(last_get, "VncViewer")) {
tv.tv_sec = 5;
}
}
if (getenv("X11VNC_HTTPS_VS_VNC_TIMEOUT")) {
tv.tv_sec = atoi(getenv("X11VNC_HTTPS_VS_VNC_TIMEOUT"));
}
if (db) fprintf(stderr, "tv_sec: %d - %s\n", (int) tv.tv_sec, last_get);
FD_ZERO(&rd);
FD_SET(s_in, &rd);
do {
nfd = select(s_in+1, &rd, NULL, NULL, &tv);
} while (nfd < 0 && errno == EINTR);
if (db) fprintf(stderr, "https nfd: %d\n", nfd);
if (nfd <= 0 || ! FD_ISSET(s_in, &rd)) {
return 0;
}
return 1;
}
#define ABSIZE 16384
static int watch_for_http_traffic(char *buf_a, int *n_a, int raw_sock) {
int is_http, err, n, n2;
char *buf;
int db = 0;
/*
* sniff the first couple bytes of the stream and try to see
* if it is http or not. if we read them OK, we must read the
* rest of the available data otherwise we may deadlock.
* what has been read is returned in buf_a and n_a.
* *buf_a is ABSIZE+1 long and zeroed.
*/
if (getenv("ACCEPT_OPENSSL_DEBUG")) {
db = atoi(getenv("ACCEPT_OPENSSL_DEBUG"));
}
if (! buf_a || ! n_a) {
return 0;
}
buf = (char *) calloc((ABSIZE+1), 1);
*n_a = 0;
if (enc_str && !strcmp(enc_str, "none")) {
n = read(raw_sock, buf, 2);
err = SSL_ERROR_NONE;
} else {
n = SSL_read(ssl, buf, 2);
err = SSL_get_error(ssl, n);
}
if (err != SSL_ERROR_NONE || n < 2) {
if (n > 0) {
strncpy(buf_a, buf, n);
*n_a = n;
}
if (db) fprintf(stderr, "watch_for_http_traffic ssl err: %d/%d\n", err, n);
return -1;
}
/* look for GET, HEAD, POST, CONNECT */
is_http = 0;
if (!strncmp("GE", buf, 2)) {
is_http = 1;
} else if (!strncmp("HE", buf, 2)) {
is_http = 1;
} else if (!strncmp("PO", buf, 2)) {
is_http = 1;
} else if (!strncmp("CO", buf, 2)) {
is_http = 1;
}
if (db) fprintf(stderr, "watch_for_http_traffic read: '%s' %d\n", buf, n);
/*
* better read all we can and fwd it along to avoid blocking
* in ssl_xfer().
*/
if (enc_str && !strcmp(enc_str, "none")) {
n2 = read(raw_sock, buf + n, ABSIZE - n);
} else {
n2 = SSL_read(ssl, buf + n, ABSIZE - n);
}
if (n2 >= 0) {
n += n2;
}
*n_a = n;
if (db) fprintf(stderr, "watch_for_http_traffic readmore: %d\n", n2);
if (n > 0) {
memcpy(buf_a, buf, n);
}
if (db > 1) {
fprintf(stderr, "watch_for_http_traffic readmore: ");
write(2, buf_a, *n_a);
fprintf(stderr, "\n");
}
if (db) fprintf(stderr, "watch_for_http_traffic return: %d\n", is_http);
return is_http;
}
static int csock_timeout_sock = -1;
static void csock_timeout (int sig) {
rfbLog("sig: %d, csock_timeout.\n", sig);
if (csock_timeout_sock >= 0) {
close(csock_timeout_sock);
csock_timeout_sock = -1;
}
}
#define PROXY_HACK 0
#if PROXY_HACK
static int wait_conn(int sock) {
int conn;
struct sockaddr_in addr;
#ifdef __hpux
int addrlen = sizeof(addr);
#else
socklen_t addrlen = sizeof(addr);
#endif
signal(SIGALRM, csock_timeout);
csock_timeout_sock = sock;
alarm(15);
conn = accept(sock, (struct sockaddr *)&addr, &addrlen);
alarm(0);
signal(SIGALRM, SIG_DFL);
return conn;
}
/* no longer used */
int proxy_hack(int vncsock, int listen, int s_in, int s_out, char *cookie,
int mode) {
int sock1, db = 0;
char reply[] = "HTTP/1.1 200 OK\r\n"
"Content-Type: octet-stream\r\n"
"Pragma: no-cache\r\n\r\n";
char reply0[] = "HTTP/1.0 200 OK\r\n"
"Content-Type: octet-stream\r\n"
"Content-Length: 9\r\n"
"Pragma: no-cache\r\n\r\nGO_AHEAD\n";
rfbLog("SSL: accept_openssl: detected https proxied connection"
" request.\n");
if (getenv("ACCEPT_OPENSSL_DEBUG")) {
db = atoi(getenv("ACCEPT_OPENSSL_DEBUG"));
}
SSL_write(ssl, reply0, strlen(reply0));
SSL_shutdown(ssl);
SSL_shutdown(ssl);
close(s_in);
close(s_out);
SSL_free(ssl);
if (mode == OPENSSL_VNC) {
listen = openssl_sock;
} else if (mode == OPENSSL_HTTPS) {
listen = https_sock;
} else {
/* inetd */
return 0;
}
sock1 = wait_conn(listen);
if (csock_timeout_sock < 0 || sock1 < 0) {
close(sock1);
return 0;
}
if (db) fprintf(stderr, "got applet input sock1: %d\n", sock1);
if (! ssl_init(sock1, sock1, 0)) {
if (db) fprintf(stderr, "ssl_init FAILED\n");
exit(1);
}
SSL_write(ssl, reply, strlen(reply));
{
char *buf;
int n = 0, ptr = 0;
buf = (char *) calloc((8192+1), 1);
while (ptr < 8192) {
n = SSL_read(ssl, buf + ptr, 8192 - ptr);
if (n > 0) {
ptr += n;
}
if (db) fprintf(stderr, "buf: '%s'\n", buf);
if (strstr(buf, "\r\n\r\n")) {
break;
}
}
}
if (cookie) {
write(vncsock, cookie, strlen(cookie));
}
ssl_xfer(vncsock, sock1, sock1, 0);
return 1;
}
#endif /* PROXY_HACK */
static int check_ssl_access(char *addr) {
static char *save_allow_once = NULL;
static time_t time_allow_once = 0;
/* due to "Fetch Cert" activities for SSL really need to "allow twice" */
if (allow_once != NULL) {
save_allow_once = strdup(allow_once);
time_allow_once = time(NULL);
} else if (save_allow_once != NULL) {
if (getenv("X11VNC_NO_SSL_ALLOW_TWICE")) {
;
} else if (time(NULL) < time_allow_once + 30) {
/* give them 30 secs to check and save the fetched cert. */
allow_once = save_allow_once;
rfbLog("SSL: Permitting 30 sec grace period for allowonce.\n");
rfbLog("SSL: Set X11VNC_NO_SSL_ALLOW_TWICE=1 to disable.\n");
}
save_allow_once = NULL;
time_allow_once = 0;
}
return check_access(addr);
}
static int write_exact(int sock, char *buf, int len);
static int read_exact(int sock, char *buf, int len);
/* XXX not in rfb.h: */
void rfbClientSendString(rfbClientPtr cl, char *reason);
static int finish_auth(rfbClientPtr client, char *type) {
int security_result, ret;
ret = 0;
if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "finish_auth type=%s\n", type);
if (!strcmp(type, "None")) {
security_result = 0; /* success */
if (write_exact(client->sock, (char *) &security_result, 4)) {
ret = 1;
}
rfbLog("finish_auth: using auth 'None'\n");
client->state = RFB_INITIALISATION;
} else if (!strcmp(type, "Vnc")) {
RAND_bytes(client->authChallenge, CHALLENGESIZE);
if (write_exact(client->sock, (char *) &client->authChallenge, CHALLENGESIZE)) {
ret = 1;
}
rfbLog("finish_auth: using auth 'Vnc', sent challenge.\n");
client->state = RFB_AUTHENTICATION;
} else if (!strcmp(type, "Plain")) {
if (!unixpw) {
rfbLog("finish_auth: *Plain not allowed outside unixpw mode.\n");
ret = 0;
} else {
char *un, *pw;
int unlen, pwlen;
if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "*Plain begin: onHold=%d client=%p unixpw_client=%p\n", client->onHold, (void *) client, (void *) unixpw_client);
if (!read_exact(client->sock, (char *)&unlen, 4)) goto fail;
unlen = Swap32IfLE(unlen);
if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "unlen: %d\n", unlen);
if (!read_exact(client->sock, (char *)&pwlen, 4)) goto fail;
pwlen = Swap32IfLE(pwlen);
if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "pwlen: %d\n", pwlen);
un = (char *) malloc(unlen+1);
memset(un, 0, unlen+1);
pw = (char *) malloc(pwlen+2);
memset(pw, 0, pwlen+2);
if (!read_exact(client->sock, un, unlen)) goto fail;
if (!read_exact(client->sock, pw, pwlen)) goto fail;
if (getenv("X11VNC_DEBUG_TLSPLAIN")) fprintf(stderr, "*Plain: %d %d '%s' ... \n", unlen, pwlen, un);
strcat(pw, "\n");
if (unixpw_verify(un, pw)) {
security_result = 0; /* success */
if (write_exact(client->sock, (char *) &security_result, 4)) {
ret = 1;
unixpw_verify_screen(un, pw);
}
client->onHold = FALSE;
client->state = RFB_INITIALISATION;
}
if (ret == 0) {
rfbClientSendString(client, "unixpw failed");
}
memset(un, 0, unlen+1);
memset(pw, 0, pwlen+2);
free(un);
free(pw);
}
} else {
rfbLog("finish_auth: unknown sub-type: %s\n", type);
ret = 0;
}
fail:
return ret;
}
static int finish_vencrypt_auth(rfbClientPtr client, int subtype) {
if (subtype == rfbVencryptTlsNone || subtype == rfbVencryptX509None) {
return finish_auth(client, "None");
} else if (subtype == rfbVencryptTlsVnc || subtype == rfbVencryptX509Vnc) {
return finish_auth(client, "Vnc");
} else if (subtype == rfbVencryptTlsPlain || subtype == rfbVencryptX509Plain) {
return finish_auth(client, "Plain");
} else {
rfbLog("finish_vencrypt_auth: unknown sub-type: %d\n", subtype);
return 0;
}
}
void accept_openssl(int mode, int presock) {
int sock = -1, listen = -1, cport, csock, vsock;
int peerport = 0;
int status, n, i, db = 0;
struct sockaddr_in addr;
#ifdef __hpux
int addrlen = sizeof(addr);
#else
socklen_t addrlen = sizeof(addr);
#endif
rfbClientPtr client;
pid_t pid;
char uniq[] = "_evilrats_";
char cookie[256], rcookie[256], *name = NULL;
int vencrypt_sel = 0;
int anontls_sel = 0;
static time_t last_https = 0;
static char last_get[256];
static int first = 1;
unsigned char *rb;
openssl_last_helper_pid = 0;
/* zero buffers for use below. */
for (i=0; i<256; i++) {
if (first) {
last_get[i] = '\0';
}
cookie[i] = '\0';
rcookie[i] = '\0';
}
first = 0;
if (getenv("ACCEPT_OPENSSL_DEBUG")) {
db = atoi(getenv("ACCEPT_OPENSSL_DEBUG"));
}
/* do INETD, VNC, or HTTPS cases (result is client socket or pipe) */
if (mode == OPENSSL_INETD) {
ssl_initialized = 1;
} else if (mode == OPENSSL_VNC) {
sock = accept(openssl_sock, (struct sockaddr *)&addr, &addrlen);
if (sock < 0) {
rfbLog("SSL: accept_openssl: accept connection failed\n");
rfbLogPerror("accept");
if (ssl_no_fail) {
clean_up_exit(1);
}
return;
}
listen = openssl_sock;
} else if (mode == OPENSSL_REVERSE) {
sock = presock;
if (sock < 0) {
rfbLog("SSL: accept_openssl: connection failed\n");
if (ssl_no_fail) {
clean_up_exit(1);
}
return;
}
listen = -1;
} else if (mode == OPENSSL_HTTPS) {
sock = accept(https_sock, (struct sockaddr *)&addr, &addrlen);
if (sock < 0) {
rfbLog("SSL: accept_openssl: accept connection failed\n");
rfbLogPerror("accept");
if (ssl_no_fail) {
clean_up_exit(1);
}
return;
}
listen = https_sock;
}
if (db) fprintf(stderr, "SSL: accept_openssl: sock: %d\n", sock);
if (openssl_last_ip) {
free(openssl_last_ip);
openssl_last_ip = NULL;
}
if (mode == OPENSSL_INETD) {
openssl_last_ip = get_remote_host(fileno(stdin));
} else {
openssl_last_ip = get_remote_host(sock);
}
if (!check_ssl_access(openssl_last_ip)) {
rfbLog("SSL: accept_openssl: denying client %s\n", openssl_last_ip);
rfbLog("SSL: accept_openssl: does not match -allow (or other reason).\n");
close(sock);
sock = -1;
if (ssl_no_fail) {
clean_up_exit(1);
}
return;
}
/* now make a listening socket for child to connect back to us by: */
cport = find_free_port(20000, 0);
if (! cport) {
rfbLog("SSL: accept_openssl: could not find open port.\n");
close(sock);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
return;
}
if (db) fprintf(stderr, "accept_openssl: cport: %d\n", cport);
csock = rfbListenOnTCPPort(cport, htonl(INADDR_LOOPBACK));
if (csock < 0) {
rfbLog("SSL: accept_openssl: could not listen on port %d.\n",
cport);
close(sock);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
return;
}
if (db) fprintf(stderr, "accept_openssl: csock: %d\n", csock);
fflush(stderr);
/*
* make a simple cookie to id the child socket, not foolproof
* but hard to guess exactly (just worrying about local lusers
* here, since we use INADDR_LOOPBACK).
*/
rb = (unsigned char *) calloc(6, 1);
RAND_bytes(rb, 6);
sprintf(cookie, "RB=%d%d%d%d%d%d/%f%f/%p",
rb[0], rb[1], rb[2], rb[3], rb[4], rb[5],
dnow() - x11vnc_start, x11vnc_start, (void *)rb);
if (mode != OPENSSL_INETD) {
name = get_remote_host(sock);
peerport = get_remote_port(sock);
} else {
openssl_last_ip = get_remote_host(fileno(stdin));
peerport = get_remote_port(fileno(stdin));
if (openssl_last_ip) {
name = strdup(openssl_last_ip);
} else {
name = strdup("unknown");
}
}
if (name) {
if (mode == OPENSSL_INETD) {
rfbLog("SSL: (inetd) spawning helper process "
"to handle: %s:%d\n", name, peerport);
} else {
rfbLog("SSL: spawning helper process to handle: "
"%s:%d\n", name, peerport);
}
free(name);
name = NULL;
}
if (certret) {
free(certret);
}
if (certret_str) {
free(certret_str);
certret_str = NULL;
}
certret = strdup("/tmp/x11vnc-certret.XXXXXX");
omode = umask(077);
certret_fd = mkstemp(certret);
umask(omode);
if (certret_fd < 0) {
free(certret);
certret = NULL;
certret_fd = -1;
}
if (dhret) {
free(dhret);
}
if (dhret_str) {
free(dhret_str);
dhret_str = NULL;
}
dhret = strdup("/tmp/x11vnc-dhret.XXXXXX");
omode = umask(077);
dhret_fd = mkstemp(dhret);
umask(omode);
if (dhret_fd < 0) {
free(dhret);
dhret = NULL;
dhret_fd = -1;
}
/* now fork the child to handle the SSL: */
pid = fork();
if (pid < 0) {
rfbLog("SSL: accept_openssl: could not fork.\n");
rfbLogPerror("fork");
close(sock);
close(csock);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
return;
} else if (pid == 0) {
int s_in, s_out, httpsock = -1;
int vncsock;
int i, have_httpd = 0;
int f_in = fileno(stdin);
int f_out = fileno(stdout);
int skip_vnc_tls = mode == OPENSSL_HTTPS ? 1 : 0;
if (db) fprintf(stderr, "helper pid in: %d %d %d %d\n", f_in, f_out, sock, listen);
/* reset all handlers to default (no interrupted() calls) */
unset_signals();
/* close all non-essential fd's */
for (i=0; i<256; i++) {
if (mode == OPENSSL_INETD) {
if (i == f_in || i == f_out) {
continue;
}
}
if (i == sock) {
continue;
}
if (i == 2) {
continue;
}
close(i);
}
/*
* sadly, we are a long lived child and so the large
* framebuffer memory areas will soon differ from parent.
* try to free as much as possible.
*/
lose_ram();
/* now connect back to parent socket: */
vncsock = rfbConnectToTcpAddr("127.0.0.1", cport);
if (vncsock < 0) {
rfbLog("SSL: ssl_helper[%d]: could not connect"
" back to: %d\n", getpid(), cport);
exit(1);
}
if (db) fprintf(stderr, "vncsock %d\n", vncsock);
/* try to initialize SSL with the remote client */
if (mode == OPENSSL_INETD) {
s_in = fileno(stdin);
s_out = fileno(stdout);
} else {
s_in = s_out = sock;
}
if (! ssl_init(s_in, s_out, skip_vnc_tls)) {
close(vncsock);
exit(1);
}
if (vencrypt_selected != 0) {
char *tbuf;
tbuf = (char *) malloc(strlen(cookie) + 100);
sprintf(tbuf, "%s,VENCRYPT=%d,%s", uniq, vencrypt_selected, cookie);
write(vncsock, tbuf, strlen(cookie));
goto wrote_cookie;
} else if (anontls_selected != 0) {
char *tbuf;
tbuf = (char *) malloc(strlen(cookie) + 100);
sprintf(tbuf, "%s,ANONTLS=%d,%s", uniq, anontls_selected, cookie);
write(vncsock, tbuf, strlen(cookie));
goto wrote_cookie;
}
/*
* things get messy below since we are trying to do
* *both* VNC and Java applet httpd through the same
* SSL socket.
*/
if (! screen) {
close(vncsock);
exit(1);
}
if (screen->httpListenSock >= 0 && screen->httpPort > 0) {
have_httpd = 1;
}
if (screen->httpListenSock == -2) {
have_httpd = 1;
}
if (mode == OPENSSL_HTTPS && ! have_httpd) {
rfbLog("SSL: accept_openssl[%d]: no httpd socket for "
"-https mode\n", getpid());
close(vncsock);
exit(1);
}
if (have_httpd) {
int n = 0, is_http = 0;
int hport = screen->httpPort;
char *iface = NULL;
char *buf, *tbuf;
buf = (char *) calloc((ABSIZE+1), 1);
tbuf = (char *) calloc((2*ABSIZE+1), 1);
if (mode == OPENSSL_HTTPS) {
/*
* for this mode we know it is HTTP traffic
* so we skip trying to guess.
*/
is_http = 1;
n = 0;
goto connect_to_httpd;
}
/*
* Check if there is stuff to read from remote end
* if so it is likely a GET or HEAD.
*/
if (! is_ssl_readable(s_in, last_https, last_get,
mode)) {
goto write_cookie;
}
/*
* read first 2 bytes to try to guess. sadly,
* the user is often pondering a "non-verified
* cert" dialog for a long time before the GET
* is ever sent. So often we timeout here.
*/
if (db) fprintf(stderr, "watch_for_http_traffic\n");
is_http = watch_for_http_traffic(buf, &n, s_in);
if (is_http < 0 || is_http == 0) {
/*
* error or http not detected, fall back
* to normal VNC socket.
*/
if (db) fprintf(stderr, "is_http err: %d n: %d\n", is_http, n);
write(vncsock, cookie, strlen(cookie));
if (n > 0) {
write(vncsock, buf, n);
}
goto wrote_cookie;
}
if (db) fprintf(stderr, "is_http: %d n: %d\n",
is_http, n);
if (db) fprintf(stderr, "buf: '%s'\n", buf);
if (strstr(buf, "/request.https.vnc.connection")) {
char reply[] = "HTTP/1.0 200 OK\r\n"
"Content-Type: octet-stream\r\n"
"Connection: Keep-Alive\r\n"
"Pragma: no-cache\r\n\r\n";
/*
* special case proxy coming thru https
* instead of a direct SSL connection.
*/
rfbLog("Handling VNC request via https GET. [%d]\n", getpid());
rfbLog("-- %s\n", buf);
if (strstr(buf, "/reverse.proxy")) {
char *buf2;
int n, ptr;
SSL_write(ssl, reply, strlen(reply));
buf2 = (char *) calloc((8192+1), 1);
n = 0;
ptr = 0;
while (ptr < 8192) {
n = SSL_read(ssl, buf2 + ptr, 1);
if (n > 0) {
ptr += n;
}
if (db) fprintf(stderr, "buf2: '%s'\n", buf2);
if (strstr(buf2, "\r\n\r\n")) {
break;
}
}
free(buf2);
}
goto write_cookie;
} else if (strstr(buf, "/check.https.proxy.connection")) {
char reply[] = "HTTP/1.0 200 OK\r\n"
"Connection: close\r\n"
"Content-Type: octet-stream\r\n"
"Pragma: no-cache\r\n\r\n";
rfbLog("Handling Check HTTPS request via https GET. [%d]\n", getpid());
rfbLog("-- %s\n", buf);
SSL_write(ssl, reply, strlen(reply));
SSL_shutdown(ssl);
strcpy(tbuf, uniq);
strcat(tbuf, cookie);
write(vncsock, tbuf, strlen(tbuf));
close(vncsock);
exit(0);
}
connect_to_httpd:
/*
* Here we go... no turning back. we have to
* send failure to parent and close socket to have
* http processed at all in a timely fashion...
*/
/* send the failure tag: */
strcpy(tbuf, uniq);
if (https_port_redir < 0 || (strstr(buf, "PORT=") || strstr(buf, "port="))) {
char *q = strstr(buf, "Host:");
int fport = 443, match = 0;
char num[16];
if (q && strstr(q, "\n")) {
q += strlen("Host:") + 1;
while (*q != '\n') {
int p;
if (*q == ':' && sscanf(q, ":%d", &p) == 1) {
if (p > 0 && p < 65536) {
fport = p;
match = 1;
break;
}
}
q++;
}
}
if (!match || !https_port_redir) {
int p;
if (sscanf(buf, "PORT=%d,", &p) == 1) {
if (p > 0 && p < 65536) {
fport = p;
}
} else if (sscanf(buf, "port=%d,", &p) == 1) {
if (p > 0 && p < 65536) {
fport = p;
}
}
}
sprintf(num, "HP=%d,", fport);
strcat(tbuf, num);
}
if (strstr(buf, "HTTP/") != NULL) {
char *q, *str;
/*
* Also send back the GET line for heuristics.
* (last_https, get file).
*/
str = strdup(buf);
q = strstr(str, "HTTP/");
if (q != NULL) {
*q = '\0';
strcat(tbuf, str);
}
free(str);
}
/*
* Also send the cookie to pad out the number of
* bytes to more than the parent wants to read.
* Since this is the failure case, it does not
* matter that we send more than strlen(cookie).
*/
strcat(tbuf, cookie);
write(vncsock, tbuf, strlen(tbuf));
usleep(150*1000);
if (db) fprintf(stderr, "close vncsock: %d\n", vncsock);
close(vncsock);
/* now, finally, connect to the libvncserver httpd: */
if (screen->listenInterface == htonl(INADDR_ANY) ||
screen->listenInterface == htonl(INADDR_NONE)) {
iface = "127.0.0.1";
} else {
struct in_addr in;
in.s_addr = screen->listenInterface;
iface = inet_ntoa(in);
}
if (iface == NULL || !strcmp(iface, "")) {
iface = "127.0.0.1";
}
if (db) fprintf(stderr, "iface: %s:%d\n", iface, hport);
usleep(150*1000);
httpsock = rfbConnectToTcpAddr(iface, hport);
if (httpsock < 0) {
/* UGH, after all of that! */
rfbLog("Could not connect to httpd socket!\n");
exit(1);
}
if (db) fprintf(stderr, "ssl_helper[%d]: httpsock: %d %d\n",
getpid(), httpsock, n);
/*
* send what we read to httpd, and then connect
* the rest of the SSL session to it:
*/
if (n > 0) {
if (db) fprintf(stderr, "sending http buffer httpsock: %d\n'%s'\n", httpsock, buf);
write(httpsock, buf, n);
}
ssl_xfer(httpsock, s_in, s_out, is_http);
exit(0);
}
/*
* ok, back from the above https mess, simply send the
* cookie back to the parent (who will attach us to
* libvncserver), and connect the rest of the SSL session
* to it.
*/
write_cookie:
write(vncsock, cookie, strlen(cookie));
wrote_cookie:
ssl_xfer(vncsock, s_in, s_out, 0);
exit(0);
}
/* parent here */
if (mode != OPENSSL_INETD) {
close(sock);
}
if (db) fprintf(stderr, "helper process is: %d\n", pid);
/* accept connection from our child. */
signal(SIGALRM, csock_timeout);
csock_timeout_sock = csock;
alarm(20);
vsock = accept(csock, (struct sockaddr *)&addr, &addrlen);
alarm(0);
signal(SIGALRM, SIG_DFL);
close(csock);
if (vsock < 0) {
rfbLog("SSL: accept_openssl: connection from ssl_helper FAILED.\n");
rfbLogPerror("accept");
kill(pid, SIGTERM);
waitpid(pid, &status, WNOHANG);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
if (certret_fd >= 0) {
close(certret_fd);
certret_fd = -1;
}
if (certret) {
unlink(certret);
}
if (dhret_fd >= 0) {
close(dhret_fd);
dhret_fd = -1;
}
if (dhret) {
unlink(dhret);
}
return;
}
if (db) fprintf(stderr, "accept_openssl: vsock: %d\n", vsock);
n = read(vsock, rcookie, strlen(cookie));
if (n < 0 && errno != 0) {
rfbLogPerror("read");
}
if (certret) {
struct stat sbuf;
sbuf.st_size = 0;
if (certret_fd >= 0 && stat(certret, &sbuf) == 0 && sbuf.st_size > 0) {
certret_str = (char *) calloc(sbuf.st_size+1, 1);
read(certret_fd, certret_str, sbuf.st_size);
close(certret_fd);
certret_fd = -1;
}
if (certret_fd >= 0) {
close(certret_fd);
certret_fd = -1;
}
unlink(certret);
if (certret_str && strstr(certret_str, "NOCERT") == certret_str) {
free(certret_str);
certret_str = NULL;
}
if (0 && certret_str) {
fprintf(stderr, "certret_str[%d]:\n%s\n", (int) sbuf.st_size, certret_str);
}
}
if (dhret) {
struct stat sbuf;
sbuf.st_size = 0;
if (dhret_fd >= 0 && stat(dhret, &sbuf) == 0 && sbuf.st_size > 0) {
dhret_str = (char *) calloc(sbuf.st_size+1, 1);
read(dhret_fd, dhret_str, sbuf.st_size);
close(dhret_fd);
dhret_fd = -1;
}
if (dhret_fd >= 0) {
close(dhret_fd);
dhret_fd = -1;
}
unlink(dhret);
if (dhret_str && strstr(dhret_str, "NOCERT") == dhret_str) {
free(dhret_str);
dhret_str = NULL;
}
if (dhret_str) {
if (new_dh_params == NULL) {
fprintf(stderr, "dhret_str[%d]:\n%s\n", (int) sbuf.st_size, dhret_str);
new_dh_params = strdup(dhret_str);
}
}
}
if (0) {
fprintf(stderr, "rcookie: %s\n", rcookie);
fprintf(stderr, "cookie: %s\n", cookie);
}
if (strstr(rcookie, uniq) == rcookie) {
char *q = strstr(rcookie, "RB=");
if (q && strstr(cookie, q) == cookie) {
vencrypt_sel = 0;
anontls_sel = 0;
q = strstr(rcookie, "VENCRYPT=");
if (q && sscanf(q, "VENCRYPT=%d,", &vencrypt_sel) == 1) {
if (vencrypt_sel != 0) {
rfbLog("SSL: VENCRYPT mode=%d accepted.\n", vencrypt_sel);
goto accept_client;
}
}
q = strstr(rcookie, "ANONTLS=");
if (q && sscanf(q, "ANONTLS=%d,", &anontls_sel) == 1) {
if (anontls_sel != 0) {
rfbLog("SSL: ANONTLS mode=%d accepted.\n", anontls_sel);
goto accept_client;
}
}
}
}
if (n != (int) strlen(cookie) || strncmp(cookie, rcookie, n)) {
rfbLog("SSL: accept_openssl: cookie from ssl_helper FAILED. %d\n", n);
if (db) fprintf(stderr, "'%s'\n'%s'\n", cookie, rcookie);
close(vsock);
if (strstr(rcookie, uniq) == rcookie) {
int i;
rfbLog("SSL: BUT WAIT! HTTPS for helper process succeeded. Good.\n");
if (mode != OPENSSL_HTTPS) {
last_https = time(NULL);
for (i=0; i<256; i++) {
last_get[i] = '\0';
}
strncpy(last_get, rcookie, 100);
if (db) fprintf(stderr, "last_get: '%s'\n", last_get);
}
if (rcookie && strstr(rcookie, "VncViewer.class")) {
rfbLog("\n");
rfbLog("***********************************************************\n");
rfbLog("SSL: WARNING CLIENT ASKED FOR NONEXISTENT 'VncViewer.class'\n");
rfbLog("SSL: USER NEEDS TO **RESTART** HIS WEB BROWSER.\n");
rfbLog("***********************************************************\n");
rfbLog("\n");
}
ssl_helper_pid(pid, -2);
if (https_port_redir) {
double start;
int origport = screen->port;
int useport = screen->port;
/* to expand $PORT correctly in index.vnc */
if (https_port_redir < 0) {
char *q = strstr(rcookie, "HP=");
if (q) {
int p;
if (sscanf(q, "HP=%d,", &p) == 1) {
useport = p;
}
}
} else {
useport = https_port_redir;
}
screen->port = useport;
if (origport != useport) {
rfbLog("SSL: -httpsredir guess port: %d\n", screen->port);
}
start = dnow();
while (dnow() < start + 10.0) {
rfbPE(10000);
usleep(10000);
waitpid(pid, &status, WNOHANG);
if (kill(pid, 0) != 0) {
rfbPE(10000);
rfbPE(10000);
break;
}
}
screen->port = origport;
rfbLog("SSL: guessing child https finished.\n");
if (mode == OPENSSL_INETD) {
clean_up_exit(1);
}
} else if (mode == OPENSSL_INETD) {
double start;
/* to expand $PORT correctly in index.vnc */
if (screen->port == 0) {
int fd = fileno(stdin);
if (getenv("X11VNC_INETD_PORT")) {
screen->port = atoi(getenv(
"X11VNC_INETD_PORT"));
} else {
int tport = get_local_port(fd);
if (tport > 0) {
screen->port = tport;
}
}
}
rfbLog("SSL: screen->port %d\n", screen->port);
/* kludge for https fetch via inetd */
start = dnow();
while (dnow() < start + 10.0) {
rfbPE(10000);
usleep(10000);
waitpid(pid, &status, WNOHANG);
if (kill(pid, 0) != 0) {
rfbPE(10000);
rfbPE(10000);
break;
}
}
rfbLog("SSL: OPENSSL_INETD guessing "
"child https finished.\n");
clean_up_exit(1);
}
return;
}
kill(pid, SIGTERM);
waitpid(pid, &status, WNOHANG);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
return;
}
accept_client:
if (db) fprintf(stderr, "accept_openssl: cookie good: %s\n", cookie);
rfbLog("SSL: handshake with helper process succeeded.\n");
openssl_last_helper_pid = pid;
ssl_helper_pid(pid, vsock);
if (vnc_redirect) {
vnc_redirect_sock = vsock;
openssl_last_helper_pid = 0;
return;
}
client = rfbNewClient(screen, vsock);
openssl_last_helper_pid = 0;
if (client) {
if (db) fprintf(stderr, "accept_openssl: client %p\n", (void *) client);
if (db) fprintf(stderr, "accept_openssl: new_client %p\n", (void *) screen->newClientHook);
if (db) fprintf(stderr, "accept_openssl: new_client %p\n", (void *) new_client);
if (mode == OPENSSL_INETD) {
inetd_client = client;
client->clientGoneHook = client_gone;
}
if (openssl_last_ip &&
strpbrk(openssl_last_ip, "0123456789") == openssl_last_ip) {
client->host = strdup(openssl_last_ip);
}
if (vencrypt_sel != 0) {
client->protocolMajorVersion = 3;
client->protocolMinorVersion = 8;
if (!finish_vencrypt_auth(client, vencrypt_sel)) {
rfbCloseClient(client);
}
} else if (anontls_sel != 0) {
client->protocolMajorVersion = 3;
client->protocolMinorVersion = 8;
rfbAuthNewClient(client);
}
} else {
rfbLog("SSL: accept_openssl: rfbNewClient failed.\n");
close(vsock);
kill(pid, SIGTERM);
waitpid(pid, &status, WNOHANG);
if (mode == OPENSSL_INETD || ssl_no_fail) {
clean_up_exit(1);
}
return;
}
}
static int read_exact(int sock, char *buf, int len) {
int n, fail = 0;
if (sock < 0) {
return 0;
}
while (len > 0) {
n = read(sock, buf, len);
if (n > 0) {
buf += n;
len -= n;
} else if (n == 0) {
fail = 1;
break;
} else if (n < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
usleep(10*1000);
} else if (n < 0 && errno != EINTR) {
fail = 1;
break;
}
}
if (fail) {
return 0;
} else {
return 1;
}
}
static int write_exact(int sock, char *buf, int len) {
int n, fail = 0;
if (sock < 0) {
return 0;
}
while (len > 0) {
n = write(sock, buf, len);
if (n > 0) {
buf += n;
len -= n;
} else if (n == 0) {
fail = 1;
break;
} else if (n < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
usleep(10*1000);
} else if (n < 0 && errno != EINTR) {
fail = 1;
break;
}
}
if (fail) {
return 0;
} else {
return 1;
}
}
static int add_anon_dh(void) {
pid_t pid, pidw;
char cnf[] = "/tmp/x11vnc-dh.XXXXXX";
char *infile = NULL;
int status, cnf_fd;
DH *dh;
BIO *bio;
FILE *in;
double ds;
/*
* These are dh parameters (prime, generator), not dh keys.
* Evidently it is ok for them to be publicly known.
* openssl dhparam -out dh.out 1024
*/
char *fixed_dh_params =
"-----BEGIN DH PARAMETERS-----\n"
"MIGHAoGBAL28w69ZnLYBvp8R2OeqtAIms+oatY19iBL4WhGI/7H1OMmkJjIe+OHs\n"
"PXoJfe5ucrnvno7Xm+HJZYa1jnPGQuWoa/VJKXdVjYdJVNzazJKM2daKKcQA4GDc\n"
"msFS5DxLbzUR5jy1n12K3EcbvpyFqDYVTJJXm7NuNuiWRfz3wTozAgEC\n"
"-----END DH PARAMETERS-----\n";
if (dhparams_file != NULL) {
infile = dhparams_file;
rfbLog("add_anon_dh: using %s\n", dhparams_file);
goto readin;
}
cnf_fd = mkstemp(cnf);
if (cnf_fd < 0) {
return 0;
}
infile = cnf;
if (create_fresh_dhparams) {
if (new_dh_params != NULL) {
write(cnf_fd, new_dh_params, strlen(new_dh_params));
close(cnf_fd);
} else {
char *exe = find_openssl_bin();
struct stat sbuf;
if (no_external_cmds || !cmd_ok("ssl")) {
rfbLog("add_anon_dh: cannot run external commands.\n");
return 0;
}
close(cnf_fd);
if (exe == NULL) {
return 0;
}
ds = dnow();
pid = fork();
if (pid < 0) {
return 0;
} else if (pid == 0) {
int i;
for (i=0; i<256; i++) {
if (i == 2) continue;
close(i);
}
/* rather slow at 1024 */
execlp(exe, exe, "dhparam", "-out", cnf, "1024", (char *)0);
exit(1);
}
pidw = waitpid(pid, &status, 0);
if (pidw != pid) {
return 0;
}
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
;
} else {
return 0;
}
rfbLog("add_anon_dh: created new DH params in %.3f secs\n", dnow() - ds);
if (stat(cnf, &sbuf) == 0 && sbuf.st_size > 0) {
/* save it to reuse during our process's lifetime: */
int d = open(cnf, O_RDONLY);
if (d >= 0) {
int n, len = sbuf.st_size;
new_dh_params = (char *) calloc(len+1, 1);
n = read(d, new_dh_params, len);
close(d);
if (n != len) {
free(new_dh_params);
new_dh_params = NULL;
} else if (dhret != NULL) {
d = open(dhret, O_WRONLY);
if (d >= 0) {
write(d, new_dh_params, strlen(new_dh_params));
close(d);
}
}
}
}
}
} else {
write(cnf_fd, fixed_dh_params, strlen(fixed_dh_params));
close(cnf_fd);
}
readin:
ds = dnow();
in = fopen(infile, "r");
if (in == NULL) {
rfbLogPerror("fopen");
unlink(cnf);
return 0;
}
bio = BIO_new_fp(in, BIO_CLOSE|BIO_FP_TEXT);
if (! bio) {
rfbLog("openssl_init: BIO_new_fp() failed.\n");
unlink(cnf);
return 0;
}
dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
if (dh == NULL) {
rfbLog("openssl_init: PEM_read_bio_DHparams() failed.\n");
unlink(cnf);
BIO_free(bio);
return 0;
}
BIO_free(bio);
SSL_CTX_set_tmp_dh(ctx, dh);
rfbLog("loaded Diffie Hellman %d bits, %.3fs\n", 8*DH_size(dh), dnow()-ds);
DH_free(dh);
unlink(cnf);
return 1;
}
static int switch_to_anon_dh(void) {
long mode;
rfbLog("Using Anonymous Diffie-Hellman mode.\n");
rfbLog("WARNING: Anonymous Diffie-Hellman uses encryption but is\n");
rfbLog("WARNING: susceptible to a Man-In-The-Middle attack.\n");
if (ssl_client_mode) {
ctx = SSL_CTX_new( SSLv23_client_method() );
} else {
ctx = SSL_CTX_new( SSLv23_server_method() );
}
if (ctx == NULL) {
return 0;
}
if (ssl_client_mode) {
return 1;
}
if (!SSL_CTX_set_cipher_list(ctx, "ADH:@STRENGTH")) {
return 0;
}
if (!add_anon_dh()) {
return 0;
}
mode = 0;
mode |= SSL_MODE_ENABLE_PARTIAL_WRITE;
mode |= SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
SSL_CTX_set_mode(ctx, mode);
SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_BOTH);
SSL_CTX_set_timeout(ctx, 300);
SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_callback);
SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
return 1;
}
static int anontls_dialog(int s_in, int s_out) {
if (s_in || s_out) {}
anontls_selected = 1;
if (!switch_to_anon_dh()) {
rfbLog("anontls: Anonymous Diffie-Hellman failed.\n");
return 0;
}
/* continue with SSL/TLS */
return 1;
}
/*
* Using spec:
* http://www.mail-archive.com/qemu-devel@nongnu.org/msg08681.html
*/
static int vencrypt_dialog(int s_in, int s_out) {
char buf[256], buf2[256];
int subtypes[16];
int n, i, ival, ok, nsubtypes = 0;
vencrypt_selected = 0;
/* send version 0.2 */
buf[0] = 0;
buf[1] = 2;
if (!write_exact(s_out, buf, 2)) {
close(s_in); close(s_out);
return 0;
}
/* read client version 0.2 */
memset(buf, 0, sizeof(buf));
if (!read_exact(s_in, buf, 2)) {
close(s_in); close(s_out);
return 0;
}
rfbLog("vencrypt: received %d.%d client version.\n", (int) buf[0], (int) buf[1]);
/* close 0.0 */
if (buf[0] == 0 && buf[1] == 0) {
rfbLog("vencrypt: received 0.0 version, closing connection.\n");
close(s_in); close(s_out);
return 0;
}
/* accept only 0.2 */
if (buf[0] != 0 || buf[1] != 2) {
rfbLog("vencrypt: unsupported VeNCrypt version, closing connection.\n");
buf[0] = (char) 255;
write_exact(s_out, buf, 1);
close(s_in); close(s_out);
return 0;
}
/* tell them OK */
buf[0] = 0;
if (!write_exact(s_out, buf, 1)) {
close(s_in); close(s_out);
return 0;
}
if (getenv("X11VNC_ENABLE_VENCRYPT_PLAIN_LOGIN")) {
vencrypt_enable_plain_login = atoi(getenv("X11VNC_ENABLE_VENCRYPT_PLAIN_LOGIN"));
}
/* load our list of sub-types: */
n = 0;
if (!ssl_verify && vencrypt_kx != VENCRYPT_NODH) {
if (screen->authPasswdData != NULL) {
subtypes[n++] = rfbVencryptTlsVnc;
} else {
if (vencrypt_enable_plain_login && unixpw) {
subtypes[n++] = rfbVencryptTlsPlain;
} else {
subtypes[n++] = rfbVencryptTlsNone;
}
}
}
if (vencrypt_kx != VENCRYPT_NOX509) {
if (screen->authPasswdData != NULL) {
subtypes[n++] = rfbVencryptX509Vnc;
} else {
if (vencrypt_enable_plain_login && unixpw) {
subtypes[n++] = rfbVencryptX509Plain;
} else {
subtypes[n++] = rfbVencryptX509None;
}
}
}
nsubtypes = n;
for (i = 0; i < nsubtypes; i++) {
((uint32_t *)buf)[i] = Swap32IfLE(subtypes[i]);
}
/* send number first: */
buf2[0] = (char) nsubtypes;
if (!write_exact(s_out, buf2, 1)) {
close(s_in); close(s_out);
return 0;
}
/* and now the list: */
if (!write_exact(s_out, buf, 4*n)) {
close(s_in); close(s_out);
return 0;
}
/* read client's selection: */
if (!read_exact(s_in, (char *)&ival, 4)) {
close(s_in); close(s_out);
return 0;
}
ival = Swap32IfLE(ival);
/* zero means no dice: */
if (ival == 0) {
rfbLog("vencrypt: client selected no sub-type, closing connection.\n");
close(s_in); close(s_out);
return 0;
}
/* check if he selected a valid one: */
ok = 0;
for (i = 0; i < nsubtypes; i++) {
if (ival == subtypes[i]) {
ok = 1;
}
}
if (!ok) {
rfbLog("vencrypt: client selected invalid sub-type: %d\n", ival);
close(s_in); close(s_out);
return 0;
} else {
char *st = "unknown!!";
if (ival == rfbVencryptTlsNone) st = "rfbVencryptTlsNone";
if (ival == rfbVencryptTlsVnc) st = "rfbVencryptTlsVnc";
if (ival == rfbVencryptTlsPlain) st = "rfbVencryptTlsPlain";
if (ival == rfbVencryptX509None) st = "rfbVencryptX509None";
if (ival == rfbVencryptX509Vnc) st = "rfbVencryptX509Vnc";
if (ival == rfbVencryptX509Plain) st = "rfbVencryptX509Plain";
rfbLog("vencrypt: client selected sub-type: %d (%s)\n", ival, st);
}
vencrypt_selected = ival;
/* not documented in spec, send OK: */
buf[0] = 1;
if (!write_exact(s_out, buf, 1)) {
close(s_in); close(s_out);
return 0;
}
if (vencrypt_selected == rfbVencryptTlsNone ||
vencrypt_selected == rfbVencryptTlsVnc ||
vencrypt_selected == rfbVencryptTlsPlain) {
/* these modes are Anonymous Diffie-Hellman */
if (!switch_to_anon_dh()) {
rfbLog("vencrypt: Anonymous Diffie-Hellman failed.\n");
return 0;
}
}
/* continue with SSL/TLS */
return 1;
}
static int check_vnc_tls_mode(int s_in, int s_out) {
double waited = 0.0, dt = 0.01, start = dnow();
struct timeval tv;
int input = 0, i, n, ok;
int major, minor, sectype = -1;
char *proto = "RFB 003.008\n";
char *stype = "unknown";
char buf[256];
vencrypt_selected = 0;
anontls_selected = 0;
if (vencrypt_mode == VENCRYPT_NONE && anontls_mode == ANONTLS_NONE) {
/* only normal SSL */
return 1;
}
if (ssl_client_mode) {
if (vencrypt_mode == VENCRYPT_FORCE || anontls_mode == ANONTLS_FORCE) {
rfbLog("check_vnc_tls_mode: VENCRYPT_FORCE/ANONTLS_FORCE in client\n");
rfbLog("check_vnc_tls_mode: connect mode.\n");
/* this is OK, continue on below for dialog. */
} else {
/* otherwise we must assume normal SSL (we send client hello) */
return 1;
}
}
if (ssl_verify && vencrypt_mode != VENCRYPT_FORCE && anontls_mode == ANONTLS_FORCE) {
rfbLog("check_vnc_tls_mode: Cannot use ANONTLS_FORCE with -sslverify (Anon DH only)\n");
/* fallback to normal SSL */
return 1;
}
while (waited < 1.1) {
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(s_in, &rfds);
tv.tv_sec = 0;
tv.tv_usec = 0;
select(s_in+1, &rfds, NULL, NULL, &tv);
if (FD_ISSET(s_in, &rfds)) {
input = 1;
break;
}
usleep((int) (1000 * 1000 * dt));
waited += dt;
}
rfbLog("check_vnc_tls_mode: waited: %f input: %s\n", dnow() - start, input ? "SSL Handshake" : "(future) RFB Handshake");
if (input) {
/* got SSL client hello, can only assume normal SSL */
if (vencrypt_mode == VENCRYPT_FORCE || anontls_mode == ANONTLS_FORCE) {
rfbLog("check_vnc_tls_mode: VENCRYPT_FORCE/ANONTLS_FORCE prevents normal SSL\n");
return 0;
}
return 1;
}
/* send RFB 003.008 -- there is no turning back from this point... */
if (!write_exact(s_out, proto, strlen(proto))) {
close(s_in); close(s_out);
return 0;
}
memset(buf, 0, sizeof(buf));
if (!read_exact(s_in, buf, 12)) {
close(s_in); close(s_out);
return 0;
}
if (sscanf(buf, "RFB %03d.%03d\n", &major, &minor) != 2) {
int i;
rfbLog("check_vnc_tls_mode: abnormal handshake: '%s'\nbytes: ", buf);
for (i=0; i < 12; i++) {
fprintf(stderr, "%x.", (int) buf[i]);
}
fprintf(stderr, "\n");
close(s_in); close(s_out);
return 0;
}
rfbLog("check_vnc_tls_mode: version: %d.%d\n", major, minor);
if (major != 3 || minor < 8) {
rfbLog("check_vnc_tls_mode: invalid version: '%s'\n", buf);
close(s_in); close(s_out);
return 0;
}
n = 1;
if (vencrypt_mode == VENCRYPT_FORCE) {
buf[n++] = rfbSecTypeVencrypt;
} else if (anontls_mode == ANONTLS_FORCE && !ssl_verify) {
buf[n++] = rfbSecTypeAnonTls;
} else if (vencrypt_mode == VENCRYPT_SOLE) {
buf[n++] = rfbSecTypeVencrypt;
} else if (anontls_mode == ANONTLS_SOLE && !ssl_verify) {
buf[n++] = rfbSecTypeAnonTls;
} else {
if (vencrypt_mode == VENCRYPT_SUPPORT) {
buf[n++] = rfbSecTypeVencrypt;
}
if (anontls_mode == ANONTLS_SUPPORT && !ssl_verify) {
buf[n++] = rfbSecTypeAnonTls;
}
}
n--;
buf[0] = (char) n;
if (!write_exact(s_out, buf, n+1)) {
close(s_in); close(s_out);
return 0;
}
if (0) fprintf(stderr, "wrote[%d] %d %d %d\n", n, buf[0], buf[1], buf[2]);
buf[0] = 0;
if (!read_exact(s_in, buf, 1)) {
close(s_in); close(s_out);
return 0;
}
if (buf[0] == rfbSecTypeVencrypt) stype = "VeNCrypt";
if (buf[0] == rfbSecTypeAnonTls) stype = "ANONTLS";
rfbLog("check_vnc_tls_mode: reply: %d (%s)\n", (int) buf[0], stype);
ok = 0;
for (i=1; i < n+1; i++) {
if (buf[0] == buf[i]) {
ok = 1;
}
}
if (!ok) {
char *msg = "check_vnc_tls_mode: invalid security-type";
int len = strlen(msg);
rfbLog("%s: %d\n", msg, (int) buf[0]);
((uint32_t *)buf)[0] = Swap32IfLE(len);
write_exact(s_out, buf, 4);
write_exact(s_out, msg, strlen(msg));
close(s_in); close(s_out);
return 0;
}
sectype = (int) buf[0];
if (sectype == rfbSecTypeVencrypt) {
return vencrypt_dialog(s_in, s_out);
} else if (sectype == rfbSecTypeAnonTls) {
return anontls_dialog(s_in, s_out);
} else {
return 0;
}
}
static void pr_ssl_info(int verb) {
SSL_CIPHER *c;
SSL_SESSION *s;
char *proto = "unknown";
if (verb) {}
if (ssl == NULL) {
return;
}
c = SSL_get_current_cipher(ssl);
s = SSL_get_session(ssl);
if (s == NULL) {
proto = "nosession";
} else if (s->ssl_version == SSL2_VERSION) {
proto = "SSLv2";
} else if (s->ssl_version == SSL3_VERSION) {
proto = "SSLv3";
} else if (s->ssl_version == TLS1_VERSION) {
proto = "TLSv1";
}
if (c != NULL) {
rfbLog("SSL: ssl_helper[%d]: Cipher: %s %s Proto: %s\n", getpid(),
SSL_CIPHER_get_version(c), SSL_CIPHER_get_name(c), proto);
} else {
rfbLog("SSL: ssl_helper[%d]: Proto: %s\n", getpid(),
proto);
}
}
static void ssl_timeout (int sig) {
int i;
rfbLog("sig: %d, ssl_init[%d] timed out.\n", sig, getpid());
for (i=0; i < 256; i++) {
close(i);
}
exit(1);
}
static int ssl_init(int s_in, int s_out, int skip_vnc_tls) {
unsigned char *sid = (unsigned char *) "x11vnc SID";
char *name = NULL;
int peerport = 0;
int db = 0, rc, err;
int ssock = s_in;
double start = dnow();
int timeout = 20;
if (enc_str != NULL) {
return 1;
}
if (getenv("SSL_DEBUG")) {
db = atoi(getenv("SSL_DEBUG"));
}
if (getenv("SSL_INIT_TIMEOUT")) {
timeout = atoi(getenv("SSL_INIT_TIMEOUT"));
}
if (db) fprintf(stderr, "ssl_init: %d/%d\n", s_in, s_out);
if (skip_vnc_tls) {
rfbLog("SSL: ssl_helper[%d]: HTTPS mode, skipping check_vnc_tls_mode()\n",
getpid());
} else if (!check_vnc_tls_mode(s_in, s_out)) {
return 0;
}
ssl = SSL_new(ctx);
if (ssl == NULL) {
fprintf(stderr, "SSL_new failed\n");
return 0;
}
if (db > 1) fprintf(stderr, "ssl_init: 1\n");
SSL_set_session_id_context(ssl, sid, strlen((char *)sid));
if (s_in == s_out) {
if (! SSL_set_fd(ssl, ssock)) {
fprintf(stderr, "SSL_set_fd failed\n");
return 0;
}
} else {
if (! SSL_set_rfd(ssl, s_in)) {
fprintf(stderr, "SSL_set_rfd failed\n");
return 0;
}
if (! SSL_set_wfd(ssl, s_out)) {
fprintf(stderr, "SSL_set_wfd failed\n");
return 0;
}
}
if (db > 1) fprintf(stderr, "ssl_init: 2\n");
if (ssl_client_mode) {
SSL_set_connect_state(ssl);
} else {
SSL_set_accept_state(ssl);
}
if (db > 1) fprintf(stderr, "ssl_init: 3\n");
name = get_remote_host(ssock);
peerport = get_remote_port(ssock);
if (db > 1) fprintf(stderr, "ssl_init: 4\n");
while (1) {
signal(SIGALRM, ssl_timeout);
alarm(timeout);
if (ssl_client_mode) {
if (db) fprintf(stderr, "calling SSL_connect...\n");
rc = SSL_connect(ssl);
} else {
if (db) fprintf(stderr, "calling SSL_accept...\n");
rc = SSL_accept(ssl);
}
err = SSL_get_error(ssl, rc);
alarm(0);
signal(SIGALRM, SIG_DFL);
if (ssl_client_mode) {
if (db) fprintf(stderr, "SSL_connect %d/%d\n", rc, err);
} else {
if (db) fprintf(stderr, "SSL_accept %d/%d\n", rc, err);
}
if (err == SSL_ERROR_NONE) {
break;
} else if (err == SSL_ERROR_WANT_READ) {
if (db) fprintf(stderr, "got SSL_ERROR_WANT_READ\n");
rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n",
getpid(), name, peerport);
pr_ssl_info(1);
return 0;
} else if (err == SSL_ERROR_WANT_WRITE) {
if (db) fprintf(stderr, "got SSL_ERROR_WANT_WRITE\n");
rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n",
getpid(), name, peerport);
pr_ssl_info(1);
return 0;
} else if (err == SSL_ERROR_SYSCALL) {
if (db) fprintf(stderr, "got SSL_ERROR_SYSCALL\n");
rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n",
getpid(), name, peerport);
pr_ssl_info(1);
return 0;
} else if (err == SSL_ERROR_ZERO_RETURN) {
if (db) fprintf(stderr, "got SSL_ERROR_ZERO_RETURN\n");
rfbLog("SSL: ssl_helper[%d]: SSL_accept() failed for: %s:%d\n",
getpid(), name, peerport);
pr_ssl_info(1);
return 0;
} else if (rc < 0) {
unsigned long err;
int cnt = 0;
rfbLog("SSL: ssl_helper[%d]: SSL_accept() *FATAL: %d SSL FAILED\n", getpid(), rc);
while ((err = ERR_get_error()) != 0) {
rfbLog("SSL: %s\n", ERR_error_string(err, NULL));
if (cnt++ > 100) {
break;
}
}
pr_ssl_info(1);
return 0;
} else if (dnow() > start + 3.0) {
rfbLog("SSL: ssl_helper[%d]: timeout looping SSL_accept() "
"fatal.\n", getpid());
pr_ssl_info(1);
return 0;
} else {
BIO *bio = SSL_get_rbio(ssl);
if (bio == NULL) {
rfbLog("SSL: ssl_helper[%d]: ssl BIO is null. "
"fatal.\n", getpid());
pr_ssl_info(1);
return 0;
}
if (BIO_eof(bio)) {
rfbLog("SSL: ssl_helper[%d]: ssl BIO is EOF. "
"fatal.\n", getpid());
pr_ssl_info(1);
return 0;
}
}
usleep(10 * 1000);
}
if (ssl_client_mode) {
rfbLog("SSL: ssl_helper[%d]: SSL_connect() succeeded for: %s:%d\n", getpid(), name, peerport);
} else {
rfbLog("SSL: ssl_helper[%d]: SSL_accept() succeeded for: %s:%d\n", getpid(), name, peerport);
}
pr_ssl_info(0);
if (SSL_get_verify_result(ssl) == X509_V_OK) {
X509 *x;
FILE *cr = NULL;
if (certret != NULL) {
cr = fopen(certret, "w");
}
x = SSL_get_peer_certificate(ssl);
if (x == NULL) {
rfbLog("SSL: ssl_helper[%d]: accepted client %s x509 peer cert is null\n", getpid(), name);
if (cr != NULL) {
fprintf(cr, "NOCERT\n");
fclose(cr);
}
} else {
rfbLog("SSL: ssl_helper[%d]: accepted client %s x509 cert is:\n", getpid(), name);
#if LIBVNCSERVER_HAVE_X509_PRINT_EX_FP
X509_print_ex_fp(stderr, x, 0, XN_FLAG_MULTILINE);
#endif
if (cr != NULL) {
#if LIBVNCSERVER_HAVE_X509_PRINT_EX_FP
X509_print_ex_fp(cr, x, 0, XN_FLAG_MULTILINE);
#else
rfbLog("** not compiled with libssl X509_print_ex_fp() function **\n");
if (users_list && strstr(users_list, "sslpeer=")) {
rfbLog("** -users sslpeer= will not work! **\n");
}
#endif
fclose(cr);
}
}
}
free(name);
return 1;
}
static void symmetric_encryption_xfer(int csock, int s_in, int s_out);
static void ssl_xfer(int csock, int s_in, int s_out, int is_https) {
int dbxfer = 0, db = 0, check_pending, fdmax, nfd, n, i, err;
char cbuf[ABSIZE], sbuf[ABSIZE];
int cptr, sptr, c_rd, c_wr, s_rd, s_wr;
fd_set rd, wr;
struct timeval tv;
int ssock, cnt = 0, ndata = 0;
/*
* we want to switch to a longer timeout for long term VNC
* connections (in case the network is not working for periods of
* time), but we also want the timeout shorter at the beginning
* in case the client went away.
*/
time_t start;
int tv_https_early = 60;
int tv_https_later = 20;
int tv_vnc_early = 40;
int tv_vnc_later = 43200; /* was 300, stunnel: 43200 */
int tv_cutover = 70;
int tv_closing = 60;
int tv_use;
if (dbxfer) {
raw_xfer(csock, s_in, s_out);
return;
}
if (enc_str != NULL) {
if (!strcmp(enc_str, "none")) {
usleep(250*1000);
rfbLog("doing '-enc none' raw transfer (no encryption)\n");
raw_xfer(csock, s_in, s_out);
} else {
symmetric_encryption_xfer(csock, s_in, s_out);
}
return;
}
if (getenv("SSL_DEBUG")) {
db = atoi(getenv("SSL_DEBUG"));
}
if (db) fprintf(stderr, "ssl_xfer begin\n");
start = time(NULL);
if (is_https) {
tv_use = tv_https_early;
} else {
tv_use = tv_vnc_early;
}
/*
* csock: clear text socket with libvncserver. "C"
* ssock: ssl data socket with remote vnc viewer. "S"
*
* to cover inetd mode, we have s_in and s_out, but in non-inetd
* mode they both ssock.
*
* cbuf[] is data from csock that we have read but not passed on to ssl
* sbuf[] is data from ssl that we have read but not passed on to csock
*/
for (i=0; i<ABSIZE; i++) {
cbuf[i] = '\0';
sbuf[i] = '\0';
}
if (s_out > s_in) {
ssock = s_out;
} else {
ssock = s_in;
}
if (csock > ssock) {
fdmax = csock;
} else {
fdmax = ssock;
}
c_rd = 1; /* clear text (libvncserver) socket open for reading */
c_wr = 1; /* clear text (libvncserver) socket open for writing */
s_rd = 1; /* ssl data (remote client) socket open for reading */
s_wr = 1; /* ssl data (remote client) socket open for writing */
cptr = 0; /* offsets into ABSIZE buffers */
sptr = 0;
if (vencrypt_selected > 0 || anontls_selected > 0) {
char tmp[16];
/* read and discard the extra RFB version */
memset(tmp, 0, sizeof(tmp));
read(csock, tmp, 12);
if (0) fprintf(stderr, "extra: %s\n", tmp);
}
while (1) {
int c_to_s, s_to_c, closing;
if ( s_wr && (c_rd || cptr > 0) ) {
/*
* S is writable and
* C is readable or some cbuf data remaining
*/
c_to_s = 1;
} else {
c_to_s = 0;
}
if ( c_wr && (s_rd || sptr > 0) ) {
/*
* C is writable and
* S is readable or some sbuf data remaining
*/
s_to_c = 1;
} else {
s_to_c = 0;
}
if (! c_to_s && ! s_to_c) {
/*
* nothing can be sent either direction.
* break out of the loop to finish all work.
*/
break;
}
cnt++;
/* set up the fd sets for the two sockets for read & write: */
FD_ZERO(&rd);
if (c_rd && cptr < ABSIZE) {
/* we could read more from C since cbuf is not full */
FD_SET(csock, &rd);
}
if (s_rd) {
/*
* we could read more from S since sbuf not full,
* OR ssl is waiting for more BIO to be able to
* read and we have some C data still buffered.
*/
if (sptr < ABSIZE || (cptr > 0 && SSL_want_read(ssl))) {
FD_SET(s_in, &rd);
}
}
FD_ZERO(&wr);
if (c_wr && sptr > 0) {
/* we could write more to C since sbuf is not empty */
FD_SET(csock, &wr);
}
if (s_wr) {
/*
* we could write more to S since cbuf not empty,
* OR ssl is waiting for more BIO to be able
* write and we haven't filled up sbuf yet.
*/
if (cptr > 0 || (sptr < ABSIZE && SSL_want_write(ssl))) {
FD_SET(s_out, &wr);
}
}
if (tv_cutover && time(NULL) > start + tv_cutover) {
rfbLog("SSL: ssl_xfer[%d]: tv_cutover: %d\n", getpid(),
tv_cutover);
tv_cutover = 0;
if (is_https) {
tv_use = tv_https_later;
} else {
tv_use = tv_vnc_later;
}
}
if (ssl_timeout_secs > 0) {
tv_use = ssl_timeout_secs;
}
if ( (s_rd && c_rd) || cptr || sptr) {
closing = 0;
} else {
closing = 1;
tv_use = tv_closing;
}
tv.tv_sec = tv_use;
tv.tv_usec = 0;
/* do the select, repeat if interrupted */
do {
if (ssl_timeout_secs == 0) {
nfd = select(fdmax+1, &rd, &wr, NULL, NULL);
} else {
nfd = select(fdmax+1, &rd, &wr, NULL, &tv);
}
} while (nfd < 0 && errno == EINTR);
if (db > 1) fprintf(stderr, "nfd: %d\n", nfd);
if (nfd < 0) {
rfbLog("SSL: ssl_xfer[%d]: select error: %d\n", getpid(), nfd);
perror("select");
/* connection finished */
return;
}
if (nfd == 0) {
if (!closing && tv_cutover && ndata > 25000) {
static int cn = 0;
/* probably ok, early windows iconify */
if (cn++ < 2) {
rfbLog("SSL: ssl_xfer[%d]: early time"
"out: %d\n", getpid(), ndata);
}
continue;
}
rfbLog("SSL: ssl_xfer[%d]: connection timedout. %d tv_use: %d\n",
getpid(), ndata, tv_use);
/* connection finished */
return;
}
/* used to see if SSL_pending() should be checked: */
check_pending = 0;
/* AUDIT */
if (c_wr && FD_ISSET(csock, &wr)) {
/* try to write some of our sbuf to C: */
n = write(csock, sbuf, sptr);
if (n < 0) {
if (errno != EINTR) {
/* connection finished */
return;
}
/* proceed */
} else if (n == 0) {
/* connection finished XXX double check */
return;
} else {
/* shift over the data in sbuf by n */
memmove(sbuf, sbuf + n, sptr - n);
if (sptr == ABSIZE) {
check_pending = 1;
}
sptr -= n;
if (! s_rd && sptr == 0) {
/* finished sending last of sbuf */
shutdown(csock, SHUT_WR);
c_wr = 0;
}
ndata += n;
}
}
if (s_wr) {
if ((cptr > 0 && FD_ISSET(s_out, &wr)) ||
(SSL_want_read(ssl) && FD_ISSET(s_in, &rd))) {
/* try to write some of our cbuf to S: */
n = SSL_write(ssl, cbuf, cptr);
err = SSL_get_error(ssl, n);
if (err == SSL_ERROR_NONE) {
/* shift over the data in cbuf by n */
memmove(cbuf, cbuf + n, cptr - n);
cptr -= n;
if (! c_rd && cptr == 0 && s_wr) {
/* finished sending last cbuf */
SSL_shutdown(ssl);
s_wr = 0;
}
ndata += n;
} else if (err == SSL_ERROR_WANT_WRITE
|| err == SSL_ERROR_WANT_READ
|| err == SSL_ERROR_WANT_X509_LOOKUP) {
; /* proceed */
} else if (err == SSL_ERROR_SYSCALL) {
if (n < 0 && errno != EINTR) {
/* connection finished */
return;
}
/* proceed */
} else if (err == SSL_ERROR_ZERO_RETURN) {
/* S finished */
s_rd = 0;
s_wr = 0;
} else if (err == SSL_ERROR_SSL) {
/* connection finished */
return;
}
}
}
if (c_rd && FD_ISSET(csock, &rd)) {
/* try to read some data from C into our cbuf */
n = read(csock, cbuf + cptr, ABSIZE - cptr);
if (n < 0) {
if (errno != EINTR) {
/* connection finished */
return;
}
/* proceed */
} else if (n == 0) {
/* C is EOF */
c_rd = 0;
if (cptr == 0 && s_wr) {
/* and no more in cbuf to send */
SSL_shutdown(ssl);
s_wr = 0;
}
} else {
/* good */
cptr += n;
ndata += n;
}
}
if (s_rd) {
if ((sptr < ABSIZE && FD_ISSET(s_in, &rd)) ||
(SSL_want_write(ssl) && FD_ISSET(s_out, &wr)) ||
(check_pending && SSL_pending(ssl))) {
/* try to read some data from S into our sbuf */
n = SSL_read(ssl, sbuf + sptr, ABSIZE - sptr);
err = SSL_get_error(ssl, n);
if (err == SSL_ERROR_NONE) {
/* good */
sptr += n;
ndata += n;
} else if (err == SSL_ERROR_WANT_WRITE
|| err == SSL_ERROR_WANT_READ
|| err == SSL_ERROR_WANT_X509_LOOKUP) {
; /* proceed */
} else if (err == SSL_ERROR_SYSCALL) {
if (n < 0) {
if(errno != EINTR) {
/* connection finished */
return;
}
/* proceed */
} else {
/* S finished */
s_rd = 0;
s_wr = 0;
}
} else if (err == SSL_ERROR_ZERO_RETURN) {
/* S is EOF */
s_rd = 0;
if (cptr == 0 && s_wr) {
/* and no more in cbuf to send */
SSL_shutdown(ssl);
s_wr = 0;
}
if (sptr == 0 && c_wr) {
/* and no more in sbuf to send */
shutdown(csock, SHUT_WR);
c_wr = 0;
}
} else if (err == SSL_ERROR_SSL) {
/* connection finished */
return;
}
}
}
}
}
void check_openssl(void) {
fd_set fds;
struct timeval tv;
int nfds;
static time_t last_waitall = 0;
static double last_check = 0.0;
double now;
if (! use_openssl || openssl_sock < 0) {
return;
}
now = dnow();
if (now < last_check + 0.5) {
return;
}
last_check = now;
if (time(NULL) > last_waitall + 150) {
last_waitall = time(NULL);
ssl_helper_pid(0, -2); /* waitall */
}
FD_ZERO(&fds);
FD_SET(openssl_sock, &fds);
tv.tv_sec = 0;
tv.tv_usec = 0;
nfds = select(openssl_sock+1, &fds, NULL, NULL, &tv);
if (nfds <= 0) {
return;
}
rfbLog("SSL: accept_openssl(OPENSSL_VNC)\n");
accept_openssl(OPENSSL_VNC, -1);
}
void check_https(void) {
fd_set fds;
struct timeval tv;
int nfds;
static double last_check = 0.0;
double now;
if (! use_openssl || https_sock < 0) {
return;
}
now = dnow();
if (now < last_check + 0.5) {
return;
}
last_check = now;
FD_ZERO(&fds);
FD_SET(https_sock, &fds);
tv.tv_sec = 0;
tv.tv_usec = 0;
nfds = select(https_sock+1, &fds, NULL, NULL, &tv);
if (nfds <= 0) {
return;
}
rfbLog("SSL: accept_openssl(OPENSSL_HTTPS)\n");
accept_openssl(OPENSSL_HTTPS, -1);
}
#define MSZ 4096
static void init_prng(void) {
int db = 0, bytes, ubytes, fd;
char file[MSZ], dtmp[100];
RAND_file_name(file, MSZ);
rfbLog("RAND_file_name: %s\n", file);
bytes = RAND_load_file(file, -1);
if (db) fprintf(stderr, "bytes read: %d\n", bytes);
ubytes = RAND_load_file("/dev/urandom", 64);
bytes += ubytes;
if (db) fprintf(stderr, "bytes read: %d / %d\n", bytes, ubytes);
/* mix in more predictable stuff as well for fallback */
sprintf(dtmp, "/tmp/p%.8f.XXXXXX", dnow());
fd = mkstemp(dtmp);
RAND_add(dtmp, strlen(dtmp), 0);
if (fd >= 0) {
close(fd);
unlink(dtmp);
}
sprintf(dtmp, "%d-%.8f", (int) getpid(), dnow());
RAND_add(dtmp, strlen(dtmp), 0);
if (!RAND_status()) {
ubytes = -1;
rfbLog("calling RAND_poll()\n");
RAND_poll();
}
if (bytes > 0) {
if (! quiet) {
rfbLog("initialized PRNG with %d random bytes.\n",
bytes);
}
if (ubytes > 32 && rnow() < 0.25) {
RAND_write_file(file);
}
return;
}
bytes += RAND_load_file("/dev/random", 8);
if (db) fprintf(stderr, "bytes read: %d\n", bytes);
RAND_poll();
if (! quiet) {
rfbLog("initialized PRNG with %d random bytes.\n", bytes);
}
}
#endif /* FORK_OK */
#endif /* LIBVNCSERVER_HAVE_LIBSSL */
void raw_xfer(int csock, int s_in, int s_out) {
char buf0[8192];
int sz = 8192, n, m, status, db = 1;
char *buf;
#ifdef FORK_OK
pid_t par = getpid();
pid_t pid = fork();
buf = buf0;
if (vnc_redirect) {
/* change buf size some direction. */
}
if (getenv("X11VNC_DEBUG_RAW_XFER")) {
db = atoi(getenv("X11VNC_DEBUG_RAW_XFER"));
}
if (pid < 0) {
exit(1);
}
/* this is for testing or special helper usage, no SSL just socket redir */
if (pid) {
if (db) rfbLog("raw_xfer start: %d -> %d/%d\n", csock, s_in, s_out);
while (1) {
n = read(csock, buf, sz);
if (n == 0 || (n < 0 && errno != EINTR) ) {
break;
} else if (n > 0) {
int len = n;
char *src = buf;
if (db > 1) write(2, buf, n);
while (len > 0) {
m = write(s_out, src, len);
if (m > 0) {
src += m;
len -= m;
continue;
}
if (m < 0 && (errno == EINTR || errno == EAGAIN)) {
continue;
}
if (db) rfbLog("raw_xfer bad write: %d -> %d | %d/%d errno=%d\n", csock, s_out, m, n, errno);
break;
}
}
}
usleep(250*1000);
kill(pid, SIGTERM);
waitpid(pid, &status, WNOHANG);
if (db) rfbLog("raw_xfer done: %d -> %d\n", csock, s_out);
} else {
if (db) usleep(50*1000);
if (db) rfbLog("raw_xfer start: %d <- %d\n", csock, s_in);
while (1) {
n = read(s_in, buf, sz);
if (n == 0 || (n < 0 && errno != EINTR) ) {
break;
} else if (n > 0) {
int len = n;
char *src = buf;
if (db > 1) write(2, buf, n);
while (len > 0) {
m = write(csock, src, len);
if (m > 0) {
src += m;
len -= m;
continue;
}
if (m < 0 && (errno == EINTR || errno == EAGAIN)) {
continue;
}
if (db) rfbLog("raw_xfer bad write: %d <- %d | %d/%d errno=%d\n", csock, s_in, m, n, errno);
break;
}
}
}
usleep(250*1000);
kill(par, SIGTERM);
waitpid(par, &status, WNOHANG);
if (db) rfbLog("raw_xfer done: %d <- %d\n", csock, s_in);
}
close(csock);
close(s_in);
close(s_out);
#endif /* FORK_OK */
}
#define ENC_MODULE
#if LIBVNCSERVER_HAVE_LIBSSL
#define ENC_HAVE_OPENSSL 1
#else
#define ENC_HAVE_OPENSSL 0
#endif
#include "enc.h"
static void symmetric_encryption_xfer(int csock, int s_in, int s_out) {
char tmp[100];
char *cipher, *keyfile, *q;
if (! enc_str) {
return;
}
cipher = (char *) malloc(strlen(enc_str) + 100);
q = strchr(enc_str, ':');
if (!q) return;
*q = '\0';
if (getenv("X11VNC_USE_ULTRADSM_IV")) {
sprintf(cipher, "rev:%s", enc_str);
} else {
sprintf(cipher, "noultra:rev:%s", enc_str);
}
keyfile = strdup(q+1);
*q = ':';
/* TBD: s_in != s_out */
if (s_out) {}
sprintf(tmp, "fd=%d,%d", s_in, csock);
enc_do(cipher, keyfile, "-1", tmp);
}
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