lobo/isync
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

move socket code to a separate file

Browse Source 
this makes the layering more obvious
This commit is contained in:
Oswald Buddenhagen 2011-01-23 13:43:00 +01:00
parent d1ee94f02c
commit ef41349035
4 changed files with 590 additions and 517 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/Makefile.am
View File

@ -5,7 +5,7 @@ SUBDIRS = $(compat_dir)
bin_PROGRAMS = mbsync mdconvert
mbsync_SOURCES = main.c sync.c config.c util.c drv_imap.c drv_maildir.c
mbsync_SOURCES = main.c sync.c config.c util.c socket.c drv_imap.c drv_maildir.c
mbsync_LDADD = -ldb $(SSL_LIBS) $(SOCK_LIBS)
noinst_HEADERS = isync.h

541
src/drv_imap.c
View File

@ -22,21 +22,10 @@
* despite that library's more restrictive license.
*/
/* This must come before isync.h to avoid our #define S messing up
* blowfish.h on MacOS X. */
#include <config.h>
#ifdef HAVE_LIBSSL
# include <openssl/ssl.h>
# include <openssl/err.h>
# include <openssl/hmac.h>
#endif
#include "isync.h"
#include <assert.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
@ -44,33 +33,16 @@
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
typedef struct imap_server_conf {
struct imap_server_conf *next;
char *name;
char *tunnel;
char *host;
int port;
server_conf_t sconf;
char *user;
char *pass;
#ifdef HAVE_LIBSSL
char *cert_file;
unsigned use_imaps:1;
unsigned require_ssl:1;
unsigned use_sslv2:1;
unsigned use_sslv3:1;
unsigned use_tlsv1:1;
unsigned require_cram:1;
X509_STORE *cert_store;
#endif
} imap_server_conf_t;
@ -94,20 +66,6 @@ typedef struct _list {
int len;
} list_t;
typedef struct {
int fd;
#ifdef HAVE_LIBSSL
SSL *ssl;
#endif
} Socket_t;
typedef struct {
Socket_t sock;
int bytes;
int offset;
char buf[1024];
} buffer_t;
struct imap_cmd;
#define max_in_progress 50 /* make this configurable? */
@ -124,9 +82,6 @@ typedef struct imap_store {
/* command queue */
int nexttag, num_in_progress, literal_pending;
struct imap_cmd *in_progress, **in_progress_append;
#ifdef HAVE_LIBSSL
SSL_CTX *SSLContext;
#endif
/* Used during sequential operations like connect */
enum { GreetingPending = 0, GreetingBad, GreetingOk, GreetingPreauth } greeting;
@ -231,305 +186,6 @@ static const char *Flags[] = {
"Deleted",
};
#ifdef HAVE_LIBSSL
/* Some of this code is inspired by / lifted from mutt. */
static int
compare_certificates( X509 *cert, X509 *peercert,
unsigned char *peermd, unsigned peermdlen )
{
unsigned char md[EVP_MAX_MD_SIZE];
unsigned mdlen;
/* Avoid CPU-intensive digest calculation if the certificates are
* not even remotely equal. */
if (X509_subject_name_cmp( cert, peercert ) ||
X509_issuer_name_cmp( cert, peercert ))
return -1;
if (!X509_digest( cert, EVP_sha1(), md, &mdlen ) ||
peermdlen != mdlen || memcmp( peermd, md, mdlen ))
return -1;
return 0;
}
#if OPENSSL_VERSION_NUMBER >= 0x00904000L
#define READ_X509_KEY(fp, key) PEM_read_X509( fp, key, 0, 0 )
#else
#define READ_X509_KEY(fp, key) PEM_read_X509( fp, key, 0 )
#endif
/* this gets called when a certificate is to be verified */
static int
verify_cert( imap_store_t *ctx )
{
imap_server_conf_t *srvc = ((imap_store_conf_t *)ctx->gen.conf)->server;
SSL *ssl = ctx->buf.sock.ssl;
X509 *cert, *lcert;
BIO *bio;
FILE *fp;
int err;
unsigned n, i;
X509_STORE_CTX xsc;
char buf[256];
unsigned char md[EVP_MAX_MD_SIZE];
cert = SSL_get_peer_certificate( ssl );
if (!cert) {
error( "Error, no server certificate\n" );
return -1;
}
while (srvc->cert_file) { // So break works
if (X509_cmp_current_time( X509_get_notBefore( cert )) >= 0) {
error( "Server certificate is not yet valid" );
break;
}
if (X509_cmp_current_time( X509_get_notAfter( cert )) <= 0) {
error( "Server certificate has expired" );
break;
}
if (!X509_digest( cert, EVP_sha1(), md, &n )) {
error( "*** Unable to calculate digest\n" );
break;
}
if (!(fp = fopen( srvc->cert_file, "rt" ))) {
error( "Unable to load CertificateFile '%s': %s\n",
srvc->cert_file, strerror( errno ) );
return 0;
}
err = -1;
for (lcert = 0; READ_X509_KEY( fp, &lcert ); )
if (!(err = compare_certificates( lcert, cert, md, n )))
break;
X509_free( lcert );
fclose( fp );
if (!err)
return 0;
break;
}
if (!srvc->cert_store) {
if (!(srvc->cert_store = X509_STORE_new())) {
error( "Error creating certificate store\n" );
return -1;
}
if (!X509_STORE_set_default_paths( srvc->cert_store ))
warn( "Error while loading default certificate files: %s\n",
ERR_error_string( ERR_get_error(), 0 ) );
if (!srvc->cert_file) {
info( "Note: CertificateFile not defined\n" );
} else if (!X509_STORE_load_locations( srvc->cert_store, srvc->cert_file, 0 )) {
error( "Error while loading certificate file '%s': %s\n",
srvc->cert_file, ERR_error_string( ERR_get_error(), 0 ) );
return -1;
}
}
X509_STORE_CTX_init( &xsc, srvc->cert_store, cert, 0 );
err = X509_verify_cert( &xsc ) > 0 ? 0 : X509_STORE_CTX_get_error( &xsc );
X509_STORE_CTX_cleanup( &xsc );
if (!err)
return 0;
error( "Error, can't verify certificate: %s (%d)\n",
X509_verify_cert_error_string( err ), err );
X509_NAME_oneline( X509_get_subject_name( cert ), buf, sizeof(buf) );
info( "\nSubject: %s\n", buf );
X509_NAME_oneline( X509_get_issuer_name( cert ), buf, sizeof(buf) );
info( "Issuer: %s\n", buf );
bio = BIO_new( BIO_s_mem() );
ASN1_TIME_print( bio, X509_get_notBefore( cert ) );
memset( buf, 0, sizeof(buf) );
BIO_read( bio, buf, sizeof(buf) - 1 );
info( "Valid from: %s\n", buf );
ASN1_TIME_print( bio, X509_get_notAfter( cert ) );
memset( buf, 0, sizeof(buf) );
BIO_read( bio, buf, sizeof(buf) - 1 );
BIO_free( bio );
info( " to: %s\n", buf );
if (!X509_digest( cert, EVP_md5(), md, &n )) {
error( "*** Unable to calculate fingerprint\n" );
} else {
info( "Fingerprint: " );
for (i = 0; i < n; i += 2)
info( "%02X%02X ", md[i], md[i + 1] );
info( "\n" );
}
fputs( "\nAccept certificate? [y/N]: ", stderr );
if (fgets( buf, sizeof(buf), stdin ) && (buf[0] == 'y' || buf[0] == 'Y'))
return 0;
return -1;
}
static int
init_ssl_ctx( imap_store_t *ctx )
{
imap_server_conf_t *srvc = ((imap_store_conf_t *)ctx->gen.conf)->server;
const SSL_METHOD *method;
int options = 0;
if (srvc->use_tlsv1 && !srvc->use_sslv2 && !srvc->use_sslv3)
method = TLSv1_client_method();
else
method = SSLv23_client_method();
ctx->SSLContext = SSL_CTX_new( method );
if (!srvc->use_sslv2)
options |= SSL_OP_NO_SSLv2;
if (!srvc->use_sslv3)
options |= SSL_OP_NO_SSLv3;
if (!srvc->use_tlsv1)
options |= SSL_OP_NO_TLSv1;
SSL_CTX_set_options( ctx->SSLContext, options );
/* we check the result of the verification after SSL_connect() */
SSL_CTX_set_verify( ctx->SSLContext, SSL_VERIFY_NONE, 0 );
return 0;
}
#endif /* HAVE_LIBSSL */
static void
socket_perror( const char *func, Socket_t *sock, int ret )
{
#ifdef HAVE_LIBSSL
int err;
if (sock->ssl) {
switch ((err = SSL_get_error( sock->ssl, ret ))) {
case SSL_ERROR_SYSCALL:
case SSL_ERROR_SSL:
if ((err = ERR_get_error()) == 0) {
if (ret == 0)
error( "SSL_%s: got EOF\n", func );
else
error( "SSL_%s: %s\n", func, strerror(errno) );
} else
error( "SSL_%s: %s\n", func, ERR_error_string( err, 0 ) );
return;
default:
error( "SSL_%s: unhandled SSL error %d\n", func, err );
break;
}
return;
}
#else
(void)sock;
#endif
if (ret < 0)
perror( func );
else
error( "%s: unexpected EOF\n", func );
}
static int
socket_read( Socket_t *sock, char *buf, int len )
{
int n;
assert( sock->fd >= 0 );
n =
#ifdef HAVE_LIBSSL
sock->ssl ? SSL_read( sock->ssl, buf, len ) :
#endif
read( sock->fd, buf, len );
if (n <= 0) {
socket_perror( "read", sock, n );
close( sock->fd );
sock->fd = -1;
}
return n;
}
static int
socket_write( Socket_t *sock, char *buf, int len )
{
int n;
assert( sock->fd >= 0 );
n =
#ifdef HAVE_LIBSSL
sock->ssl ? SSL_write( sock->ssl, buf, len ) :
#endif
write( sock->fd, buf, len );
if (n != len) {
socket_perror( "write", sock, n );
close( sock->fd );
sock->fd = -1;
}
return n;
}
static int
socket_pending( Socket_t *sock )
{
int num = -1;
if (ioctl( sock->fd, FIONREAD, &num ) < 0)
return -1;
if (num > 0)
return num;
#ifdef HAVE_LIBSSL
if (sock->ssl)
return SSL_pending( sock->ssl );
#endif
return 0;
}
/* simple line buffering */
static int
buffer_gets( buffer_t * b, char **s )
{
int n;
int start = b->offset;
*s = b->buf + start;
for (;;) {
/* make sure we have enough data to read the \r\n sequence */
if (b->offset + 1 >= b->bytes) {
if (start) {
/* shift down used bytes */
*s = b->buf;
assert( start <= b->bytes );
n = b->bytes - start;
if (n)
memmove( b->buf, b->buf + start, n );
b->offset -= start;
b->bytes = n;
start = 0;
}
n = socket_read( &b->sock, b->buf + b->bytes,
sizeof(b->buf) - b->bytes );
if (n <= 0)
return -1;
b->bytes += n;
}
if (b->buf[b->offset] == '\r') {
assert( b->offset + 1 < b->bytes );
if (b->buf[b->offset + 1] == '\n') {
b->buf[b->offset] = 0; /* terminate the string */
b->offset += 2; /* next line */
if (DFlags & VERBOSE)
puts( *s );
return 0;
}
}
b->offset++;
}
/* not reached */
}
static struct imap_cmd *
new_imap_cmd( int size )
{
@ -1270,16 +926,9 @@ imap_cancel_store( store_t *gctx )
{
imap_store_t *ctx = (imap_store_t *)gctx;
socket_close( &ctx->buf.sock );
free_generic_messages( ctx->gen.msgs );
free_string_list( ctx->gen.boxes );
if (ctx->buf.sock.fd >= 0)
close( ctx->buf.sock.fd );
#ifdef HAVE_LIBSSL
if (ctx->buf.sock.ssl)
SSL_free( ctx->buf.sock.ssl );
if (ctx->SSLContext)
SSL_CTX_free( ctx->SSLContext );
#endif
free_list( ctx->ns_personal );
free_list( ctx->ns_other );
free_list( ctx->ns_shared );
@ -1369,87 +1018,6 @@ imap_cleanup_p2( imap_store_t *ctx,
/******************* imap_open_store *******************/
#ifdef HAVE_LIBSSL
static int
start_tls( imap_store_t *ctx )
{
int ret;
static int ssl_inited;
if (!ssl_inited) {
SSL_library_init();
SSL_load_error_strings();
ssl_inited = 1;
}
if (init_ssl_ctx( ctx ))
return 1;
ctx->buf.sock.ssl = SSL_new( ctx->SSLContext );
SSL_set_fd( ctx->buf.sock.ssl, ctx->buf.sock.fd );
if ((ret = SSL_connect( ctx->buf.sock.ssl )) <= 0) {
socket_perror( "connect", &ctx->buf.sock, ret );
return 1;
}
/* verify the server certificate */
if (verify_cert( ctx ))
return 1;
info( "Connection is now encrypted\n" );
return 0;
}
#define ENCODED_SIZE(n) (4*((n+2)/3))
static char
hexchar( unsigned int b )
{
if (b < 10)
return '0' + b;
return 'a' + (b - 10);
}
static void
cram( const char *challenge, const char *user, const char *pass, char **_final, int *_finallen )
{
unsigned char *response, *final;
unsigned hashlen;
int i, clen, rlen, blen, flen, olen;
unsigned char hash[16];
char buf[256], hex[33];
HMAC_CTX hmac;
HMAC_Init( &hmac, (unsigned char *)pass, strlen( pass ), EVP_md5() );
clen = strlen( challenge );
/* response will always be smaller than challenge because we are decoding. */
response = nfcalloc( 1 + clen );
rlen = EVP_DecodeBlock( response, (unsigned char *)challenge, clen );
HMAC_Update( &hmac, response, rlen );
free( response );
hashlen = sizeof(hash);
HMAC_Final( &hmac, hash, &hashlen );
assert( hashlen == sizeof(hash) );
hex[32] = 0;
for (i = 0; i < 16; i++) {
hex[2 * i] = hexchar( (hash[i] >> 4) & 0xf );
hex[2 * i + 1] = hexchar( hash[i] & 0xf );
}
blen = nfsnprintf( buf, sizeof(buf), "%s %s", user, hex );
flen = ENCODED_SIZE( blen );
final = nfmalloc( flen + 1 );
final[flen] = 0;
olen = EVP_EncodeBlock( (unsigned char *)final, (unsigned char *)buf, blen );
assert( olen == flen );
*_final = (char *)final;
*_finallen = flen;
}
static int
do_cram_auth( imap_store_t *ctx, struct imap_cmd *cmdp, const char *prompt )
{
@ -1495,9 +1063,6 @@ imap_open_store( store_conf_t *conf,
imap_server_conf_t *srvc = cfg->server;
imap_store_t *ctx;
store_t **ctxp;
struct hostent *he;
struct sockaddr_in addr;
int s, a[2];
for (ctxp = &unowned; (ctx = (imap_store_t *)*ctxp); ctxp = &ctx->gen.next)
if (((imap_store_conf_t *)ctx->gen.conf)->server == srvc) {
@ -1524,68 +1089,12 @@ imap_open_store( store_conf_t *conf,
set_bad_callback( &ctx->gen, (void (*)(void *))imap_open_store_bail, ctx );
ctx->in_progress_append = &ctx->in_progress;
/* open connection to IMAP server */
if (srvc->tunnel) {
infon( "Starting tunnel '%s'... ", srvc->tunnel );
if (socketpair( PF_UNIX, SOCK_STREAM, 0, a )) {
perror( "socketpair" );
exit( 1 );
}
if (fork() == 0) {
if (dup2( a[0], 0 ) == -1 || dup2( a[0], 1 ) == -1)
_exit( 127 );
close( a[0] );
close( a[1] );
execl( "/bin/sh", "sh", "-c", srvc->tunnel, (char *)0 );
_exit( 127 );
}
close (a[0]);
ctx->buf.sock.fd = a[1];
info( "ok\n" );
} else {
memset( &addr, 0, sizeof(addr) );
addr.sin_port = srvc->port ? htons( srvc->port ) :
#ifdef HAVE_LIBSSL
srvc->use_imaps ? htons( 993 ) :
#endif
htons( 143 );
addr.sin_family = AF_INET;
infon( "Resolving %s... ", srvc->host );
he = gethostbyname( srvc->host );
if (!he) {
error( "IMAP error: Cannot resolve server '%s'\n", srvc->host );
goto bail;
}
info( "ok\n" );
addr.sin_addr.s_addr = *((int *) he->h_addr_list[0]);
s = socket( PF_INET, SOCK_STREAM, 0 );
if (s < 0) {
perror( "socket" );
exit( 1 );
}
infon( "Connecting to %s:%hu... ", inet_ntoa( addr.sin_addr ), ntohs( addr.sin_port ) );
if (connect( s, (struct sockaddr *)&addr, sizeof(addr) )) {
close( s );
perror( "connect" );
goto bail;
}
info( "ok\n" );
ctx->buf.sock.fd = s;
}
if (!socket_connect( &srvc->sconf, &ctx->buf.sock ))
goto bail;
#ifdef HAVE_LIBSSL
if (srvc->use_imaps) {
if (start_tls( ctx )) {
if (srvc->sconf.use_imaps) {
if (socket_start_tls( &srvc->sconf, &ctx->buf.sock )) {
imap_open_store_ssl_bail( ctx );
return;
}
@ -1630,7 +1139,8 @@ imap_open_store_authenticate( imap_store_t *ctx )
imap_store_conf_t *cfg = (imap_store_conf_t *)ctx->gen.conf;
imap_server_conf_t *srvc = cfg->server;
if (!srvc->use_imaps && (srvc->use_sslv2 || srvc->use_sslv3 || srvc->use_tlsv1)) {
if (!srvc->sconf.use_imaps &&
(srvc->sconf.use_sslv2 || srvc->sconf.use_sslv3 || srvc->sconf.use_tlsv1)) {
/* always try to select SSL support if available */
if (CAP(STARTTLS)) {
imap_exec( ctx, 0, imap_open_store_authenticate_p2, "STARTTLS" );
@ -1658,7 +1168,7 @@ imap_open_store_authenticate_p2( imap_store_t *ctx, struct imap_cmd *cmd ATTR_UN
{
if (response != RESP_OK)
imap_open_store_bail( ctx );
else if (start_tls( ctx ))
else if (socket_start_tls( &((imap_server_conf_t *)ctx->gen.conf)->sconf, &ctx->buf.sock ))
imap_open_store_ssl_bail( ctx );
else
imap_exec( ctx, 0, imap_open_store_authenticate_p3, "CAPABILITY" );
@ -1797,8 +1307,7 @@ static void
imap_open_store_ssl_bail( imap_store_t *ctx )
{
/* This avoids that we try to send LOGOUT to an unusable socket. */
close( ctx->buf.sock.fd );
ctx->buf.sock.fd = -1;
socket_close( &ctx->buf.sock );
imap_open_store_bail( ctx );
}
#endif
@ -2197,7 +1706,7 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
* case people forget to turn it on
*/
server->require_ssl = 1;
server->use_tlsv1 = 1;
server->sconf.use_tlsv1 = 1;
#endif
while (getcline( cfg ) && cfg->cmd) {
@ -2206,9 +1715,9 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
#ifdef HAVE_LIBSSL
if (!memcmp( "imaps:", cfg->val, 6 )) {
cfg->val += 6;
server->use_imaps = 1;
server->use_sslv2 = 1;
server->use_sslv3 = 1;
server->sconf.use_imaps = 1;
server->sconf.use_sslv2 = 1;
server->sconf.use_sslv3 = 1;
} else
#endif
{
@ -2217,37 +1726,37 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
}
if (!memcmp( "//", cfg->val, 2 ))
cfg->val += 2;
server->host = nfstrdup( cfg->val );
server->sconf.host = nfstrdup( cfg->val );
}
else if (!strcasecmp( "User", cfg->cmd ))
server->user = nfstrdup( cfg->val );
else if (!strcasecmp( "Pass", cfg->cmd ))
server->pass = nfstrdup( cfg->val );
else if (!strcasecmp( "Port", cfg->cmd ))
server->port = parse_int( cfg );
server->sconf.port = parse_int( cfg );
#ifdef HAVE_LIBSSL
else if (!strcasecmp( "CertificateFile", cfg->cmd )) {
server->cert_file = expand_strdup( cfg->val );
if (access( server->cert_file, R_OK )) {
server->sconf.cert_file = expand_strdup( cfg->val );
if (access( server->sconf.cert_file, R_OK )) {
error( "%s:%d: CertificateFile '%s': %s\n",
cfg->file, cfg->line, server->cert_file, strerror( errno ) );
cfg->file, cfg->line, server->sconf.cert_file, strerror( errno ) );
*err = 1;
}
} else if (!strcasecmp( "RequireSSL", cfg->cmd ))
server->require_ssl = parse_bool( cfg );
else if (!strcasecmp( "UseIMAPS", cfg->cmd ))
server->use_imaps = parse_bool( cfg );
server->sconf.use_imaps = parse_bool( cfg );
else if (!strcasecmp( "UseSSLv2", cfg->cmd ))
server->use_sslv2 = parse_bool( cfg );
server->sconf.use_sslv2 = parse_bool( cfg );
else if (!strcasecmp( "UseSSLv3", cfg->cmd ))
server->use_sslv3 = parse_bool( cfg );
server->sconf.use_sslv3 = parse_bool( cfg );
else if (!strcasecmp( "UseTLSv1", cfg->cmd ))
server->use_tlsv1 = parse_bool( cfg );
server->sconf.use_tlsv1 = parse_bool( cfg );
else if (!strcasecmp( "RequireCRAM", cfg->cmd ))
server->require_cram = parse_bool( cfg );
#endif
else if (!strcasecmp( "Tunnel", cfg->cmd ))
server->tunnel = nfstrdup( cfg->val );
server->sconf.tunnel = nfstrdup( cfg->val );
else if (store) {
if (!strcasecmp( "Account", cfg->cmd )) {
for (srv = servers; srv; srv = srv->next)
@ -2273,7 +1782,7 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
acc_opt = 1;
}
if (!store || !store->server) {
if (!server->tunnel && !server->host) {
if (!server->sconf.tunnel && !server->sconf.host) {
if (store)
error( "IMAP store '%s' has incomplete/missing connection details\n", store->gen.name );
else

50
src/isync.h
View File

@ -52,6 +52,41 @@
#define EXE "mbsync"
typedef struct ssl_st SSL;
typedef struct ssl_ctx_st SSL_CTX;
typedef struct x509_store_st X509_STORE;
typedef struct server_conf {
char *tunnel;
char *host;
int port;
#ifdef HAVE_LIBSSL
char *cert_file;
unsigned use_imaps:1;
unsigned use_sslv2:1;
unsigned use_sslv3:1;
unsigned use_tlsv1:1;
/* these are actually variables and are leaked at the end */
SSL_CTX *SSLContext;
X509_STORE *cert_store;
#endif
} server_conf_t;
typedef struct {
int fd;
#ifdef HAVE_LIBSSL
SSL *ssl;
#endif
} Socket_t;
typedef struct {
Socket_t sock;
int bytes;
int offset;
char buf[1024];
} buffer_t;
typedef struct {
const char *file;
FILE *fp;
@ -295,6 +330,21 @@ extern char Hostname[256];
extern const char *Home;
/* socket.c */
int socket_connect( const server_conf_t *conf, Socket_t *sock );
int socket_start_tls( const server_conf_t *conf, Socket_t *sock );
void socket_close( Socket_t *sock );
int socket_read( Socket_t *sock, char *buf, int len );
int socket_write( Socket_t *sock, char *buf, int len );
int socket_pending( Socket_t *sock );
int buffer_gets( buffer_t *b, char **s );
void cram( const char *challenge, const char *user, const char *pass,
char **_final, int *_finallen );
/* util.c */
#define DEBUG 1

514
src/socket.c Normal file
View File

@ -0,0 +1,514 @@
/*
* mbsync - mailbox synchronizer
* Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
* Copyright (C) 2002-2006,2008,2010,2011 Oswald Buddenhagen <ossi@users.sf.net>
* Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*
* As a special exception, mbsync may be linked with the OpenSSL library,
* despite that library's more restrictive license.
*/
/* This must come before isync.h to avoid our #define S messing up
* blowfish.h on MacOS X. */
#include <config.h>
#ifdef HAVE_LIBSSL
# include <openssl/ssl.h>
# include <openssl/err.h>
# include <openssl/hmac.h>
#endif
#include "isync.h"
#include <assert.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
static void
socket_perror( const char *func, Socket_t *sock, int ret )
{
#ifdef HAVE_LIBSSL
int err;
if (sock->ssl) {
switch ((err = SSL_get_error( sock->ssl, ret ))) {
case SSL_ERROR_SYSCALL:
case SSL_ERROR_SSL:
if ((err = ERR_get_error()) == 0) {
if (ret == 0)
error( "SSL_%s: got EOF\n", func );
else
error( "SSL_%s: %s\n", func, strerror(errno) );
} else
error( "SSL_%s: %s\n", func, ERR_error_string( err, 0 ) );
return;
default:
error( "SSL_%s: unhandled SSL error %d\n", func, err );
break;
}
return;
}
#else
(void)sock;
#endif
if (ret < 0)
perror( func );
else
error( "%s: unexpected EOF\n", func );
}
#ifdef HAVE_LIBSSL
/* Some of this code is inspired by / lifted from mutt. */
static int
compare_certificates( X509 *cert, X509 *peercert,
unsigned char *peermd, unsigned peermdlen )
{
unsigned char md[EVP_MAX_MD_SIZE];
unsigned mdlen;
/* Avoid CPU-intensive digest calculation if the certificates are
* not even remotely equal. */
if (X509_subject_name_cmp( cert, peercert ) ||
X509_issuer_name_cmp( cert, peercert ))
return -1;
if (!X509_digest( cert, EVP_sha1(), md, &mdlen ) ||
peermdlen != mdlen || memcmp( peermd, md, mdlen ))
return -1;
return 0;
}
#if OPENSSL_VERSION_NUMBER >= 0x00904000L
#define READ_X509_KEY(fp, key) PEM_read_X509( fp, key, 0, 0 )
#else
#define READ_X509_KEY(fp, key) PEM_read_X509( fp, key, 0 )
#endif
/* this gets called when a certificate is to be verified */
static int
verify_cert( const server_conf_t *conf, Socket_t *sock )
{
server_conf_t *mconf = (server_conf_t *)conf;
SSL *ssl = sock->ssl;
X509 *cert, *lcert;
BIO *bio;
FILE *fp;
int err;
unsigned n, i;
X509_STORE_CTX xsc;
char buf[256];
unsigned char md[EVP_MAX_MD_SIZE];
cert = SSL_get_peer_certificate( ssl );
if (!cert) {
error( "Error, no server certificate\n" );
return -1;
}
while (conf->cert_file) { /* while() instead of if() so break works */
if (X509_cmp_current_time( X509_get_notBefore( cert )) >= 0) {
error( "Server certificate is not yet valid" );
break;
}
if (X509_cmp_current_time( X509_get_notAfter( cert )) <= 0) {
error( "Server certificate has expired" );
break;
}
if (!X509_digest( cert, EVP_sha1(), md, &n )) {
error( "*** Unable to calculate digest\n" );
break;
}
if (!(fp = fopen( conf->cert_file, "rt" ))) {
error( "Unable to load CertificateFile '%s': %s\n",
conf->cert_file, strerror( errno ) );
return 0;
}
err = -1;
for (lcert = 0; READ_X509_KEY( fp, &lcert ); )
if (!(err = compare_certificates( lcert, cert, md, n )))
break;
X509_free( lcert );
fclose( fp );
if (!err)
return 0;
break;
}
if (!mconf->cert_store) {
if (!(mconf->cert_store = X509_STORE_new())) {
error( "Error creating certificate store\n" );
return -1;
}
if (!X509_STORE_set_default_paths( mconf->cert_store ))
warn( "Error while loading default certificate files: %s\n",
ERR_error_string( ERR_get_error(), 0 ) );
if (!conf->cert_file) {
info( "Note: CertificateFile not defined\n" );
} else if (!X509_STORE_load_locations( mconf->cert_store, conf->cert_file, 0 )) {
error( "Error while loading certificate file '%s': %s\n",
conf->cert_file, ERR_error_string( ERR_get_error(), 0 ) );
return -1;
}
}
X509_STORE_CTX_init( &xsc, mconf->cert_store, cert, 0 );
err = X509_verify_cert( &xsc ) > 0 ? 0 : X509_STORE_CTX_get_error( &xsc );
X509_STORE_CTX_cleanup( &xsc );
if (!err)
return 0;
error( "Error, can't verify certificate: %s (%d)\n",
X509_verify_cert_error_string( err ), err );
X509_NAME_oneline( X509_get_subject_name( cert ), buf, sizeof(buf) );
info( "\nSubject: %s\n", buf );
X509_NAME_oneline( X509_get_issuer_name( cert ), buf, sizeof(buf) );
info( "Issuer: %s\n", buf );
bio = BIO_new( BIO_s_mem() );
ASN1_TIME_print( bio, X509_get_notBefore( cert ) );
memset( buf, 0, sizeof(buf) );
BIO_read( bio, buf, sizeof(buf) - 1 );
info( "Valid from: %s\n", buf );
ASN1_TIME_print( bio, X509_get_notAfter( cert ) );
memset( buf, 0, sizeof(buf) );
BIO_read( bio, buf, sizeof(buf) - 1 );
BIO_free( bio );
info( " to: %s\n", buf );
if (!X509_digest( cert, EVP_md5(), md, &n )) {
error( "*** Unable to calculate fingerprint\n" );
} else {
info( "Fingerprint: " );
for (i = 0; i < n; i += 2)
info( "%02X%02X ", md[i], md[i + 1] );
info( "\n" );
}
fputs( "\nAccept certificate? [y/N]: ", stderr );
if (fgets( buf, sizeof(buf), stdin ) && (buf[0] == 'y' || buf[0] == 'Y'))
return 0;
return -1;
}
static int
init_ssl_ctx( const server_conf_t *conf )
{
server_conf_t *mconf = (server_conf_t *)conf;
const SSL_METHOD *method;
int options = 0;
if (conf->use_tlsv1 && !conf->use_sslv2 && !conf->use_sslv3)
method = TLSv1_client_method();
else
method = SSLv23_client_method();
mconf->SSLContext = SSL_CTX_new( method );
if (!conf->use_sslv2)
options |= SSL_OP_NO_SSLv2;
if (!conf->use_sslv3)
options |= SSL_OP_NO_SSLv3;
if (!conf->use_tlsv1)
options |= SSL_OP_NO_TLSv1;
SSL_CTX_set_options( mconf->SSLContext, options );
/* we check the result of the verification after SSL_connect() */
SSL_CTX_set_verify( mconf->SSLContext, SSL_VERIFY_NONE, 0 );
return 0;
}
int
socket_start_tls( const server_conf_t *conf, Socket_t *sock )
{
int ret;
static int ssl_inited;
if (!ssl_inited) {
SSL_library_init();
SSL_load_error_strings();
ssl_inited = 1;
}
if (!conf->SSLContext && init_ssl_ctx( conf ))
return 1;
sock->ssl = SSL_new( ((server_conf_t *)conf)->SSLContext );
SSL_set_fd( sock->ssl, sock->fd );
if ((ret = SSL_connect( sock->ssl )) <= 0) {
socket_perror( "connect", sock, ret );
return 1;
}
/* verify the server certificate */
if (verify_cert( conf, sock ))
return 1;
info( "Connection is now encrypted\n" );
return 0;
}
#endif /* HAVE_LIBSSL */
int
socket_connect( const server_conf_t *conf, Socket_t *sock )
{
struct hostent *he;
struct sockaddr_in addr;
int s, a[2];
/* open connection to IMAP server */
if (conf->tunnel) {
infon( "Starting tunnel '%s'... ", conf->tunnel );
if (socketpair( PF_UNIX, SOCK_STREAM, 0, a )) {
perror( "socketpair" );
exit( 1 );
}
if (fork() == 0) {
if (dup2( a[0], 0 ) == -1 || dup2( a[0], 1 ) == -1)
_exit( 127 );
close( a[0] );
close( a[1] );
execl( "/bin/sh", "sh", "-c", conf->tunnel, (char *)0 );
_exit( 127 );
}
close( a[0] );
sock->fd = a[1];
} else {
memset( &addr, 0, sizeof(addr) );
addr.sin_port = conf->port ? htons( conf->port ) :
#ifdef HAVE_LIBSSL
conf->use_imaps ? htons( 993 ) :
#endif
htons( 143 );
addr.sin_family = AF_INET;
infon( "Resolving %s... ", conf->host );
he = gethostbyname( conf->host );
if (!he) {
error( "IMAP error: Cannot resolve server '%s'\n", conf->host );
return -1;
}
info( "ok\n" );
addr.sin_addr.s_addr = *((int *)he->h_addr_list[0]);
s = socket( PF_INET, SOCK_STREAM, 0 );
if (s < 0) {
perror( "socket" );
exit( 1 );
}
infon( "Connecting to %s:%hu... ", inet_ntoa( addr.sin_addr ), ntohs( addr.sin_port ) );
if (connect( s, (struct sockaddr *)&addr, sizeof(addr) )) {
close( s );
perror( "connect" );
return -1;
}
sock->fd = s;
}
info( "ok\n" );
return 0;
}
void
socket_close( Socket_t *sock )
{
if (sock->fd >= 0) {
close( sock->fd );
sock->fd = -1;
}
#ifdef HAVE_LIBSSL
if (sock->ssl) {
SSL_free( sock->ssl );
sock->ssl = 0;
}
#endif
}
int
socket_read( Socket_t *sock, char *buf, int len )
{
int n;
assert( sock->fd >= 0 );
n =
#ifdef HAVE_LIBSSL
sock->ssl ? SSL_read( sock->ssl, buf, len ) :
#endif
read( sock->fd, buf, len );
if (n <= 0) {
socket_perror( "read", sock, n );
close( sock->fd );
sock->fd = -1;
}
return n;
}
int
socket_write( Socket_t *sock, char *buf, int len )
{
int n;
assert( sock->fd >= 0 );
n =
#ifdef HAVE_LIBSSL
sock->ssl ? SSL_write( sock->ssl, buf, len ) :
#endif
write( sock->fd, buf, len );
if (n != len) {
socket_perror( "write", sock, n );
close( sock->fd );
sock->fd = -1;
}
return n;
}
int
socket_pending( Socket_t *sock )
{
int num = -1;
if (ioctl( sock->fd, FIONREAD, &num ) < 0)
return -1;
if (num > 0)
return num;
#ifdef HAVE_LIBSSL
if (sock->ssl)
return SSL_pending( sock->ssl );
#endif
return 0;
}
/* simple line buffering */
int
buffer_gets( buffer_t * b, char **s )
{
int n;
int start = b->offset;
*s = b->buf + start;
for (;;) {
/* make sure we have enough data to read the \r\n sequence */
if (b->offset + 1 >= b->bytes) {
if (start) {
/* shift down used bytes */
*s = b->buf;
assert( start <= b->bytes );
n = b->bytes - start;
if (n)
memmove( b->buf, b->buf + start, n );
b->offset -= start;
b->bytes = n;
start = 0;
}
n = socket_read( &b->sock, b->buf + b->bytes,
sizeof(b->buf) - b->bytes );
if (n <= 0)
return -1;
b->bytes += n;
}
if (b->buf[b->offset] == '\r') {
assert( b->offset + 1 < b->bytes );
if (b->buf[b->offset + 1] == '\n') {
b->buf[b->offset] = 0; /* terminate the string */
b->offset += 2; /* next line */
if (DFlags & VERBOSE)
puts( *s );
return 0;
}
}
b->offset++;
}
/* not reached */
}
#ifdef HAVE_LIBSSL
/* this isn't strictly socket code, but let's have all OpenSSL use in one file. */
#define ENCODED_SIZE(n) (4*((n+2)/3))
static char
hexchar( unsigned int b )
{
if (b < 10)
return '0' + b;
return 'a' + (b - 10);
}
void
cram( const char *challenge, const char *user, const char *pass, char **_final, int *_finallen )
{
unsigned char *response, *final;
unsigned hashlen;
int i, clen, rlen, blen, flen, olen;
unsigned char hash[16];
char buf[256], hex[33];
HMAC_CTX hmac;
HMAC_Init( &hmac, (unsigned char *)pass, strlen( pass ), EVP_md5() );
clen = strlen( challenge );
/* response will always be smaller than challenge because we are decoding. */
response = nfcalloc( 1 + clen );
rlen = EVP_DecodeBlock( response, (unsigned char *)challenge, clen );
HMAC_Update( &hmac, response, rlen );
free( response );
hashlen = sizeof(hash);
HMAC_Final( &hmac, hash, &hashlen );
assert( hashlen == sizeof(hash) );
hex[32] = 0;
for (i = 0; i < 16; i++) {
hex[2 * i] = hexchar( (hash[i] >> 4) & 0xf );
hex[2 * i + 1] = hexchar( hash[i] & 0xf );
}
blen = nfsnprintf( buf, sizeof(buf), "%s %s", user, hex );
flen = ENCODED_SIZE( blen );
final = nfmalloc( flen + 1 );
final[flen] = 0;
olen = EVP_EncodeBlock( (unsigned char *)final, (unsigned char *)buf, blen );
assert( olen == flen );
*_final = (char *)final;
*_finallen = flen;
}
#endif