/*
* petal.c - https daemon that is small and beautiful.
*
* Copyright (c) 2010, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* HTTP1.1/SSL server.
*/
#include "config.h"
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#ifdef HAVE_OPENSSL_SSL_H
#include <openssl/ssl.h>
#endif
#ifdef HAVE_OPENSSL_ERR_H
#include <openssl/err.h>
#endif
#ifdef HAVE_OPENSSL_RAND_H
#include <openssl/rand.h>
#endif
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <ctype.h>
#include <signal.h>
#if defined(UNBOUND_ALLOC_LITE) || defined(UNBOUND_ALLOC_STATS)
#ifdef malloc
#undef malloc
#endif
#ifdef free
#undef free
#endif
#endif /* alloc lite or alloc stats */
/** verbosity for this application */
static int verb = 0;
/** Give petal usage, and exit (1). */
static void
usage(void)
{
printf("Usage: petal [opts]\n");
printf(" https daemon serves files from ./'host'/filename\n");
printf(" (no hostname: from the 'default' directory)\n");
printf("-a addr bind to this address, 127.0.0.1\n");
printf("-p port port number, default 443\n");
printf("-k keyfile SSL private key file (PEM), petal.key\n");
printf("-c certfile SSL certificate file (PEM), petal.pem\n");
printf("-v more verbose\n");
printf("-h show this usage help\n");
printf("Version %s\n", PACKAGE_VERSION);
printf("BSD licensed, see LICENSE in source package for details.\n");
printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
exit(1);
}
/** fatal exit */
static void print_exit(const char* str) {printf("error %s\n", str); exit(1);}
/** print errno */
static void log_errno(const char* str)
{printf("error %s: %s\n", str, strerror(errno));}
/** parse a text IP address into a sockaddr */
static int
parse_ip_addr(char* str, int port, struct sockaddr_storage* ret, socklen_t* l)
{
socklen_t len = 0;
struct sockaddr_storage* addr = NULL;
struct sockaddr_in6 a6;
struct sockaddr_in a;
uint16_t p = (uint16_t)port;
int fam = 0;
memset(&a6, 0, sizeof(a6));
memset(&a, 0, sizeof(a));
if(inet_pton(AF_INET6, str, &a6.sin6_addr) > 0) {
/* it is an IPv6 */
fam = AF_INET6;
a6.sin6_family = AF_INET6;
a6.sin6_port = (in_port_t)htons(p);
addr = (struct sockaddr_storage*)&a6;
len = (socklen_t)sizeof(struct sockaddr_in6);
}
if(inet_pton(AF_INET, str, &a.sin_addr) > 0) {
/* it is an IPv4 */
fam = AF_INET;
a.sin_family = AF_INET;
a.sin_port = (in_port_t)htons(p);
addr = (struct sockaddr_storage*)&a;
len = (socklen_t)sizeof(struct sockaddr_in);
}
if(!len) print_exit("cannot parse addr");
*l = len;
memmove(ret, addr, len);
return fam;
}
/** close the fd */
static void
fd_close(int fd)
{
#ifndef USE_WINSOCK
close(fd);
#else
closesocket(fd);
#endif
}
/**
* Read one line from SSL
* zero terminates.
* skips "\r\n" (but not copied to buf).
* @param ssl: the SSL connection to read from (blocking).
* @param buf: buffer to return line in.
* @param len: size of the buffer.
* @return 0 on error, 1 on success.
*/
static int
read_ssl_line(SSL* ssl, char* buf, size_t len)
{
size_t n = 0;
int r;
int endnl = 0;
while(1) {
if(n >= len) {
if(verb) printf("line too long\n");
return 0;
}
if((r = SSL_read(ssl, buf+n, 1)) <= 0) {
if(SSL_get_error(ssl, r) == SSL_ERROR_ZERO_RETURN) {
/* EOF */
break;
}
if(verb) printf("could not SSL_read\n");
return 0;
}
if(endnl && buf[n] == '\n') {
break;
} else if(endnl) {
/* bad data */
if(verb) printf("error: stray linefeeds\n");
return 0;
} else if(buf[n] == '\r') {
/* skip \r, and also \n on the wire */
endnl = 1;
continue;
} else if(buf[n] == '\n') {
/* skip the \n, we are done */
break;
} else n++;
}
buf[n] = 0;
return 1;
}
/** process one http header */
static int
process_one_header(char* buf, char* file, size_t flen, char* host, size_t hlen,
int* vs)
{
if(strncasecmp(buf, "GET ", 4) == 0) {
char* e = strstr(buf, " HTTP/1.1");
if(!e) e = strstr(buf, " http/1.1");
if(!e) {
e = strstr(buf, " HTTP/1.0");
if(!e) e = strstr(buf, " http/1.0");
if(!e) e = strrchr(buf, ' ');
if(!e) e = strrchr(buf, '\t');
if(e) *vs = 10;
}
if(e) *e = 0;
if(strlen(buf) < 4) return 0;
(void)strlcpy(file, buf+4, flen);
} else if(strncasecmp(buf, "Host: ", 6) == 0) {
(void)strlcpy(host, buf+6, hlen);
}
return 1;
}
/** read http headers and process them */
static int
read_http_headers(SSL* ssl, char* file, size_t flen, char* host, size_t hlen,
int* vs)
{
char buf[1024];
file[0] = 0;
host[0] = 0;
while(read_ssl_line(ssl, buf, sizeof(buf))) {
if(verb>=2) printf("read: %s\n", buf);
if(buf[0] == 0) {
int e = ERR_peek_error();
printf("error string: %s\n", ERR_reason_error_string(e));
return 1;
}
if(!process_one_header(buf, file, flen, host, hlen, vs))
return 0;
}
return 0;
}
/** setup SSL context */
static SSL_CTX*
setup_ctx(char* key, char* cert)
{
SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
if(!ctx) print_exit("out of memory");
#if SSL_OP_NO_SSLv2 != 0
(void)SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2);
#endif
(void)SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3);
#ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL
SSL_CTX_set_security_level(ctx, 0); /* for keys in tests */
#endif
if(!SSL_CTX_use_certificate_chain_file(ctx, cert)) {
int e = ERR_peek_error();
printf("error string: %s\n", ERR_reason_error_string(e));
print_exit("cannot read cert");
}
if(!SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM))
print_exit("cannot read key");
if(!SSL_CTX_check_private_key(ctx))
print_exit("private key is not correct");
#if HAVE_DECL_SSL_CTX_SET_ECDH_AUTO
if (!SSL_CTX_set_ecdh_auto(ctx,1))
if(verb>=1) printf("failed to set_ecdh_auto, not enabling ECDHE\n");
#elif defined(USE_ECDSA)
if(1) {
EC_KEY *ecdh = EC_KEY_new_by_curve_name (NID_X9_62_prime256v1);
if (!ecdh) {
if(verb>=1) printf("could not find p256, not enabling ECDHE\n");
} else {
if (1 != SSL_CTX_set_tmp_ecdh (ctx, ecdh)) {
if(verb>=1) printf("Error in SSL_CTX_set_tmp_ecdh, not enabling ECDHE\n");
}
EC_KEY_free(ecdh);
}
}
#endif
if(!SSL_CTX_load_verify_locations(ctx, cert, NULL))
print_exit("cannot load cert verify locations");
return ctx;
}
/** setup listening TCP */
static int
setup_fd(char* addr, int port)
{
struct sockaddr_storage ad;
socklen_t len;
int fd;
int c = 1;
int fam = parse_ip_addr(addr, port, &ad, &len);
fd = socket(fam, SOCK_STREAM, 0);
if(fd == -1) {
log_errno("socket");
return -1;
}
if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
(void*)&c, (socklen_t) sizeof(int)) < 0) {
log_errno("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
}
if(bind(fd, (struct sockaddr*)&ad, len) == -1) {
log_errno("bind");
fd_close(fd);
return -1;
}
if(listen(fd, 5) == -1) {
log_errno("listen");
fd_close(fd);
return -1;
}
return fd;
}
/** setup SSL connection to the client */
static SSL*
setup_ssl(int s, SSL_CTX* ctx)
{
SSL* ssl = SSL_new(ctx);
if(!ssl) return NULL;
SSL_set_accept_state(ssl);
(void)SSL_set_mode(ssl, (long)SSL_MODE_AUTO_RETRY);
if(!SSL_set_fd(ssl, s)) {
SSL_free(ssl);
return NULL;
}
return ssl;
}
/** check a file name for safety */
static int
file_name_is_safe(char* s)
{
size_t l = strlen(s);
if(s[0] != '/')
return 0; /* must start with / */
if(strstr(s, "/../"))
return 0; /* no updirs in URL */
if(l>=3 && s[l-1]=='.' && s[l-2]=='.' && s[l-3]=='/')
return 0; /* ends with /.. */
return 1;
}
/** adjust host */
static void
adjust_host(char* host)
{
size_t i, len;
/* remove a port number if present */
if(strrchr(host, ':'))
*strrchr(host, ':') = 0;
/* lowercase */
len = strlen(host);
for(i=0; i<len; i++)
host[i] = tolower((unsigned char)host[i]);
}
/** adjust filename */
static void
adjust_file(char* file)
{
size_t i, len;
len = strlen(file);
for(i=0; i<len; i++)
file[i] = tolower((unsigned char)file[i]);
}
/** check a host name for safety */
static int
host_name_is_safe(char* s)
{
if(strchr(s, '/'))
return 0;
if(strcmp(s, "..") == 0)
return 0;
if(strcmp(s, ".") == 0)
return 0;
return 1;
}
/** provide file in whole transfer */
static void
provide_file_10(SSL* ssl, char* fname)
{
char* buf, *at;
size_t len, avail, header_reserve=1024;
FILE* in = fopen(fname,
#ifndef USE_WINSOCK
"r"
#else
"rb"
#endif
);
size_t r;
const char* rcode = "200 OK";
if(!in) {
char hdr[1024];
rcode = "404 File not found";
snprintf(hdr, sizeof(hdr), "HTTP/1.1 %s\r\n\r\n", rcode);
r = strlen(hdr);
if(SSL_write(ssl, hdr, (int)r) <= 0) {
/* write failure */
}
return;
}
fseek(in, 0, SEEK_END);
len = (size_t)ftell(in);
fseek(in, 0, SEEK_SET);
/* plus some space for the header */
buf = (char*)malloc(len+header_reserve);
if(!buf) {
fclose(in);
return;
}
avail = len+header_reserve;
at = buf;
snprintf(at, avail, "HTTP/1.1 %s\r\n", rcode);
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "Server: petal/%s\r\n", PACKAGE_VERSION);
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "Content-Length: %u\r\n", (unsigned)len);
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "\r\n");
r = strlen(at);
at += r;
avail -= r;
if(avail < len) { /* robust */
free(buf);
fclose(in);
return;
}
if(fread(at, 1, len, in) != len) {
free(buf);
fclose(in);
return;
}
fclose(in);
at += len;
/* avail -= len; unused */
if(SSL_write(ssl, buf, at-buf) <= 0) {
/* write failure */
}
free(buf);
}
/** provide file over SSL, chunked encoding */
static void
provide_file_chunked(SSL* ssl, char* fname)
{
char buf[16384];
char* tmpbuf = NULL;
char* at = buf;
size_t avail = sizeof(buf);
size_t r;
FILE* in = fopen(fname,
#ifndef USE_WINSOCK
"r"
#else
"rb"
#endif
);
const char* rcode = "200 OK";
if(!in) {
rcode = "404 File not found";
}
/* print headers */
snprintf(at, avail, "HTTP/1.1 %s\r\n", rcode);
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "Server: petal/%s\r\n", PACKAGE_VERSION);
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "Transfer-Encoding: chunked\r\n");
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "Connection: close\r\n");
r = strlen(at);
at += r;
avail -= r;
snprintf(at, avail, "\r\n");
r = strlen(at);
at += r;
avail -= r;
if(avail < 16) { /* robust */
if(in) fclose(in);
return;
}
do {
size_t red;
free(tmpbuf);
tmpbuf = malloc(avail-16);
if(!tmpbuf)
break;
/* read chunk; space-16 for xxxxCRLF..CRLF0CRLFCRLF (3 spare)*/
red = in?fread(tmpbuf, 1, avail-16, in):0;
/* prepare chunk */
snprintf(at, avail, "%x\r\n", (unsigned)red);
r = strlen(at);
if(verb >= 3)
{printf("chunk len %x\n", (unsigned)red); fflush(stdout);}
at += r;
avail -= r;
if(red != 0) {
if(red > avail) break; /* robust */
memmove(at, tmpbuf, red);
at += red;
avail -= red;
snprintf(at, avail, "\r\n");
r = strlen(at);
at += r;
avail -= r;
}
if(in && feof(in) && red != 0) {
snprintf(at, avail, "0\r\n");
r = strlen(at);
at += r;
avail -= r;
}
if(!in || feof(in)) {
snprintf(at, avail, "\r\n");
r = strlen(at);
at += r;
/* avail -= r; unused */
}
/* send chunk */
if(SSL_write(ssl, buf, at-buf) <= 0) {
/* SSL error */
break;
}
/* setup for next chunk */
at = buf;
avail = sizeof(buf);
} while(in && !feof(in) && !ferror(in));
free(tmpbuf);
if(in) fclose(in);
}
/** provide service to the ssl descriptor */
static void
service_ssl(SSL* ssl, struct sockaddr_storage* from, socklen_t falen)
{
char file[1024];
char host[1024];
char combined[2048];
int vs = 11;
if(!read_http_headers(ssl, file, sizeof(file), host, sizeof(host),
&vs))
return;
if(host[0] != 0) adjust_host(host);
if(file[0] != 0) adjust_file(file);
if(host[0] == 0 || !host_name_is_safe(host))
(void)strlcpy(host, "default", sizeof(host));
if(!file_name_is_safe(file)) {
return;
}
snprintf(combined, sizeof(combined), "%s%s", host, file);
if(verb) {
char out[100];
void* a = &((struct sockaddr_in*)from)->sin_addr;
if(falen != (socklen_t)sizeof(struct sockaddr_in))
a = &((struct sockaddr_in6*)from)->sin6_addr;
out[0]=0;
(void)inet_ntop((int)((struct sockaddr_in*)from)->sin_family,
a, out, (socklen_t)sizeof(out));
printf("%s requests %s\n", out, combined);
fflush(stdout);
}
if(vs == 10)
provide_file_10(ssl, combined);
else provide_file_chunked(ssl, combined);
}
/** provide ssl service */
static void
do_service(char* addr, int port, char* key, char* cert)
{
SSL_CTX* sslctx = setup_ctx(key, cert);
int fd = setup_fd(addr, port);
if(fd == -1) print_exit("could not setup sockets");
if(verb) {printf("petal start\n"); fflush(stdout);}
while(1) {
struct sockaddr_storage from;
socklen_t flen = (socklen_t)sizeof(from);
int s;
memset(&from, 0, sizeof(from));
s = accept(fd, (struct sockaddr*)&from, &flen);
if(verb) fflush(stdout);
if(s != -1) {
SSL* ssl = setup_ssl(s, sslctx);
if(verb) fflush(stdout);
if(ssl) {
service_ssl(ssl, &from, flen);
if(verb) fflush(stdout);
SSL_shutdown(ssl);
SSL_free(ssl);
}
fd_close(s);
} else if (verb >=2) log_errno("accept");
if(verb) fflush(stdout);
}
/* if we get a kill signal, the process dies and the OS reaps us */
if(verb) printf("petal end\n");
fd_close(fd);
SSL_CTX_free(sslctx);
}
/** getopt global, in case header files fail to declare it. */
extern int optind;
/** getopt global, in case header files fail to declare it. */
extern char* optarg;
/** Main routine for petal */
int main(int argc, char* argv[])
{
int c;
int port = 443;
char* addr = "127.0.0.1", *key = "petal.key", *cert = "petal.pem";
#ifdef USE_WINSOCK
WSADATA wsa_data;
if((c=WSAStartup(MAKEWORD(2,2), &wsa_data)) != 0)
{ printf("WSAStartup failed\n"); exit(1); }
atexit((void (*)(void))WSACleanup);
#endif
/* parse the options */
while( (c=getopt(argc, argv, "a:c:k:hp:v")) != -1) {
switch(c) {
case 'a':
addr = optarg;
break;
case 'c':
cert = optarg;
break;
case 'k':
key = optarg;
break;
case 'p':
port = atoi(optarg);
break;
case 'v':
verb++;
break;
case '?':
case 'h':
default:
usage();
}
}
argc -= optind;
/* argv += optind; not using further arguments */
if(argc != 0)
usage();
#ifdef SIGPIPE
(void)signal(SIGPIPE, SIG_IGN);
#endif
#ifdef HAVE_ERR_LOAD_CRYPTO_STRINGS
ERR_load_crypto_strings();
#endif
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_SSL)
ERR_load_SSL_strings();
#endif
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_CRYPTO)
# ifndef S_SPLINT_S
OpenSSL_add_all_algorithms();
# endif
#else
OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
| OPENSSL_INIT_ADD_ALL_DIGESTS
| OPENSSL_INIT_LOAD_CRYPTO_STRINGS, NULL);
#endif
#if OPENSSL_VERSION_NUMBER < 0x10100000 || !defined(HAVE_OPENSSL_INIT_SSL)
(void)SSL_library_init();
#else
(void)OPENSSL_init_ssl(OPENSSL_INIT_LOAD_SSL_STRINGS, NULL);
#endif
do_service(addr, port, key, cert);
#ifdef HAVE_CRYPTO_CLEANUP_ALL_EX_DATA
CRYPTO_cleanup_all_ex_data();
#endif
#ifdef HAVE_ERR_FREE_STRINGS
ERR_free_strings();
#endif
return 0;
}