#include "para.h"
#include "error.h"
+ #include "crypt.h"
+ #include "command.h"
#include "server.cmdline.h"
#include "string.h"
#include "afh.h"
/** Commands including options must be shorter than this. */
#define MAX_COMMAND_LEN 32768
- static RC4_KEY rc4_recv_key;
- static RC4_KEY rc4_send_key;
- static unsigned char rc4_buf[2 * RC4_KEY_LEN];
-
extern int mmd_mutex;
extern struct misc_meta_data *mmd;
extern struct sender senders[];
break;
case SENDER_DENY:
case SENDER_ALLOW:
- if (argc != 4 && argc != 5)
+ if (argc != 4 || parse_cidr(argv[3], scd->host,
+ sizeof(scd->host), &scd->netmask) == NULL)
return -E_COMMAND_SYNTAX;
- if (!is_valid_ipv4_address(argv[3]))
- return -E_COMMAND_SYNTAX;
- scd->netmask = 32;
- if (argc == 5) {
- scd->netmask = atoi(argv[4]);
- if (scd->netmask < 0 || scd->netmask > 32)
- return -E_COMMAND_SYNTAX;
- }
- strncpy(scd->host, argv[3], sizeof(scd->host));
break;
case SENDER_ADD:
case SENDER_DELETE:
return 1;
}
- int com_sender(int fd, int argc, char * const * argv)
+ int com_sender(struct rc4_context *rc4c, int argc, char * const * argv)
{
int i, ret;
struct sender_command_data scd;
free(msg);
msg = tmp;
}
- ret = send_buffer(fd, msg);
+ ret = rc4_send_buffer(rc4c, msg);
free(msg);
return ret;
}
if (scd.sender_num < 0)
return ret;
msg = senders[scd.sender_num].help();
- ret = send_buffer(fd, msg);
+ ret = rc4_send_buffer(rc4c, msg);
free(msg);
return ret;
}
}
/* server info */
- int com_si(int fd, int argc, __a_unused char * const * argv)
+ int com_si(struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
int i, ret;
char *ut;
sender_list = para_strcat(sender_list, " ");
}
ut = uptime_str();
- ret = send_va_buffer(fd, "up: %s\nplayed: %u\n"
+ ret = rc4_send_va_buffer(rc4c, "up: %s\nplayed: %u\n"
"server_pid: %d\n"
"afs_pid: %d\n"
"connections (active/accepted/total): %u/%u/%u\n"
}
/* version */
- int com_version(int fd, int argc, __a_unused char * const * argv)
+ int com_version(struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
- return send_buffer(fd, VERSION_TEXT("server")
+ return rc4_send_buffer(rc4c, VERSION_TEXT("server")
"built: " BUILD_DATE "\n"
UNAME_RS ", " CC_VERSION "\n"
);
}
/* stat */
- int com_stat(int fd, int argc, char * const * argv)
+ int com_stat(struct rc4_context *rc4c, int argc, char * const * argv)
{
int ret, num = 0;/* status will be printed that many
* times. num <= 0 means: print forever
mmd_dup(nmmd);
s = get_status(nmmd);
- ret = send_buffer(fd, s);
+ ret = rc4_send_buffer(rc4c, s);
free(s);
if (ret < 0)
goto out;
return ret;
}
- static int send_list_of_commands(int fd, struct server_command *cmd,
+ static int send_list_of_commands(struct rc4_context *rc4c, struct server_command *cmd,
const char *handler)
{
int ret, i;
for (i = 1; cmd->name; cmd++, i++) {
char *perms = cmd_perms_itohuman(cmd->perms);
- ret = send_va_buffer(fd, "%s\t%s\t%s\t%s\n", cmd->name,
+ ret = rc4_send_va_buffer(rc4c, "%s\t%s\t%s\t%s\n", cmd->name,
handler,
perms,
cmd->description);
}
/* help */
- int com_help(int fd, int argc, char * const * argv)
+ int com_help(struct rc4_context *rc4c, int argc, char * const * argv)
{
struct server_command *cmd;
char *perms, *handler;
if (argc < 2) {
/* no argument given, print list of commands */
- if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0)
+ if ((ret = send_list_of_commands(rc4c, server_cmds, "server")) < 0)
return ret;
- return send_list_of_commands(fd, afs_cmds, "afs");
+ return send_list_of_commands(rc4c, afs_cmds, "afs");
}
/* argument given for help */
cmd = get_cmd_ptr(argv[1], &handler);
return -E_BAD_CMD;
}
perms = cmd_perms_itohuman(cmd->perms);
- ret = send_va_buffer(fd,
+ ret = rc4_send_va_buffer(rc4c,
"%s - %s\n\n"
"handler: %s\n"
"permissions: %s\n"
}
/* hup */
- int com_hup(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_hup(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* term */
- int com_term(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_term(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
return 1;
}
- int com_play(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_play(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* stop */
- int com_stop(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_stop(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* pause */
- int com_pause(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_pause(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* next */
- int com_next(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_next(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* nomore */
- int com_nomore(__a_unused int fd, int argc, __a_unused char * const * argv)
+ int com_nomore(__a_unused struct rc4_context *rc4c, int argc, __a_unused char * const * argv)
{
if (argc != 1)
return -E_COMMAND_SYNTAX;
}
/* ff */
- int com_ff(__a_unused int fd, int argc, char * const * argv)
+ int com_ff(__a_unused struct rc4_context *rc4c, int argc, char * const * argv)
{
long promille;
int ret, backwards = 0;
}
/* jmp */
- int com_jmp(__a_unused int fd, int argc, char * const * argv)
+ int com_jmp(__a_unused struct rc4_context *rc4c, int argc, char * const * argv)
{
long unsigned int i;
int ret;
return get_cmd_ptr(buf, NULL);
}
- static void init_rc4_keys(void)
- {
- int i;
-
- for (i = 0; i < 2 * RC4_KEY_LEN; i++)
- rc4_buf[i] = para_random(256);
- PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
- (unsigned char) rc4_buf[0],
- (unsigned char) rc4_buf[RC4_KEY_LEN]);
- RC4_set_key(&rc4_recv_key, RC4_KEY_LEN, rc4_buf);
- RC4_set_key(&rc4_send_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
- }
-
- static void rc4_recv(unsigned long len, const unsigned char *indata,
- unsigned char *outdata, __a_unused void *private_data)
- {
- RC4(&rc4_recv_key, len, indata, outdata);
- }
-
- static void rc4_send(unsigned long len, const unsigned char *indata,
- unsigned char *outdata, __a_unused void *private_data)
- {
- RC4(&rc4_send_key, len, indata, outdata);
- }
-
- static int read_command(int fd, char **result)
+ static int read_command(struct rc4_context *rc4c, char **result)
{
int ret;
char buf[4096];
size_t numbytes;
char *p;
- ret = recv_buffer(fd, buf, sizeof(buf));
+ ret = rc4_recv_buffer(rc4c, buf, sizeof(buf));
if (ret < 0)
goto out;
if (!ret)
*/
__noreturn void handle_connect(int fd, const char *peername)
{
- int ret, argc, use_rc4 = 0;
+ int ret, argc;
char buf[4096];
- unsigned char crypt_buf[MAXLINE];
+ unsigned char rand_buf[CHALLENGE_SIZE + 2 * RC4_KEY_LEN];
+ unsigned char challenge_sha1[HASH_SIZE];
struct user *u;
struct server_command *cmd = NULL;
- long unsigned challenge_nr, chall_response;
char **argv = NULL;
char *p, *command = NULL;
size_t numbytes;
+ struct rc4_context rc4c = {.fd = fd};
reset_signals();
/* we need a blocking fd here as recv() might return EAGAIN otherwise. */
ret = mark_fd_blocking(fd);
if (ret < 0)
goto err_out;
- challenge_nr = random();
/* send Welcome message */
ret = send_va_buffer(fd, "This is para_server, version "
PACKAGE_VERSION ".\n" );
ret = recv_buffer(fd, buf, sizeof(buf));
if (ret < 0)
goto err_out;
- if (ret <= 6) {
- ret = -E_AUTH;
+ if (ret < 10) {
+ ret = -E_AUTH_REQUEST;
goto err_out;
}
numbytes = ret;
- ret = -E_AUTH;
- if (strncmp(buf, "auth ", 5))
+ ret = -E_AUTH_REQUEST;
+ if (strncmp(buf, AUTH_REQUEST_MSG, strlen(AUTH_REQUEST_MSG)))
goto err_out;
-
- if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
- p = buf + 5; /* client version < 0.2.6 */
- else {
- p = buf + 9; /* client version >= 0.2.6 */
- use_rc4 = 1;
- }
- PARA_DEBUG_LOG("received %s request for user %s\n",
- use_rc4? "rc4" : "auth", p);
+ p = buf + strlen(AUTH_REQUEST_MSG);
+ PARA_DEBUG_LOG("received auth request for user %s\n", p);
ret = -E_BAD_USER;
u = lookup_user(p);
- if (!u)
- goto err_out;
- ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
- if (ret <= 0)
- goto err_out;
- numbytes = ret;
- PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes);
- /* We can't use send_buffer here since buf may contain null bytes */
- ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes);
+ if (u) {
+ get_random_bytes_or_die(rand_buf, sizeof(rand_buf));
+ ret = para_encrypt_buffer(u->rsa, rand_buf, sizeof(rand_buf),
+ (unsigned char *)buf);
+ if (ret < 0)
+ goto err_out;
+ numbytes = ret;
+ } else {
+ /*
+ * We don't want to reveal our user names, so we send a
+ * challenge to the client even if the user does not exist, and
+ * fail the authentication later.
+ */
+ numbytes = 256;
+ get_random_bytes_or_die((unsigned char *)buf, numbytes);
+ }
+ PARA_DEBUG_LOG("sending %zu byte challenge + rc4 keys (%u bytes)\n",
+ CHALLENGE_SIZE, numbytes);
+ ret = send_bin_buffer(fd, buf, numbytes);
if (ret < 0)
goto net_err;
- /* recv decrypted number */
- ret = recv_buffer(fd, buf, sizeof(buf));
+ /* recv challenge response */
+ ret = recv_bin_buffer(fd, buf, HASH_SIZE);
if (ret < 0)
goto net_err;
numbytes = ret;
- ret = -E_AUTH;
- if (!numbytes)
+ PARA_DEBUG_LOG("received %zu bytes challenge response\n", ret);
+ ret = -E_BAD_USER;
+ if (!u)
goto net_err;
- if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
- || chall_response != challenge_nr)
- goto err_out;
- /* auth successful, send 'Proceed' message */
- PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
- sprintf(buf, "%s", PROCEED_MSG);
- if (use_rc4) {
- init_rc4_keys();
- ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
- (unsigned char *)buf + PROCEED_MSG_LEN + 1);
- if (ret <= 0)
- goto err_out;
- numbytes = ret + strlen(PROCEED_MSG) + 1;
- } else
- numbytes = strlen(buf);
- ret = send_bin_buffer(fd, buf, numbytes);
+ /*
+ * The correct response is the sha1 of the first CHALLENGE_SIZE bytes
+ * of the random data.
+ */
+ ret = -E_BAD_AUTH;
+ if (numbytes != HASH_SIZE)
+ goto net_err;
+ sha1_hash((char *)rand_buf, CHALLENGE_SIZE, challenge_sha1);
+ if (memcmp(challenge_sha1, buf, HASH_SIZE))
+ goto net_err;
+ /* auth successful */
+ alarm(0);
+ PARA_INFO_LOG("good auth for %s\n", u->name);
+ /* init rc4 keys with the second part of the random buffer */
+ RC4_set_key(&rc4c.recv_key, RC4_KEY_LEN, rand_buf + CHALLENGE_SIZE);
+ RC4_set_key(&rc4c.send_key, RC4_KEY_LEN, rand_buf + CHALLENGE_SIZE
+ + RC4_KEY_LEN);
+ ret = rc4_send_buffer(&rc4c, PROCEED_MSG);
if (ret < 0)
goto net_err;
- if (use_rc4)
- enable_crypt(fd, rc4_recv, rc4_send, NULL);
- ret = read_command(fd, &command);
+ ret = read_command(&rc4c, &command);
if (ret == -E_COMMAND_SYNTAX)
goto err_out;
if (ret < 0)
if (ret < 0)
goto err_out;
/* valid command and sufficient perms */
- alarm(0);
argc = split_args(command, &argv, "\n");
PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
peername);
- ret = cmd->handler(fd, argc, argv);
+ ret = cmd->handler(&rc4c, argc, argv);
mutex_lock(mmd_mutex);
mmd->num_commands++;
mutex_unlock(mmd_mutex);
if (ret >= 0)
goto out;
err_out:
- send_va_buffer(fd, "%s\n", para_strerror(-ret));
+ rc4_send_va_buffer(&rc4c, "%s\n", para_strerror(-ret));
net_err:
PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
out:
#include <dirent.h>
#include <regex.h>
+ #include <openssl/rc4.h>
#include "para.h"
#include "error.h"
+ #include "crypt.h"
#include "net.h"
#include "string.h"
#include "fd.h"
-
- /** Information about one encrypted connection. */
- struct crypt_data {
- /** Function used to decrypt received data. */
- crypt_function *recv;
- /** Function used to encrypt data to be sent. */
- crypt_function *send;
- /**
- * Context-dependent data (crypt keys), passed verbatim to the above
- * crypt functions.
- */
- void *private_data;
- };
- /** Array holding per fd crypt data. */
- static struct crypt_data *crypt_data_array;
- /** Current size of the crypt data array. */
- static unsigned cda_size = 0;
-
- /**
- * Activate encryption for one file descriptor.
- *
- * \param fd The file descriptor.
- * \param recv_f The function used for decrypting received data.
- * \param send_f The function used for encrypting before sending.
- * \param private_data User data supplied by the caller.
- */
- void enable_crypt(int fd, crypt_function *recv_f, crypt_function *send_f,
- void *private_data)
- {
- if (fd + 1 > cda_size) {
- crypt_data_array = para_realloc(crypt_data_array,
- (fd + 1) * sizeof(struct crypt_data));
- memset(crypt_data_array + cda_size, 0,
- (fd + 1 - cda_size) * sizeof(struct crypt_data));
- cda_size = fd + 1;
- }
- crypt_data_array[fd].recv = recv_f;
- crypt_data_array[fd].send = send_f;
- crypt_data_array[fd].private_data = private_data;
- PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd);
- }
-
- /**
- * Deactivate encryption for a given fd.
- *
- * \param fd The file descriptor.
- *
- * This must be called if and only if \p fd was activated via enable_crypt().
- */
- void disable_crypt(int fd)
- {
- if (cda_size < fd + 1)
- return;
- crypt_data_array[fd].recv = NULL;
- crypt_data_array[fd].send = NULL;
- crypt_data_array[fd].private_data = NULL;
- }
-
+/**
+ * Parse and validate IPv4 address/netmask string.
+ *
+ * \param cidr Address in CIDR notation
+ * \param addr Copy of the IPv4 address part of \a cidr
+ * \param addrlen Size of \a addr in bytes
+ * \param netmask Value of the netmask part in \a cidr or the
+ * default of 32 if not specified.
+ *
+ * \return Pointer to \a addr if succesful, NULL on error.
+ * \sa RFC 4632
+ */
+char *parse_cidr(const char *cidr,
+ char *addr, ssize_t addrlen,
+ int32_t *netmask)
+{
+ const char *o = cidr;
+ char *c = addr, *end = c + (addrlen - 1);
+
+ *netmask = 0x20;
+
+ if (cidr == NULL || addrlen < 1)
+ goto failed;
+
+ for (o = cidr; (*c = *o == '/'? '\0' : *o); c++, o++)
+ if (c == end)
+ goto failed;
+
+ if (*o == '/')
+ if (para_atoi32(++o, netmask) < 0 ||
+ *netmask < 0 || *netmask > 0x20)
+ goto failed;
+
+ if (is_valid_ipv4_address(addr))
+ return addr;
+failed:
+ *addr = '\0';
+ return NULL;
+}
+
+
/**
* Match string as a candidate IPv4 address.
*
}
/**
- * Encrypt and send a binary buffer.
+ * Send a binary buffer.
*
* \param fd The file descriptor.
- * \param buf The buffer to be encrypted and sent.
+ * \param buf The buffer to be sent.
* \param len The length of \a buf.
*
- * Check if encryption is available. If yes, encrypt the given buffer. Send
- * out the buffer, encrypted or not, and try to resend the remaining part in
- * case of short writes.
+ * Send out the buffer and try to resend the remaining part in case of short
+ * writes.
*
* \return Standard.
*/
int send_bin_buffer(int fd, const char *buf, size_t len)
{
- int ret;
- crypt_function *cf = NULL;
-
if (!len)
PARA_CRIT_LOG("len == 0\n");
- if (fd + 1 <= cda_size)
- cf = crypt_data_array[fd].send;
- if (cf) {
- void *private = crypt_data_array[fd].private_data;
- /* RC4 may write more than len to the output buffer */
- unsigned char *outbuf = para_malloc(ROUND_UP(len, 8));
- (*cf)(len, (unsigned char *)buf, outbuf, private);
- ret = write_all(fd, (char *)outbuf, &len);
- free(outbuf);
- } else
- ret = write_all(fd, buf, &len);
- return ret;
+ return write_all(fd, buf, &len);
}
/**
- * Encrypt and send null terminated buffer.
+ * Send a \p NULL-terminated buffer.
*
* \param fd The file descriptor.
* \param buf The null-terminated buffer to be send.
return send_bin_buffer(fd, buf, strlen(buf));
}
-
/**
- * Send and encrypt a buffer given by a format string.
+ * Send a buffer given by a format string.
*
* \param fd The file descriptor.
* \param fmt A format string.
}
/**
- * Receive and decrypt.
+ * Receive data from a file descriptor.
*
* \param fd The file descriptor.
- * \param buf The buffer to write the decrypted data to.
+ * \param buf The buffer to write the data to.
* \param size The size of \a buf.
*
- * Receive at most \a size bytes from file descriptor \a fd. If encryption is
- * available, decrypt the received buffer.
+ * Receive at most \a size bytes from file descriptor \a fd.
*
- * \return The number of bytes received on success, negative on errors.
+ * \return The number of bytes received on success, negative on errors, zero if
+ * the peer has performed an orderly shutdown.
*
- * \sa recv(2)
+ * \sa recv(2).
*/
__must_check int recv_bin_buffer(int fd, char *buf, size_t size)
{
ssize_t n;
- crypt_function *cf = NULL;
-
- if (fd + 1 <= cda_size)
- cf = crypt_data_array[fd].recv;
- if (cf) {
- unsigned char *tmp = para_malloc(size);
- void *private = crypt_data_array[fd].private_data;
- n = recv(fd, tmp, size, 0);
- if (n > 0) {
- size_t numbytes = n;
- unsigned char *b = (unsigned char *)buf;
- (*cf)(numbytes, tmp, b, private);
- }
- free(tmp);
- } else
- n = recv(fd, buf, size, 0);
+
+ n = recv(fd, buf, size, 0);
if (n == -1)
return -ERRNO_TO_PARA_ERROR(errno);
return n;
}
/**
- * Receive, decrypt and write terminating NULL byte.
+ * Receive and write terminating NULL byte.
*
* \param fd The file descriptor.
- * \param buf The buffer to write the decrypted data to.
+ * \param buf The buffer to write the data to.
* \param size The size of \a buf.
*
- * Read and decrypt at most \a size - 1 bytes from file descriptor \a fd and
+ * Read at most \a size - 1 bytes from file descriptor \a fd and
* write a NULL byte at the end of the received data.
*
* \return The return value of the underlying call to \a recv_bin_buffer().
projects / paraslash.git / commitdiff