X-Git-Url: http://git.demorecorder.com/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fxcb_auth.c;h=d774d106942bf46e157e91e73f995c4f9e274a63;hb=a546d00091de0ab16374dec55e8e2fa87d6bbebf;hp=afab3189a14a5ef1c0b66adb8787e184e2e00f86;hpb=684b8271a4539527daa15da82ad0cc302fb44727;p=free-sw%2Fxcb%2Flibxcb diff --git a/src/xcb_auth.c b/src/xcb_auth.c index afab318..d774d10 100644 --- a/src/xcb_auth.c +++ b/src/xcb_auth.c @@ -49,11 +49,21 @@ enum auth_protos { N_AUTH_PROTOS }; +#define AUTH_PROTO_XDM_AUTHORIZATION "XDM-AUTHORIZATION-1" +#define AUTH_PROTO_MIT_MAGIC_COOKIE "MIT-MAGIC-COOKIE-1" + static char *authnames[N_AUTH_PROTOS] = { #ifdef HASXDMAUTH - "XDM-AUTHORIZATION-1", + AUTH_PROTO_XDM_AUTHORIZATION, +#endif + AUTH_PROTO_MIT_MAGIC_COOKIE, +}; + +static int authnameslen[N_AUTH_PROTOS] = { +#ifdef HASXDMAUTH + sizeof(AUTH_PROTO_XDM_AUTHORIZATION) - 1, #endif - "MIT-MAGIC-COOKIE-1", + sizeof(AUTH_PROTO_MIT_MAGIC_COOKIE) - 1, }; static size_t memdup(char **dst, void *src, size_t len) @@ -68,40 +78,42 @@ static size_t memdup(char **dst, void *src, size_t len) return len; } -static int authname_match(enum auth_protos kind, char *name, int namelen) +static int authname_match(enum auth_protos kind, char *name, size_t namelen) { - if(strlen(authnames[kind]) != namelen) + if(authnameslen[kind] != namelen) return 0; if(memcmp(authnames[kind], name, namelen)) return 0; return 1; } -static Xauth *get_authptr(struct sockaddr *sockname, unsigned int socknamelen, - int display) +#define SIN6_ADDR(s) (&((struct sockaddr_in6 *)s)->sin6_addr) + +static Xauth *get_authptr(struct sockaddr *sockname, int display) { char *addr = 0; int addrlen = 0; unsigned short family; char hostnamebuf[256]; /* big enough for max hostname */ char dispbuf[40]; /* big enough to hold more than 2^64 base 10 */ - int authnamelens[N_AUTH_PROTOS]; - int i; + int dispbuflen; family = FamilyLocal; /* 256 */ switch(sockname->sa_family) { +#ifdef AF_INET6 case AF_INET6: - addr = (char *) &((struct sockaddr_in6 *)sockname)->sin6_addr; - addrlen = sizeof(((struct sockaddr_in6 *)sockname)->sin6_addr); - if(!IN6_IS_ADDR_V4MAPPED(addr)) + addr = (char *) SIN6_ADDR(sockname); + addrlen = sizeof(*SIN6_ADDR(sockname)); + if(!IN6_IS_ADDR_V4MAPPED(SIN6_ADDR(sockname))) { - if(!IN6_IS_ADDR_LOOPBACK(addr)) + if(!IN6_IS_ADDR_LOOPBACK(SIN6_ADDR(sockname))) family = XCB_FAMILY_INTERNET_6; break; } addr += 12; /* if v4-mapped, fall through. */ +#endif case AF_INET: if(!addr) addr = (char *) &((struct sockaddr_in *)sockname)->sin_addr; @@ -115,7 +127,11 @@ static Xauth *get_authptr(struct sockaddr *sockname, unsigned int socknamelen, return 0; /* cannot authenticate this family */ } - snprintf(dispbuf, sizeof(dispbuf), "%d", display); + dispbuflen = snprintf(dispbuf, sizeof(dispbuf), "%d", display); + if(dispbuflen < 0) + return 0; + /* snprintf may have truncate our text */ + dispbuflen = MIN(dispbuflen, sizeof(dispbuf) - 1); if (family == FamilyLocal) { if (gethostname(hostnamebuf, sizeof(hostnamebuf)) == -1) @@ -124,12 +140,10 @@ static Xauth *get_authptr(struct sockaddr *sockname, unsigned int socknamelen, addrlen = strlen(addr); } - for (i = 0; i < N_AUTH_PROTOS; i++) - authnamelens[i] = strlen(authnames[i]); return XauGetBestAuthByAddr (family, (unsigned short) addrlen, addr, - (unsigned short) strlen(dispbuf), dispbuf, - N_AUTH_PROTOS, authnames, authnamelens); + (unsigned short) dispbuflen, dispbuf, + N_AUTH_PROTOS, authnames, authnameslen); } #ifdef HASXDMAUTH @@ -177,12 +191,13 @@ static int compute_auth(xcb_auth_info_t *info, Xauth *authptr, struct sockaddr * APPEND(info->data, j, si->sin_port); } break; +#ifdef AF_INET6 case AF_INET6: /*block*/ { struct sockaddr_in6 *si6 = (struct sockaddr_in6 *) sockname; - if(IN6_IS_ADDR_V4MAPPED(si6->sin6_addr.s6_addr)) + if(IN6_IS_ADDR_V4MAPPED(SIN6_ADDR(sockname))) { - APPEND(info->data, j, si6->sin6_addr.s6_addr[12]); + do_append(info->data, &j, &si6->sin6_addr.s6_addr[12], 4); APPEND(info->data, j, si6->sin6_port); } else @@ -190,17 +205,18 @@ static int compute_auth(xcb_auth_info_t *info, Xauth *authptr, struct sockaddr * /* XDM-AUTHORIZATION-1 does not handle IPv6 correctly. Do the same thing Xlib does: use all zeroes for the 4-byte address and 2-byte port number. */ - long fakeaddr = 0; - short fakeport = 0; + uint32_t fakeaddr = 0; + uint16_t fakeport = 0; APPEND(info->data, j, fakeaddr); APPEND(info->data, j, fakeport); } } break; +#endif case AF_UNIX: /*block*/ { - long fakeaddr = htonl(0xffffffff - next_nonce()); - short fakeport = htons(getpid()); + uint32_t fakeaddr = htonl(0xffffffff - next_nonce()); + uint16_t fakeport = htons(getpid()); APPEND(info->data, j, fakeaddr); APPEND(info->data, j, fakeport); } @@ -210,9 +226,7 @@ static int compute_auth(xcb_auth_info_t *info, Xauth *authptr, struct sockaddr * return 0; /* do not know how to build this */ } { - long now; - time(&now); - now = htonl(now); + uint32_t now = htonl(time(0)); APPEND(info->data, j, now); } assert(j <= 192 / 8); @@ -228,32 +242,110 @@ static int compute_auth(xcb_auth_info_t *info, Xauth *authptr, struct sockaddr * return 0; /* Unknown authorization type */ } +/* `sockaddr_un.sun_path' typical size usually ranges between 92 and 108 */ +#define INITIAL_SOCKNAME_SLACK 108 + +/* Return a dynamically allocated socket address structure according + to the value returned by either getpeername() or getsockname() + (according to POSIX, applications should not assume a particular + length for `sockaddr_un.sun_path') */ +static struct sockaddr *get_peer_sock_name(int (*socket_func)(int, + struct sockaddr *, + socklen_t *), + int fd) +{ + socklen_t socknamelen = sizeof(struct sockaddr) + INITIAL_SOCKNAME_SLACK; + socklen_t actual_socknamelen = socknamelen; + struct sockaddr *sockname = malloc(socknamelen), *new_sockname = NULL; + + if (sockname == NULL) + return NULL; + + /* Both getpeername() and getsockname() truncates sockname if + there is not enough space and set the required length in + actual_socknamelen */ + if (socket_func(fd, sockname, &actual_socknamelen) == -1) + goto sock_or_realloc_error; + + if (actual_socknamelen > socknamelen) + { + socknamelen = actual_socknamelen; + + if ((new_sockname = realloc(sockname, actual_socknamelen)) == NULL || + socket_func(fd, new_sockname, &actual_socknamelen) == -1 || + actual_socknamelen > socknamelen) + goto sock_or_realloc_error; + + sockname = new_sockname; + } + + return sockname; + + sock_or_realloc_error: + free(sockname); + return NULL; +} + int _xcb_get_auth_info(int fd, xcb_auth_info_t *info, int display) { /* code adapted from Xlib/ConnDis.c, xtrans/Xtranssocket.c, xtrans/Xtransutils.c */ - char sockbuf[sizeof(struct sockaddr) + MAXPATHLEN]; - unsigned int socknamelen = sizeof(sockbuf); /* need extra space */ - struct sockaddr *sockname = (struct sockaddr *) &sockbuf; + struct sockaddr *sockname = NULL; + int gotsockname = 0; Xauth *authptr = 0; int ret = 1; - if (getpeername(fd, sockname, &socknamelen) == -1) - return 0; /* can only authenticate sockets */ + /* Some systems like hpux or Hurd do not expose peer names + * for UNIX Domain Sockets, but this is irrelevant, + * since compute_auth() ignores the peer name in this + * case anyway.*/ + if ((sockname = get_peer_sock_name(getpeername, fd)) == NULL) + { + if ((sockname = get_peer_sock_name(getsockname, fd)) == NULL) + return 0; /* can only authenticate sockets */ + if (sockname->sa_family != AF_UNIX) + { + free(sockname); + return 0; /* except for AF_UNIX, sockets should have peernames */ + } + gotsockname = 1; + } - authptr = get_authptr(sockname, socknamelen, display); + authptr = get_authptr(sockname, display); if (authptr == 0) + { + free(sockname); return 0; /* cannot find good auth data */ + } info->namelen = memdup(&info->name, authptr->name, authptr->name_length); - if(info->namelen) - ret = compute_auth(info, authptr, sockname); + if (!info->namelen) + goto no_auth; /* out of memory */ + + if (!gotsockname && (sockname = get_peer_sock_name(getsockname, fd)) == NULL) + { + free(info->name); + goto no_auth; /* can only authenticate sockets */ + } + + ret = compute_auth(info, authptr, sockname); if(!ret) { - free(info->name); - info->name = 0; - info->namelen = 0; + free(info->name); + goto no_auth; /* cannot build auth record */ } + + free(sockname); + sockname = NULL; + XauDisposeAuth(authptr); return ret; + + no_auth: + free(sockname); + + info->name = 0; + info->namelen = 0; + XauDisposeAuth(authptr); + return 0; }