diff options
Diffstat (limited to 'fs/smb/client/cifsencrypt.c')
-rw-r--r-- | fs/smb/client/cifsencrypt.c | 733 |
1 files changed, 733 insertions, 0 deletions
diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c new file mode 100644 index 000000000..d0ac2648c --- /dev/null +++ b/fs/smb/client/cifsencrypt.c @@ -0,0 +1,733 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * + * Encryption and hashing operations relating to NTLM, NTLMv2. See MS-NLMP + * for more detailed information + * + * Copyright (C) International Business Machines Corp., 2005,2013 + * Author(s): Steve French (sfrench@us.ibm.com) + * + */ + +#include <linux/fs.h> +#include <linux/slab.h> +#include "cifspdu.h" +#include "cifsglob.h" +#include "cifs_debug.h" +#include "cifs_unicode.h" +#include "cifsproto.h" +#include "ntlmssp.h" +#include <linux/ctype.h> +#include <linux/random.h> +#include <linux/highmem.h> +#include <linux/fips.h> +#include "../common/arc4.h" +#include <crypto/aead.h> + +int __cifs_calc_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, char *signature, + struct shash_desc *shash) +{ + int i; + int rc; + struct kvec *iov = rqst->rq_iov; + int n_vec = rqst->rq_nvec; + + /* iov[0] is actual data and not the rfc1002 length for SMB2+ */ + if (!is_smb1(server)) { + if (iov[0].iov_len <= 4) + return -EIO; + i = 0; + } else { + if (n_vec < 2 || iov[0].iov_len != 4) + return -EIO; + i = 1; /* skip rfc1002 length */ + } + + for (; i < n_vec; i++) { + if (iov[i].iov_len == 0) + continue; + if (iov[i].iov_base == NULL) { + cifs_dbg(VFS, "null iovec entry\n"); + return -EIO; + } + + rc = crypto_shash_update(shash, + iov[i].iov_base, iov[i].iov_len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with payload\n", + __func__); + return rc; + } + } + + /* now hash over the rq_pages array */ + for (i = 0; i < rqst->rq_npages; i++) { + void *kaddr; + unsigned int len, offset; + + rqst_page_get_length(rqst, i, &len, &offset); + + kaddr = (char *) kmap(rqst->rq_pages[i]) + offset; + + rc = crypto_shash_update(shash, kaddr, len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with payload\n", + __func__); + kunmap(rqst->rq_pages[i]); + return rc; + } + + kunmap(rqst->rq_pages[i]); + } + + rc = crypto_shash_final(shash, signature); + if (rc) + cifs_dbg(VFS, "%s: Could not generate hash\n", __func__); + + return rc; +} + +/* + * Calculate and return the CIFS signature based on the mac key and SMB PDU. + * The 16 byte signature must be allocated by the caller. Note we only use the + * 1st eight bytes and that the smb header signature field on input contains + * the sequence number before this function is called. Also, this function + * should be called with the server->srv_mutex held. + */ +static int cifs_calc_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, char *signature) +{ + int rc; + + if (!rqst->rq_iov || !signature || !server) + return -EINVAL; + + rc = cifs_alloc_hash("md5", &server->secmech.md5); + if (rc) + return -1; + + rc = crypto_shash_init(server->secmech.md5); + if (rc) { + cifs_dbg(VFS, "%s: Could not init md5\n", __func__); + return rc; + } + + rc = crypto_shash_update(server->secmech.md5, + server->session_key.response, server->session_key.len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with response\n", __func__); + return rc; + } + + return __cifs_calc_signature(rqst, server, signature, server->secmech.md5); +} + +/* must be called with server->srv_mutex held */ +int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server, + __u32 *pexpected_response_sequence_number) +{ + int rc = 0; + char smb_signature[20]; + struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; + + if (rqst->rq_iov[0].iov_len != 4 || + rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) + return -EIO; + + if ((cifs_pdu == NULL) || (server == NULL)) + return -EINVAL; + + spin_lock(&server->srv_lock); + if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) || + server->tcpStatus == CifsNeedNegotiate) { + spin_unlock(&server->srv_lock); + return rc; + } + spin_unlock(&server->srv_lock); + + if (!server->session_estab) { + memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8); + return rc; + } + + cifs_pdu->Signature.Sequence.SequenceNumber = + cpu_to_le32(server->sequence_number); + cifs_pdu->Signature.Sequence.Reserved = 0; + + *pexpected_response_sequence_number = ++server->sequence_number; + ++server->sequence_number; + + rc = cifs_calc_signature(rqst, server, smb_signature); + if (rc) + memset(cifs_pdu->Signature.SecuritySignature, 0, 8); + else + memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8); + + return rc; +} + +int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server, + __u32 *pexpected_response_sequence) +{ + struct smb_rqst rqst = { .rq_iov = iov, + .rq_nvec = n_vec }; + + return cifs_sign_rqst(&rqst, server, pexpected_response_sequence); +} + +/* must be called with server->srv_mutex held */ +int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server, + __u32 *pexpected_response_sequence_number) +{ + struct kvec iov[2]; + + iov[0].iov_base = cifs_pdu; + iov[0].iov_len = 4; + iov[1].iov_base = (char *)cifs_pdu + 4; + iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length); + + return cifs_sign_smbv(iov, 2, server, + pexpected_response_sequence_number); +} + +int cifs_verify_signature(struct smb_rqst *rqst, + struct TCP_Server_Info *server, + __u32 expected_sequence_number) +{ + unsigned int rc; + char server_response_sig[8]; + char what_we_think_sig_should_be[20]; + struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base; + + if (rqst->rq_iov[0].iov_len != 4 || + rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) + return -EIO; + + if (cifs_pdu == NULL || server == NULL) + return -EINVAL; + + if (!server->session_estab) + return 0; + + if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) { + struct smb_com_lock_req *pSMB = + (struct smb_com_lock_req *)cifs_pdu; + if (pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE) + return 0; + } + + /* BB what if signatures are supposed to be on for session but + server does not send one? BB */ + + /* Do not need to verify session setups with signature "BSRSPYL " */ + if (memcmp(cifs_pdu->Signature.SecuritySignature, "BSRSPYL ", 8) == 0) + cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", + cifs_pdu->Command); + + /* save off the origiginal signature so we can modify the smb and check + its signature against what the server sent */ + memcpy(server_response_sig, cifs_pdu->Signature.SecuritySignature, 8); + + cifs_pdu->Signature.Sequence.SequenceNumber = + cpu_to_le32(expected_sequence_number); + cifs_pdu->Signature.Sequence.Reserved = 0; + + cifs_server_lock(server); + rc = cifs_calc_signature(rqst, server, what_we_think_sig_should_be); + cifs_server_unlock(server); + + if (rc) + return rc; + +/* cifs_dump_mem("what we think it should be: ", + what_we_think_sig_should_be, 16); */ + + if (memcmp(server_response_sig, what_we_think_sig_should_be, 8)) + return -EACCES; + else + return 0; + +} + +/* Build a proper attribute value/target info pairs blob. + * Fill in netbios and dns domain name and workstation name + * and client time (total five av pairs and + one end of fields indicator. + * Allocate domain name which gets freed when session struct is deallocated. + */ +static int +build_avpair_blob(struct cifs_ses *ses, const struct nls_table *nls_cp) +{ + unsigned int dlen; + unsigned int size = 2 * sizeof(struct ntlmssp2_name); + char *defdmname = "WORKGROUP"; + unsigned char *blobptr; + struct ntlmssp2_name *attrptr; + + if (!ses->domainName) { + ses->domainName = kstrdup(defdmname, GFP_KERNEL); + if (!ses->domainName) + return -ENOMEM; + } + + dlen = strlen(ses->domainName); + + /* + * The length of this blob is two times the size of a + * structure (av pair) which holds name/size + * ( for NTLMSSP_AV_NB_DOMAIN_NAME followed by NTLMSSP_AV_EOL ) + + * unicode length of a netbios domain name + */ + kfree_sensitive(ses->auth_key.response); + ses->auth_key.len = size + 2 * dlen; + ses->auth_key.response = kzalloc(ses->auth_key.len, GFP_KERNEL); + if (!ses->auth_key.response) { + ses->auth_key.len = 0; + return -ENOMEM; + } + + blobptr = ses->auth_key.response; + attrptr = (struct ntlmssp2_name *) blobptr; + + /* + * As defined in MS-NTLM 3.3.2, just this av pair field + * is sufficient as part of the temp + */ + attrptr->type = cpu_to_le16(NTLMSSP_AV_NB_DOMAIN_NAME); + attrptr->length = cpu_to_le16(2 * dlen); + blobptr = (unsigned char *)attrptr + sizeof(struct ntlmssp2_name); + cifs_strtoUTF16((__le16 *)blobptr, ses->domainName, dlen, nls_cp); + + return 0; +} + +/* Server has provided av pairs/target info in the type 2 challenge + * packet and we have plucked it and stored within smb session. + * We parse that blob here to find netbios domain name to be used + * as part of ntlmv2 authentication (in Target String), if not already + * specified on the command line. + * If this function returns without any error but without fetching + * domain name, authentication may fail against some server but + * may not fail against other (those who are not very particular + * about target string i.e. for some, just user name might suffice. + */ +static int +find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp) +{ + unsigned int attrsize; + unsigned int type; + unsigned int onesize = sizeof(struct ntlmssp2_name); + unsigned char *blobptr; + unsigned char *blobend; + struct ntlmssp2_name *attrptr; + + if (!ses->auth_key.len || !ses->auth_key.response) + return 0; + + blobptr = ses->auth_key.response; + blobend = blobptr + ses->auth_key.len; + + while (blobptr + onesize < blobend) { + attrptr = (struct ntlmssp2_name *) blobptr; + type = le16_to_cpu(attrptr->type); + if (type == NTLMSSP_AV_EOL) + break; + blobptr += 2; /* advance attr type */ + attrsize = le16_to_cpu(attrptr->length); + blobptr += 2; /* advance attr size */ + if (blobptr + attrsize > blobend) + break; + if (type == NTLMSSP_AV_NB_DOMAIN_NAME) { + if (!attrsize || attrsize >= CIFS_MAX_DOMAINNAME_LEN) + break; + if (!ses->domainName) { + ses->domainName = + kmalloc(attrsize + 1, GFP_KERNEL); + if (!ses->domainName) + return -ENOMEM; + cifs_from_utf16(ses->domainName, + (__le16 *)blobptr, attrsize, attrsize, + nls_cp, NO_MAP_UNI_RSVD); + break; + } + } + blobptr += attrsize; /* advance attr value */ + } + + return 0; +} + +/* Server has provided av pairs/target info in the type 2 challenge + * packet and we have plucked it and stored within smb session. + * We parse that blob here to find the server given timestamp + * as part of ntlmv2 authentication (or local current time as + * default in case of failure) + */ +static __le64 +find_timestamp(struct cifs_ses *ses) +{ + unsigned int attrsize; + unsigned int type; + unsigned int onesize = sizeof(struct ntlmssp2_name); + unsigned char *blobptr; + unsigned char *blobend; + struct ntlmssp2_name *attrptr; + struct timespec64 ts; + + if (!ses->auth_key.len || !ses->auth_key.response) + return 0; + + blobptr = ses->auth_key.response; + blobend = blobptr + ses->auth_key.len; + + while (blobptr + onesize < blobend) { + attrptr = (struct ntlmssp2_name *) blobptr; + type = le16_to_cpu(attrptr->type); + if (type == NTLMSSP_AV_EOL) + break; + blobptr += 2; /* advance attr type */ + attrsize = le16_to_cpu(attrptr->length); + blobptr += 2; /* advance attr size */ + if (blobptr + attrsize > blobend) + break; + if (type == NTLMSSP_AV_TIMESTAMP) { + if (attrsize == sizeof(u64)) + return *((__le64 *)blobptr); + } + blobptr += attrsize; /* advance attr value */ + } + + ktime_get_real_ts64(&ts); + return cpu_to_le64(cifs_UnixTimeToNT(ts)); +} + +static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash, + const struct nls_table *nls_cp) +{ + int rc = 0; + int len; + char nt_hash[CIFS_NTHASH_SIZE]; + __le16 *user; + wchar_t *domain; + wchar_t *server; + + if (!ses->server->secmech.hmacmd5) { + cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__); + return -1; + } + + /* calculate md4 hash of password */ + E_md4hash(ses->password, nt_hash, nls_cp); + + rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm, nt_hash, + CIFS_NTHASH_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Could not set NT Hash as a key\n", __func__); + return rc; + } + + rc = crypto_shash_init(ses->server->secmech.hmacmd5); + if (rc) { + cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__); + return rc; + } + + /* convert ses->user_name to unicode */ + len = ses->user_name ? strlen(ses->user_name) : 0; + user = kmalloc(2 + (len * 2), GFP_KERNEL); + if (user == NULL) { + rc = -ENOMEM; + return rc; + } + + if (len) { + len = cifs_strtoUTF16(user, ses->user_name, len, nls_cp); + UniStrupr(user); + } else { + memset(user, '\0', 2); + } + + rc = crypto_shash_update(ses->server->secmech.hmacmd5, + (char *)user, 2 * len); + kfree(user); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with user\n", __func__); + return rc; + } + + /* convert ses->domainName to unicode and uppercase */ + if (ses->domainName) { + len = strlen(ses->domainName); + + domain = kmalloc(2 + (len * 2), GFP_KERNEL); + if (domain == NULL) { + rc = -ENOMEM; + return rc; + } + len = cifs_strtoUTF16((__le16 *)domain, ses->domainName, len, + nls_cp); + rc = + crypto_shash_update(ses->server->secmech.hmacmd5, + (char *)domain, 2 * len); + kfree(domain); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with domain\n", + __func__); + return rc; + } + } else { + /* We use ses->ip_addr if no domain name available */ + len = strlen(ses->ip_addr); + + server = kmalloc(2 + (len * 2), GFP_KERNEL); + if (server == NULL) { + rc = -ENOMEM; + return rc; + } + len = cifs_strtoUTF16((__le16 *)server, ses->ip_addr, len, + nls_cp); + rc = + crypto_shash_update(ses->server->secmech.hmacmd5, + (char *)server, 2 * len); + kfree(server); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with server\n", + __func__); + return rc; + } + } + + rc = crypto_shash_final(ses->server->secmech.hmacmd5, + ntlmv2_hash); + if (rc) + cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__); + + return rc; +} + +static int +CalcNTLMv2_response(const struct cifs_ses *ses, char *ntlmv2_hash) +{ + int rc; + struct ntlmv2_resp *ntlmv2 = (struct ntlmv2_resp *) + (ses->auth_key.response + CIFS_SESS_KEY_SIZE); + unsigned int hash_len; + + /* The MD5 hash starts at challenge_key.key */ + hash_len = ses->auth_key.len - (CIFS_SESS_KEY_SIZE + + offsetof(struct ntlmv2_resp, challenge.key[0])); + + if (!ses->server->secmech.hmacmd5) { + cifs_dbg(VFS, "%s: can't generate ntlmv2 hash\n", __func__); + return -1; + } + + rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm, + ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n", + __func__); + return rc; + } + + rc = crypto_shash_init(ses->server->secmech.hmacmd5); + if (rc) { + cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__); + return rc; + } + + if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) + memcpy(ntlmv2->challenge.key, + ses->ntlmssp->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); + else + memcpy(ntlmv2->challenge.key, + ses->server->cryptkey, CIFS_SERVER_CHALLENGE_SIZE); + rc = crypto_shash_update(ses->server->secmech.hmacmd5, + ntlmv2->challenge.key, hash_len); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with response\n", __func__); + return rc; + } + + /* Note that the MD5 digest over writes anon.challenge_key.key */ + rc = crypto_shash_final(ses->server->secmech.hmacmd5, + ntlmv2->ntlmv2_hash); + if (rc) + cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__); + + return rc; +} + +int +setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) +{ + int rc; + int baselen; + unsigned int tilen; + struct ntlmv2_resp *ntlmv2; + char ntlmv2_hash[16]; + unsigned char *tiblob = NULL; /* target info blob */ + __le64 rsp_timestamp; + + if (nls_cp == NULL) { + cifs_dbg(VFS, "%s called with nls_cp==NULL\n", __func__); + return -EINVAL; + } + + if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) { + if (!ses->domainName) { + if (ses->domainAuto) { + rc = find_domain_name(ses, nls_cp); + if (rc) { + cifs_dbg(VFS, "error %d finding domain name\n", + rc); + goto setup_ntlmv2_rsp_ret; + } + } else { + ses->domainName = kstrdup("", GFP_KERNEL); + } + } + } else { + rc = build_avpair_blob(ses, nls_cp); + if (rc) { + cifs_dbg(VFS, "error %d building av pair blob\n", rc); + goto setup_ntlmv2_rsp_ret; + } + } + + /* Must be within 5 minutes of the server (or in range +/-2h + * in case of Mac OS X), so simply carry over server timestamp + * (as Windows 7 does) + */ + rsp_timestamp = find_timestamp(ses); + + baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); + tilen = ses->auth_key.len; + tiblob = ses->auth_key.response; + + ses->auth_key.response = kmalloc(baselen + tilen, GFP_KERNEL); + if (!ses->auth_key.response) { + rc = -ENOMEM; + ses->auth_key.len = 0; + goto setup_ntlmv2_rsp_ret; + } + ses->auth_key.len += baselen; + + ntlmv2 = (struct ntlmv2_resp *) + (ses->auth_key.response + CIFS_SESS_KEY_SIZE); + ntlmv2->blob_signature = cpu_to_le32(0x00000101); + ntlmv2->reserved = 0; + ntlmv2->time = rsp_timestamp; + + get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal)); + ntlmv2->reserved2 = 0; + + memcpy(ses->auth_key.response + baselen, tiblob, tilen); + + cifs_server_lock(ses->server); + + rc = cifs_alloc_hash("hmac(md5)", &ses->server->secmech.hmacmd5); + if (rc) { + goto unlock; + } + + /* calculate ntlmv2_hash */ + rc = calc_ntlmv2_hash(ses, ntlmv2_hash, nls_cp); + if (rc) { + cifs_dbg(VFS, "Could not get v2 hash rc %d\n", rc); + goto unlock; + } + + /* calculate first part of the client response (CR1) */ + rc = CalcNTLMv2_response(ses, ntlmv2_hash); + if (rc) { + cifs_dbg(VFS, "Could not calculate CR1 rc: %d\n", rc); + goto unlock; + } + + /* now calculate the session key for NTLMv2 */ + rc = crypto_shash_setkey(ses->server->secmech.hmacmd5->tfm, + ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Could not set NTLMV2 Hash as a key\n", + __func__); + goto unlock; + } + + rc = crypto_shash_init(ses->server->secmech.hmacmd5); + if (rc) { + cifs_dbg(VFS, "%s: Could not init hmacmd5\n", __func__); + goto unlock; + } + + rc = crypto_shash_update(ses->server->secmech.hmacmd5, + ntlmv2->ntlmv2_hash, + CIFS_HMAC_MD5_HASH_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Could not update with response\n", __func__); + goto unlock; + } + + rc = crypto_shash_final(ses->server->secmech.hmacmd5, + ses->auth_key.response); + if (rc) + cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__); + +unlock: + cifs_server_unlock(ses->server); +setup_ntlmv2_rsp_ret: + kfree_sensitive(tiblob); + + return rc; +} + +int +calc_seckey(struct cifs_ses *ses) +{ + unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */ + struct arc4_ctx *ctx_arc4; + + if (fips_enabled) + return -ENODEV; + + get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE); + + ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL); + if (!ctx_arc4) { + cifs_dbg(VFS, "Could not allocate arc4 context\n"); + return -ENOMEM; + } + + cifs_arc4_setkey(ctx_arc4, ses->auth_key.response, CIFS_SESS_KEY_SIZE); + cifs_arc4_crypt(ctx_arc4, ses->ntlmssp->ciphertext, sec_key, + CIFS_CPHTXT_SIZE); + + /* make secondary_key/nonce as session key */ + memcpy(ses->auth_key.response, sec_key, CIFS_SESS_KEY_SIZE); + /* and make len as that of session key only */ + ses->auth_key.len = CIFS_SESS_KEY_SIZE; + + memzero_explicit(sec_key, CIFS_SESS_KEY_SIZE); + kfree_sensitive(ctx_arc4); + return 0; +} + +void +cifs_crypto_secmech_release(struct TCP_Server_Info *server) +{ + cifs_free_hash(&server->secmech.aes_cmac); + cifs_free_hash(&server->secmech.hmacsha256); + cifs_free_hash(&server->secmech.md5); + cifs_free_hash(&server->secmech.sha512); + cifs_free_hash(&server->secmech.hmacmd5); + + if (server->secmech.enc) { + crypto_free_aead(server->secmech.enc); + server->secmech.enc = NULL; + } + + if (server->secmech.dec) { + crypto_free_aead(server->secmech.dec); + server->secmech.dec = NULL; + } +} |