From 21e733930be6458e0c33482b6783e7c15ba984eb Mon Sep 17 00:00:00 2001 From: Shirish Pargaonkar Date: Thu, 21 Oct 2010 06:42:55 -0500 Subject: NTLM auth and sign - Allocate session key/client response dynamically Start calculating auth response within a session. Move/Add pertinet data structures like session key, server challenge and ntlmv2_hash in a session structure. We should do the calculations within a session before copying session key and response over to server data structures because a session setup can fail. Only after a very first smb session succeeds, it copy/make its session key, session key of smb connection. This key stays with the smb connection throughout its life. sequence_number within server is set to 0x2. The authentication Message Authentication Key (mak) which consists of session key followed by client response within structure session_key is now dynamic. Every authentication type allocates the key + response sized memory within its session structure and later either assigns or frees it once the client response is sent and if session's session key becomes connetion's session key. ntlm/ntlmi authentication functions are rearranged. A function named setup_ntlm_resp(), similar to setup_ntlmv2_resp(), replaces function cifs_calculate_session_key(). size of CIFS_SESS_KEY_SIZE is changed to 16, to reflect the byte size of the key it holds. Reviewed-by: Jeff Layton Signed-off-by: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifsencrypt.c | 113 +++++++++++++++++++++++++++++--------------------- 1 file changed, 65 insertions(+), 48 deletions(-) (limited to 'fs/cifs/cifsencrypt.c') diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 7ac0056294cf..987b479d55dd 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -43,15 +43,16 @@ extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24); static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu, - const struct session_key *key, char *signature) + struct TCP_Server_Info *server, char *signature) { struct MD5Context context; - if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL)) + if (cifs_pdu == NULL || signature == NULL || server == NULL) return -EINVAL; cifs_MD5_init(&context); - cifs_MD5_update(&context, (char *)&key->data, key->len); + cifs_MD5_update(&context, server->session_key.response, + server->session_key.len); cifs_MD5_update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length); cifs_MD5_final(signature, &context); @@ -79,8 +80,7 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server, server->sequence_number++; spin_unlock(&GlobalMid_Lock); - rc = cifs_calculate_signature(cifs_pdu, &server->session_key, - smb_signature); + rc = cifs_calculate_signature(cifs_pdu, server, smb_signature); if (rc) memset(cifs_pdu->Signature.SecuritySignature, 0, 8); else @@ -90,16 +90,17 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server, } static int cifs_calc_signature2(const struct kvec *iov, int n_vec, - const struct session_key *key, char *signature) + struct TCP_Server_Info *server, char *signature) { struct MD5Context context; int i; - if ((iov == NULL) || (signature == NULL) || (key == NULL)) + if (iov == NULL || signature == NULL || server == NULL) return -EINVAL; cifs_MD5_init(&context); - cifs_MD5_update(&context, (char *)&key->data, key->len); + cifs_MD5_update(&context, server->session_key.response, + server->session_key.len); for (i = 0; i < n_vec; i++) { if (iov[i].iov_len == 0) continue; @@ -146,8 +147,7 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server, server->sequence_number++; spin_unlock(&GlobalMid_Lock); - rc = cifs_calc_signature2(iov, n_vec, &server->session_key, - smb_signature); + rc = cifs_calc_signature2(iov, n_vec, server, smb_signature); if (rc) memset(cifs_pdu->Signature.SecuritySignature, 0, 8); else @@ -157,14 +157,14 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server, } int cifs_verify_signature(struct smb_hdr *cifs_pdu, - const struct session_key *session_key, + 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]; - if (cifs_pdu == NULL || session_key == NULL) + if (cifs_pdu == NULL || server == NULL) return -EINVAL; if (cifs_pdu->Command == SMB_COM_NEGOTIATE) @@ -193,7 +193,7 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu, cpu_to_le32(expected_sequence_number); cifs_pdu->Signature.Sequence.Reserved = 0; - rc = cifs_calculate_signature(cifs_pdu, session_key, + rc = cifs_calculate_signature(cifs_pdu, server, what_we_think_sig_should_be); if (rc) @@ -209,18 +209,28 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu, } -/* We fill in key by putting in 40 byte array which was allocated by caller */ -int cifs_calculate_session_key(struct session_key *key, const char *rn, - const char *password) +/* first calculate 24 bytes ntlm response and then 16 byte session key */ +int setup_ntlm_response(struct cifsSesInfo *ses) { - char temp_key[16]; - if ((key == NULL) || (rn == NULL)) + unsigned int temp_len = CIFS_SESS_KEY_SIZE + CIFS_AUTH_RESP_SIZE; + char temp_key[CIFS_SESS_KEY_SIZE]; + + if (!ses) return -EINVAL; - E_md4hash(password, temp_key); - mdfour(key->data.ntlm, temp_key, 16); - memcpy(key->data.ntlm+16, rn, CIFS_SESS_KEY_SIZE); - key->len = 40; + ses->auth_key.response = kmalloc(temp_len, GFP_KERNEL); + if (!ses->auth_key.response) { + cERROR(1, "NTLM can't allocate (%u bytes) memory", temp_len); + return -ENOMEM; + } + ses->auth_key.len = temp_len; + + SMBNTencrypt(ses->password, ses->cryptKey, + ses->auth_key.response + CIFS_SESS_KEY_SIZE); + + E_md4hash(ses->password, temp_key); + mdfour(ses->auth_key.response, temp_key, CIFS_SESS_KEY_SIZE); + return 0; } @@ -465,19 +475,13 @@ calc_exit_2: } int -setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf, - const struct nls_table *nls_cp) +setup_ntlmv2_rsp(struct cifsSesInfo *ses, const struct nls_table *nls_cp) { int rc; - struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf; + int baselen; + struct ntlmv2_resp *buf; struct HMACMD5Context context; - buf->blob_signature = cpu_to_le32(0x00000101); - buf->reserved = 0; - buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME)); - get_random_bytes(&buf->client_chal, sizeof(buf->client_chal)); - buf->reserved2 = 0; - if (ses->server->secType == RawNTLMSSP) { if (!ses->domainName) { rc = find_domain_name(ses); @@ -494,22 +498,38 @@ setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf, } } + baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp); + ses->auth_key.len = baselen + ses->tilen; + ses->auth_key.response = kmalloc(ses->auth_key.len, GFP_KERNEL); + if (!ses->auth_key.response) { + rc = ENOMEM; + cERROR(1, "%s: Can't allocate auth blob", __func__); + goto setup_ntlmv2_rsp_ret; + } + + buf = (struct ntlmv2_resp *) + (ses->auth_key.response + CIFS_SESS_KEY_SIZE); + buf->blob_signature = cpu_to_le32(0x00000101); + buf->reserved = 0; + buf->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME)); + get_random_bytes(&buf->client_chal, sizeof(buf->client_chal)); + buf->reserved2 = 0; + + memcpy(ses->auth_key.response + baselen, ses->tiblob, ses->tilen); + /* calculate buf->ntlmv2_hash */ rc = calc_ntlmv2_hash(ses, nls_cp); if (rc) { cERROR(1, "could not get v2 hash rc %d", rc); goto setup_ntlmv2_rsp_ret; } - CalcNTLMv2_response(ses, resp_buf); + CalcNTLMv2_response(ses); /* now calculate the session key for NTLMv2 */ hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context); - hmac_md5_update(resp_buf, 16, &context); - hmac_md5_final(ses->auth_key.data.ntlmv2.key, &context); - - memcpy(&ses->auth_key.data.ntlmv2.resp, resp_buf, - sizeof(struct ntlmv2_resp)); - ses->auth_key.len = 16 + sizeof(struct ntlmv2_resp); + hmac_md5_update(ses->auth_key.response + CIFS_SESS_KEY_SIZE, + 16, &context); + hmac_md5_final(ses->auth_key.response, &context); return 0; @@ -521,20 +541,17 @@ setup_ntlmv2_rsp_ret: return rc; } -void CalcNTLMv2_response(const struct cifsSesInfo *ses, - char *v2_session_response) +void CalcNTLMv2_response(const struct cifsSesInfo *ses) { + unsigned int offset = CIFS_SESS_KEY_SIZE + 8; struct HMACMD5Context context; + /* rest of v2 struct already generated */ - memcpy(v2_session_response + 8, ses->cryptKey, 8); + memcpy(ses->auth_key.response + offset, ses->cryptKey, 8); hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context); - hmac_md5_update(v2_session_response+8, - sizeof(struct ntlmv2_resp) - 8, &context); - - if (ses->tilen) - hmac_md5_update(ses->tiblob, ses->tilen, &context); + hmac_md5_update(ses->auth_key.response + offset, + ses->auth_key.len - offset, &context); - hmac_md5_final(v2_session_response, &context); -/* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */ + hmac_md5_final(ses->auth_key.response + CIFS_SESS_KEY_SIZE, &context); } -- cgit