7 files changed, 184 insertions, 10 deletions

diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
index 917b7d449bb2..0ed213970ced 100644
--- a/fs/cifs/Kconfig
+++ b/fs/cifs/Kconfig
@@ -2,6 +2,9 @@ config CIFS
         tristate "CIFS support (advanced network filesystem, SMBFS successor)"
         depends on INET
         select NLS
+        select CRYPTO
+        select CRYPTO_MD5
+        select CRYPTO_ARC4
         help
           This is the client VFS module for the Common Internet File System
           (CIFS) protocol which is the successor to the Server Message Block
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 987b479d55dd..eaa2327ee7af 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -541,6 +541,119 @@ setup_ntlmv2_rsp_ret:
         return rc;
 }
 
+int
+calc_seckey(struct cifsSesInfo *ses)
+{
+        int rc;
+        struct crypto_blkcipher *tfm_arc4;
+        struct scatterlist sgin, sgout;
+        struct blkcipher_desc desc;
+        unsigned char sec_key[CIFS_SESS_KEY_SIZE]; /* a nonce */
+
+        get_random_bytes(sec_key, CIFS_SESS_KEY_SIZE);
+
+        tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
+        if (!tfm_arc4 || IS_ERR(tfm_arc4)) {
+                cERROR(1, "could not allocate crypto API arc4\n");
+                return PTR_ERR(tfm_arc4);
+        }
+
+        desc.tfm = tfm_arc4;
+
+        crypto_blkcipher_setkey(tfm_arc4, ses->auth_key.response,
+                                        CIFS_SESS_KEY_SIZE);
+
+        sg_init_one(&sgin, sec_key, CIFS_SESS_KEY_SIZE);
+        sg_init_one(&sgout, ses->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+
+        rc = crypto_blkcipher_encrypt(&desc, &sgout, &sgin, CIFS_CPHTXT_SIZE);
+        if (rc) {
+                cERROR(1, "could not encrypt session key rc: %d\n", rc);
+                crypto_free_blkcipher(tfm_arc4);
+                return rc;
+        }
+
+        /* 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;
+
+        crypto_free_blkcipher(tfm_arc4);
+
+        return 0;
+}
+
+void
+cifs_crypto_shash_release(struct TCP_Server_Info *server)
+{
+        if (server->secmech.md5)
+                crypto_free_shash(server->secmech.md5);
+
+        if (server->secmech.hmacmd5)
+                crypto_free_shash(server->secmech.hmacmd5);
+
+        kfree(server->secmech.sdeschmacmd5);
+
+        kfree(server->secmech.sdescmd5);
+}
+
+int
+cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
+{
+        int rc;
+        unsigned int size;
+
+        server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
+        if (!server->secmech.hmacmd5 ||
+                        IS_ERR(server->secmech.hmacmd5)) {
+                cERROR(1, "could not allocate crypto hmacmd5\n");
+                return PTR_ERR(server->secmech.hmacmd5);
+        }
+
+        server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
+        if (!server->secmech.md5 || IS_ERR(server->secmech.md5)) {
+                cERROR(1, "could not allocate crypto md5\n");
+                rc = PTR_ERR(server->secmech.md5);
+                goto crypto_allocate_md5_fail;
+        }
+
+        size = sizeof(struct shash_desc) +
+                        crypto_shash_descsize(server->secmech.hmacmd5);
+        server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
+        if (!server->secmech.sdeschmacmd5) {
+                cERROR(1, "cifs_crypto_shash_allocate: can't alloc hmacmd5\n");
+                rc = -ENOMEM;
+                goto crypto_allocate_hmacmd5_sdesc_fail;
+        }
+        server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
+        server->secmech.sdeschmacmd5->shash.flags = 0x0;
+
+
+        size = sizeof(struct shash_desc) +
+                        crypto_shash_descsize(server->secmech.md5);
+        server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
+        if (!server->secmech.sdescmd5) {
+                cERROR(1, "cifs_crypto_shash_allocate: can't alloc md5\n");
+                rc = -ENOMEM;
+                goto crypto_allocate_md5_sdesc_fail;
+        }
+        server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
+        server->secmech.sdescmd5->shash.flags = 0x0;
+
+        return 0;
+
+crypto_allocate_md5_sdesc_fail:
+        kfree(server->secmech.sdeschmacmd5);
+
+crypto_allocate_hmacmd5_sdesc_fail:
+        crypto_free_shash(server->secmech.md5);
+
+crypto_allocate_md5_fail:
+        crypto_free_shash(server->secmech.hmacmd5);
+
+        return rc;
+}
+
 void CalcNTLMv2_response(const struct cifsSesInfo *ses)
 {
         unsigned int offset = CIFS_SESS_KEY_SIZE + 8;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 66f76b2d270b..7ca5f6d8ed80 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -25,6 +25,9 @@
 #include <linux/workqueue.h>
 #include "cifs_fs_sb.h"
 #include "cifsacl.h"
+#include <crypto/internal/hash.h>
+#include <linux/scatterlist.h>
+
 /*
  * The sizes of various internal tables and strings
  */
@@ -102,6 +105,27 @@ struct session_key {
         char *response;
 };
 
+/* crypto security descriptor definition */
+struct sdesc {
+        struct shash_desc shash;
+        char ctx[];
+};
+
+/* crypto hashing related structure/fields, not speicific to a sec mech */
+struct cifs_secmech {
+        struct crypto_shash *hmacmd5; /* hmac-md5 hash function */
+        struct crypto_shash *md5; /* md5 hash function */
+        struct sdesc *sdeschmacmd5;  /* ctxt to generate ntlmv2 hash, CR1 */
+        struct sdesc *sdescmd5; /* ctxt to generate cifs/smb signature */
+};
+
+/* per smb connection structure/fields */
+struct ntlmssp_auth {
+        __u32 client_flags; /* sent by client in type 1 ntlmsssp exchange */
+        __u32 server_flags; /* sent by server in type 2 ntlmssp exchange */
+        unsigned char ciphertext[CIFS_CPHTXT_SIZE]; /* sent to server */
+};
+
 struct cifs_cred {
         int uid;
         int gid;
@@ -178,6 +202,7 @@ struct TCP_Server_Info {
         struct session_key session_key;
         unsigned long lstrp; /* when we got last response from this server */
         u16 dialect; /* dialect index that server chose */
+        struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */
         /* extended security flavors that server supports */
         bool    sec_kerberos;           /* supports plain Kerberos */
         bool    sec_mskerberos;         /* supports legacy MS Kerberos */
@@ -220,6 +245,7 @@ struct cifsSesInfo {
         char ntlmv2_hash[16];
         unsigned int tilen; /* length of the target info blob */
         unsigned char *tiblob; /* target info blob in challenge response */
+        struct ntlmssp_auth ntlmssp; /* ciphertext, flags */
         bool need_reconnect:1; /* connection reset, uid now invalid */
 };
 /* no more than one of the following three session flags may be set */
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index a152cd6db99b..de36b09763a8 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -140,6 +140,12 @@
  */
 #define CIFS_SESS_KEY_SIZE (16)
 
+#define CIFS_CLIENT_CHALLENGE_SIZE (8)
+#define CIFS_SERVER_CHALLENGE_SIZE (8)
+#define CIFS_HMAC_MD5_HASH_SIZE (16)
+#define CIFS_CPHTXT_SIZE (16)
+#define CIFS_NTHASH_SIZE (16)
+
 /*
  * Maximum user name length
  */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 8c2d0cf1a62f..1e4728bcf065 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -368,6 +368,10 @@ extern void SMBNTencrypt(unsigned char *, unsigned char *, unsigned char *);
 extern int setup_ntlm_response(struct cifsSesInfo *);
 extern void CalcNTLMv2_response(const struct cifsSesInfo *);
 extern int setup_ntlmv2_rsp(struct cifsSesInfo *, const struct nls_table *);
+extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
+extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
+extern int calc_seckey(struct cifsSesInfo *);
+
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern void calc_lanman_hash(const char *password, const char *cryptkey,
                                 bool encrypt, char *lnm_session_key);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index dd9a4ae1d21d..04239a7ff320 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1563,6 +1563,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
         server->tcpStatus = CifsExiting;
         spin_unlock(&GlobalMid_Lock);
 
+        cifs_crypto_shash_release(server);
         cifs_fscache_release_client_cookie(server);
 
         kfree(server->session_key.response);
@@ -1621,10 +1622,16 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
                 goto out_err;
         }
 
+        rc = cifs_crypto_shash_allocate(tcp_ses);
+        if (rc) {
+                cERROR(1, "could not setup hash structures rc %d", rc);
+                goto out_err;
+        }
+
         tcp_ses->hostname = extract_hostname(volume_info->UNC);
         if (IS_ERR(tcp_ses->hostname)) {
                 rc = PTR_ERR(tcp_ses->hostname);
-                goto out_err;
+                goto out_err2;
         }
 
         tcp_ses->noblocksnd = volume_info->noblocksnd;
@@ -1668,7 +1675,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
         }
         if (rc < 0) {
                 cERROR(1, "Error connecting to socket. Aborting operation");
-                goto out_err;
+                goto out_err2;
         }
 
         /*
@@ -1682,7 +1689,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
                 rc = PTR_ERR(tcp_ses->tsk);
                 cERROR(1, "error %d create cifsd thread", rc);
                 module_put(THIS_MODULE);
-                goto out_err;
+                goto out_err2;
         }
 
         /* thread spawned, put it on the list */
@@ -1694,6 +1701,9 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
 
         return tcp_ses;
 
+out_err2:
+        cifs_crypto_shash_release(tcp_ses);
+
 out_err:
         if (tcp_ses) {
                 if (!IS_ERR(tcp_ses->hostname))
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index b2934683bd08..d998c4f7aae5 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -404,7 +404,7 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
         /* In particular we can examine sign flags */
         /* BB spec says that if AvId field of MsvAvTimestamp is populated then
                 we must set the MIC field of the AUTHENTICATE_MESSAGE */
-
+        ses->ntlmssp.server_flags = le32_to_cpu(pblob->NegotiateFlags);
         tioffset = cpu_to_le16(pblob->TargetInfoArray.BufferOffset);
         tilen = cpu_to_le16(pblob->TargetInfoArray.Length);
         ses->tilen = tilen;
@@ -440,10 +440,12 @@ static void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
                 NTLMSSP_NEGOTIATE_NTLM;
         if (ses->server->secMode &
-           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
+                        (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
                 flags |= NTLMSSP_NEGOTIATE_SIGN;
-        if (ses->server->secMode & SECMODE_SIGN_REQUIRED)
-                flags |= NTLMSSP_NEGOTIATE_ALWAYS_SIGN;
+                if (!ses->server->session_estab)
+                        flags |= NTLMSSP_NEGOTIATE_KEY_XCH |
+                                NTLMSSP_NEGOTIATE_EXTENDED_SEC;
+        }
 
         sec_blob->NegotiateFlags |= cpu_to_le32(flags);
 
@@ -543,9 +545,19 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
         sec_blob->WorkstationName.MaximumLength = 0;
         tmp += 2;
 
-        sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
-        sec_blob->SessionKey.Length = 0;
-        sec_blob->SessionKey.MaximumLength = 0;
+        if ((ses->ntlmssp.server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
+                        !calc_seckey(ses)) {
+                memcpy(tmp, ses->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+                sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+                sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
+                sec_blob->SessionKey.MaximumLength =
+                                cpu_to_le16(CIFS_CPHTXT_SIZE);
+                tmp += CIFS_CPHTXT_SIZE;
+        } else {
+                sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+                sec_blob->SessionKey.Length = 0;
+                sec_blob->SessionKey.MaximumLength = 0;
+        }
 
 setup_ntlmv2_ret:
         *buflen = tmp - pbuffer;