[PATCH 2/2] ksmbd: remove NTLMv1 authentication

Namjae Jeon
2021-09-27T12:48:02Z

Remove insecure NTLMv1 authentication.

Cc: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Ralph Böhme <slow@samba.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
fs/ksmbd/auth.c | 205 ------------------------------------------
fs/ksmbd/crypto_ctx.c | 16 ----
fs/ksmbd/crypto_ctx.h | 8 --
3 files changed, 229 deletions(-)

diff --git a/fs/ksmbd/auth.c b/fs/ksmbd/auth.c
index de36f12070bf..71c989f1568d 100644
--- a/fs/ksmbd/auth.c
+++ b/fs/ksmbd/auth.c
@@ -68,125 +68,6 @@ void ksmbd_copy_gss_neg_header(void *buf)
memcpy(buf, NEGOTIATE_GSS_HEADER, AUTH_GSS_LENGTH);
}

-static void
-str_to_key(unsigned char *str, unsigned char *key)
-{
- int i;
-
- key[0] = str[0] >> 1;
- key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
- key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
- key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
- key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
- key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
- key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
- key[7] = str[6] & 0x7F;
- for (i = 0; i < 8; i++)
- key[i] = (key[i] << 1);
-}
-
-static int
-smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
-{
- unsigned char key2[8];
- struct des_ctx ctx;
-
- if (fips_enabled) {
- ksmbd_debug(AUTH, "FIPS compliance enabled: DES not permitted\n");
- return -ENOENT;
- }
-
- str_to_key(key, key2);
- des_expand_key(&ctx, key2, DES_KEY_SIZE);
- des_encrypt(&ctx, out, in);
- memzero_explicit(&ctx, sizeof(ctx));
- return 0;
-}
-
-static int ksmbd_enc_p24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
-{
- int rc;
-
- rc = smbhash(p24, c8, p21);
- if (rc)
- return rc;
- rc = smbhash(p24 + 8, c8, p21 + 7);
- if (rc)
- return rc;
- return smbhash(p24 + 16, c8, p21 + 14);
-}
-
-/* produce a md4 message digest from data of length n bytes */
-static int ksmbd_enc_md4(unsigned char *md4_hash, unsigned char *link_str,
- int link_len)
-{
- int rc;
- struct ksmbd_crypto_ctx *ctx;
-
- ctx = ksmbd_crypto_ctx_find_md4();
- if (!ctx) {
- ksmbd_debug(AUTH, "Crypto md4 allocation error\n");
- return -ENOMEM;
- }
-
- rc = crypto_shash_init(CRYPTO_MD4(ctx));
- if (rc) {
- ksmbd_debug(AUTH, "Could not init md4 shash\n");
- goto out;
- }
-
- rc = crypto_shash_update(CRYPTO_MD4(ctx), link_str, link_len);
- if (rc) {
- ksmbd_debug(AUTH, "Could not update with link_str\n");
- goto out;
- }
-
- rc = crypto_shash_final(CRYPTO_MD4(ctx), md4_hash);
- if (rc)
- ksmbd_debug(AUTH, "Could not generate md4 hash\n");
-out:
- ksmbd_release_crypto_ctx(ctx);
- return rc;
-}
-
-static int ksmbd_enc_update_sess_key(unsigned char *md5_hash, char *nonce,
- char *server_challenge, int len)
-{
- int rc;
- struct ksmbd_crypto_ctx *ctx;
-
- ctx = ksmbd_crypto_ctx_find_md5();
- if (!ctx) {
- ksmbd_debug(AUTH, "Crypto md5 allocation error\n");
- return -ENOMEM;
- }
-
- rc = crypto_shash_init(CRYPTO_MD5(ctx));
- if (rc) {
- ksmbd_debug(AUTH, "Could not init md5 shash\n");
- goto out;
- }
-
- rc = crypto_shash_update(CRYPTO_MD5(ctx), server_challenge, len);
- if (rc) {
- ksmbd_debug(AUTH, "Could not update with challenge\n");
- goto out;
- }
-
- rc = crypto_shash_update(CRYPTO_MD5(ctx), nonce, len);
- if (rc) {
- ksmbd_debug(AUTH, "Could not update with nonce\n");
- goto out;
- }
-
- rc = crypto_shash_final(CRYPTO_MD5(ctx), md5_hash);
- if (rc)
- ksmbd_debug(AUTH, "Could not generate md5 hash\n");
-out:
- ksmbd_release_crypto_ctx(ctx);
- return rc;
-}
-
/**
* ksmbd_gen_sess_key() - function to generate session key
* @sess: session of connection
@@ -324,43 +205,6 @@ static int calc_ntlmv2_hash(struct ksmbd_session *sess, char *ntlmv2_hash,
return ret;
}

-/**
- * ksmbd_auth_ntlm() - NTLM authentication handler
- * @sess: session of connection
- * @pw_buf: NTLM challenge response
- * @passkey: user password
- *
- * Return: 0 on success, error number on error
- */
-int ksmbd_auth_ntlm(struct ksmbd_session *sess, char *pw_buf)
-{
- int rc;
- unsigned char p21[21];
- char key[CIFS_AUTH_RESP_SIZE];
-
- memset(p21, '\0', 21);
- memcpy(p21, user_passkey(sess->user), CIFS_NTHASH_SIZE);
- rc = ksmbd_enc_p24(p21, sess->ntlmssp.cryptkey, key);
- if (rc) {
- pr_err("password processing failed\n");
- return rc;
- }
-
- ksmbd_enc_md4(sess->sess_key, user_passkey(sess->user),
- CIFS_SMB1_SESSKEY_SIZE);
- memcpy(sess->sess_key + CIFS_SMB1_SESSKEY_SIZE, key,
- CIFS_AUTH_RESP_SIZE);
- sess->sequence_number = 1;
-
- if (strncmp(pw_buf, key, CIFS_AUTH_RESP_SIZE) != 0) {
- ksmbd_debug(AUTH, "ntlmv1 authentication failed\n");
- return -EINVAL;
- }
-
- ksmbd_debug(AUTH, "ntlmv1 authentication pass\n");
- return 0;
-}
-
/**
* ksmbd_auth_ntlmv2() - NTLMv2 authentication handler
* @sess: session of connection
@@ -441,44 +285,6 @@ int ksmbd_auth_ntlmv2(struct ksmbd_session *sess, struct ntlmv2_resp *ntlmv2,
return rc;
}

-/**
- * __ksmbd_auth_ntlmv2() - NTLM2(extended security) authentication handler
- * @sess: session of connection
- * @client_nonce: client nonce from LM response.
- * @ntlm_resp: ntlm response data from client.
- *
- * Return: 0 on success, error number on error
- */
-static int __ksmbd_auth_ntlmv2(struct ksmbd_session *sess, char *client_nonce,
- char *ntlm_resp)
-{
- char sess_key[CIFS_SMB1_SESSKEY_SIZE] = {0};
- int rc;
- unsigned char p21[21];
- char key[CIFS_AUTH_RESP_SIZE];
-
- rc = ksmbd_enc_update_sess_key(sess_key,
- client_nonce,
- (char *)sess->ntlmssp.cryptkey, 8);
- if (rc) {
- pr_err("password processing failed\n");
- goto out;
- }
-
- memset(p21, '\0', 21);
- memcpy(p21, user_passkey(sess->user), CIFS_NTHASH_SIZE);
- rc = ksmbd_enc_p24(p21, sess_key, key);
- if (rc) {
- pr_err("password processing failed\n");
- goto out;
- }
-
- if (memcmp(ntlm_resp, key, CIFS_AUTH_RESP_SIZE) != 0)
- rc = -EINVAL;
-out:
- return rc;
-}
-
/**
* ksmbd_decode_ntlmssp_auth_blob() - helper function to construct
* authenticate blob
@@ -512,17 +318,6 @@ int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
nt_off = le32_to_cpu(authblob->NtChallengeResponse.BufferOffset);
nt_len = le16_to_cpu(authblob->NtChallengeResponse.Length);

- /* process NTLM authentication */
- if (nt_len == CIFS_AUTH_RESP_SIZE) {
- if (le32_to_cpu(authblob->NegotiateFlags) &
- NTLMSSP_NEGOTIATE_EXTENDED_SEC)
- return __ksmbd_auth_ntlmv2(sess, (char *)authblob +
- lm_off, (char *)authblob + nt_off);
- else
- return ksmbd_auth_ntlm(sess, (char *)authblob +
- nt_off);
- }
-
/* TODO : use domain name that imported from configuration file */
domain_name = smb_strndup_from_utf16((const char *)authblob +
le32_to_cpu(authblob->DomainName.BufferOffset),
diff --git a/fs/ksmbd/crypto_ctx.c b/fs/ksmbd/crypto_ctx.c
index 5f4b1008d17e..81488d04199d 100644
--- a/fs/ksmbd/crypto_ctx.c
+++ b/fs/ksmbd/crypto_ctx.c
@@ -81,12 +81,6 @@ static struct shash_desc *alloc_shash_desc(int id)
case CRYPTO_SHASH_SHA512:
tfm = crypto_alloc_shash("sha512", 0, 0);
break;
- case CRYPTO_SHASH_MD4:
- tfm = crypto_alloc_shash("md4", 0, 0);
- break;
- case CRYPTO_SHASH_MD5:
- tfm = crypto_alloc_shash("md5", 0, 0);
- break;
default:
return NULL;
}
@@ -214,16 +208,6 @@ struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha512(void)
return ____crypto_shash_ctx_find(CRYPTO_SHASH_SHA512);
}

-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md4(void)
-{
- return ____crypto_shash_ctx_find(CRYPTO_SHASH_MD4);
-}
-
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md5(void)
-{
- return ____crypto_shash_ctx_find(CRYPTO_SHASH_MD5);
-}
-
static struct ksmbd_crypto_ctx *____crypto_aead_ctx_find(int id)
{
struct ksmbd_crypto_ctx *ctx;
diff --git a/fs/ksmbd/crypto_ctx.h b/fs/ksmbd/crypto_ctx.h
index ef11154b43df..4a367c62f653 100644
--- a/fs/ksmbd/crypto_ctx.h
+++ b/fs/ksmbd/crypto_ctx.h
@@ -15,8 +15,6 @@ enum {
CRYPTO_SHASH_CMACAES,
CRYPTO_SHASH_SHA256,
CRYPTO_SHASH_SHA512,
- CRYPTO_SHASH_MD4,
- CRYPTO_SHASH_MD5,
CRYPTO_SHASH_MAX,
};

@@ -43,8 +41,6 @@ struct ksmbd_crypto_ctx {
#define CRYPTO_CMACAES(c) ((c)->desc[CRYPTO_SHASH_CMACAES])
#define CRYPTO_SHA256(c) ((c)->desc[CRYPTO_SHASH_SHA256])
#define CRYPTO_SHA512(c) ((c)->desc[CRYPTO_SHASH_SHA512])
-#define CRYPTO_MD4(c) ((c)->desc[CRYPTO_SHASH_MD4])
-#define CRYPTO_MD5(c) ((c)->desc[CRYPTO_SHASH_MD5])

#define CRYPTO_HMACMD5_TFM(c) ((c)->desc[CRYPTO_SHASH_HMACMD5]->tfm)
#define CRYPTO_HMACSHA256_TFM(c)\
@@ -52,8 +48,6 @@ struct ksmbd_crypto_ctx {
#define CRYPTO_CMACAES_TFM(c) ((c)->desc[CRYPTO_SHASH_CMACAES]->tfm)
#define CRYPTO_SHA256_TFM(c) ((c)->desc[CRYPTO_SHASH_SHA256]->tfm)
#define CRYPTO_SHA512_TFM(c) ((c)->desc[CRYPTO_SHASH_SHA512]->tfm)
-#define CRYPTO_MD4_TFM(c) ((c)->desc[CRYPTO_SHASH_MD4]->tfm)
-#define CRYPTO_MD5_TFM(c) ((c)->desc[CRYPTO_SHASH_MD5]->tfm)

#define CRYPTO_GCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES_GCM])
#define CRYPTO_CCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES_CCM])
@@ -64,8 +58,6 @@ struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_hmacsha256(void);
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_cmacaes(void);
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha512(void);
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha256(void);
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md4(void);
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md5(void);
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_gcm(void);
struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_ccm(void);
void ksmbd_crypto_destroy(void);
--
2.25.1