Re: [PATCH 2/2] ksmbd: remove NTLMv1 authentication

Steve French
2021-09-29T21:20:03Z

merged into cifsd-for-next (and ksmbd-for-next)

On Wed, Sep 29, 2021 at 10:02 AM Tom Talpey <tom@talpey.com> wrote:
>
> Ok, feel to free to add my
> Reviewed-By: Tom Talpey <tom@talpey.com>
>
> On 9/28/2021 8:34 PM, Namjae Jeon wrote:
> > 2021-09-28 23:32 GMT+09:00, Tom Talpey <tom@talpey.com>:
> >> On 9/27/2021 8:47 AM, Namjae Jeon wrote:
> >>> Remove insecure NTLMv1 authentication.
> >>
> >> There are some extremely confusing name overloads in this file.
> >> Apparently "ksmbd_auth_ntlmv2()" and "__ksmb2_auth_ntlmv2()"
> >> are entirely different things! Yes, this patch removes one,
> >> but it's not easy to review.
> > A long time ago, There was a mistake to rename this function to
> > current name during clean-up.
> >>
> >>> /**
> >>> * ksmbd_auth_ntlmv2() - NTLMv2 authentication handler
> >>> * @sess: session of connection
> >>> * @ntlmv2: NTLMv2 challenge response
> >>> * @blen: NTLMv2 blob length
> >>> * @domain_name: domain name
> >>> *
> >>> * Return: 0 on success, error number on error
> >>> */
> >>
> >>> /**
> >>> * __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
> >>> */
> >>
> >> Two questions:
> >> 1) Have you tested this does not remove existing NTLMv2 support?
> > Yes, tested. This is NTLM2 not NTLMv2.
> >> 2) Does this fully clean up the rather insane function naming?
> > Yes, This patch will do all(remove NTLM and insane fucntion name) :)
> >>
> >> Tom.
> > Thank you for your review!
> >>
> >>> 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);
> >>>
> >>
> >

--
Thanks,

Steve