From 924067ef183bd17f39d790752190f99982524598 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 14 Oct 2025 16:17:58 -0700 Subject: [PATCH] ksmbd: Use HMAC-SHA256 library for message signing and key generation Convert ksmbd_sign_smb2_pdu() and generate_key() to use the HMAC-SHA256 library instead of a "hmac(sha256)" crypto_shash. This is simpler and faster. With the library there's no need to allocate memory, no need to handle errors, and the HMAC-SHA256 code is accessed directly without inefficient indirect calls and other unnecessary API overhead. Signed-off-by: Eric Biggers Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/Kconfig | 1 - fs/smb/server/auth.c | 176 ++++++++----------------------------- fs/smb/server/auth.h | 10 +-- fs/smb/server/crypto_ctx.c | 8 -- fs/smb/server/crypto_ctx.h | 5 -- fs/smb/server/server.c | 1 - fs/smb/server/smb2pdu.c | 25 ++---- fs/smb/server/smb_common.h | 2 +- 8 files changed, 52 insertions(+), 176 deletions(-) diff --git a/fs/smb/server/Kconfig b/fs/smb/server/Kconfig index d5f3a417246d4..788104cfb082f 100644 --- a/fs/smb/server/Kconfig +++ b/fs/smb/server/Kconfig @@ -14,7 +14,6 @@ config SMB_SERVER select CRYPTO_LIB_DES select CRYPTO_LIB_SHA256 select CRYPTO_LIB_SHA512 - select CRYPTO_SHA256 select CRYPTO_CMAC select CRYPTO_AEAD2 select CRYPTO_CCM diff --git a/fs/smb/server/auth.c b/fs/smb/server/auth.c index b7f2feede221f..54918f43d2c6b 100644 --- a/fs/smb/server/auth.c +++ b/fs/smb/server/auth.c @@ -590,46 +590,16 @@ int ksmbd_krb5_authenticate(struct ksmbd_session *sess, char *in_blob, * @sig: signature value generated for client request packet * */ -int ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov, - int n_vec, char *sig) +void ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov, + int n_vec, char *sig) { - struct ksmbd_crypto_ctx *ctx; - int rc, i; - - ctx = ksmbd_crypto_ctx_find_hmacsha256(); - if (!ctx) { - ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n"); - return -ENOMEM; - } + struct hmac_sha256_ctx ctx; + int i; - rc = crypto_shash_setkey(CRYPTO_HMACSHA256_TFM(ctx), - key, - SMB2_NTLMV2_SESSKEY_SIZE); - if (rc) - goto out; - - rc = crypto_shash_init(CRYPTO_HMACSHA256(ctx)); - if (rc) { - ksmbd_debug(AUTH, "hmacsha256 init error %d\n", rc); - goto out; - } - - for (i = 0; i < n_vec; i++) { - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), - iov[i].iov_base, - iov[i].iov_len); - if (rc) { - ksmbd_debug(AUTH, "hmacsha256 update error %d\n", rc); - goto out; - } - } - - rc = crypto_shash_final(CRYPTO_HMACSHA256(ctx), sig); - if (rc) - ksmbd_debug(AUTH, "hmacsha256 generation error %d\n", rc); -out: - ksmbd_release_crypto_ctx(ctx); - return rc; + hmac_sha256_init_usingrawkey(&ctx, key, SMB2_NTLMV2_SESSKEY_SIZE); + for (i = 0; i < n_vec; i++) + hmac_sha256_update(&ctx, iov[i].iov_base, iov[i].iov_len); + hmac_sha256_final(&ctx, sig); } /** @@ -689,98 +659,39 @@ struct derivation { bool binding; }; -static int generate_key(struct ksmbd_conn *conn, struct ksmbd_session *sess, - struct kvec label, struct kvec context, __u8 *key, - unsigned int key_size) +static void generate_key(struct ksmbd_conn *conn, struct ksmbd_session *sess, + struct kvec label, struct kvec context, __u8 *key, + unsigned int key_size) { unsigned char zero = 0x0; __u8 i[4] = {0, 0, 0, 1}; __u8 L128[4] = {0, 0, 0, 128}; __u8 L256[4] = {0, 0, 1, 0}; - int rc; unsigned char prfhash[SMB2_HMACSHA256_SIZE]; - unsigned char *hashptr = prfhash; - struct ksmbd_crypto_ctx *ctx; - - memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE); - memset(key, 0x0, key_size); - - ctx = ksmbd_crypto_ctx_find_hmacsha256(); - if (!ctx) { - ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n"); - return -ENOMEM; - } + struct hmac_sha256_ctx ctx; - rc = crypto_shash_setkey(CRYPTO_HMACSHA256_TFM(ctx), - sess->sess_key, - SMB2_NTLMV2_SESSKEY_SIZE); - if (rc) - goto smb3signkey_ret; - - rc = crypto_shash_init(CRYPTO_HMACSHA256(ctx)); - if (rc) { - ksmbd_debug(AUTH, "hmacsha256 init error %d\n", rc); - goto smb3signkey_ret; - } - - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), i, 4); - if (rc) { - ksmbd_debug(AUTH, "could not update with n\n"); - goto smb3signkey_ret; - } - - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), - label.iov_base, - label.iov_len); - if (rc) { - ksmbd_debug(AUTH, "could not update with label\n"); - goto smb3signkey_ret; - } - - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), &zero, 1); - if (rc) { - ksmbd_debug(AUTH, "could not update with zero\n"); - goto smb3signkey_ret; - } - - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), - context.iov_base, - context.iov_len); - if (rc) { - ksmbd_debug(AUTH, "could not update with context\n"); - goto smb3signkey_ret; - } + hmac_sha256_init_usingrawkey(&ctx, sess->sess_key, + SMB2_NTLMV2_SESSKEY_SIZE); + hmac_sha256_update(&ctx, i, 4); + hmac_sha256_update(&ctx, label.iov_base, label.iov_len); + hmac_sha256_update(&ctx, &zero, 1); + hmac_sha256_update(&ctx, context.iov_base, context.iov_len); if (key_size == SMB3_ENC_DEC_KEY_SIZE && (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM || conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L256, 4); + hmac_sha256_update(&ctx, L256, 4); else - rc = crypto_shash_update(CRYPTO_HMACSHA256(ctx), L128, 4); - if (rc) { - ksmbd_debug(AUTH, "could not update with L\n"); - goto smb3signkey_ret; - } + hmac_sha256_update(&ctx, L128, 4); - rc = crypto_shash_final(CRYPTO_HMACSHA256(ctx), hashptr); - if (rc) { - ksmbd_debug(AUTH, "Could not generate hmacmd5 hash error %d\n", - rc); - goto smb3signkey_ret; - } - - memcpy(key, hashptr, key_size); - -smb3signkey_ret: - ksmbd_release_crypto_ctx(ctx); - return rc; + hmac_sha256_final(&ctx, prfhash); + memcpy(key, prfhash, key_size); } static int generate_smb3signingkey(struct ksmbd_session *sess, struct ksmbd_conn *conn, const struct derivation *signing) { - int rc; struct channel *chann; char *key; @@ -793,10 +704,8 @@ static int generate_smb3signingkey(struct ksmbd_session *sess, else key = sess->smb3signingkey; - rc = generate_key(conn, sess, signing->label, signing->context, key, - SMB3_SIGN_KEY_SIZE); - if (rc) - return rc; + generate_key(conn, sess, signing->label, signing->context, key, + SMB3_SIGN_KEY_SIZE); if (!(conn->dialect >= SMB30_PROT_ID && signing->binding)) memcpy(chann->smb3signingkey, key, SMB3_SIGN_KEY_SIZE); @@ -852,23 +761,17 @@ struct derivation_twin { struct derivation decryption; }; -static int generate_smb3encryptionkey(struct ksmbd_conn *conn, - struct ksmbd_session *sess, - const struct derivation_twin *ptwin) +static void generate_smb3encryptionkey(struct ksmbd_conn *conn, + struct ksmbd_session *sess, + const struct derivation_twin *ptwin) { - int rc; + generate_key(conn, sess, ptwin->encryption.label, + ptwin->encryption.context, sess->smb3encryptionkey, + SMB3_ENC_DEC_KEY_SIZE); - rc = generate_key(conn, sess, ptwin->encryption.label, - ptwin->encryption.context, sess->smb3encryptionkey, - SMB3_ENC_DEC_KEY_SIZE); - if (rc) - return rc; - - rc = generate_key(conn, sess, ptwin->decryption.label, - ptwin->decryption.context, - sess->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE); - if (rc) - return rc; + generate_key(conn, sess, ptwin->decryption.label, + ptwin->decryption.context, + sess->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE); ksmbd_debug(AUTH, "dumping generated AES encryption keys\n"); ksmbd_debug(AUTH, "Cipher type %d\n", conn->cipher_type); @@ -887,11 +790,10 @@ static int generate_smb3encryptionkey(struct ksmbd_conn *conn, ksmbd_debug(AUTH, "ServerOut Key %*ph\n", SMB3_GCM128_CRYPTKEY_SIZE, sess->smb3decryptionkey); } - return 0; } -int ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn, - struct ksmbd_session *sess) +void ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn, + struct ksmbd_session *sess) { struct derivation_twin twin; struct derivation *d; @@ -908,11 +810,11 @@ int ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn, d->context.iov_base = "ServerIn "; d->context.iov_len = 10; - return generate_smb3encryptionkey(conn, sess, &twin); + generate_smb3encryptionkey(conn, sess, &twin); } -int ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn, - struct ksmbd_session *sess) +void ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn, + struct ksmbd_session *sess) { struct derivation_twin twin; struct derivation *d; @@ -929,7 +831,7 @@ int ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn, d->context.iov_base = sess->Preauth_HashValue; d->context.iov_len = 64; - return generate_smb3encryptionkey(conn, sess, &twin); + generate_smb3encryptionkey(conn, sess, &twin); } int ksmbd_gen_preauth_integrity_hash(struct ksmbd_conn *conn, char *buf, diff --git a/fs/smb/server/auth.h b/fs/smb/server/auth.h index 6879a1bd1b91f..6d351d61b0e57 100644 --- a/fs/smb/server/auth.h +++ b/fs/smb/server/auth.h @@ -52,18 +52,18 @@ ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob, struct ksmbd_conn *conn); int ksmbd_krb5_authenticate(struct ksmbd_session *sess, char *in_blob, int in_len, char *out_blob, int *out_len); -int ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov, - int n_vec, char *sig); +void ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov, + int n_vec, char *sig); int ksmbd_sign_smb3_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov, int n_vec, char *sig); int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess, struct ksmbd_conn *conn); int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess, struct ksmbd_conn *conn); -int ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn, - struct ksmbd_session *sess); -int ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn, +void ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn, struct ksmbd_session *sess); +void ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn, + struct ksmbd_session *sess); int ksmbd_gen_preauth_integrity_hash(struct ksmbd_conn *conn, char *buf, __u8 *pi_hash); #endif diff --git a/fs/smb/server/crypto_ctx.c b/fs/smb/server/crypto_ctx.c index 1de41b10528bc..a5ec22ba8ae37 100644 --- a/fs/smb/server/crypto_ctx.c +++ b/fs/smb/server/crypto_ctx.c @@ -69,9 +69,6 @@ static struct shash_desc *alloc_shash_desc(int id) case CRYPTO_SHASH_HMACMD5: tfm = crypto_alloc_shash("hmac(md5)", 0, 0); break; - case CRYPTO_SHASH_HMACSHA256: - tfm = crypto_alloc_shash("hmac(sha256)", 0, 0); - break; case CRYPTO_SHASH_CMACAES: tfm = crypto_alloc_shash("cmac(aes)", 0, 0); break; @@ -182,11 +179,6 @@ struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_hmacmd5(void) return ____crypto_shash_ctx_find(CRYPTO_SHASH_HMACMD5); } -struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_hmacsha256(void) -{ - return ____crypto_shash_ctx_find(CRYPTO_SHASH_HMACSHA256); -} - struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_cmacaes(void) { return ____crypto_shash_ctx_find(CRYPTO_SHASH_CMACAES); diff --git a/fs/smb/server/crypto_ctx.h b/fs/smb/server/crypto_ctx.h index 4e8954acd8b8b..c571d65a16f3e 100644 --- a/fs/smb/server/crypto_ctx.h +++ b/fs/smb/server/crypto_ctx.h @@ -11,7 +11,6 @@ enum { CRYPTO_SHASH_HMACMD5 = 0, - CRYPTO_SHASH_HMACSHA256, CRYPTO_SHASH_CMACAES, CRYPTO_SHASH_MAX, }; @@ -35,12 +34,9 @@ struct ksmbd_crypto_ctx { }; #define CRYPTO_HMACMD5(c) ((c)->desc[CRYPTO_SHASH_HMACMD5]) -#define CRYPTO_HMACSHA256(c) ((c)->desc[CRYPTO_SHASH_HMACSHA256]) #define CRYPTO_CMACAES(c) ((c)->desc[CRYPTO_SHASH_CMACAES]) #define CRYPTO_HMACMD5_TFM(c) ((c)->desc[CRYPTO_SHASH_HMACMD5]->tfm) -#define CRYPTO_HMACSHA256_TFM(c)\ - ((c)->desc[CRYPTO_SHASH_HMACSHA256]->tfm) #define CRYPTO_CMACAES_TFM(c) ((c)->desc[CRYPTO_SHASH_CMACAES]->tfm) #define CRYPTO_GCM(c) ((c)->ccmaes[CRYPTO_AEAD_AES_GCM]) @@ -48,7 +44,6 @@ struct ksmbd_crypto_ctx { void ksmbd_release_crypto_ctx(struct ksmbd_crypto_ctx *ctx); struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_hmacmd5(void); -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_gcm(void); struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_ccm(void); diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c index 51e2aee2a6985..8bce97633e01a 100644 --- a/fs/smb/server/server.c +++ b/fs/smb/server/server.c @@ -627,7 +627,6 @@ MODULE_SOFTDEP("pre: md5"); MODULE_SOFTDEP("pre: nls"); MODULE_SOFTDEP("pre: aes"); MODULE_SOFTDEP("pre: cmac"); -MODULE_SOFTDEP("pre: sha256"); MODULE_SOFTDEP("pre: aead2"); MODULE_SOFTDEP("pre: ccm"); MODULE_SOFTDEP("pre: gcm"); diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index f901ae18e68ad..17ce41fb99957 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1538,12 +1538,7 @@ static int ntlm_authenticate(struct ksmbd_work *work, if (smb3_encryption_negotiated(conn) && !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { - rc = conn->ops->generate_encryptionkey(conn, sess); - if (rc) { - ksmbd_debug(SMB, - "SMB3 encryption key generation failed\n"); - return -EINVAL; - } + conn->ops->generate_encryptionkey(conn, sess); sess->enc = true; if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION) rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE; @@ -1640,12 +1635,7 @@ static int krb5_authenticate(struct ksmbd_work *work, if (smb3_encryption_negotiated(conn) && !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { - retval = conn->ops->generate_encryptionkey(conn, sess); - if (retval) { - ksmbd_debug(SMB, - "SMB3 encryption key generation failed\n"); - return -EINVAL; - } + conn->ops->generate_encryptionkey(conn, sess); sess->enc = true; if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION) rsp->SessionFlags = SMB2_SESSION_FLAG_ENCRYPT_DATA_LE; @@ -8861,9 +8851,8 @@ int smb2_check_sign_req(struct ksmbd_work *work) iov[0].iov_base = (char *)&hdr->ProtocolId; iov[0].iov_len = len; - if (ksmbd_sign_smb2_pdu(work->conn, work->sess->sess_key, iov, 1, - signature)) - return 0; + ksmbd_sign_smb2_pdu(work->conn, work->sess->sess_key, iov, 1, + signature); if (memcmp(signature, signature_req, SMB2_SIGNATURE_SIZE)) { pr_err("bad smb2 signature\n"); @@ -8896,9 +8885,9 @@ void smb2_set_sign_rsp(struct ksmbd_work *work) iov = &work->iov[work->iov_idx]; } - if (!ksmbd_sign_smb2_pdu(work->conn, work->sess->sess_key, iov, n_vec, - signature)) - memcpy(hdr->Signature, signature, SMB2_SIGNATURE_SIZE); + ksmbd_sign_smb2_pdu(work->conn, work->sess->sess_key, iov, n_vec, + signature); + memcpy(hdr->Signature, signature, SMB2_SIGNATURE_SIZE); } /** diff --git a/fs/smb/server/smb_common.h b/fs/smb/server/smb_common.h index 863716207a0de..9fa1da647d90e 100644 --- a/fs/smb/server/smb_common.h +++ b/fs/smb/server/smb_common.h @@ -402,7 +402,7 @@ struct smb_version_ops { int (*check_sign_req)(struct ksmbd_work *work); void (*set_sign_rsp)(struct ksmbd_work *work); int (*generate_signingkey)(struct ksmbd_session *sess, struct ksmbd_conn *conn); - int (*generate_encryptionkey)(struct ksmbd_conn *conn, struct ksmbd_session *sess); + void (*generate_encryptionkey)(struct ksmbd_conn *conn, struct ksmbd_session *sess); bool (*is_transform_hdr)(void *buf); int (*decrypt_req)(struct ksmbd_work *work); int (*encrypt_resp)(struct ksmbd_work *work); -- 2.47.3