gss_krb5: Add support for rc4-hmac encryption
Kevin Coffman [Wed, 17 Mar 2010 17:03:06 +0000 (13:03 -0400)]
Add necessary changes to add kernel support for the rc4-hmac Kerberos
encryption type used by Microsoft and described in rfc4757.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/gss_krb5.h
net/sunrpc/auth_gss/gss_krb5_crypto.c
net/sunrpc/auth_gss/gss_krb5_mech.c
net/sunrpc/auth_gss/gss_krb5_seal.c
net/sunrpc/auth_gss/gss_krb5_seqnum.c
net/sunrpc/auth_gss/gss_krb5_unseal.c
net/sunrpc/auth_gss/gss_krb5_wrap.c

index 79f6ac2..5e774a5 100644 (file)
@@ -317,5 +317,14 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset,
                     struct xdr_buf *buf, u32 *plainoffset,
                     u32 *plainlen);
 
+int
+krb5_rc4_setup_seq_key(struct krb5_ctx *kctx,
+                      struct crypto_blkcipher *cipher,
+                      unsigned char *cksum);
+
+int
+krb5_rc4_setup_enc_key(struct krb5_ctx *kctx,
+                      struct crypto_blkcipher *cipher,
+                      s32 seqnum);
 void
 gss_krb5_make_confounder(char *p, u32 conflen);
index ed4106a..75ee993 100644 (file)
@@ -124,6 +124,114 @@ checksummer(struct scatterlist *sg, void *data)
        return crypto_hash_update(desc, sg, sg->length);
 }
 
+static int
+arcfour_hmac_md5_usage_to_salt(unsigned int usage, u8 salt[4])
+{
+       unsigned int ms_usage;
+
+       switch (usage) {
+       case KG_USAGE_SIGN:
+               ms_usage = 15;
+               break;
+       case KG_USAGE_SEAL:
+               ms_usage = 13;
+               break;
+       default:
+               return EINVAL;;
+       }
+       salt[0] = (ms_usage >> 0) & 0xff;
+       salt[1] = (ms_usage >> 8) & 0xff;
+       salt[2] = (ms_usage >> 16) & 0xff;
+       salt[3] = (ms_usage >> 24) & 0xff;
+
+       return 0;
+}
+
+static u32
+make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen,
+                      struct xdr_buf *body, int body_offset, u8 *cksumkey,
+                      unsigned int usage, struct xdr_netobj *cksumout)
+{
+       struct hash_desc                desc;
+       struct scatterlist              sg[1];
+       int err;
+       u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+       u8 rc4salt[4];
+       struct crypto_hash *md5;
+       struct crypto_hash *hmac_md5;
+
+       if (cksumkey == NULL)
+               return GSS_S_FAILURE;
+
+       if (cksumout->len < kctx->gk5e->cksumlength) {
+               dprintk("%s: checksum buffer length, %u, too small for %s\n",
+                       __func__, cksumout->len, kctx->gk5e->name);
+               return GSS_S_FAILURE;
+       }
+
+       if (arcfour_hmac_md5_usage_to_salt(usage, rc4salt)) {
+               dprintk("%s: invalid usage value %u\n", __func__, usage);
+               return GSS_S_FAILURE;
+       }
+
+       md5 = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(md5))
+               return GSS_S_FAILURE;
+
+       hmac_md5 = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+                                    CRYPTO_ALG_ASYNC);
+       if (IS_ERR(hmac_md5)) {
+               crypto_free_hash(md5);
+               return GSS_S_FAILURE;
+       }
+
+       desc.tfm = md5;
+       desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+       err = crypto_hash_init(&desc);
+       if (err)
+               goto out;
+       sg_init_one(sg, rc4salt, 4);
+       err = crypto_hash_update(&desc, sg, 4);
+       if (err)
+               goto out;
+
+       sg_init_one(sg, header, hdrlen);
+       err = crypto_hash_update(&desc, sg, hdrlen);
+       if (err)
+               goto out;
+       err = xdr_process_buf(body, body_offset, body->len - body_offset,
+                             checksummer, &desc);
+       if (err)
+               goto out;
+       err = crypto_hash_final(&desc, checksumdata);
+       if (err)
+               goto out;
+
+       desc.tfm = hmac_md5;
+       desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+       err = crypto_hash_init(&desc);
+       if (err)
+               goto out;
+       err = crypto_hash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength);
+       if (err)
+               goto out;
+
+       sg_init_one(sg, checksumdata, crypto_hash_digestsize(md5));
+       err = crypto_hash_digest(&desc, sg, crypto_hash_digestsize(md5),
+                                checksumdata);
+       if (err)
+               goto out;
+
+       memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+       cksumout->len = kctx->gk5e->cksumlength;
+out:
+       crypto_free_hash(md5);
+       crypto_free_hash(hmac_md5);
+       return err ? GSS_S_FAILURE : 0;
+}
+
 /*
  * checksum the plaintext data and hdrlen bytes of the token header
  * The checksum is performed over the first 8 bytes of the
@@ -140,6 +248,11 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
        u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
        unsigned int checksumlen;
 
+       if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
+               return make_checksum_hmac_md5(kctx, header, hdrlen,
+                                             body, body_offset,
+                                             cksumkey, usage, cksumout);
+
        if (cksumout->len < kctx->gk5e->cksumlength) {
                dprintk("%s: checksum buffer length, %u, too small for %s\n",
                        __func__, cksumout->len, kctx->gk5e->name);
@@ -733,3 +846,145 @@ out_err:
                ret = GSS_S_FAILURE;
        return ret;
 }
+
+/*
+ * Compute Kseq given the initial session key and the checksum.
+ * Set the key of the given cipher.
+ */
+int
+krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+                      unsigned char *cksum)
+{
+       struct crypto_hash *hmac;
+       struct hash_desc desc;
+       struct scatterlist sg[1];
+       u8 Kseq[GSS_KRB5_MAX_KEYLEN];
+       u32 zeroconstant = 0;
+       int err;
+
+       dprintk("%s: entered\n", __func__);
+
+       hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(hmac)) {
+               dprintk("%s: error %ld, allocating hash '%s'\n",
+                       __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+               return PTR_ERR(hmac);
+       }
+
+       desc.tfm = hmac;
+       desc.flags = 0;
+
+       err = crypto_hash_init(&desc);
+       if (err)
+               goto out_err;
+
+       /* Compute intermediate Kseq from session key */
+       err = crypto_hash_setkey(hmac, kctx->Ksess, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       sg_init_table(sg, 1);
+       sg_set_buf(sg, &zeroconstant, 4);
+
+       err = crypto_hash_digest(&desc, sg, 4, Kseq);
+       if (err)
+               goto out_err;
+
+       /* Compute final Kseq from the checksum and intermediate Kseq */
+       err = crypto_hash_setkey(hmac, Kseq, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       sg_set_buf(sg, cksum, 8);
+
+       err = crypto_hash_digest(&desc, sg, 8, Kseq);
+       if (err)
+               goto out_err;
+
+       err = crypto_blkcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       err = 0;
+
+out_err:
+       crypto_free_hash(hmac);
+       dprintk("%s: returning %d\n", __func__, err);
+       return err;
+}
+
+/*
+ * Compute Kcrypt given the initial session key and the plaintext seqnum.
+ * Set the key of cipher kctx->enc.
+ */
+int
+krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+                      s32 seqnum)
+{
+       struct crypto_hash *hmac;
+       struct hash_desc desc;
+       struct scatterlist sg[1];
+       u8 Kcrypt[GSS_KRB5_MAX_KEYLEN];
+       u8 zeroconstant[4] = {0};
+       u8 seqnumarray[4];
+       int err, i;
+
+       dprintk("%s: entered, seqnum %u\n", __func__, seqnum);
+
+       hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(hmac)) {
+               dprintk("%s: error %ld, allocating hash '%s'\n",
+                       __func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+               return PTR_ERR(hmac);
+       }
+
+       desc.tfm = hmac;
+       desc.flags = 0;
+
+       err = crypto_hash_init(&desc);
+       if (err)
+               goto out_err;
+
+       /* Compute intermediate Kcrypt from session key */
+       for (i = 0; i < kctx->gk5e->keylength; i++)
+               Kcrypt[i] = kctx->Ksess[i] ^ 0xf0;
+
+       err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       sg_init_table(sg, 1);
+       sg_set_buf(sg, zeroconstant, 4);
+
+       err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+       if (err)
+               goto out_err;
+
+       /* Compute final Kcrypt from the seqnum and intermediate Kcrypt */
+       err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       seqnumarray[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+       seqnumarray[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+       seqnumarray[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+       seqnumarray[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+
+       sg_set_buf(sg, seqnumarray, 4);
+
+       err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+       if (err)
+               goto out_err;
+
+       err = crypto_blkcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
+       if (err)
+               goto out_err;
+
+       err = 0;
+
+out_err:
+       crypto_free_hash(hmac);
+       dprintk("%s: returning %d\n", __func__, err);
+       return err;
+}
+
index ef6b313..54eda5f 100644 (file)
@@ -73,6 +73,27 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
          .keyed_cksum = 0,
        },
        /*
+        * RC4-HMAC
+        */
+       {
+         .etype = ENCTYPE_ARCFOUR_HMAC,
+         .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
+         .name = "rc4-hmac",
+         .encrypt_name = "ecb(arc4)",
+         .cksum_name = "hmac(md5)",
+         .encrypt = krb5_encrypt,
+         .decrypt = krb5_decrypt,
+         .mk_key = NULL,
+         .signalg = SGN_ALG_HMAC_MD5,
+         .sealalg = SEAL_ALG_MICROSOFT_RC4,
+         .keybytes = 16,
+         .keylength = 16,
+         .blocksize = 1,
+         .conflen = 8,
+         .cksumlength = 8,
+         .keyed_cksum = 1,
+       },
+       /*
         * 3DES
         */
        {
@@ -392,6 +413,79 @@ out_err:
        return -EINVAL;
 }
 
+/*
+ * Note that RC4 depends on deriving keys using the sequence
+ * number or the checksum of a token.  Therefore, the final keys
+ * cannot be calculated until the token is being constructed!
+ */
+static int
+context_derive_keys_rc4(struct krb5_ctx *ctx)
+{
+       struct crypto_hash *hmac;
+       char sigkeyconstant[] = "signaturekey";
+       int slen = strlen(sigkeyconstant) + 1;  /* include null terminator */
+       struct hash_desc desc;
+       struct scatterlist sg[1];
+       int err;
+
+       dprintk("RPC:       %s: entered\n", __func__);
+       /*
+        * derive cksum (aka Ksign) key
+        */
+       hmac = crypto_alloc_hash(ctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(hmac)) {
+               dprintk("%s: error %ld allocating hash '%s'\n",
+                       __func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
+               err = PTR_ERR(hmac);
+               goto out_err;
+       }
+
+       err = crypto_hash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
+       if (err)
+               goto out_err_free_hmac;
+
+       sg_init_table(sg, 1);
+       sg_set_buf(sg, sigkeyconstant, slen);
+
+       desc.tfm = hmac;
+       desc.flags = 0;
+
+       err = crypto_hash_init(&desc);
+       if (err)
+               goto out_err_free_hmac;
+
+       err = crypto_hash_digest(&desc, sg, slen, ctx->cksum);
+       if (err)
+               goto out_err_free_hmac;
+       /*
+        * allocate hash, and blkciphers for data and seqnum encryption
+        */
+       ctx->enc = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
+                                         CRYPTO_ALG_ASYNC);
+       if (IS_ERR(ctx->enc)) {
+               err = PTR_ERR(ctx->enc);
+               goto out_err_free_hmac;
+       }
+
+       ctx->seq = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
+                                         CRYPTO_ALG_ASYNC);
+       if (IS_ERR(ctx->seq)) {
+               crypto_free_blkcipher(ctx->enc);
+               err = PTR_ERR(ctx->seq);
+               goto out_err_free_hmac;
+       }
+
+       dprintk("RPC:       %s: returning success\n", __func__);
+
+       err = 0;
+
+out_err_free_hmac:
+       crypto_free_hash(hmac);
+out_err:
+       dprintk("RPC:       %s: returning %d\n", __func__, err);
+       return err;
+}
+
 static int
 context_derive_keys_new(struct krb5_ctx *ctx)
 {
@@ -561,6 +655,8 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx)
        switch (ctx->enctype) {
        case ENCTYPE_DES3_CBC_RAW:
                return context_derive_keys_des3(ctx);
+       case ENCTYPE_ARCFOUR_HMAC:
+               return context_derive_keys_rc4(ctx);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
                return context_derive_keys_new(ctx);
index 36fe487..d7941ea 100644 (file)
@@ -213,6 +213,7 @@ gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
                BUG();
        case ENCTYPE_DES_CBC_RAW:
        case ENCTYPE_DES3_CBC_RAW:
+       case ENCTYPE_ARCFOUR_HMAC:
                return gss_get_mic_v1(ctx, text, token);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
index 83b5930..415c013 100644 (file)
 # define RPCDBG_FACILITY        RPCDBG_AUTH
 #endif
 
+static s32
+krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
+                     unsigned char *cksum, unsigned char *buf)
+{
+       struct crypto_blkcipher *cipher;
+       unsigned char plain[8];
+       s32 code;
+
+       dprintk("RPC:       %s:\n", __func__);
+       cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+                                       CRYPTO_ALG_ASYNC);
+       if (IS_ERR(cipher))
+               return PTR_ERR(cipher);
+
+       plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+       plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+       plain[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+       plain[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+       plain[4] = direction;
+       plain[5] = direction;
+       plain[6] = direction;
+       plain[7] = direction;
+
+       code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+       if (code)
+               goto out;
+
+       code = krb5_encrypt(cipher, cksum, plain, buf, 8);
+out:
+       crypto_free_blkcipher(cipher);
+       return code;
+}
 s32
 krb5_make_seq_num(struct krb5_ctx *kctx,
                struct crypto_blkcipher *key,
@@ -48,6 +80,10 @@ krb5_make_seq_num(struct krb5_ctx *kctx,
 {
        unsigned char plain[8];
 
+       if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+               return krb5_make_rc4_seq_num(kctx, direction, seqnum,
+                                            cksum, buf);
+
        plain[0] = (unsigned char) (seqnum & 0xff);
        plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
        plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
@@ -61,6 +97,43 @@ krb5_make_seq_num(struct krb5_ctx *kctx,
        return krb5_encrypt(key, cksum, plain, buf, 8);
 }
 
+static s32
+krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum,
+                    unsigned char *buf, int *direction, s32 *seqnum)
+{
+       struct crypto_blkcipher *cipher;
+       unsigned char plain[8];
+       s32 code;
+
+       dprintk("RPC:       %s:\n", __func__);
+       cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+                                       CRYPTO_ALG_ASYNC);
+       if (IS_ERR(cipher))
+               return PTR_ERR(cipher);
+
+       code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+       if (code)
+               goto out;
+
+       code = krb5_decrypt(cipher, cksum, buf, plain, 8);
+       if (code)
+               goto out;
+
+       if ((plain[4] != plain[5]) || (plain[4] != plain[6])
+                                  || (plain[4] != plain[7])) {
+               code = (s32)KG_BAD_SEQ;
+               goto out;
+       }
+
+       *direction = plain[4];
+
+       *seqnum = ((plain[0] << 24) | (plain[1] << 16) |
+                                       (plain[2] << 8) | (plain[3]));
+out:
+       crypto_free_blkcipher(cipher);
+       return code;
+}
+
 s32
 krb5_get_seq_num(struct krb5_ctx *kctx,
               unsigned char *cksum,
@@ -73,6 +146,10 @@ krb5_get_seq_num(struct krb5_ctx *kctx,
 
        dprintk("RPC:       krb5_get_seq_num:\n");
 
+       if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+               return krb5_get_rc4_seq_num(kctx, cksum, buf,
+                                           direction, seqnum);
+
        if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
                return code;
 
index 97eb91b..6cd930f 100644 (file)
@@ -216,6 +216,7 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
                BUG();
        case ENCTYPE_DES_CBC_RAW:
        case ENCTYPE_DES3_CBC_RAW:
+       case ENCTYPE_ARCFOUR_HMAC:
                return gss_verify_mic_v1(ctx, message_buffer, read_token);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
index 383db89..2763e3e 100644 (file)
@@ -232,9 +232,26 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
                               seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)))
                return GSS_S_FAILURE;
 
-       if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - conflen,
-                                                                       pages))
-               return GSS_S_FAILURE;
+       if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
+               struct crypto_blkcipher *cipher;
+               int err;
+               cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+                                               CRYPTO_ALG_ASYNC);
+               if (IS_ERR(cipher))
+                       return GSS_S_FAILURE;
+
+               krb5_rc4_setup_enc_key(kctx, cipher, seq_send);
+
+               err = gss_encrypt_xdr_buf(cipher, buf,
+                                         offset + headlen - conflen, pages);
+               crypto_free_blkcipher(cipher);
+               if (err)
+                       return GSS_S_FAILURE;
+       } else {
+               if (gss_encrypt_xdr_buf(kctx->enc, buf,
+                                       offset + headlen - conflen, pages))
+                       return GSS_S_FAILURE;
+       }
 
        return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
@@ -291,8 +308,37 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
         */
        crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) -
                                        (unsigned char *)buf->head[0].iov_base;
-       if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset))
-               return GSS_S_DEFECTIVE_TOKEN;
+
+       /*
+        * Need plaintext seqnum to derive encryption key for arcfour-hmac
+        */
+       if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN,
+                            ptr + 8, &direction, &seqnum))
+               return GSS_S_BAD_SIG;
+
+       if ((kctx->initiate && direction != 0xff) ||
+           (!kctx->initiate && direction != 0))
+               return GSS_S_BAD_SIG;
+
+       if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
+               struct crypto_blkcipher *cipher;
+               int err;
+
+               cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+                                               CRYPTO_ALG_ASYNC);
+               if (IS_ERR(cipher))
+                       return GSS_S_FAILURE;
+
+               krb5_rc4_setup_enc_key(kctx, cipher, seqnum);
+
+               err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset);
+               crypto_free_blkcipher(cipher);
+               if (err)
+                       return GSS_S_DEFECTIVE_TOKEN;
+       } else {
+               if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset))
+                       return GSS_S_DEFECTIVE_TOKEN;
+       }
 
        if (kctx->gk5e->keyed_cksum)
                cksumkey = kctx->cksum;
@@ -316,14 +362,6 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 
        /* do sequencing checks */
 
-       if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN,
-                                   ptr + 8, &direction, &seqnum))
-               return GSS_S_BAD_SIG;
-
-       if ((kctx->initiate && direction != 0xff) ||
-           (!kctx->initiate && direction != 0))
-               return GSS_S_BAD_SIG;
-
        /* Copy the data back to the right position.  XXX: Would probably be
         * better to copy and encrypt at the same time. */
 
@@ -521,6 +559,7 @@ gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
                BUG();
        case ENCTYPE_DES_CBC_RAW:
        case ENCTYPE_DES3_CBC_RAW:
+       case ENCTYPE_ARCFOUR_HMAC:
                return gss_wrap_kerberos_v1(kctx, offset, buf, pages);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
@@ -538,6 +577,7 @@ gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf)
                BUG();
        case ENCTYPE_DES_CBC_RAW:
        case ENCTYPE_DES3_CBC_RAW:
+       case ENCTYPE_ARCFOUR_HMAC:
                return gss_unwrap_kerberos_v1(kctx, offset, buf);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96: