#include <linux/sunrpc/gss_asn1.h>
 
 struct spkm3_ctx {
-       struct xdr_netobj       ctx_id; /* per message context id */
-       int                     qop;         /* negotiated qop */
+       struct xdr_netobj       ctx_id;  /* per message context id */
+       int                     endtime; /* endtime of the context */
        struct xdr_netobj       mech_used;
        unsigned int            ret_flags ;
-       unsigned int            req_flags ;
-       struct xdr_netobj       share_key;
-       int                     conf_alg;
-       struct crypto_blkcipher *derived_conf_key;
-       int                     intg_alg;
-       struct crypto_blkcipher *derived_integ_key;
-       int                     keyestb_alg;   /* alg used to get share_key */
-       int                     owf_alg;   /* one way function */
+       struct xdr_netobj       conf_alg;
+       struct xdr_netobj       derived_conf_key;
+       struct xdr_netobj       intg_alg;
+       struct xdr_netobj       derived_integ_key;
 };
 
-/* from openssl/objects.h */
-/* XXX need SEAL_ALG_NONE */
-#define NID_md5                4
-#define NID_dhKeyAgreement     28 
-#define NID_des_cbc            31 
-#define NID_sha1               64
-#define NID_cast5_cbc          108
+/* OIDs declarations for K-ALG, I-ALG, C-ALG, and OWF-ALG */
+extern const struct xdr_netobj hmac_md5_oid;
+extern const struct xdr_netobj cast5_cbc_oid;
 
 /* SPKM InnerContext Token types */
 
 u32 spkm3_read_token(struct spkm3_ctx *ctx, struct xdr_netobj *read_token, struct xdr_buf *message_buffer, int toktype);
 
 #define CKSUMTYPE_RSA_MD5            0x0007
+#define CKSUMTYPE_HMAC_MD5           0x0008
 
-s32 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
-                   int body_offset, struct xdr_netobj *cksum);
+s32 make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header,
+               unsigned int hdrlen, struct xdr_buf *body,
+               unsigned int body_offset, struct xdr_netobj *cksum);
 void asn1_bitstring_len(struct xdr_netobj *in, int *enclen, int *zerobits);
-int decode_asn1_bitstring(struct xdr_netobj *out, char *in, int enclen, 
+int decode_asn1_bitstring(struct xdr_netobj *out, char *in, int enclen,
                    int explen);
 void spkm3_mic_header(unsigned char **hdrbuf, unsigned int *hdrlen, 
                    unsigned char *ctxhdr, int elen, int zbit);
 
 #define GSS_CRED_SLACK         1024            /* XXX: unused */
 /* length of a krb5 verifier (48), plus data added before arguments when
  * using integrity (two 4-byte integers): */
-#define GSS_VERF_SLACK         56
+#define GSS_VERF_SLACK         100
 
 /* XXX this define must match the gssd define
 * as it is passed to gssd to signal the use of
 
        return q;
 }
 
-static inline const void *
-get_key(const void *p, const void *end, struct crypto_blkcipher **res,
-       int *resalg)
-{
-       struct xdr_netobj       key = { 0 };
-       int                     setkey = 0;
-       char                    *alg_name;
-
-       p = simple_get_bytes(p, end, resalg, sizeof(*resalg));
-       if (IS_ERR(p))
-               goto out_err;
-       p = simple_get_netobj(p, end, &key);
-       if (IS_ERR(p))
-               goto out_err;
-
-       switch (*resalg) {
-               case NID_des_cbc:
-                       alg_name = "cbc(des)";
-                       setkey = 1;
-                       break;
-               case NID_cast5_cbc:
-                       /* XXXX here in name only, not used */
-                       alg_name = "cbc(cast5)";
-                       setkey = 0; /* XXX will need to set to 1 */
-                       break;
-               case NID_md5:
-                       if (key.len == 0) {
-                               dprintk("RPC: SPKM3 get_key: NID_md5 zero Key length\n");
-                       }
-                       alg_name = "md5";
-                       setkey = 0;
-                       break;
-               default:
-                       dprintk("gss_spkm3_mech: unsupported algorithm %d\n", *resalg);
-                       goto out_err_free_key;
-       }
-       *res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC);
-       if (IS_ERR(*res)) {
-               printk("gss_spkm3_mech: unable to initialize crypto algorthm %s\n", alg_name);
-               *res = NULL;
-               goto out_err_free_key;
-       }
-       if (setkey) {
-               if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
-                       printk("gss_spkm3_mech: error setting key for crypto algorthm %s\n", alg_name);
-                       goto out_err_free_tfm;
-               }
-       }
-
-       if(key.len > 0)
-               kfree(key.data);
-       return p;
-
-out_err_free_tfm:
-       crypto_free_blkcipher(*res);
-out_err_free_key:
-       if(key.len > 0)
-               kfree(key.data);
-       p = ERR_PTR(-EINVAL);
-out_err:
-       return p;
-}
-
 static int
 gss_import_sec_context_spkm3(const void *p, size_t len,
                                struct gss_ctx *ctx_id)
 {
        const void *end = (const void *)((const char *)p + len);
        struct  spkm3_ctx *ctx;
+       int     version;
 
        if (!(ctx = kzalloc(sizeof(*ctx), GFP_KERNEL)))
                goto out_err;
 
+       p = simple_get_bytes(p, end, &version, sizeof(version));
+       if (IS_ERR(p))
+               goto out_err_free_ctx;
+       if (version != 1) {
+               dprintk("RPC: unknown spkm3 token format: obsolete nfs-utils?\n");
+               goto out_err_free_ctx;
+       }
+
        p = simple_get_netobj(p, end, &ctx->ctx_id);
        if (IS_ERR(p))
                goto out_err_free_ctx;
 
-       p = simple_get_bytes(p, end, &ctx->qop, sizeof(ctx->qop));
+       p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
        if (IS_ERR(p))
                goto out_err_free_ctx_id;
 
        p = simple_get_netobj(p, end, &ctx->mech_used);
        if (IS_ERR(p))
-               goto out_err_free_mech;
+               goto out_err_free_ctx_id;
 
        p = simple_get_bytes(p, end, &ctx->ret_flags, sizeof(ctx->ret_flags));
        if (IS_ERR(p))
                goto out_err_free_mech;
 
-       p = simple_get_bytes(p, end, &ctx->req_flags, sizeof(ctx->req_flags));
+       p = simple_get_netobj(p, end, &ctx->conf_alg);
        if (IS_ERR(p))
                goto out_err_free_mech;
 
-       p = simple_get_netobj(p, end, &ctx->share_key);
-       if (IS_ERR(p))
-               goto out_err_free_s_key;
-
-       p = get_key(p, end, &ctx->derived_conf_key, &ctx->conf_alg);
+       p = simple_get_netobj(p, end, &ctx->derived_conf_key);
        if (IS_ERR(p))
-               goto out_err_free_s_key;
+               goto out_err_free_conf_alg;
 
-       p = get_key(p, end, &ctx->derived_integ_key, &ctx->intg_alg);
+       p = simple_get_netobj(p, end, &ctx->intg_alg);
        if (IS_ERR(p))
-               goto out_err_free_key1;
+               goto out_err_free_conf_key;
 
-       p = simple_get_bytes(p, end, &ctx->keyestb_alg, sizeof(ctx->keyestb_alg));
+       p = simple_get_netobj(p, end, &ctx->derived_integ_key);
        if (IS_ERR(p))
-               goto out_err_free_key2;
-
-       p = simple_get_bytes(p, end, &ctx->owf_alg, sizeof(ctx->owf_alg));
-       if (IS_ERR(p))
-               goto out_err_free_key2;
+               goto out_err_free_intg_alg;
 
        if (p != end)
-               goto out_err_free_key2;
+               goto out_err_free_intg_key;
 
        ctx_id->internal_ctx_id = ctx;
 
        dprintk("Successfully imported new spkm context.\n");
        return 0;
 
-out_err_free_key2:
-       crypto_free_blkcipher(ctx->derived_integ_key);
-out_err_free_key1:
-       crypto_free_blkcipher(ctx->derived_conf_key);
-out_err_free_s_key:
-       kfree(ctx->share_key.data);
+out_err_free_intg_key:
+       kfree(ctx->derived_integ_key.data);
+out_err_free_intg_alg:
+       kfree(ctx->intg_alg.data);
+out_err_free_conf_key:
+       kfree(ctx->derived_conf_key.data);
+out_err_free_conf_alg:
+       kfree(ctx->conf_alg.data);
 out_err_free_mech:
        kfree(ctx->mech_used.data);
 out_err_free_ctx_id:
 }
 
 static void
-gss_delete_sec_context_spkm3(void *internal_ctx) {
+gss_delete_sec_context_spkm3(void *internal_ctx)
+{
        struct spkm3_ctx *sctx = internal_ctx;
 
-       crypto_free_blkcipher(sctx->derived_integ_key);
-       crypto_free_blkcipher(sctx->derived_conf_key);
-       kfree(sctx->share_key.data);
+       kfree(sctx->derived_integ_key.data);
+       kfree(sctx->intg_alg.data);
+       kfree(sctx->derived_conf_key.data);
+       kfree(sctx->conf_alg.data);
        kfree(sctx->mech_used.data);
+       kfree(sctx->ctx_id.data);
        kfree(sctx);
 }
 
        u32 maj_stat = 0;
        struct spkm3_ctx *sctx = ctx->internal_ctx_id;
 
-       dprintk("RPC: gss_verify_mic_spkm3 calling spkm3_read_token\n");
        maj_stat = spkm3_read_token(sctx, checksum, signbuf, SPKM_MIC_TOK);
 
        dprintk("RPC: gss_verify_mic_spkm3 returning %d\n", maj_stat);
        u32 err = 0;
        struct spkm3_ctx *sctx = ctx->internal_ctx_id;
 
-       dprintk("RPC: gss_get_mic_spkm3\n");
-
        err = spkm3_make_token(sctx, message_buffer,
-                             message_token, SPKM_MIC_TOK);
+                               message_token, SPKM_MIC_TOK);
+       dprintk("RPC: gss_get_mic_spkm3 returning %d\n", err);
        return err;
 }
 
 
 #include <linux/sunrpc/gss_spkm3.h>
 #include <linux/random.h>
 #include <linux/crypto.h>
+#include <linux/pagemap.h>
+#include <linux/scatterlist.h>
+#include <linux/sunrpc/xdr.h>
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY        RPCDBG_AUTH
 #endif
 
+const struct xdr_netobj hmac_md5_oid = { 8, "\x2B\x06\x01\x05\x05\x08\x01\x01"};
+const struct xdr_netobj cast5_cbc_oid = {9, "\x2A\x86\x48\x86\xF6\x7D\x07\x42\x0A"};
+
 /*
  * spkm3_make_token()
  *
        int                     ctxelen = 0, ctxzbit = 0;
        int                     md5elen = 0, md5zbit = 0;
 
-       dprintk("RPC: spkm3_make_token\n");
-
        now = jiffies;
 
        if (ctx->ctx_id.len != 16) {
                dprintk("RPC: spkm3_make_token BAD ctx_id.len %d\n",
-                       ctx->ctx_id.len);
+                               ctx->ctx_id.len);
                goto out_err;
        }
-               
-       switch (ctx->intg_alg) {
-               case NID_md5:
-                       checksum_type = CKSUMTYPE_RSA_MD5;
-                       break;
-               default:
-                       dprintk("RPC: gss_spkm3_seal: ctx->signalg %d not"
-                               " supported\n", ctx->intg_alg);
-                       goto out_err;
-       }
-       /* XXX since we don't support WRAP, perhaps we don't care... */
-       if (ctx->conf_alg != NID_cast5_cbc) {
-               dprintk("RPC: gss_spkm3_seal: ctx->sealalg %d not supported\n",
-                       ctx->conf_alg);
+
+       if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) {
+               dprintk("RPC: gss_spkm3_seal: unsupported I-ALG algorithm."
+                               "only support hmac-md5 I-ALG.\n");
+               goto out_err;
+       } else
+               checksum_type = CKSUMTYPE_HMAC_MD5;
+
+       if (!g_OID_equal(&ctx->conf_alg, &cast5_cbc_oid)) {
+               dprintk("RPC: gss_spkm3_seal: unsupported C-ALG algorithm\n");
                goto out_err;
        }
 
                /* Calculate checksum over the mic-header */
                asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit);
                spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data,
-                                        ctxelen, ctxzbit);
-
-               if (make_checksum(checksum_type, mic_hdr.data, mic_hdr.len, 
-                                            text, 0, &md5cksum))
+                               ctxelen, ctxzbit);
+               if (make_spkm3_checksum(checksum_type, &ctx->derived_integ_key,
+                                       (char *)mic_hdr.data, mic_hdr.len,
+                                       text, 0, &md5cksum))
                        goto out_err;
 
                asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit);
 
        return  GSS_S_COMPLETE;
 out_err:
+       if (md5cksum.data)
+               kfree(md5cksum.data);
+
        token->data = NULL;
        token->len = 0;
        return GSS_S_FAILURE;
 }
+
+static int
+spkm3_checksummer(struct scatterlist *sg, void *data)
+{
+       struct hash_desc *desc = data;
+
+       return crypto_hash_update(desc, sg, sg->length);
+}
+
+/* checksum the plaintext data and hdrlen bytes of the token header */
+s32
+make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header,
+                   unsigned int hdrlen, struct xdr_buf *body,
+                   unsigned int body_offset, struct xdr_netobj *cksum)
+{
+       char                            *cksumname;
+       struct hash_desc                desc; /* XXX add to ctx? */
+       struct scatterlist              sg[1];
+       int err;
+
+       switch (cksumtype) {
+               case CKSUMTYPE_HMAC_MD5:
+                       cksumname = "md5";
+                       break;
+               default:
+                       dprintk("RPC:      spkm3_make_checksum:"
+                                       " unsupported checksum %d", cksumtype);
+                       return GSS_S_FAILURE;
+       }
+
+       if (key->data == NULL || key->len <= 0) return GSS_S_FAILURE;
+
+       desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
+       if (IS_ERR(desc.tfm))
+               return GSS_S_FAILURE;
+       cksum->len = crypto_hash_digestsize(desc.tfm);
+       desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+       err = crypto_hash_setkey(desc.tfm, key->data, key->len);
+       if (err)
+               goto out;
+
+       sg_set_buf(sg, header, hdrlen);
+       crypto_hash_update(&desc, sg, 1);
+
+       xdr_process_buf(body, body_offset, body->len - body_offset,
+                       spkm3_checksummer, &desc);
+       crypto_hash_final(&desc, cksum->data);
+
+out:
+       crypto_free_hash(desc.tfm);
+
+       return err ? GSS_S_FAILURE : 0;
+}
+
+EXPORT_SYMBOL(make_spkm3_checksum);
 
        *(u8 *)hptr++ = zbit;
        memcpy(hptr, ctxdata, elen);
        hptr += elen;
-       *hdrlen = hptr - top; 
+       *hdrlen = hptr - top;
 }
-               
-/* 
+
+/*
  * spkm3_mic_innercontext_token()
  *
  * *tokp points to the beginning of the SPKM_MIC token  described 
 
                struct xdr_buf *message_buffer, /* signbuf */
                int toktype)
 {
+       s32                     checksum_type;
        s32                     code;
        struct xdr_netobj       wire_cksum = {.len =0, .data = NULL};
        char                    cksumdata[16];
        struct xdr_netobj       md5cksum = {.len = 0, .data = cksumdata};
        unsigned char           *ptr = (unsigned char *)read_token->data;
-       unsigned char           *cksum;
+       unsigned char           *cksum;
        int                     bodysize, md5elen;
        int                     mic_hdrlen;
        u32                     ret = GSS_S_DEFECTIVE_TOKEN;
 
-       dprintk("RPC: spkm3_read_token read_token->len %d\n", read_token->len);
-
        if (g_verify_token_header((struct xdr_netobj *) &ctx->mech_used,
                                        &bodysize, &ptr, read_token->len))
                goto out;
 
        /* decode the token */
 
-       if (toktype == SPKM_MIC_TOK) {
-
-               if ((ret = spkm3_verify_mic_token(&ptr, &mic_hdrlen, &cksum))) 
-                       goto out;
-
-               if (*cksum++ != 0x03) {
-                       dprintk("RPC: spkm3_read_token BAD checksum type\n");
-                       goto out;
-               }
-               md5elen = *cksum++; 
-               cksum++;        /* move past the zbit */
-       
-               if(!decode_asn1_bitstring(&wire_cksum, cksum, md5elen - 1, 16))
-                       goto out;
-
-               /* HARD CODED FOR MD5 */
-
-               /* compute the checksum of the message.
-               *  ptr + 2 = start of header piece of checksum
-               *  mic_hdrlen + 2 = length of header piece of checksum
-               */
-               ret = GSS_S_DEFECTIVE_TOKEN;
-               code = make_checksum(CKSUMTYPE_RSA_MD5, ptr + 2, 
-                                       mic_hdrlen + 2, 
-                                       message_buffer, 0, &md5cksum);
-
-               if (code)
-                       goto out;
-
-               dprintk("RPC: spkm3_read_token: digest wire_cksum.len %d:\n", 
-                       wire_cksum.len);
-
-               ret = GSS_S_BAD_SIG;
-               code = memcmp(md5cksum.data, wire_cksum.data, wire_cksum.len);
-               if (code)
-                       goto out;
-
-       } else { 
-               dprintk("RPC: BAD or UNSUPPORTED SPKM3 token type: %d\n",toktype);
+       if (toktype != SPKM_MIC_TOK) {
+               dprintk("RPC: BAD SPKM3 token type: %d\n", toktype);
+               goto out;
+       }
+
+       if ((ret = spkm3_verify_mic_token(&ptr, &mic_hdrlen, &cksum)))
+               goto out;
+
+       if (*cksum++ != 0x03) {
+               dprintk("RPC: spkm3_read_token BAD checksum type\n");
+               goto out;
+       }
+       md5elen = *cksum++;
+       cksum++;        /* move past the zbit */
+
+       if (!decode_asn1_bitstring(&wire_cksum, cksum, md5elen - 1, 16))
+               goto out;
+
+       /* HARD CODED FOR MD5 */
+
+       /* compute the checksum of the message.
+        * ptr + 2 = start of header piece of checksum
+        * mic_hdrlen + 2 = length of header piece of checksum
+        */
+       ret = GSS_S_DEFECTIVE_TOKEN;
+       if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) {
+               dprintk("RPC: gss_spkm3_seal: unsupported I-ALG algorithm\n");
+               goto out;
+       }
+
+       checksum_type = CKSUMTYPE_HMAC_MD5;
+
+       code = make_spkm3_checksum(checksum_type,
+               &ctx->derived_integ_key, ptr + 2, mic_hdrlen + 2,
+               message_buffer, 0, &md5cksum);
+
+       if (code)
+               goto out;
+
+       ret = GSS_S_BAD_SIG;
+       code = memcmp(md5cksum.data, wire_cksum.data, wire_cksum.len);
+       if (code) {
+               dprintk("RPC: bad MIC checksum\n");
                goto out;
        }
 
+
        /* XXX: need to add expiration and sequencing */
        ret = GSS_S_COMPLETE;
 out: