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author | Kevin Coffman <kwc@citi.umich.edu> | 2010-03-17 13:03:06 -0400 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-05-14 15:09:20 -0400 |
commit | fffdaef2eb4a7333952e55cf97f1fc0fcc35f981 (patch) | |
tree | bd4e4b39ec901feb27b91d33d4f52e723f3584d7 /net/sunrpc/auth_gss/gss_krb5_crypto.c | |
parent | 5af46547ec451918f3ba51efe59b317d33adf701 (diff) | |
download | op-kernel-dev-fffdaef2eb4a7333952e55cf97f1fc0fcc35f981.zip op-kernel-dev-fffdaef2eb4a7333952e55cf97f1fc0fcc35f981.tar.gz |
gss_krb5: Add support for rc4-hmac encryption
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>
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_crypto.c')
-rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_crypto.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c index ed4106a..75ee993 100644 --- a/net/sunrpc/auth_gss/gss_krb5_crypto.c +++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c @@ -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; +} + |