提交 934a95aa 编写于 作者: K Kevin Coffman 提交者: Trond Myklebust

gss_krb5: add remaining pieces to enable AES encryption support

Add the remaining pieces to enable support for Kerberos AES
encryption types.
Signed-off-by: NKevin Coffman <kwc@citi.umich.edu>
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
上级 de9c17eb
......@@ -99,6 +99,8 @@ struct krb5_ctx {
struct crypto_blkcipher *seq;
struct crypto_blkcipher *acceptor_enc;
struct crypto_blkcipher *initiator_enc;
struct crypto_blkcipher *acceptor_enc_aux;
struct crypto_blkcipher *initiator_enc_aux;
u8 cksum[GSS_KRB5_MAX_KEYLEN];
s32 endtime;
u32 seq_send;
......@@ -294,3 +296,21 @@ u32
gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
struct xdr_netobj *randombits,
struct xdr_netobj *key);
u32
gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
struct xdr_netobj *randombits,
struct xdr_netobj *key);
u32
gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
struct xdr_buf *buf, int ec,
struct page **pages);
u32
gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset,
struct xdr_buf *buf, u32 *plainoffset,
u32 *plainlen);
void
gss_krb5_make_confounder(char *p, u32 conflen);
......@@ -41,6 +41,7 @@
#include <linux/crypto.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/random.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
......@@ -478,3 +479,250 @@ xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
return 0;
}
static u32
gss_krb5_cts_crypt(struct crypto_blkcipher *cipher, struct xdr_buf *buf,
u32 offset, u8 *iv, struct page **pages, int encrypt)
{
u32 ret;
struct scatterlist sg[1];
struct blkcipher_desc desc = { .tfm = cipher, .info = iv };
u8 data[crypto_blkcipher_blocksize(cipher) * 2];
struct page **save_pages;
u32 len = buf->len - offset;
BUG_ON(len > crypto_blkcipher_blocksize(cipher) * 2);
/*
* For encryption, we want to read from the cleartext
* page cache pages, and write the encrypted data to
* the supplied xdr_buf pages.
*/
save_pages = buf->pages;
if (encrypt)
buf->pages = pages;
ret = read_bytes_from_xdr_buf(buf, offset, data, len);
buf->pages = save_pages;
if (ret)
goto out;
sg_init_one(sg, data, len);
if (encrypt)
ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, len);
else
ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, len);
if (ret)
goto out;
ret = write_bytes_to_xdr_buf(buf, offset, data, len);
out:
return ret;
}
u32
gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
struct xdr_buf *buf, int ec, struct page **pages)
{
u32 err;
struct xdr_netobj hmac;
u8 *cksumkey;
u8 *ecptr;
struct crypto_blkcipher *cipher, *aux_cipher;
int blocksize;
struct page **save_pages;
int nblocks, nbytes;
struct encryptor_desc desc;
u32 cbcbytes;
if (kctx->initiate) {
cipher = kctx->initiator_enc;
aux_cipher = kctx->initiator_enc_aux;
cksumkey = kctx->initiator_integ;
} else {
cipher = kctx->acceptor_enc;
aux_cipher = kctx->acceptor_enc_aux;
cksumkey = kctx->acceptor_integ;
}
blocksize = crypto_blkcipher_blocksize(cipher);
/* hide the gss token header and insert the confounder */
offset += GSS_KRB5_TOK_HDR_LEN;
if (xdr_extend_head(buf, offset, blocksize))
return GSS_S_FAILURE;
gss_krb5_make_confounder(buf->head[0].iov_base + offset, blocksize);
offset -= GSS_KRB5_TOK_HDR_LEN;
if (buf->tail[0].iov_base != NULL) {
ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
} else {
buf->tail[0].iov_base = buf->head[0].iov_base
+ buf->head[0].iov_len;
buf->tail[0].iov_len = 0;
ecptr = buf->tail[0].iov_base;
}
memset(ecptr, 'X', ec);
buf->tail[0].iov_len += ec;
buf->len += ec;
/* copy plaintext gss token header after filler (if any) */
memcpy(ecptr + ec, buf->head[0].iov_base + offset,
GSS_KRB5_TOK_HDR_LEN);
buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
buf->len += GSS_KRB5_TOK_HDR_LEN;
/* Do the HMAC */
hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
/*
* When we are called, pages points to the real page cache
* data -- which we can't go and encrypt! buf->pages points
* to scratch pages which we are going to send off to the
* client/server. Swap in the plaintext pages to calculate
* the hmac.
*/
save_pages = buf->pages;
buf->pages = pages;
err = make_checksum_v2(kctx, NULL, 0, buf,
offset + GSS_KRB5_TOK_HDR_LEN, cksumkey, &hmac);
buf->pages = save_pages;
if (err)
return GSS_S_FAILURE;
nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
nblocks = (nbytes + blocksize - 1) / blocksize;
cbcbytes = 0;
if (nblocks > 2)
cbcbytes = (nblocks - 2) * blocksize;
memset(desc.iv, 0, sizeof(desc.iv));
if (cbcbytes) {
desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
desc.fragno = 0;
desc.fraglen = 0;
desc.pages = pages;
desc.outbuf = buf;
desc.desc.info = desc.iv;
desc.desc.flags = 0;
desc.desc.tfm = aux_cipher;
sg_init_table(desc.infrags, 4);
sg_init_table(desc.outfrags, 4);
err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
cbcbytes, encryptor, &desc);
if (err)
goto out_err;
}
/* Make sure IV carries forward from any CBC results. */
err = gss_krb5_cts_crypt(cipher, buf,
offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
desc.iv, pages, 1);
if (err) {
err = GSS_S_FAILURE;
goto out_err;
}
/* Now update buf to account for HMAC */
buf->tail[0].iov_len += kctx->gk5e->cksumlength;
buf->len += kctx->gk5e->cksumlength;
out_err:
if (err)
err = GSS_S_FAILURE;
return err;
}
u32
gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
u32 *headskip, u32 *tailskip)
{
struct xdr_buf subbuf;
u32 ret = 0;
u8 *cksum_key;
struct crypto_blkcipher *cipher, *aux_cipher;
struct xdr_netobj our_hmac_obj;
u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
int nblocks, blocksize, cbcbytes;
struct decryptor_desc desc;
if (kctx->initiate) {
cipher = kctx->acceptor_enc;
aux_cipher = kctx->acceptor_enc_aux;
cksum_key = kctx->acceptor_integ;
} else {
cipher = kctx->initiator_enc;
aux_cipher = kctx->initiator_enc_aux;
cksum_key = kctx->initiator_integ;
}
blocksize = crypto_blkcipher_blocksize(cipher);
/* create a segment skipping the header and leaving out the checksum */
xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
(buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
kctx->gk5e->cksumlength));
nblocks = (subbuf.len + blocksize - 1) / blocksize;
cbcbytes = 0;
if (nblocks > 2)
cbcbytes = (nblocks - 2) * blocksize;
memset(desc.iv, 0, sizeof(desc.iv));
if (cbcbytes) {
desc.fragno = 0;
desc.fraglen = 0;
desc.desc.info = desc.iv;
desc.desc.flags = 0;
desc.desc.tfm = aux_cipher;
sg_init_table(desc.frags, 4);
ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
if (ret)
goto out_err;
}
/* Make sure IV carries forward from any CBC results. */
ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
if (ret)
goto out_err;
/* Calculate our hmac over the plaintext data */
our_hmac_obj.len = sizeof(our_hmac);
our_hmac_obj.data = our_hmac;
ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
cksum_key, &our_hmac_obj);
if (ret)
goto out_err;
/* Get the packet's hmac value */
ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
pkt_hmac, kctx->gk5e->cksumlength);
if (ret)
goto out_err;
if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
ret = GSS_S_BAD_SIG;
goto out_err;
}
*headskip = crypto_blkcipher_blocksize(cipher);
*tailskip = kctx->gk5e->cksumlength;
out_err:
if (ret && ret != GSS_S_BAD_SIG)
ret = GSS_S_FAILURE;
return ret;
}
......@@ -303,3 +303,33 @@ u32 gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
err_out:
return ret;
}
/*
* This is the aes key derivation postprocess function
*/
u32 gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
struct xdr_netobj *randombits,
struct xdr_netobj *key)
{
u32 ret = EINVAL;
if (key->len != 16 && key->len != 32) {
dprintk("%s: key->len is %d\n", __func__, key->len);
goto err_out;
}
if (randombits->len != 16 && randombits->len != 32) {
dprintk("%s: randombits->len is %d\n",
__func__, randombits->len);
goto err_out;
}
if (randombits->len != key->len) {
dprintk("%s: randombits->len is %d, key->len is %d\n",
__func__, randombits->len, key->len);
goto err_out;
}
memcpy(key->data, randombits->data, key->len);
ret = 0;
err_out:
return ret;
}
......@@ -91,6 +91,50 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
.cksumlength = 20,
.keyed_cksum = 1,
},
/*
* AES128
*/
{
.etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
.ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
.name = "aes128-cts",
.encrypt_name = "cts(cbc(aes))",
.cksum_name = "hmac(sha1)",
.encrypt = krb5_encrypt,
.decrypt = krb5_decrypt,
.mk_key = gss_krb5_aes_make_key,
.encrypt_v2 = gss_krb5_aes_encrypt,
.decrypt_v2 = gss_krb5_aes_decrypt,
.signalg = -1,
.sealalg = -1,
.keybytes = 16,
.keylength = 16,
.blocksize = 16,
.cksumlength = 12,
.keyed_cksum = 1,
},
/*
* AES256
*/
{
.etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
.ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
.name = "aes256-cts",
.encrypt_name = "cts(cbc(aes))",
.cksum_name = "hmac(sha1)",
.encrypt = krb5_encrypt,
.decrypt = krb5_decrypt,
.mk_key = gss_krb5_aes_make_key,
.encrypt_v2 = gss_krb5_aes_encrypt,
.decrypt_v2 = gss_krb5_aes_decrypt,
.signalg = -1,
.sealalg = -1,
.keybytes = 32,
.keylength = 32,
.blocksize = 16,
.cksumlength = 12,
.keyed_cksum = 1,
},
};
static const int num_supported_enctypes =
......@@ -270,20 +314,19 @@ gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
}
struct crypto_blkcipher *
context_v2_alloc_cipher(struct krb5_ctx *ctx, u8 *key)
context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
{
struct crypto_blkcipher *cp;
cp = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name,
0, CRYPTO_ALG_ASYNC);
cp = crypto_alloc_blkcipher(cname, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(cp)) {
dprintk("gss_kerberos_mech: unable to initialize "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
"crypto algorithm %s\n", cname);
return NULL;
}
if (crypto_blkcipher_setkey(cp, key, ctx->gk5e->keylength)) {
dprintk("gss_kerberos_mech: error setting key for "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
"crypto algorithm %s\n", cname);
crypto_free_blkcipher(cp);
return NULL;
}
......@@ -315,11 +358,13 @@ context_derive_keys_des3(struct krb5_ctx *ctx, u8 *rawkey, u32 keylen)
keyout.len = keylen;
/* seq uses the raw key */
ctx->seq = context_v2_alloc_cipher(ctx, rawkey);
ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
rawkey);
if (ctx->seq == NULL)
goto out_err;
ctx->enc = context_v2_alloc_cipher(ctx, rawkey);
ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
rawkey);
if (ctx->enc == NULL)
goto out_free_seq;
......@@ -366,7 +411,9 @@ context_derive_keys_new(struct krb5_ctx *ctx, u8 *rawkey, u32 keylen)
__func__, err);
goto out_err;
}
ctx->initiator_enc = context_v2_alloc_cipher(ctx, ctx->initiator_seal);
ctx->initiator_enc = context_v2_alloc_cipher(ctx,
ctx->gk5e->encrypt_name,
ctx->initiator_seal);
if (ctx->initiator_enc == NULL)
goto out_err;
......@@ -379,7 +426,9 @@ context_derive_keys_new(struct krb5_ctx *ctx, u8 *rawkey, u32 keylen)
__func__, err);
goto out_free_initiator_enc;
}
ctx->acceptor_enc = context_v2_alloc_cipher(ctx, ctx->acceptor_seal);
ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
ctx->gk5e->encrypt_name,
ctx->acceptor_seal);
if (ctx->acceptor_enc == NULL)
goto out_free_initiator_enc;
......@@ -423,6 +472,23 @@ context_derive_keys_new(struct krb5_ctx *ctx, u8 *rawkey, u32 keylen)
goto out_free_acceptor_enc;
}
switch (ctx->enctype) {
case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
ctx->initiator_enc_aux =
context_v2_alloc_cipher(ctx, "cbc(aes)",
ctx->initiator_seal);
if (ctx->initiator_enc_aux == NULL)
goto out_free_acceptor_enc;
ctx->acceptor_enc_aux =
context_v2_alloc_cipher(ctx, "cbc(aes)",
ctx->acceptor_seal);
if (ctx->acceptor_enc_aux == NULL) {
crypto_free_blkcipher(ctx->initiator_enc_aux);
goto out_free_acceptor_enc;
}
}
return 0;
out_free_acceptor_enc:
......@@ -537,6 +603,8 @@ gss_delete_sec_context_kerberos(void *internal_ctx) {
crypto_free_blkcipher(kctx->enc);
crypto_free_blkcipher(kctx->acceptor_enc);
crypto_free_blkcipher(kctx->initiator_enc);
crypto_free_blkcipher(kctx->acceptor_enc_aux);
crypto_free_blkcipher(kctx->initiator_enc_aux);
kfree(kctx->mech_used.data);
kfree(kctx);
}
......
......@@ -113,8 +113,8 @@ gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
return 0;
}
static void
make_confounder(char *p, u32 conflen)
void
gss_krb5_make_confounder(char *p, u32 conflen)
{
static u64 i = 0;
u64 *q = (u64 *)p;
......@@ -204,7 +204,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
memset(ptr + 4, 0xff, 4);
*(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
make_confounder(msg_start, blocksize);
gss_krb5_make_confounder(msg_start, blocksize);
if (kctx->gk5e->keyed_cksum)
cksumkey = kctx->cksum;
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册