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-rw-r--r--net/sunrpc/auth_gss/gss_krb5_wrap.c404
1 files changed, 345 insertions, 59 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index a6e905637e03..2763e3e48db4 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -1,3 +1,33 @@
+/*
+ * COPYRIGHT (c) 2008
+ * The Regents of the University of Michigan
+ * ALL RIGHTS RESERVED
+ *
+ * Permission is granted to use, copy, create derivative works
+ * and redistribute this software and such derivative works
+ * for any purpose, so long as the name of The University of
+ * Michigan is not used in any advertising or publicity
+ * pertaining to the use of distribution of this software
+ * without specific, written prior authorization. If the
+ * above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any
+ * portion of this software, then the disclaimer below must
+ * also be included.
+ *
+ * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
+ * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
+ * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
+ * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
+ * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
+ * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
+ * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGES.
+ */
+
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/sunrpc/gss_krb5.h>
@@ -12,10 +42,7 @@
static inline int
gss_krb5_padding(int blocksize, int length)
{
- /* Most of the code is block-size independent but currently we
- * use only 8: */
- BUG_ON(blocksize != 8);
- return 8 - (length & 7);
+ return blocksize - (length % blocksize);
}
static inline void
@@ -86,8 +113,8 @@ out:
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;
@@ -127,69 +154,73 @@ make_confounder(char *p, u32 conflen)
/* XXX factor out common code with seal/unseal. */
-u32
-gss_wrap_kerberos(struct gss_ctx *ctx, int offset,
+static u32
+gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
struct xdr_buf *buf, struct page **pages)
{
- struct krb5_ctx *kctx = ctx->internal_ctx_id;
- char cksumdata[16];
- struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj md5cksum = {.len = sizeof(cksumdata),
+ .data = cksumdata};
int blocksize = 0, plainlen;
unsigned char *ptr, *msg_start;
s32 now;
int headlen;
struct page **tmp_pages;
u32 seq_send;
+ u8 *cksumkey;
+ u32 conflen = kctx->gk5e->conflen;
- dprintk("RPC: gss_wrap_kerberos\n");
+ dprintk("RPC: %s\n", __func__);
now = get_seconds();
blocksize = crypto_blkcipher_blocksize(kctx->enc);
gss_krb5_add_padding(buf, offset, blocksize);
BUG_ON((buf->len - offset) % blocksize);
- plainlen = blocksize + buf->len - offset;
+ plainlen = conflen + buf->len - offset;
- headlen = g_token_size(&kctx->mech_used, 24 + plainlen) -
- (buf->len - offset);
+ headlen = g_token_size(&kctx->mech_used,
+ GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) -
+ (buf->len - offset);
ptr = buf->head[0].iov_base + offset;
/* shift data to make room for header. */
+ xdr_extend_head(buf, offset, headlen);
+
/* XXX Would be cleverer to encrypt while copying. */
- /* XXX bounds checking, slack, etc. */
- memmove(ptr + headlen, ptr, buf->head[0].iov_len - offset);
- buf->head[0].iov_len += headlen;
- buf->len += headlen;
BUG_ON((buf->len - offset - headlen) % blocksize);
g_make_token_header(&kctx->mech_used,
- GSS_KRB5_TOK_HDR_LEN + 8 + plainlen, &ptr);
+ GSS_KRB5_TOK_HDR_LEN +
+ kctx->gk5e->cksumlength + plainlen, &ptr);
/* ptr now at header described in rfc 1964, section 1.2.1: */
ptr[0] = (unsigned char) ((KG_TOK_WRAP_MSG >> 8) & 0xff);
ptr[1] = (unsigned char) (KG_TOK_WRAP_MSG & 0xff);
- msg_start = ptr + 24;
+ msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength;
- *(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5);
+ *(__be16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg);
memset(ptr + 4, 0xff, 4);
- *(__be16 *)(ptr + 4) = htons(SEAL_ALG_DES);
+ *(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
- make_confounder(msg_start, blocksize);
+ gss_krb5_make_confounder(msg_start, conflen);
+
+ if (kctx->gk5e->keyed_cksum)
+ cksumkey = kctx->cksum;
+ else
+ cksumkey = NULL;
/* XXXJBF: UGH!: */
tmp_pages = buf->pages;
buf->pages = pages;
- if (make_checksum("md5", ptr, 8, buf,
- offset + headlen - blocksize, &md5cksum))
+ if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen,
+ cksumkey, KG_USAGE_SEAL, &md5cksum))
return GSS_S_FAILURE;
buf->pages = tmp_pages;
- if (krb5_encrypt(kctx->seq, NULL, md5cksum.data,
- md5cksum.data, md5cksum.len))
- return GSS_S_FAILURE;
- memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data + md5cksum.len - 8, 8);
+ memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
spin_lock(&krb5_seq_lock);
seq_send = kctx->seq_send++;
@@ -197,25 +228,42 @@ gss_wrap_kerberos(struct gss_ctx *ctx, int offset,
/* XXX would probably be more efficient to compute checksum
* and encrypt at the same time: */
- if ((krb5_make_seq_num(kctx->seq, kctx->initiate ? 0 : 0xff,
+ if ((krb5_make_seq_num(kctx, kctx->seq, kctx->initiate ? 0 : 0xff,
seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)))
return GSS_S_FAILURE;
- if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - blocksize,
- 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;
}
-u32
-gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
+static u32
+gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
{
- struct krb5_ctx *kctx = ctx->internal_ctx_id;
int signalg;
int sealalg;
- char cksumdata[16];
- struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj md5cksum = {.len = sizeof(cksumdata),
+ .data = cksumdata};
s32 now;
int direction;
s32 seqnum;
@@ -224,6 +272,9 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
void *data_start, *orig_start;
int data_len;
int blocksize;
+ u32 conflen = kctx->gk5e->conflen;
+ int crypt_offset;
+ u8 *cksumkey;
dprintk("RPC: gss_unwrap_kerberos\n");
@@ -241,29 +292,65 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
/* get the sign and seal algorithms */
signalg = ptr[2] + (ptr[3] << 8);
- if (signalg != SGN_ALG_DES_MAC_MD5)
+ if (signalg != kctx->gk5e->signalg)
return GSS_S_DEFECTIVE_TOKEN;
sealalg = ptr[4] + (ptr[5] << 8);
- if (sealalg != SEAL_ALG_DES)
+ if (sealalg != kctx->gk5e->sealalg)
return GSS_S_DEFECTIVE_TOKEN;
if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
return GSS_S_DEFECTIVE_TOKEN;
- if (gss_decrypt_xdr_buf(kctx->enc, buf,
- ptr + GSS_KRB5_TOK_HDR_LEN + 8 - (unsigned char *)buf->head[0].iov_base))
- return GSS_S_DEFECTIVE_TOKEN;
+ /*
+ * Data starts after token header and checksum. ptr points
+ * to the beginning of the token header
+ */
+ crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) -
+ (unsigned char *)buf->head[0].iov_base;
+
+ /*
+ * 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 (make_checksum("md5", ptr, 8, buf,
- ptr + GSS_KRB5_TOK_HDR_LEN + 8 - (unsigned char *)buf->head[0].iov_base, &md5cksum))
- return GSS_S_FAILURE;
+ 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);
- if (krb5_encrypt(kctx->seq, NULL, md5cksum.data,
- md5cksum.data, md5cksum.len))
+ 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;
+ else
+ cksumkey = NULL;
+
+ if (make_checksum(kctx, ptr, 8, buf, crypt_offset,
+ cksumkey, KG_USAGE_SEAL, &md5cksum))
return GSS_S_FAILURE;
- if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, 8))
+ if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+ kctx->gk5e->cksumlength))
return GSS_S_BAD_SIG;
/* it got through unscathed. Make sure the context is unexpired */
@@ -275,19 +362,12 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
/* do sequencing checks */
- if (krb5_get_seq_num(kctx->seq, 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. */
blocksize = crypto_blkcipher_blocksize(kctx->enc);
- data_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8 + blocksize;
+ data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) +
+ conflen;
orig_start = buf->head[0].iov_base + offset;
data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start;
memmove(orig_start, data_start, data_len);
@@ -299,3 +379,209 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
return GSS_S_COMPLETE;
}
+
+/*
+ * We cannot currently handle tokens with rotated data. We need a
+ * generalized routine to rotate the data in place. It is anticipated
+ * that we won't encounter rotated data in the general case.
+ */
+static u32
+rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc)
+{
+ unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN);
+
+ if (realrrc == 0)
+ return 0;
+
+ dprintk("%s: cannot process token with rotated data: "
+ "rrc %u, realrrc %u\n", __func__, rrc, realrrc);
+ return 1;
+}
+
+static u32
+gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, struct page **pages)
+{
+ int blocksize;
+ u8 *ptr, *plainhdr;
+ s32 now;
+ u8 flags = 0x00;
+ __be16 *be16ptr, ec = 0;
+ __be64 *be64ptr;
+ u32 err;
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->encrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ /* make room for gss token header */
+ if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN))
+ return GSS_S_FAILURE;
+
+ /* construct gss token header */
+ ptr = plainhdr = buf->head[0].iov_base + offset;
+ *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff);
+ *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff);
+
+ if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+ flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR;
+ if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0)
+ flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY;
+ /* We always do confidentiality in wrap tokens */
+ flags |= KG2_TOKEN_FLAG_SEALED;
+
+ *ptr++ = flags;
+ *ptr++ = 0xff;
+ be16ptr = (__be16 *)ptr;
+
+ blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc);
+ *be16ptr++ = cpu_to_be16(ec);
+ /* "inner" token header always uses 0 for RRC */
+ *be16ptr++ = cpu_to_be16(0);
+
+ be64ptr = (__be64 *)be16ptr;
+ spin_lock(&krb5_seq_lock);
+ *be64ptr = cpu_to_be64(kctx->seq_send64++);
+ spin_unlock(&krb5_seq_lock);
+
+ err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages);
+ if (err)
+ return err;
+
+ now = get_seconds();
+ return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+{
+ s32 now;
+ u64 seqnum;
+ u8 *ptr;
+ u8 flags = 0x00;
+ u16 ec, rrc;
+ int err;
+ u32 headskip, tailskip;
+ u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN];
+ unsigned int movelen;
+
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->decrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ ptr = buf->head[0].iov_base + offset;
+
+ if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ flags = ptr[2];
+ if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+ (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+ return GSS_S_BAD_SIG;
+
+ if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) {
+ dprintk("%s: token missing expected sealed flag\n", __func__);
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (ptr[3] != 0xff)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ ec = be16_to_cpup((__be16 *)(ptr + 4));
+ rrc = be16_to_cpup((__be16 *)(ptr + 6));
+
+ seqnum = be64_to_cpup((__be64 *)(ptr + 8));
+
+ if (rrc != 0) {
+ err = rotate_left(kctx, offset, buf, rrc);
+ if (err)
+ return GSS_S_FAILURE;
+ }
+
+ err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf,
+ &headskip, &tailskip);
+ if (err)
+ return GSS_S_FAILURE;
+
+ /*
+ * Retrieve the decrypted gss token header and verify
+ * it against the original
+ */
+ err = read_bytes_from_xdr_buf(buf,
+ buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip,
+ decrypted_hdr, GSS_KRB5_TOK_HDR_LEN);
+ if (err) {
+ dprintk("%s: error %u getting decrypted_hdr\n", __func__, err);
+ return GSS_S_FAILURE;
+ }
+ if (memcmp(ptr, decrypted_hdr, 6)
+ || memcmp(ptr + 8, decrypted_hdr + 8, 8)) {
+ dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__);
+ return GSS_S_FAILURE;
+ }
+
+ /* do sequencing checks */
+
+ /* it got through unscathed. Make sure the context is unexpired */
+ now = get_seconds();
+ if (now > kctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /*
+ * Move the head data back to the right position in xdr_buf.
+ * We ignore any "ec" data since it might be in the head or
+ * the tail, and we really don't need to deal with it.
+ * Note that buf->head[0].iov_len may indicate the available
+ * head buffer space rather than that actually occupied.
+ */
+ movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len);
+ movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
+ BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
+ buf->head[0].iov_len);
+ memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen);
+ buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+ buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+
+ return GSS_S_COMPLETE;
+}
+
+u32
+gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
+ struct xdr_buf *buf, struct page **pages)
+{
+ struct krb5_ctx *kctx = gctx->internal_ctx_id;
+
+ switch (kctx->enctype) {
+ default:
+ 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:
+ return gss_wrap_kerberos_v2(kctx, offset, buf, pages);
+ }
+}
+
+u32
+gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf)
+{
+ struct krb5_ctx *kctx = gctx->internal_ctx_id;
+
+ switch (kctx->enctype) {
+ default:
+ 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:
+ return gss_unwrap_kerberos_v2(kctx, offset, buf);
+ }
+}
+
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.