gss_krb5: create a define for token header size and clean up ptr location

cleanup:
Document token header size with a #define instead of open-coding it.

Don't needlessly increment "ptr" past the beginning of the header
which makes the values passed to functions more understandable and
eliminates the need for extra "krb5_hdr" pointer.

Clean up some intersecting  white-space issues flagged by checkpatch.pl.

This leaves the checksum length hard-coded at 8 for DES.  A later patch
cleans that up.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Kevin Coffman 2008-04-30 12:45:53 -04:00 committed by J. Bruce Fields
parent 8837abcab3
commit d00953a53e
4 changed files with 49 additions and 46 deletions

View File

@ -51,6 +51,9 @@ struct krb5_ctx {
extern spinlock_t krb5_seq_lock;
/* The length of the Kerberos GSS token header */
#define GSS_KRB5_TOK_HDR_LEN (16)
#define KG_TOK_MIC_MSG 0x0101
#define KG_TOK_WRAP_MSG 0x0201

View File

@ -78,7 +78,7 @@ gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
char cksumdata[16];
struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
unsigned char *ptr, *krb5_hdr, *msg_start;
unsigned char *ptr, *msg_start;
s32 now;
u32 seq_send;
@ -87,36 +87,36 @@ gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
now = get_seconds();
token->len = g_token_size(&ctx->mech_used, 24);
token->len = g_token_size(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8);
ptr = token->data;
g_make_token_header(&ctx->mech_used, 24, &ptr);
g_make_token_header(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8, &ptr);
*ptr++ = (unsigned char) ((KG_TOK_MIC_MSG>>8)&0xff);
*ptr++ = (unsigned char) (KG_TOK_MIC_MSG&0xff);
/* ptr now at header described in rfc 1964, section 1.2.1: */
ptr[0] = (unsigned char) ((KG_TOK_MIC_MSG >> 8) & 0xff);
ptr[1] = (unsigned char) (KG_TOK_MIC_MSG & 0xff);
/* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
krb5_hdr = ptr - 2;
msg_start = krb5_hdr + 24;
msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8;
*(__be16 *)(krb5_hdr + 2) = htons(SGN_ALG_DES_MAC_MD5);
memset(krb5_hdr + 4, 0xff, 4);
*(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5);
memset(ptr + 4, 0xff, 4);
if (make_checksum("md5", krb5_hdr, 8, text, 0, &md5cksum))
if (make_checksum("md5", ptr, 8, text, 0, &md5cksum))
return GSS_S_FAILURE;
if (krb5_encrypt(ctx->seq, NULL, md5cksum.data,
md5cksum.data, md5cksum.len))
return GSS_S_FAILURE;
memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - 8, 8);
memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data + md5cksum.len - 8, 8);
spin_lock(&krb5_seq_lock);
seq_send = ctx->seq_send++;
spin_unlock(&krb5_seq_lock);
if (krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff,
seq_send, krb5_hdr + 16, krb5_hdr + 8))
seq_send, ptr + GSS_KRB5_TOK_HDR_LEN,
ptr + 8))
return GSS_S_FAILURE;
return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;

View File

@ -92,30 +92,30 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
read_token->len))
return GSS_S_DEFECTIVE_TOKEN;
if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) ||
(*ptr++ != ( KG_TOK_MIC_MSG &0xff)) )
if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) ||
(ptr[1] != (KG_TOK_MIC_MSG & 0xff)))
return GSS_S_DEFECTIVE_TOKEN;
/* XXX sanity-check bodysize?? */
signalg = ptr[0] + (ptr[1] << 8);
signalg = ptr[2] + (ptr[3] << 8);
if (signalg != SGN_ALG_DES_MAC_MD5)
return GSS_S_DEFECTIVE_TOKEN;
sealalg = ptr[2] + (ptr[3] << 8);
sealalg = ptr[4] + (ptr[5] << 8);
if (sealalg != SEAL_ALG_NONE)
return GSS_S_DEFECTIVE_TOKEN;
if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
return GSS_S_DEFECTIVE_TOKEN;
if (make_checksum("md5", ptr - 2, 8, message_buffer, 0, &md5cksum))
if (make_checksum("md5", ptr, 8, message_buffer, 0, &md5cksum))
return GSS_S_FAILURE;
if (krb5_encrypt(ctx->seq, NULL, md5cksum.data, md5cksum.data, 16))
return GSS_S_FAILURE;
if (memcmp(md5cksum.data + 8, ptr + 14, 8))
if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, 8))
return GSS_S_BAD_SIG;
/* it got through unscathed. Make sure the context is unexpired */
@ -127,7 +127,7 @@ gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
/* do sequencing checks */
if (krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction, &seqnum))
if (krb5_get_seq_num(ctx->seq, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8, &direction, &seqnum))
return GSS_S_FAILURE;
if ((ctx->initiate && direction != 0xff) ||

View File

@ -122,7 +122,7 @@ gss_wrap_kerberos(struct gss_ctx *ctx, int offset,
char cksumdata[16];
struct xdr_netobj md5cksum = {.len = 0, .data = cksumdata};
int blocksize = 0, plainlen;
unsigned char *ptr, *krb5_hdr, *msg_start;
unsigned char *ptr, *msg_start;
s32 now;
int headlen;
struct page **tmp_pages;
@ -149,26 +149,26 @@ gss_wrap_kerberos(struct gss_ctx *ctx, int offset,
buf->len += headlen;
BUG_ON((buf->len - offset - headlen) % blocksize);
g_make_token_header(&kctx->mech_used, 24 + plainlen, &ptr);
g_make_token_header(&kctx->mech_used,
GSS_KRB5_TOK_HDR_LEN + 8 + plainlen, &ptr);
*ptr++ = (unsigned char) ((KG_TOK_WRAP_MSG>>8)&0xff);
*ptr++ = (unsigned char) (KG_TOK_WRAP_MSG&0xff);
/* 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);
/* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
krb5_hdr = ptr - 2;
msg_start = krb5_hdr + 24;
msg_start = ptr + 24;
*(__be16 *)(krb5_hdr + 2) = htons(SGN_ALG_DES_MAC_MD5);
memset(krb5_hdr + 4, 0xff, 4);
*(__be16 *)(krb5_hdr + 4) = htons(SEAL_ALG_DES);
*(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5);
memset(ptr + 4, 0xff, 4);
*(__be16 *)(ptr + 4) = htons(SEAL_ALG_DES);
make_confounder(msg_start, blocksize);
/* XXXJBF: UGH!: */
tmp_pages = buf->pages;
buf->pages = pages;
if (make_checksum("md5", krb5_hdr, 8, buf,
if (make_checksum("md5", ptr, 8, buf,
offset + headlen - blocksize, &md5cksum))
return GSS_S_FAILURE;
buf->pages = tmp_pages;
@ -176,7 +176,7 @@ gss_wrap_kerberos(struct gss_ctx *ctx, int offset,
if (krb5_encrypt(kctx->seq, NULL, md5cksum.data,
md5cksum.data, md5cksum.len))
return GSS_S_FAILURE;
memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - 8, 8);
memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data + md5cksum.len - 8, 8);
spin_lock(&krb5_seq_lock);
seq_send = kctx->seq_send++;
@ -185,7 +185,7 @@ 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,
seq_send, krb5_hdr + 16, krb5_hdr + 8)))
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,
@ -219,38 +219,38 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
buf->len - offset))
return GSS_S_DEFECTIVE_TOKEN;
if ((*ptr++ != ((KG_TOK_WRAP_MSG>>8)&0xff)) ||
(*ptr++ != (KG_TOK_WRAP_MSG &0xff)) )
if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) ||
(ptr[1] != (KG_TOK_WRAP_MSG & 0xff)))
return GSS_S_DEFECTIVE_TOKEN;
/* XXX sanity-check bodysize?? */
/* get the sign and seal algorithms */
signalg = ptr[0] + (ptr[1] << 8);
signalg = ptr[2] + (ptr[3] << 8);
if (signalg != SGN_ALG_DES_MAC_MD5)
return GSS_S_DEFECTIVE_TOKEN;
sealalg = ptr[2] + (ptr[3] << 8);
sealalg = ptr[4] + (ptr[5] << 8);
if (sealalg != SEAL_ALG_DES)
return GSS_S_DEFECTIVE_TOKEN;
if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
return GSS_S_DEFECTIVE_TOKEN;
if (gss_decrypt_xdr_buf(kctx->enc, buf,
ptr + 22 - (unsigned char *)buf->head[0].iov_base))
ptr + GSS_KRB5_TOK_HDR_LEN + 8 - (unsigned char *)buf->head[0].iov_base))
return GSS_S_DEFECTIVE_TOKEN;
if (make_checksum("md5", ptr - 2, 8, buf,
ptr + 22 - (unsigned char *)buf->head[0].iov_base, &md5cksum))
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 (krb5_encrypt(kctx->seq, NULL, md5cksum.data,
md5cksum.data, md5cksum.len))
return GSS_S_FAILURE;
if (memcmp(md5cksum.data + 8, ptr + 14, 8))
if (memcmp(md5cksum.data + 8, ptr + GSS_KRB5_TOK_HDR_LEN, 8))
return GSS_S_BAD_SIG;
/* it got through unscathed. Make sure the context is unexpired */
@ -262,8 +262,8 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
/* do sequencing checks */
if (krb5_get_seq_num(kctx->seq, ptr + 14, ptr + 6, &direction,
&seqnum))
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) ||
@ -274,7 +274,7 @@ gss_unwrap_kerberos(struct gss_ctx *ctx, int offset, struct xdr_buf *buf)
* better to copy and encrypt at the same time. */
blocksize = crypto_blkcipher_blocksize(kctx->enc);
data_start = ptr + 22 + blocksize;
data_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8 + blocksize;
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);