From: Kevin Coffman Subject: [enctypes round 2: PATCH 01/26] gss_krb5: create a define for token header size and clean up ptr location Date: Wed, 30 Apr 2008 12:45:53 -0400 Message-ID: <20080430164553.16010.32928.stgit@jazz.citi.umich.edu> References: <20080430164306.16010.44650.stgit@jazz.citi.umich.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-nfs@vger.kernel.org To: bfields@fieldses.org Return-path: Received: from citi.umich.edu ([141.211.133.111]:48256 "EHLO citi.umich.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755861AbYD3Qpy (ORCPT ); Wed, 30 Apr 2008 12:45:54 -0400 In-Reply-To: <20080430164306.16010.44650.stgit-zTNJhAanYLVZN1qrTdtDg5Vzexx5G7lz@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- include/linux/sunrpc/gss_krb5.h | 3 ++ net/sunrpc/auth_gss/gss_krb5_seal.c | 26 +++++++++-------- net/sunrpc/auth_gss/gss_krb5_unseal.c | 16 +++++------ net/sunrpc/auth_gss/gss_krb5_wrap.c | 50 +++++++++++++++++---------------- 4 files changed, 49 insertions(+), 46 deletions(-) diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h index a10f1fb..e7bbdba 100644 --- a/include/linux/sunrpc/gss_krb5.h +++ b/include/linux/sunrpc/gss_krb5.h @@ -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 diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c index 5f1d36d..b8f42ef 100644 --- a/net/sunrpc/auth_gss/gss_krb5_seal.c +++ b/net/sunrpc/auth_gss/gss_krb5_seal.c @@ -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; diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c index d91a5d0..066ec73 100644 --- a/net/sunrpc/auth_gss/gss_krb5_unseal.c +++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c @@ -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) || diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c index b00b1b4..283cb25 100644 --- a/net/sunrpc/auth_gss/gss_krb5_wrap.c +++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c @@ -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);