1 files changed, 119 insertions, 74 deletions

diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c
index db055fd7d77..6c981ddc19f 100644
--- a/net/sunrpc/auth_gss/gss_krb5_unseal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c
@@ -3,7 +3,7 @@
  *
  *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
  *
- *  Copyright (c) 2000 The Regents of the University of Michigan.
+ *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
  *  All rights reserved.
  *
  *  Andy Adamson   <andros@umich.edu>
@@ -58,7 +58,6 @@
  */
 
 #include <linux/types.h>
-#include <linux/slab.h>
 #include <linux/jiffies.h>
 #include <linux/sunrpc/gss_krb5.h>
 #include <linux/crypto.h>
@@ -71,111 +70,157 @@
 /* read_token is a mic token, and message_buffer is the data that the mic was
  * supposedly taken over. */
 
-u32
-gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
+static u32
+gss_verify_mic_v1(struct krb5_ctx *ctx,
 		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
 {
-	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
 	int			signalg;
 	int			sealalg;
-	s32			checksum_type;
-	struct xdr_netobj	md5cksum = {.len = 0, .data = NULL};
+	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
+					    .data = cksumdata};
 	s32			now;
 	int			direction;
-	s32			seqnum;
+	u32			seqnum;
 	unsigned char		*ptr = (unsigned char *)read_token->data;
 	int			bodysize;
-	u32			ret = GSS_S_DEFECTIVE_TOKEN;
+	u8			*cksumkey;
 
-	dprintk("RPC:      krb5_read_token\n");
+	dprintk("RPC:       krb5_read_token\n");
 
 	if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
 					read_token->len))
-		goto out;
+		return GSS_S_DEFECTIVE_TOKEN;
 
-	if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) ||
-	    (*ptr++ != ( KG_TOK_MIC_MSG    &0xff))   )
-		goto out;
+	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?? */
 
-	/* get the sign and seal algorithms */
+	signalg = ptr[2] + (ptr[3] << 8);
+	if (signalg != ctx->gk5e->signalg)
+		return GSS_S_DEFECTIVE_TOKEN;
 
-	signalg = ptr[0] + (ptr[1] << 8);
-	sealalg = ptr[2] + (ptr[3] << 8);
+	sealalg = ptr[4] + (ptr[5] << 8);
+	if (sealalg != SEAL_ALG_NONE)
+		return GSS_S_DEFECTIVE_TOKEN;
 
-	/* Sanity checks */
+	if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
+		return GSS_S_DEFECTIVE_TOKEN;
 
-	if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
-		goto out;
+	if (ctx->gk5e->keyed_cksum)
+		cksumkey = ctx->cksum;
+	else
+		cksumkey = NULL;
 
-	if (sealalg != 0xffff)
-		goto out;
+	if (make_checksum(ctx, ptr, 8, message_buffer, 0,
+			  cksumkey, KG_USAGE_SIGN, &md5cksum))
+		return GSS_S_FAILURE;
 
-	/* there are several mappings of seal algorithms to sign algorithms,
-	   but few enough that we can try them all. */
+	if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+					ctx->gk5e->cksumlength))
+		return GSS_S_BAD_SIG;
 
-	if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) ||
-	    (ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) ||
-	    (ctx->sealalg == SEAL_ALG_DES3KD &&
-	     signalg != SGN_ALG_HMAC_SHA1_DES3_KD))
-		goto out;
+	/* it got through unscathed.  Make sure the context is unexpired */
 
-	/* compute the checksum of the message */
+	now = get_seconds();
 
-	/* initialize the the cksum */
-	switch (signalg) {
-	case SGN_ALG_DES_MAC_MD5:
-		checksum_type = CKSUMTYPE_RSA_MD5;
-		break;
-	default:
-		ret = GSS_S_DEFECTIVE_TOKEN;
-		goto out;
+	if (now > ctx->endtime)
+		return GSS_S_CONTEXT_EXPIRED;
+
+	/* do sequencing checks */
+
+	if (krb5_get_seq_num(ctx, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8,
+			     &direction, &seqnum))
+		return GSS_S_FAILURE;
+
+	if ((ctx->initiate && direction != 0xff) ||
+	    (!ctx->initiate && direction != 0))
+		return GSS_S_BAD_SIG;
+
+	return GSS_S_COMPLETE;
+}
+
+static u32
+gss_verify_mic_v2(struct krb5_ctx *ctx,
+		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+	char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
+				      .data = cksumdata};
+	s32 now;
+	u8 *ptr = read_token->data;
+	u8 *cksumkey;
+	u8 flags;
+	int i;
+	unsigned int cksum_usage;
+
+	dprintk("RPC:       %s\n", __func__);
+
+	if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_MIC)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	flags = ptr[2];
+	if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+	    (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+		return GSS_S_BAD_SIG;
+
+	if (flags & KG2_TOKEN_FLAG_SEALED) {
+		dprintk("%s: token has unexpected sealed flag\n", __func__);
+		return GSS_S_FAILURE;
 	}
 
-	switch (signalg) {
-	case SGN_ALG_DES_MAC_MD5:
-		ret = make_checksum(checksum_type, ptr - 2, 8,
-					 message_buffer, 0, &md5cksum);
-		if (ret)
-			goto out;
-
-		ret = krb5_encrypt(ctx->seq, NULL, md5cksum.data,
-				   md5cksum.data, 16);
-		if (ret)
-			goto out;
-
-		if (memcmp(md5cksum.data + 8, ptr + 14, 8)) {
-			ret = GSS_S_BAD_SIG;
-			goto out;
-		}
-		break;
-	default:
-		ret = GSS_S_DEFECTIVE_TOKEN;
-		goto out;
+	for (i = 3; i < 8; i++)
+		if (ptr[i] != 0xff)
+			return GSS_S_DEFECTIVE_TOKEN;
+
+	if (ctx->initiate) {
+		cksumkey = ctx->acceptor_sign;
+		cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
+	} else {
+		cksumkey = ctx->initiator_sign;
+		cksum_usage = KG_USAGE_INITIATOR_SIGN;
 	}
 
-	/* it got through unscathed.  Make sure the context is unexpired */
+	if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0,
+			     cksumkey, cksum_usage, &cksumobj))
+		return GSS_S_FAILURE;
 
-	now = get_seconds();
+	if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+				ctx->gk5e->cksumlength))
+		return GSS_S_BAD_SIG;
 
-	ret = GSS_S_CONTEXT_EXPIRED;
+	/* it got through unscathed.  Make sure the context is unexpired */
+	now = get_seconds();
 	if (now > ctx->endtime)
-		goto out;
+		return GSS_S_CONTEXT_EXPIRED;
 
-	/* do sequencing checks */
+	/*
+	 * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss
+	 * doesn't want it checked; see page 6 of rfc 2203.
+	 */
 
-	ret = GSS_S_BAD_SIG;
-	if ((ret = krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction,
-				    &seqnum)))
-		goto out;
+	return GSS_S_COMPLETE;
+}
 
-	if ((ctx->initiate && direction != 0xff) ||
-	    (!ctx->initiate && direction != 0))
-		goto out;
+u32
+gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
+			struct xdr_buf *message_buffer,
+			struct xdr_netobj *read_token)
+{
+	struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
 
-	ret = GSS_S_COMPLETE;
-out:
-	kfree(md5cksum.data);
-	return ret;
+	switch (ctx->enctype) {
+	default:
+		BUG();
+	case ENCTYPE_DES_CBC_RAW:
+	case ENCTYPE_DES3_CBC_RAW:
+	case ENCTYPE_ARCFOUR_HMAC:
+		return gss_verify_mic_v1(ctx, message_buffer, read_token);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return gss_verify_mic_v2(ctx, message_buffer, read_token);
+	}
 }
+