RPCSEC_GSS: Add support for privacy to krb5 rpcsec_gss mechanism.

 Add support for privacy to the krb5 rpcsec_gss mechanism.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/gss_krb5.h

@@ -116,7 +116,7 @@ enum seal_alg {
 
 s32
 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
-		   struct xdr_netobj *cksum);
+		   int body_offset, struct xdr_netobj *cksum);
 
 u32
 krb5_make_token(struct krb5_ctx *context_handle, int qop_req,
@@ -128,6 +128,15 @@ krb5_read_token(struct krb5_ctx *context_handle,
 	  struct xdr_netobj *input_token_buffer,
 	  struct xdr_buf *message_buffer, int *qop_state);
 
+u32
+gss_wrap_kerberos(struct gss_ctx *ctx_id, u32 qop, int offset,
+		struct xdr_buf *outbuf, struct page **pages);
+
+u32
+gss_unwrap_kerberos(struct gss_ctx *ctx_id, u32 *qop, int offset,
+		struct xdr_buf *buf);
+
+
 u32
 krb5_encrypt(struct crypto_tfm * key,
 	     void *iv, void *in, void *out, int length);
@@ -136,6 +145,13 @@ u32
 krb5_decrypt(struct crypto_tfm * key,
 	     void *iv, void *in, void *out, int length); 
 
+int
+gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *outbuf, int offset,
+		struct page **pages);
+
+int
+gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *inbuf, int offset);
+
 s32
 krb5_make_seq_num(struct crypto_tfm * key,
 		int direction,

net/sunrpc/auth_gss/Makefile

@@ -10,7 +10,7 @@ auth_rpcgss-objs := auth_gss.o gss_generic_token.o \
 obj-$(CONFIG_RPCSEC_GSS_KRB5) += rpcsec_gss_krb5.o
 
 rpcsec_gss_krb5-objs := gss_krb5_mech.o gss_krb5_seal.o gss_krb5_unseal.o \
-	gss_krb5_seqnum.o
+	gss_krb5_seqnum.o gss_krb5_wrap.o
 
 obj-$(CONFIG_RPCSEC_GSS_SPKM3) += rpcsec_gss_spkm3.o
 

net/sunrpc/auth_gss/gss_krb5_crypto.c

@@ -218,7 +218,7 @@ checksummer(struct scatterlist *sg, void *data)
 /* checksum the plaintext data and hdrlen bytes of the token header */
 s32
 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
-		   struct xdr_netobj *cksum)
+		   int body_offset, struct xdr_netobj *cksum)
 {
 	char                            *cksumname;
 	struct crypto_tfm               *tfm = NULL; /* XXX add to ctx? */
@@ -243,7 +243,8 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
 	crypto_digest_init(tfm);
 	buf_to_sg(sg, header, hdrlen);
 	crypto_digest_update(tfm, sg, 1);
-	process_xdr_buf(body, 0, body->len, checksummer, tfm);
+	process_xdr_buf(body, body_offset, body->len - body_offset,
+			checksummer, tfm);
 	crypto_digest_final(tfm, cksum->data);
 	code = 0;
 out:
@@ -252,3 +253,154 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
 }
 
 EXPORT_SYMBOL(make_checksum);
+
+struct encryptor_desc {
+	u8 iv[8]; /* XXX hard-coded blocksize */
+	struct crypto_tfm *tfm;
+	int pos;
+	struct xdr_buf *outbuf;
+	struct page **pages;
+	struct scatterlist infrags[4];
+	struct scatterlist outfrags[4];
+	int fragno;
+	int fraglen;
+};
+
+static int
+encryptor(struct scatterlist *sg, void *data)
+{
+	struct encryptor_desc *desc = data;
+	struct xdr_buf *outbuf = desc->outbuf;
+	struct page *in_page;
+	int thislen = desc->fraglen + sg->length;
+	int fraglen, ret;
+	int page_pos;
+
+	/* Worst case is 4 fragments: head, end of page 1, start
+	 * of page 2, tail.  Anything more is a bug. */
+	BUG_ON(desc->fragno > 3);
+	desc->infrags[desc->fragno] = *sg;
+	desc->outfrags[desc->fragno] = *sg;
+
+	page_pos = desc->pos - outbuf->head[0].iov_len;
+	if (page_pos >= 0 && page_pos < outbuf->page_len) {
+		/* pages are not in place: */
+		int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
+		in_page = desc->pages[i];
+	} else {
+		in_page = sg->page;
+	}
+	desc->infrags[desc->fragno].page = in_page;
+	desc->fragno++;
+	desc->fraglen += sg->length;
+	desc->pos += sg->length;
+
+	fraglen = thislen & 7; /* XXX hardcoded blocksize */
+	thislen -= fraglen;
+
+	if (thislen == 0)
+		return 0;
+
+	ret = crypto_cipher_encrypt_iv(desc->tfm, desc->outfrags, desc->infrags,
+					thislen, desc->iv);
+	if (ret)
+		return ret;
+	if (fraglen) {
+		desc->outfrags[0].page = sg->page;
+		desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
+		desc->outfrags[0].length = fraglen;
+		desc->infrags[0] = desc->outfrags[0];
+		desc->infrags[0].page = in_page;
+		desc->fragno = 1;
+		desc->fraglen = fraglen;
+	} else {
+		desc->fragno = 0;
+		desc->fraglen = 0;
+	}
+	return 0;
+}
+
+int
+gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset,
+		struct page **pages)
+{
+	int ret;
+	struct encryptor_desc desc;
+
+	BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+	desc.tfm = tfm;
+	desc.pos = offset;
+	desc.outbuf = buf;
+	desc.pages = pages;
+	desc.fragno = 0;
+	desc.fraglen = 0;
+
+	ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc);
+	return ret;
+}
+
+EXPORT_SYMBOL(gss_encrypt_xdr_buf);
+
+struct decryptor_desc {
+	u8 iv[8]; /* XXX hard-coded blocksize */
+	struct crypto_tfm *tfm;
+	struct scatterlist frags[4];
+	int fragno;
+	int fraglen;
+};
+
+static int
+decryptor(struct scatterlist *sg, void *data)
+{
+	struct decryptor_desc *desc = data;
+	int thislen = desc->fraglen + sg->length;
+	int fraglen, ret;
+
+	/* Worst case is 4 fragments: head, end of page 1, start
+	 * of page 2, tail.  Anything more is a bug. */
+	BUG_ON(desc->fragno > 3);
+	desc->frags[desc->fragno] = *sg;
+	desc->fragno++;
+	desc->fraglen += sg->length;
+
+	fraglen = thislen & 7; /* XXX hardcoded blocksize */
+	thislen -= fraglen;
+
+	if (thislen == 0)
+		return 0;
+
+	ret = crypto_cipher_decrypt_iv(desc->tfm, desc->frags, desc->frags,
+					thislen, desc->iv);
+	if (ret)
+		return ret;
+	if (fraglen) {
+		desc->frags[0].page = sg->page;
+		desc->frags[0].offset = sg->offset + sg->length - fraglen;
+		desc->frags[0].length = fraglen;
+		desc->fragno = 1;
+		desc->fraglen = fraglen;
+	} else {
+		desc->fragno = 0;
+		desc->fraglen = 0;
+	}
+	return 0;
+}
+
+int
+gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset)
+{
+	struct decryptor_desc desc;
+
+	/* XXXJBF: */
+	BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+	desc.tfm = tfm;
+	desc.fragno = 0;
+	desc.fraglen = 0;
+	return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc);
+}
+
+EXPORT_SYMBOL(gss_decrypt_xdr_buf);

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -226,6 +226,8 @@ static struct gss_api_ops gss_kerberos_ops = {
 	.gss_import_sec_context	= gss_import_sec_context_kerberos,
 	.gss_get_mic		= gss_get_mic_kerberos,
 	.gss_verify_mic		= gss_verify_mic_kerberos,
+	.gss_wrap		= gss_wrap_kerberos,
+	.gss_unwrap		= gss_unwrap_kerberos,
 	.gss_delete_sec_context	= gss_delete_sec_context_kerberos,
 };
 
@@ -240,6 +242,11 @@ static struct pf_desc gss_kerberos_pfs[] = {
 		.service = RPC_GSS_SVC_INTEGRITY,
 		.name = "krb5i",
 	},
+	[2] = {
+		.pseudoflavor = RPC_AUTH_GSS_KRB5P,
+		.service = RPC_GSS_SVC_PRIVACY,
+		.name = "krb5p",
+	},
 };
 
 static struct gss_api_mech gss_kerberos_mech = {

net/sunrpc/auth_gss/gss_krb5_seal.c

@@ -116,8 +116,8 @@ krb5_make_token(struct krb5_ctx *ctx, int qop_req,
 	*(u16 *)(krb5_hdr + 2) = htons(ctx->signalg);
 	memset(krb5_hdr + 4, 0xff, 4);
 
-	if (make_checksum(checksum_type, krb5_hdr, 8, text, &md5cksum))
-		goto out_err;
+	if (make_checksum(checksum_type, krb5_hdr, 8, text, 0, &md5cksum))
+			goto out_err;
 
 	switch (ctx->signalg) {
 	case SGN_ALG_DES_MAC_MD5:

net/sunrpc/auth_gss/gss_krb5_unseal.c

@@ -136,7 +136,7 @@ krb5_read_token(struct krb5_ctx *ctx,
 	switch (signalg) {
 	case SGN_ALG_DES_MAC_MD5:
 		ret = make_checksum(checksum_type, ptr - 2, 8,
-					 message_buffer, &md5cksum);
+					 message_buffer, 0, &md5cksum);
 		if (ret)
 			goto out;