1 files changed, 15 insertions, 413 deletions

diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index cf0fd170ac18..b3e1738ff6bf 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -32,366 +32,14 @@
 #include <linux/types.h>
 #include <linux/jiffies.h>
 #include <linux/sunrpc/gss_krb5.h>
-#include <linux/random.h>
 #include <linux/pagemap.h>
 
+#include "gss_krb5_internal.h"
+
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY	RPCDBG_AUTH
 #endif
 
-static inline int
-gss_krb5_padding(int blocksize, int length)
-{
-	return blocksize - (length % blocksize);
-}
-
-static inline void
-gss_krb5_add_padding(struct xdr_buf *buf, int offset, int blocksize)
-{
-	int padding = gss_krb5_padding(blocksize, buf->len - offset);
-	char *p;
-	struct kvec *iov;
-
-	if (buf->page_len || buf->tail[0].iov_len)
-		iov = &buf->tail[0];
-	else
-		iov = &buf->head[0];
-	p = iov->iov_base + iov->iov_len;
-	iov->iov_len += padding;
-	buf->len += padding;
-	memset(p, padding, padding);
-}
-
-static inline int
-gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
-{
-	u8 *ptr;
-	u8 pad;
-	size_t len = buf->len;
-
-	if (len <= buf->head[0].iov_len) {
-		pad = *(u8 *)(buf->head[0].iov_base + len - 1);
-		if (pad > buf->head[0].iov_len)
-			return -EINVAL;
-		buf->head[0].iov_len -= pad;
-		goto out;
-	} else
-		len -= buf->head[0].iov_len;
-	if (len <= buf->page_len) {
-		unsigned int last = (buf->page_base + len - 1)
-					>>PAGE_SHIFT;
-		unsigned int offset = (buf->page_base + len - 1)
-					& (PAGE_SIZE - 1);
-		ptr = kmap_atomic(buf->pages[last]);
-		pad = *(ptr + offset);
-		kunmap_atomic(ptr);
-		goto out;
-	} else
-		len -= buf->page_len;
-	BUG_ON(len > buf->tail[0].iov_len);
-	pad = *(u8 *)(buf->tail[0].iov_base + len - 1);
-out:
-	/* XXX: NOTE: we do not adjust the page lengths--they represent
-	 * a range of data in the real filesystem page cache, and we need
-	 * to know that range so the xdr code can properly place read data.
-	 * However adjusting the head length, as we do above, is harmless.
-	 * In the case of a request that fits into a single page, the server
-	 * also uses length and head length together to determine the original
-	 * start of the request to copy the request for deferal; so it's
-	 * easier on the server if we adjust head and tail length in tandem.
-	 * It's not really a problem that we don't fool with the page and
-	 * tail lengths, though--at worst badly formed xdr might lead the
-	 * server to attempt to parse the padding.
-	 * XXX: Document all these weird requirements for gss mechanism
-	 * wrap/unwrap functions. */
-	if (pad > blocksize)
-		return -EINVAL;
-	if (buf->len > pad)
-		buf->len -= pad;
-	else
-		return -EINVAL;
-	return 0;
-}
-
-void
-gss_krb5_make_confounder(char *p, u32 conflen)
-{
-	static u64 i = 0;
-	u64 *q = (u64 *)p;
-
-	/* rfc1964 claims this should be "random".  But all that's really
-	 * necessary is that it be unique.  And not even that is necessary in
-	 * our case since our "gssapi" implementation exists only to support
-	 * rpcsec_gss, so we know that the only buffers we will ever encrypt
-	 * already begin with a unique sequence number.  Just to hedge my bets
-	 * I'll make a half-hearted attempt at something unique, but ensuring
-	 * uniqueness would mean worrying about atomicity and rollover, and I
-	 * don't care enough. */
-
-	/* initialize to random value */
-	if (i == 0) {
-		i = prandom_u32();
-		i = (i << 32) | prandom_u32();
-	}
-
-	switch (conflen) {
-	case 16:
-		*q++ = i++;
-		/* fall through */
-	case 8:
-		*q++ = i++;
-		break;
-	default:
-		BUG();
-	}
-}
-
-/* Assumptions: the head and tail of inbuf are ours to play with.
- * The pages, however, may be real pages in the page cache and we replace
- * them with scratch pages from **pages before writing to them. */
-/* XXX: obviously the above should be documentation of wrap interface,
- * and shouldn't be in this kerberos-specific file. */
-
-/* XXX factor out common code with seal/unseal. */
-
-static u32
-gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
-		struct xdr_buf *buf, struct page **pages)
-{
-	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;
-	time64_t		now;
-	int			headlen;
-	struct page		**tmp_pages;
-	u32			seq_send;
-	u8			*cksumkey;
-	u32			conflen = kctx->gk5e->conflen;
-
-	dprintk("RPC:       %s\n", __func__);
-
-	now = ktime_get_real_seconds();
-
-	blocksize = crypto_sync_skcipher_blocksize(kctx->enc);
-	gss_krb5_add_padding(buf, offset, blocksize);
-	BUG_ON((buf->len - offset) % blocksize);
-	plainlen = conflen + 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. */
-	BUG_ON((buf->len - offset - headlen) % blocksize);
-
-	g_make_token_header(&kctx->mech_used,
-				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 + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength;
-
-	/*
-	 * signalg and sealalg are stored as if they were converted from LE
-	 * to host endian, even though they're opaque pairs of bytes according
-	 * to the RFC.
-	 */
-	*(__le16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg);
-	*(__le16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
-	ptr[6] = 0xff;
-	ptr[7] = 0xff;
-
-	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(kctx, ptr, 8, buf, offset + headlen - conflen,
-					cksumkey, KG_USAGE_SEAL, &md5cksum))
-		return GSS_S_FAILURE;
-	buf->pages = tmp_pages;
-
-	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
-
-	seq_send = atomic_fetch_inc(&kctx->seq_send);
-
-	/* XXX would probably be more efficient to compute checksum
-	 * and encrypt at the same time: */
-	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 (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
-		struct crypto_sync_skcipher *cipher;
-		int err;
-		cipher = crypto_alloc_sync_skcipher(kctx->gk5e->encrypt_name,
-						    0, 0);
-		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_sync_skcipher(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;
-}
-
-static u32
-gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, int len,
-		       struct xdr_buf *buf, unsigned int *slack,
-		       unsigned int *align)
-{
-	int			signalg;
-	int			sealalg;
-	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
-	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
-					    .data = cksumdata};
-	time64_t		now;
-	int			direction;
-	s32			seqnum;
-	unsigned char		*ptr;
-	int			bodysize;
-	void			*data_start, *orig_start;
-	int			data_len;
-	int			blocksize;
-	u32			conflen = kctx->gk5e->conflen;
-	int			crypt_offset;
-	u8			*cksumkey;
-	unsigned int		saved_len = buf->len;
-
-	dprintk("RPC:       gss_unwrap_kerberos\n");
-
-	ptr = (u8 *)buf->head[0].iov_base + offset;
-	if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr,
-					len - offset))
-		return GSS_S_DEFECTIVE_TOKEN;
-
-	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[2] + (ptr[3] << 8);
-	if (signalg != kctx->gk5e->signalg)
-		return GSS_S_DEFECTIVE_TOKEN;
-
-	sealalg = ptr[4] + (ptr[5] << 8);
-	if (sealalg != kctx->gk5e->sealalg)
-		return GSS_S_DEFECTIVE_TOKEN;
-
-	if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
-		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 ((kctx->initiate && direction != 0xff) ||
-	    (!kctx->initiate && direction != 0))
-		return GSS_S_BAD_SIG;
-
-	buf->len = len;
-	if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
-		struct crypto_sync_skcipher *cipher;
-		int err;
-
-		cipher = crypto_alloc_sync_skcipher(kctx->gk5e->encrypt_name,
-						    0, 0);
-		if (IS_ERR(cipher))
-			return GSS_S_FAILURE;
-
-		krb5_rc4_setup_enc_key(kctx, cipher, seqnum);
-
-		err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset);
-		crypto_free_sync_skcipher(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, ptr + GSS_KRB5_TOK_HDR_LEN,
-						kctx->gk5e->cksumlength))
-		return GSS_S_BAD_SIG;
-
-	/* it got through unscathed.  Make sure the context is unexpired */
-
-	now = ktime_get_real_seconds();
-
-	if (now > kctx->endtime)
-		return GSS_S_CONTEXT_EXPIRED;
-
-	/* do sequencing checks */
-
-	/* Copy the data back to the right position.  XXX: Would probably be
-	 * better to copy and encrypt at the same time. */
-
-	blocksize = crypto_sync_skcipher_blocksize(kctx->enc);
-	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);
-	buf->head[0].iov_len -= (data_start - orig_start);
-	buf->len = len - (data_start - orig_start);
-
-	if (gss_krb5_remove_padding(buf, blocksize))
-		return GSS_S_DEFECTIVE_TOKEN;
-
-	/* slack must include room for krb5 padding */
-	*slack = XDR_QUADLEN(saved_len - buf->len);
-	/* The GSS blob always precedes the RPC message payload */
-	*align = *slack;
-	return GSS_S_COMPLETE;
-}
-
 /*
  * We can shift data by up to LOCAL_BUF_LEN bytes in a pass.  If we need
  * to do more than that, we shift repeatedly.  Kevin Coffman reports
@@ -442,11 +90,11 @@ static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift)
 	_rotate_left(&subbuf, shift);
 }
 
-static u32
-gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
-		     struct xdr_buf *buf, struct page **pages)
+u32
+gss_krb5_wrap_v2(struct krb5_ctx *kctx, int offset,
+		 struct xdr_buf *buf, struct page **pages)
 {
-	u8		*ptr, *plainhdr;
+	u8		*ptr;
 	time64_t	now;
 	u8		flags = 0x00;
 	__be16		*be16ptr;
@@ -455,15 +103,12 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 
 	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 = buf->head[0].iov_base + offset;
 	*ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff);
 	*ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff);
 
@@ -485,7 +130,7 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	be64ptr = (__be64 *)be16ptr;
 	*be64ptr = cpu_to_be64(atomic64_fetch_inc(&kctx->seq_send64));
 
-	err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, pages);
+	err = (*kctx->gk5e->encrypt)(kctx, offset, buf, pages);
 	if (err)
 		return err;
 
@@ -493,10 +138,10 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
 
-static u32
-gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
-		       struct xdr_buf *buf, unsigned int *slack,
-		       unsigned int *align)
+u32
+gss_krb5_unwrap_v2(struct krb5_ctx *kctx, int offset, int len,
+		   struct xdr_buf *buf, unsigned int *slack,
+		   unsigned int *align)
 {
 	time64_t	now;
 	u8		*ptr;
@@ -510,9 +155,6 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
 
 	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)
@@ -542,8 +184,8 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
 	if (rrc != 0)
 		rotate_left(offset + 16, buf, rrc);
 
-	err = (*kctx->gk5e->decrypt_v2)(kctx, offset, len, buf,
-					&headskip, &tailskip);
+	err = (*kctx->gk5e->decrypt)(kctx, offset, len, buf,
+				     &headskip, &tailskip);
 	if (err)
 		return GSS_S_FAILURE;
 
@@ -584,7 +226,7 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
 							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 = len - GSS_KRB5_TOK_HDR_LEN + headskip;
+	buf->len = len - (GSS_KRB5_TOK_HDR_LEN + headskip);
 
 	/* Trim off the trailing "extra count" and checksum blob */
 	xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip);
@@ -593,43 +235,3 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
 	*slack = *align + XDR_QUADLEN(ec + GSS_KRB5_TOK_HDR_LEN + tailskip);
 	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,
-		    int len, 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, len, buf,
-					      &gctx->slack, &gctx->align);
-	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
-	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-		return gss_unwrap_kerberos_v2(kctx, offset, len, buf,
-					      &gctx->slack, &gctx->align);
-	}
-}