- if (body->tail[0].iov_len) {
- buf_to_sg(sg, body->tail[0].iov_base, body->tail[0].iov_len);
- crypto_digest_update(tfm, sg, 1);
+ return 0;
+}
+
+int
+gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf,
+ int offset, struct page **pages)
+{
+ int ret;
+ struct encryptor_desc desc;
+
+ BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
+
+ memset(desc.iv, 0, sizeof(desc.iv));
+ desc.desc.tfm = tfm;
+ desc.desc.info = desc.iv;
+ desc.desc.flags = 0;
+ desc.pos = offset;
+ desc.outbuf = buf;
+ desc.pages = pages;
+ desc.fragno = 0;
+ desc.fraglen = 0;
+
+ ret = xdr_process_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 blkcipher_desc desc;
+ 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_blkcipher_decrypt_iv(&desc->desc, desc->frags,
+ desc->frags, thislen);
+ 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;