gss_krb5: add remaining pieces to enable AES encryption support
Add the remaining pieces to enable support for Kerberos AES
encryption types.
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index ca52ac2..967484a 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -41,6 +41,7 @@
#include <linux/crypto.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
+#include <linux/random.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
@@ -478,3 +479,250 @@
return 0;
}
+
+static u32
+gss_krb5_cts_crypt(struct crypto_blkcipher *cipher, struct xdr_buf *buf,
+ u32 offset, u8 *iv, struct page **pages, int encrypt)
+{
+ u32 ret;
+ struct scatterlist sg[1];
+ struct blkcipher_desc desc = { .tfm = cipher, .info = iv };
+ u8 data[crypto_blkcipher_blocksize(cipher) * 2];
+ struct page **save_pages;
+ u32 len = buf->len - offset;
+
+ BUG_ON(len > crypto_blkcipher_blocksize(cipher) * 2);
+
+ /*
+ * For encryption, we want to read from the cleartext
+ * page cache pages, and write the encrypted data to
+ * the supplied xdr_buf pages.
+ */
+ save_pages = buf->pages;
+ if (encrypt)
+ buf->pages = pages;
+
+ ret = read_bytes_from_xdr_buf(buf, offset, data, len);
+ buf->pages = save_pages;
+ if (ret)
+ goto out;
+
+ sg_init_one(sg, data, len);
+
+ if (encrypt)
+ ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, len);
+ else
+ ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, len);
+
+ if (ret)
+ goto out;
+
+ ret = write_bytes_to_xdr_buf(buf, offset, data, len);
+
+out:
+ return ret;
+}
+
+u32
+gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, int ec, struct page **pages)
+{
+ u32 err;
+ struct xdr_netobj hmac;
+ u8 *cksumkey;
+ u8 *ecptr;
+ struct crypto_blkcipher *cipher, *aux_cipher;
+ int blocksize;
+ struct page **save_pages;
+ int nblocks, nbytes;
+ struct encryptor_desc desc;
+ u32 cbcbytes;
+
+ if (kctx->initiate) {
+ cipher = kctx->initiator_enc;
+ aux_cipher = kctx->initiator_enc_aux;
+ cksumkey = kctx->initiator_integ;
+ } else {
+ cipher = kctx->acceptor_enc;
+ aux_cipher = kctx->acceptor_enc_aux;
+ cksumkey = kctx->acceptor_integ;
+ }
+ blocksize = crypto_blkcipher_blocksize(cipher);
+
+ /* hide the gss token header and insert the confounder */
+ offset += GSS_KRB5_TOK_HDR_LEN;
+ if (xdr_extend_head(buf, offset, blocksize))
+ return GSS_S_FAILURE;
+ gss_krb5_make_confounder(buf->head[0].iov_base + offset, blocksize);
+ offset -= GSS_KRB5_TOK_HDR_LEN;
+
+ if (buf->tail[0].iov_base != NULL) {
+ ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
+ } else {
+ buf->tail[0].iov_base = buf->head[0].iov_base
+ + buf->head[0].iov_len;
+ buf->tail[0].iov_len = 0;
+ ecptr = buf->tail[0].iov_base;
+ }
+
+ memset(ecptr, 'X', ec);
+ buf->tail[0].iov_len += ec;
+ buf->len += ec;
+
+ /* copy plaintext gss token header after filler (if any) */
+ memcpy(ecptr + ec, buf->head[0].iov_base + offset,
+ GSS_KRB5_TOK_HDR_LEN);
+ buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
+ buf->len += GSS_KRB5_TOK_HDR_LEN;
+
+ /* Do the HMAC */
+ hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
+ hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
+
+ /*
+ * When we are called, pages points to the real page cache
+ * data -- which we can't go and encrypt! buf->pages points
+ * to scratch pages which we are going to send off to the
+ * client/server. Swap in the plaintext pages to calculate
+ * the hmac.
+ */
+ save_pages = buf->pages;
+ buf->pages = pages;
+
+ err = make_checksum_v2(kctx, NULL, 0, buf,
+ offset + GSS_KRB5_TOK_HDR_LEN, cksumkey, &hmac);
+ buf->pages = save_pages;
+ if (err)
+ return GSS_S_FAILURE;
+
+ nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
+ nblocks = (nbytes + blocksize - 1) / blocksize;
+ cbcbytes = 0;
+ if (nblocks > 2)
+ cbcbytes = (nblocks - 2) * blocksize;
+
+ memset(desc.iv, 0, sizeof(desc.iv));
+
+ if (cbcbytes) {
+ desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
+ desc.fragno = 0;
+ desc.fraglen = 0;
+ desc.pages = pages;
+ desc.outbuf = buf;
+ desc.desc.info = desc.iv;
+ desc.desc.flags = 0;
+ desc.desc.tfm = aux_cipher;
+
+ sg_init_table(desc.infrags, 4);
+ sg_init_table(desc.outfrags, 4);
+
+ err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
+ cbcbytes, encryptor, &desc);
+ if (err)
+ goto out_err;
+ }
+
+ /* Make sure IV carries forward from any CBC results. */
+ err = gss_krb5_cts_crypt(cipher, buf,
+ offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
+ desc.iv, pages, 1);
+ if (err) {
+ err = GSS_S_FAILURE;
+ goto out_err;
+ }
+
+ /* Now update buf to account for HMAC */
+ buf->tail[0].iov_len += kctx->gk5e->cksumlength;
+ buf->len += kctx->gk5e->cksumlength;
+
+out_err:
+ if (err)
+ err = GSS_S_FAILURE;
+ return err;
+}
+
+u32
+gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
+ u32 *headskip, u32 *tailskip)
+{
+ struct xdr_buf subbuf;
+ u32 ret = 0;
+ u8 *cksum_key;
+ struct crypto_blkcipher *cipher, *aux_cipher;
+ struct xdr_netobj our_hmac_obj;
+ u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+ u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+ int nblocks, blocksize, cbcbytes;
+ struct decryptor_desc desc;
+
+ if (kctx->initiate) {
+ cipher = kctx->acceptor_enc;
+ aux_cipher = kctx->acceptor_enc_aux;
+ cksum_key = kctx->acceptor_integ;
+ } else {
+ cipher = kctx->initiator_enc;
+ aux_cipher = kctx->initiator_enc_aux;
+ cksum_key = kctx->initiator_integ;
+ }
+ blocksize = crypto_blkcipher_blocksize(cipher);
+
+
+ /* create a segment skipping the header and leaving out the checksum */
+ xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
+ (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
+ kctx->gk5e->cksumlength));
+
+ nblocks = (subbuf.len + blocksize - 1) / blocksize;
+
+ cbcbytes = 0;
+ if (nblocks > 2)
+ cbcbytes = (nblocks - 2) * blocksize;
+
+ memset(desc.iv, 0, sizeof(desc.iv));
+
+ if (cbcbytes) {
+ desc.fragno = 0;
+ desc.fraglen = 0;
+ desc.desc.info = desc.iv;
+ desc.desc.flags = 0;
+ desc.desc.tfm = aux_cipher;
+
+ sg_init_table(desc.frags, 4);
+
+ ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
+ if (ret)
+ goto out_err;
+ }
+
+ /* Make sure IV carries forward from any CBC results. */
+ ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
+ if (ret)
+ goto out_err;
+
+
+ /* Calculate our hmac over the plaintext data */
+ our_hmac_obj.len = sizeof(our_hmac);
+ our_hmac_obj.data = our_hmac;
+
+ ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
+ cksum_key, &our_hmac_obj);
+ if (ret)
+ goto out_err;
+
+ /* Get the packet's hmac value */
+ ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
+ pkt_hmac, kctx->gk5e->cksumlength);
+ if (ret)
+ goto out_err;
+
+ if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
+ ret = GSS_S_BAD_SIG;
+ goto out_err;
+ }
+ *headskip = crypto_blkcipher_blocksize(cipher);
+ *tailskip = kctx->gk5e->cksumlength;
+out_err:
+ if (ret && ret != GSS_S_BAD_SIG)
+ ret = GSS_S_FAILURE;
+ return ret;
+}