crypto: algif_aead - Switch to new AEAD interface

This patch makes use of the new AEAD interface which uses a single
SG list instead of separate lists for the AD and plain text.

Note that the user-space interface now requires both input and
output to be of the same length, and both must include space for
the AD as well as the authentication tag.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 8 insertions, 58 deletions

diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index a55e4e6fa3d8..38a6cab7aeca 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -72,7 +72,7 @@ static inline bool aead_sufficient_data(struct aead_ctx *ctx)
 {
         unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
 
-        return (ctx->used >= (ctx->aead_assoclen + (ctx->enc ? 0 : as)));
+        return ctx->used >= ctx->aead_assoclen + as;
 }
 
 static void aead_put_sgl(struct sock *sk)
@@ -353,12 +353,8 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
         struct sock *sk = sock->sk;
         struct alg_sock *ask = alg_sk(sk);
         struct aead_ctx *ctx = ask->private;
-        unsigned bs = crypto_aead_blocksize(crypto_aead_reqtfm(&ctx->aead_req));
         unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
         struct aead_sg_list *sgl = &ctx->tsgl;
-        struct scatterlist *sg = NULL;
-        struct scatterlist assoc[ALG_MAX_PAGES];
-        size_t assoclen = 0;
         unsigned int i = 0;
         int err = -EINVAL;
         unsigned long used = 0;
@@ -407,23 +403,13 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
         if (!aead_sufficient_data(ctx))
                 goto unlock;
 
+        outlen = used;
+
         /*
          * The cipher operation input data is reduced by the associated data
          * length as this data is processed separately later on.
          */
-        used -= ctx->aead_assoclen;
-
-        if (ctx->enc) {
-                /* round up output buffer to multiple of block size */
-                outlen = ((used + bs - 1) / bs * bs);
-                /* add the size needed for the auth tag to be created */
-                outlen += as;
-        } else {
-                /* output data size is input without the authentication tag */
-                outlen = used - as;
-                /* round up output buffer to multiple of block size */
-                outlen = ((outlen + bs - 1) / bs * bs);
-        }
+        used -= ctx->aead_assoclen + (ctx->enc ? as : 0);
 
         /* convert iovecs of output buffers into scatterlists */
         while (iov_iter_count(&msg->msg_iter)) {
@@ -452,47 +438,11 @@ static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
         if (usedpages < outlen)
                 goto unlock;
 
-        sg_init_table(assoc, ALG_MAX_PAGES);
-        assoclen = ctx->aead_assoclen;
-        /*
-         * Split scatterlist into two: first part becomes AD, second part
-         * is plaintext / ciphertext. The first part is assigned to assoc
-         * scatterlist. When this loop finishes, sg points to the start of the
-         * plaintext / ciphertext.
-         */
-        for (i = 0; i < ctx->tsgl.cur; i++) {
-                sg = sgl->sg + i;
-                if (sg->length <= assoclen) {
-                        /* AD is larger than one page */
-                        sg_set_page(assoc + i, sg_page(sg),
-                                    sg->length, sg->offset);
-                        assoclen -= sg->length;
-                        if (i >= ctx->tsgl.cur)
-                                goto unlock;
-                } else if (!assoclen) {
-                        /* current page is to start of plaintext / ciphertext */
-                        if (i)
-                                /* AD terminates at page boundary */
-                                sg_mark_end(assoc + i - 1);
-                        else
-                                /* AD size is zero */
-                                sg_mark_end(assoc);
-                        break;
-                } else {
-                        /* AD does not terminate at page boundary */
-                        sg_set_page(assoc + i, sg_page(sg),
-                                    assoclen, sg->offset);
-                        sg_mark_end(assoc + i);
-                        /* plaintext / ciphertext starts after AD */
-                        sg->length -= assoclen;
-                        sg->offset += assoclen;
-                        break;
-                }
-        }
+        sg_mark_end(sgl->sg + sgl->cur - 1);
 
-        aead_request_set_assoc(&ctx->aead_req, assoc, ctx->aead_assoclen);
-        aead_request_set_crypt(&ctx->aead_req, sg, ctx->rsgl[0].sg, used,
-                               ctx->iv);
+        aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->rsgl[0].sg,
+                               used, ctx->iv);
+        aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
 
         err = af_alg_wait_for_completion(ctx->enc ?
                                          crypto_aead_encrypt(&ctx->aead_req) :