[CRYPTO] authenc: Add givencrypt operation

This patch implements the givencrypt function for authenc.  It simply
calls the givencrypt operation on the underlying cipher instead of encrypt.

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

1 files changed, 114 insertions, 22 deletions

diff --git a/crypto/authenc.c b/crypto/authenc.c
index 2d609b72f5be..ed8ac5a6fa5f 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -10,6 +10,7 @@
  *
  */
 
+#include <crypto/aead.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/authenc.h>
 #include <crypto/scatterwalk.h>
@@ -87,6 +88,20 @@ badkey:
         goto out;
 }
 
+static void authenc_chain(struct scatterlist *head, struct scatterlist *sg,
+                          int chain)
+{
+        if (chain) {
+                head->length += sg->length;
+                sg = scatterwalk_sg_next(sg);
+        }
+
+        if (sg)
+                scatterwalk_sg_chain(head, 2, sg);
+        else
+                sg_mark_end(head);
+}
+
 static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
                                struct scatterlist *cipher,
                                unsigned int cryptlen)
@@ -127,18 +142,31 @@ auth_unlock:
         return hash;
 }
 
-static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
+static int crypto_authenc_genicv(struct aead_request *req, u8 *iv,
+                                 unsigned int flags)
 {
         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
         struct scatterlist *dst = req->dst;
-        unsigned int cryptlen = req->cryptlen;
+        struct scatterlist cipher[2];
+        struct page *dstp;
+        unsigned int ivsize = crypto_aead_ivsize(authenc);
+        unsigned int cryptlen;
+        u8 *vdst;
         u8 *hash;
 
-        hash = crypto_authenc_hash(req, flags, dst, cryptlen);
+        dstp = sg_page(dst);
+        vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + dst->offset;
+
+        sg_init_table(cipher, 2);
+        sg_set_buf(cipher, iv, ivsize);
+        authenc_chain(cipher, dst, vdst == iv + ivsize);
+
+        cryptlen = req->cryptlen + ivsize;
+        hash = crypto_authenc_hash(req, flags, cipher, cryptlen);
         if (IS_ERR(hash))
                 return PTR_ERR(hash);
 
-        scatterwalk_map_and_copy(hash, dst, cryptlen,
+        scatterwalk_map_and_copy(hash, cipher, cryptlen,
                                  crypto_aead_authsize(authenc), 1);
         return 0;
 }
@@ -146,8 +174,16 @@ static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
 static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
                                         int err)
 {
-        if (!err)
-                err = crypto_authenc_genicv(req->data, 0);
+        if (!err) {
+                struct aead_request *areq = req->data;
+                struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
+                struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+                struct ablkcipher_request *abreq = aead_request_ctx(areq);
+                u8 *iv = (u8 *)(abreq + 1) +
+                         crypto_ablkcipher_reqsize(ctx->enc);
+
+                err = crypto_authenc_genicv(areq, iv, 0);
+        }
 
         aead_request_complete(req->data, err);
 }
@@ -157,45 +193,99 @@ static int crypto_authenc_encrypt(struct aead_request *req)
         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
         struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
         struct ablkcipher_request *abreq = aead_request_ctx(req);
+        struct crypto_ablkcipher *enc = ctx->enc;
+        struct scatterlist *dst = req->dst;
+        unsigned int cryptlen = req->cryptlen;
+        u8 *iv = (u8 *)(abreq + 1) + crypto_ablkcipher_reqsize(enc);
         int err;
 
-        ablkcipher_request_set_tfm(abreq, ctx->enc);
+        ablkcipher_request_set_tfm(abreq, enc);
         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
                                         crypto_authenc_encrypt_done, req);
-        ablkcipher_request_set_crypt(abreq, req->src, req->dst, req->cryptlen,
-                                     req->iv);
+        ablkcipher_request_set_crypt(abreq, req->src, dst, cryptlen, req->iv);
+
+        memcpy(iv, req->iv, crypto_aead_ivsize(authenc));
 
         err = crypto_ablkcipher_encrypt(abreq);
         if (err)
                 return err;
 
-        return crypto_authenc_genicv(req, CRYPTO_TFM_REQ_MAY_SLEEP);
+        return crypto_authenc_genicv(req, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
+}
+
+static void crypto_authenc_givencrypt_done(struct crypto_async_request *req,
+                                           int err)
+{
+        if (!err) {
+                struct aead_givcrypt_request *greq = req->data;
+
+                err = crypto_authenc_genicv(&greq->areq, greq->giv, 0);
+        }
+
+        aead_request_complete(req->data, err);
+}
+
+static int crypto_authenc_givencrypt(struct aead_givcrypt_request *req)
+{
+        struct crypto_aead *authenc = aead_givcrypt_reqtfm(req);
+        struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
+        struct aead_request *areq = &req->areq;
+        struct skcipher_givcrypt_request *greq = aead_request_ctx(areq);
+        u8 *iv = req->giv;
+        int err;
+
+        skcipher_givcrypt_set_tfm(greq, ctx->enc);
+        skcipher_givcrypt_set_callback(greq, aead_request_flags(areq),
+                                       crypto_authenc_givencrypt_done, areq);
+        skcipher_givcrypt_set_crypt(greq, areq->src, areq->dst, areq->cryptlen,
+                                    areq->iv);
+        skcipher_givcrypt_set_giv(greq, iv, req->seq);
+
+        err = crypto_skcipher_givencrypt(greq);
+        if (err)
+                return err;
+
+        return crypto_authenc_genicv(areq, iv, CRYPTO_TFM_REQ_MAY_SLEEP);
 }
 
 static int crypto_authenc_verify(struct aead_request *req,
+                                 struct scatterlist *cipher,
                                  unsigned int cryptlen)
 {
         struct crypto_aead *authenc = crypto_aead_reqtfm(req);
         u8 *ohash;
         u8 *ihash;
-        struct scatterlist *src = req->src;
         unsigned int authsize;
 
-        ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, src,
+        ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, cipher,
                                     cryptlen);
         if (IS_ERR(ohash))
                 return PTR_ERR(ohash);
 
         authsize = crypto_aead_authsize(authenc);
         ihash = ohash + authsize;
-        scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0);
+        scatterwalk_map_and_copy(ihash, cipher, cryptlen, authsize, 0);
         return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
 }
 
-static void crypto_authenc_decrypt_done(struct crypto_async_request *req,
-                                        int err)
+static int crypto_authenc_iverify(struct aead_request *req, u8 *iv,
+                                  unsigned int cryptlen)
 {
-        aead_request_complete(req->data, err);
+        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+        struct scatterlist *src = req->src;
+        struct scatterlist cipher[2];
+        struct page *srcp;
+        unsigned int ivsize = crypto_aead_ivsize(authenc);
+        u8 *vsrc;
+
+        srcp = sg_page(src);
+        vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + src->offset;
+
+        sg_init_table(cipher, 2);
+        sg_set_buf(cipher, iv, ivsize);
+        authenc_chain(cipher, src, vsrc == iv + ivsize);
+
+        return crypto_authenc_verify(req, cipher, cryptlen + ivsize);
 }
 
 static int crypto_authenc_decrypt(struct aead_request *req)
@@ -205,21 +295,21 @@ static int crypto_authenc_decrypt(struct aead_request *req)
         struct ablkcipher_request *abreq = aead_request_ctx(req);
         unsigned int cryptlen = req->cryptlen;
         unsigned int authsize = crypto_aead_authsize(authenc);
+        u8 *iv = req->iv;
         int err;
 
         if (cryptlen < authsize)
                 return -EINVAL;
         cryptlen -= authsize;
 
-        err = crypto_authenc_verify(req, cryptlen);
+        err = crypto_authenc_iverify(req, iv, cryptlen);
         if (err)
                 return err;
 
         ablkcipher_request_set_tfm(abreq, ctx->enc);
         ablkcipher_request_set_callback(abreq, aead_request_flags(req),
-                                        crypto_authenc_decrypt_done, req);
-        ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen,
-                                     req->iv);
+                                        req->base.complete, req->base.data);
+        ablkcipher_request_set_crypt(abreq, req->src, req->dst, cryptlen, iv);
 
         return crypto_ablkcipher_decrypt(abreq);
 }
@@ -248,8 +338,9 @@ static int crypto_authenc_init_tfm(struct crypto_tfm *tfm)
                                       (crypto_hash_alignmask(auth) &
                                        ~(crypto_tfm_ctx_alignment() - 1)) +
                                       crypto_hash_digestsize(auth) * 2,
-                                      sizeof(struct ablkcipher_request) +
-                                      crypto_ablkcipher_reqsize(enc));
+                                      sizeof(struct skcipher_givcrypt_request) +
+                                      crypto_ablkcipher_reqsize(enc) +
+                                      crypto_ablkcipher_ivsize(enc));
 
         spin_lock_init(&ctx->auth_lock);
 
@@ -347,6 +438,7 @@ static struct crypto_instance *crypto_authenc_alloc(struct rtattr **tb)
         inst->alg.cra_aead.setkey = crypto_authenc_setkey;
         inst->alg.cra_aead.encrypt = crypto_authenc_encrypt;
         inst->alg.cra_aead.decrypt = crypto_authenc_decrypt;
+        inst->alg.cra_aead.givencrypt = crypto_authenc_givencrypt;
 
 out:
         crypto_mod_put(auth);