1 files changed, 157 insertions, 1 deletions

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index 092d965..d1df528 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -18,6 +18,8 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 
@@ -68,6 +70,16 @@ static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 	return alg->cra_ctxsize;
 }
 
+int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
+{
+	return crypto_ablkcipher_encrypt(&req->creq);
+}
+
+int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
+{
+	return crypto_ablkcipher_decrypt(&req->creq);
+}
+
 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 				      u32 mask)
 {
@@ -80,6 +92,10 @@ static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 	crt->setkey = setkey;
 	crt->encrypt = alg->encrypt;
 	crt->decrypt = alg->decrypt;
+	if (!alg->ivsize) {
+		crt->givencrypt = skcipher_null_givencrypt;
+		crt->givdecrypt = skcipher_null_givdecrypt;
+	}
 	crt->base = __crypto_ablkcipher_cast(tfm);
 	crt->ivsize = alg->ivsize;
 
@@ -163,6 +179,108 @@ const char *crypto_default_geniv(const struct crypto_alg *alg)
 	return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv";
 }
 
+static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
+{
+	struct rtattr *tb[3];
+	struct {
+		struct rtattr attr;
+		struct crypto_attr_type data;
+	} ptype;
+	struct {
+		struct rtattr attr;
+		struct crypto_attr_alg data;
+	} palg;
+	struct crypto_template *tmpl;
+	struct crypto_instance *inst;
+	struct crypto_alg *larval;
+	const char *geniv;
+	int err;
+
+	larval = crypto_larval_lookup(alg->cra_driver_name,
+				      CRYPTO_ALG_TYPE_GIVCIPHER,
+				      CRYPTO_ALG_TYPE_MASK);
+	err = PTR_ERR(larval);
+	if (IS_ERR(larval))
+		goto out;
+
+	err = -EAGAIN;
+	if (!crypto_is_larval(larval))
+		goto drop_larval;
+
+	ptype.attr.rta_len = sizeof(ptype);
+	ptype.attr.rta_type = CRYPTOA_TYPE;
+	ptype.data.type = type | CRYPTO_ALG_GENIV;
+	/* GENIV tells the template that we're making a default geniv. */
+	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
+	tb[0] = &ptype.attr;
+
+	palg.attr.rta_len = sizeof(palg);
+	palg.attr.rta_type = CRYPTOA_ALG;
+	/* Must use the exact name to locate ourselves. */
+	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
+	tb[1] = &palg.attr;
+
+	tb[2] = NULL;
+
+	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER)
+		geniv = alg->cra_blkcipher.geniv;
+	else
+		geniv = alg->cra_ablkcipher.geniv;
+
+	if (!geniv)
+		geniv = crypto_default_geniv(alg);
+
+	tmpl = crypto_lookup_template(geniv);
+	err = -ENOENT;
+	if (!tmpl)
+		goto kill_larval;
+
+	inst = tmpl->alloc(tb);
+	err = PTR_ERR(inst);
+	if (IS_ERR(inst))
+		goto put_tmpl;
+
+	if ((err = crypto_register_instance(tmpl, inst))) {
+		tmpl->free(inst);
+		goto put_tmpl;
+	}
+
+	/* Redo the lookup to use the instance we just registered. */
+	err = -EAGAIN;
+
+put_tmpl:
+	crypto_tmpl_put(tmpl);
+kill_larval:
+	crypto_larval_kill(larval);
+drop_larval:
+	crypto_mod_put(larval);
+out:
+	crypto_mod_put(alg);
+	return err;
+}
+
+static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
+						 u32 mask)
+{
+	struct crypto_alg *alg;
+
+	alg = crypto_alg_mod_lookup(name, type, mask);
+	if (IS_ERR(alg))
+		return alg;
+
+	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_GIVCIPHER)
+		return alg;
+
+	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	      CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
+					  alg->cra_ablkcipher.ivsize))
+		return alg;
+
+	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
+}
+
 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 			 u32 type, u32 mask)
 {
@@ -172,7 +290,7 @@ int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 	type = crypto_skcipher_type(type);
 	mask = crypto_skcipher_mask(mask);
 
-	alg = crypto_alg_mod_lookup(name, type, mask);
+	alg = crypto_lookup_skcipher(name, type, mask);
 	if (IS_ERR(alg))
 		return PTR_ERR(alg);
 
@@ -182,5 +300,43 @@ int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 }
 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 
+struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
+						  u32 type, u32 mask)
+{
+	struct crypto_tfm *tfm;
+	int err;
+
+	type = crypto_skcipher_type(type);
+	mask = crypto_skcipher_mask(mask);
+
+	for (;;) {
+		struct crypto_alg *alg;
+
+		alg = crypto_lookup_skcipher(alg_name, type, mask);
+		if (IS_ERR(alg)) {
+			err = PTR_ERR(alg);
+			goto err;
+		}
+
+		tfm = __crypto_alloc_tfm(alg, type, mask);
+		if (!IS_ERR(tfm))
+			return __crypto_ablkcipher_cast(tfm);
+
+		crypto_mod_put(alg);
+		err = PTR_ERR(tfm);
+
+err:
+		if (err != -EAGAIN)
+			break;
+		if (signal_pending(current)) {
+			err = -EINTR;
+			break;
+		}
+	}
+
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Asynchronous block chaining cipher type");