1 files changed, 245 insertions, 0 deletions
diff --git a/crypto/skcipher.c b/crypto/skcipher.c
new file mode 100644
index 000000000000..dd5fc1bf6447
--- /dev/null
+++ b/crypto/skcipher.c
@@ -0,0 +1,245 @@
+/*
+ * Symmetric key cipher operations.
+ *
+ * Generic encrypt/decrypt wrapper for ciphers, handles operations across
+ * multiple page boundaries by using temporary blocks.  In user context,
+ * the kernel is given a chance to schedule us once per page.
+ *
+ * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <crypto/internal/skcipher.h>
+#include <linux/bug.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
+{
+	if (alg->cra_type == &crypto_blkcipher_type)
+		return sizeof(struct crypto_blkcipher *);
+
+	BUG_ON(alg->cra_type != &crypto_ablkcipher_type &&
+	       alg->cra_type != &crypto_givcipher_type);
+
+	return sizeof(struct crypto_ablkcipher *);
+}
+
+static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
+				     const u8 *key, unsigned int keylen)
+{
+	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_blkcipher *blkcipher = *ctx;
+	int err;
+
+	crypto_blkcipher_clear_flags(blkcipher, ~0);
+	crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
+					      CRYPTO_TFM_REQ_MASK);
+	err = crypto_blkcipher_setkey(blkcipher, key, keylen);
+	crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
+				       CRYPTO_TFM_RES_MASK);
+
+	return err;
+}
+
+static int skcipher_crypt_blkcipher(struct skcipher_request *req,
+				    int (*crypt)(struct blkcipher_desc *,
+						 struct scatterlist *,
+						 struct scatterlist *,
+						 unsigned int))
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct blkcipher_desc desc = {
+		.tfm = *ctx,
+		.info = req->iv,
+		.flags = req->base.flags,
+	};
+
+
+	return crypt(&desc, req->dst, req->src, req->cryptlen);
+}
+
+static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	return skcipher_crypt_blkcipher(req, alg->encrypt);
+}
+
+static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	return skcipher_crypt_blkcipher(req, alg->decrypt);
+}
+
+static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_blkcipher(*ctx);
+}
+
+int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_blkcipher *blkcipher;
+	struct crypto_tfm *btfm;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
+					CRYPTO_ALG_TYPE_MASK);
+	if (IS_ERR(btfm)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(btfm);
+	}
+
+	blkcipher = __crypto_blkcipher_cast(btfm);
+	*ctx = blkcipher;
+	tfm->exit = crypto_exit_skcipher_ops_blkcipher;
+
+	skcipher->setkey = skcipher_setkey_blkcipher;
+	skcipher->encrypt = skcipher_encrypt_blkcipher;
+	skcipher->decrypt = skcipher_decrypt_blkcipher;
+
+	skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
+
+	return 0;
+}
+
+static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
+				      const u8 *key, unsigned int keylen)
+{
+	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_ablkcipher *ablkcipher = *ctx;
+	int err;
+
+	crypto_ablkcipher_clear_flags(ablkcipher, ~0);
+	crypto_ablkcipher_set_flags(ablkcipher,
+				    crypto_skcipher_get_flags(tfm) &
+				    CRYPTO_TFM_REQ_MASK);
+	err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
+	crypto_skcipher_set_flags(tfm,
+				  crypto_ablkcipher_get_flags(ablkcipher) &
+				  CRYPTO_TFM_RES_MASK);
+
+	return err;
+}
+
+static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
+				     int (*crypt)(struct ablkcipher_request *))
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct ablkcipher_request *subreq = skcipher_request_ctx(req);
+
+	ablkcipher_request_set_tfm(subreq, *ctx);
+	ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
+					req->base.complete, req->base.data);
+	ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
+				     req->iv);
+
+	return crypt(subreq);
+}
+
+static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+
+	return skcipher_crypt_ablkcipher(req, alg->encrypt);
+}
+
+static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+
+	return skcipher_crypt_ablkcipher(req, alg->decrypt);
+}
+
+static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_ablkcipher(*ctx);
+}
+
+int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_ablkcipher *ablkcipher;
+	struct crypto_tfm *abtfm;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	abtfm = __crypto_alloc_tfm(calg, 0, 0);
+	if (IS_ERR(abtfm)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(abtfm);
+	}
+
+	ablkcipher = __crypto_ablkcipher_cast(abtfm);
+	*ctx = ablkcipher;
+	tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
+
+	skcipher->setkey = skcipher_setkey_ablkcipher;
+	skcipher->encrypt = skcipher_encrypt_ablkcipher;
+	skcipher->decrypt = skcipher_decrypt_ablkcipher;
+
+	skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
+	skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
+			    sizeof(struct ablkcipher_request);
+
+	return 0;
+}
+
+static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
+{
+	if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
+		return crypto_init_skcipher_ops_blkcipher(tfm);
+
+	BUG_ON(tfm->__crt_alg->cra_type != &crypto_ablkcipher_type &&
+	       tfm->__crt_alg->cra_type != &crypto_givcipher_type);
+
+	return crypto_init_skcipher_ops_ablkcipher(tfm);
+}
+
+static const struct crypto_type crypto_skcipher_type2 = {
+	.extsize = crypto_skcipher_extsize,
+	.init_tfm = crypto_skcipher_init_tfm,
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
+	.type = CRYPTO_ALG_TYPE_BLKCIPHER,
+	.tfmsize = offsetof(struct crypto_skcipher, base),
+};
+
+struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
+					      u32 type, u32 mask)
+{
+	return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Symmetric key cipher type");