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-rw-r--r--crypto/skcipher.c245
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");