[CRYPTO] api: Add async blkcipher type

This patch adds the mid-level interface for asynchronous block ciphers.
It also includes a generic queueing mechanism that can be used by other
asynchronous crypto operations in future.

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

crypto/ablkcipher.c

@@ -0,0 +1,83 @@
+/*
+ * Asynchronous block chaining cipher operations.
+ * 
+ * This is the asynchronous version of blkcipher.c indicating completion
+ * via a callback.
+ *
+ * Copyright (c) 2006 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/algapi.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+
+static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+		  unsigned int keylen)
+{
+	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
+
+	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
+		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	return cipher->setkey(tfm, key, keylen);
+}
+
+static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
+					      u32 mask)
+{
+	return alg->cra_ctxsize;
+}
+
+static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
+				      u32 mask)
+{
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
+
+	if (alg->ivsize > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	crt->setkey = setkey;
+	crt->encrypt = alg->encrypt;
+	crt->decrypt = alg->decrypt;
+	crt->ivsize = alg->ivsize;
+
+	return 0;
+}
+
+static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
+
+	seq_printf(m, "type         : ablkcipher\n");
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
+	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
+	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
+	seq_printf(m, "qlen         : %u\n", ablkcipher->queue->qlen);
+	seq_printf(m, "max qlen     : %u\n", ablkcipher->queue->max_qlen);
+}
+
+const struct crypto_type crypto_ablkcipher_type = {
+	.ctxsize = crypto_ablkcipher_ctxsize,
+	.init = crypto_init_ablkcipher_ops,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_ablkcipher_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Asynchronous block chaining cipher type");