4 * s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
6 * Copyright IBM Corp. 2011
7 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
10 #include <crypto/internal/hash.h>
11 #include <linux/module.h>
13 #include "crypt_s390.h"
15 #define GHASH_BLOCK_SIZE 16
16 #define GHASH_DIGEST_SIZE 16
23 struct ghash_desc_ctx {
24 u8 buffer[GHASH_BLOCK_SIZE];
28 static int ghash_init(struct shash_desc *desc)
30 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
32 memset(dctx, 0, sizeof(*dctx));
37 static int ghash_setkey(struct crypto_shash *tfm,
38 const u8 *key, unsigned int keylen)
40 struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
42 if (keylen != GHASH_BLOCK_SIZE) {
43 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
47 memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
48 memset(ctx->icv, 0, GHASH_BLOCK_SIZE);
53 static int ghash_update(struct shash_desc *desc,
54 const u8 *src, unsigned int srclen)
56 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
57 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
59 u8 *buf = dctx->buffer;
63 u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
65 n = min(srclen, dctx->bytes);
73 ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf,
75 BUG_ON(ret != GHASH_BLOCK_SIZE);
79 n = srclen & ~(GHASH_BLOCK_SIZE - 1);
81 ret = crypt_s390_kimd(KIMD_GHASH, ctx, src, n);
88 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
89 memcpy(buf, src, srclen);
95 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
97 u8 *buf = dctx->buffer;
101 u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
103 memset(pos, 0, dctx->bytes);
105 ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf, GHASH_BLOCK_SIZE);
106 BUG_ON(ret != GHASH_BLOCK_SIZE);
112 static int ghash_final(struct shash_desc *desc, u8 *dst)
114 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
115 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
117 ghash_flush(ctx, dctx);
118 memcpy(dst, ctx->icv, GHASH_BLOCK_SIZE);
123 static struct shash_alg ghash_alg = {
124 .digestsize = GHASH_DIGEST_SIZE,
126 .update = ghash_update,
127 .final = ghash_final,
128 .setkey = ghash_setkey,
129 .descsize = sizeof(struct ghash_desc_ctx),
132 .cra_driver_name = "ghash-s390",
133 .cra_priority = CRYPT_S390_PRIORITY,
134 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
135 .cra_blocksize = GHASH_BLOCK_SIZE,
136 .cra_ctxsize = sizeof(struct ghash_ctx),
137 .cra_module = THIS_MODULE,
138 .cra_list = LIST_HEAD_INIT(ghash_alg.base.cra_list),
142 static int __init ghash_mod_init(void)
144 if (!crypt_s390_func_available(KIMD_GHASH,
145 CRYPT_S390_MSA | CRYPT_S390_MSA4))
148 return crypto_register_shash(&ghash_alg);
151 static void __exit ghash_mod_exit(void)
153 crypto_unregister_shash(&ghash_alg);
156 module_init(ghash_mod_init);
157 module_exit(ghash_mod_exit);
159 MODULE_ALIAS("ghash");
161 MODULE_LICENSE("GPL");
162 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");