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 if (ret != GHASH_BLOCK_SIZE)
80 n = srclen & ~(GHASH_BLOCK_SIZE - 1);
82 ret = crypt_s390_kimd(KIMD_GHASH, ctx, src, n);
90 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
91 memcpy(buf, src, srclen);
97 static int ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
99 u8 *buf = dctx->buffer;
103 u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
105 memset(pos, 0, dctx->bytes);
107 ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf, GHASH_BLOCK_SIZE);
108 if (ret != GHASH_BLOCK_SIZE)
116 static int ghash_final(struct shash_desc *desc, u8 *dst)
118 struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
119 struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
122 ret = ghash_flush(ctx, dctx);
124 memcpy(dst, ctx->icv, GHASH_BLOCK_SIZE);
128 static struct shash_alg ghash_alg = {
129 .digestsize = GHASH_DIGEST_SIZE,
131 .update = ghash_update,
132 .final = ghash_final,
133 .setkey = ghash_setkey,
134 .descsize = sizeof(struct ghash_desc_ctx),
137 .cra_driver_name = "ghash-s390",
138 .cra_priority = CRYPT_S390_PRIORITY,
139 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
140 .cra_blocksize = GHASH_BLOCK_SIZE,
141 .cra_ctxsize = sizeof(struct ghash_ctx),
142 .cra_module = THIS_MODULE,
146 static int __init ghash_mod_init(void)
148 if (!crypt_s390_func_available(KIMD_GHASH,
149 CRYPT_S390_MSA | CRYPT_S390_MSA4))
152 return crypto_register_shash(&ghash_alg);
155 static void __exit ghash_mod_exit(void)
157 crypto_unregister_shash(&ghash_alg);
160 module_init(ghash_mod_init);
161 module_exit(ghash_mod_exit);
163 MODULE_ALIAS("ghash");
165 MODULE_LICENSE("GPL");
166 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, s390 implementation");