summaryrefslogtreecommitdiff
path: root/arch/s390/crypto
diff options
context:
space:
mode:
authorHarald Freudenberger <freude@linux.vnet.ibm.com>2017-09-18 13:48:09 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-09-29 16:51:25 +0300
commitbf7fa038707c4c7a51a8f3fc1872a7c0d2adf1d3 (patch)
tree20385a170ee0be230e4489fe866be850f91d990f /arch/s390/crypto
parenteecd49c4624a2c35e74f6f4e6352edf7eba545ca (diff)
downloadlinux-bf7fa038707c4c7a51a8f3fc1872a7c0d2adf1d3.tar.xz
s390/crypto: add s390 platform specific aes gcm support.
This patch introduces gcm(aes) support into the aes_s390 kernel module. Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/crypto')
-rw-r--r--arch/s390/crypto/aes_s390.c296
1 files changed, 293 insertions, 3 deletions
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 591cbdf615af..b48e20dd94e9 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -4,9 +4,11 @@
* s390 implementation of the AES Cipher Algorithm.
*
* s390 Version:
- * Copyright IBM Corp. 2005, 2007
+ * Copyright IBM Corp. 2005, 2017
* Author(s): Jan Glauber (jang@de.ibm.com)
* Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
+ * Patrick Steuer <patrick.steuer@de.ibm.com>
+ * Harald Freudenberger <freude@de.ibm.com>
*
* Derived from "crypto/aes_generic.c"
*
@@ -22,20 +24,25 @@
#include <crypto/aes.h>
#include <crypto/algapi.h>
+#include <crypto/ghash.h>
+#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/cpufeature.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/fips.h>
+#include <linux/string.h>
#include <crypto/xts.h>
#include <asm/cpacf.h>
static u8 *ctrblk;
static DEFINE_SPINLOCK(ctrblk_lock);
-static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
+static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
+ kma_functions;
struct s390_aes_ctx {
u8 key[AES_MAX_KEY_SIZE];
@@ -55,6 +62,17 @@ struct s390_xts_ctx {
struct crypto_skcipher *fallback;
};
+struct gcm_sg_walk {
+ struct scatter_walk walk;
+ unsigned int walk_bytes;
+ u8 *walk_ptr;
+ unsigned int walk_bytes_remain;
+ u8 buf[AES_BLOCK_SIZE];
+ unsigned int buf_bytes;
+ u8 *ptr;
+ unsigned int nbytes;
+};
+
static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
@@ -771,6 +789,267 @@ static struct crypto_alg ctr_aes_alg = {
}
};
+static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
+
+ switch (keylen) {
+ case AES_KEYSIZE_128:
+ ctx->fc = CPACF_KMA_GCM_AES_128;
+ break;
+ case AES_KEYSIZE_192:
+ ctx->fc = CPACF_KMA_GCM_AES_192;
+ break;
+ case AES_KEYSIZE_256:
+ ctx->fc = CPACF_KMA_GCM_AES_256;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ memcpy(ctx->key, key, keylen);
+ ctx->key_len = keylen;
+ return 0;
+}
+
+static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+ switch (authsize) {
+ case 4:
+ case 8:
+ case 12:
+ case 13:
+ case 14:
+ case 15:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void gcm_sg_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
+ unsigned int len)
+{
+ memset(gw, 0, sizeof(*gw));
+ gw->walk_bytes_remain = len;
+ scatterwalk_start(&gw->walk, sg);
+}
+
+static int gcm_sg_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
+{
+ int n;
+
+ /* minbytesneeded <= AES_BLOCK_SIZE */
+ if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
+ gw->ptr = gw->buf;
+ gw->nbytes = gw->buf_bytes;
+ goto out;
+ }
+
+ if (gw->walk_bytes_remain == 0) {
+ gw->ptr = NULL;
+ gw->nbytes = 0;
+ goto out;
+ }
+
+ gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
+ if (!gw->walk_bytes) {
+ scatterwalk_start(&gw->walk, sg_next(gw->walk.sg));
+ gw->walk_bytes = scatterwalk_clamp(&gw->walk,
+ gw->walk_bytes_remain);
+ }
+ gw->walk_ptr = scatterwalk_map(&gw->walk);
+
+ if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
+ gw->ptr = gw->walk_ptr;
+ gw->nbytes = gw->walk_bytes;
+ goto out;
+ }
+
+ while (1) {
+ n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
+ memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
+ gw->buf_bytes += n;
+ gw->walk_bytes_remain -= n;
+ scatterwalk_unmap(&gw->walk);
+ scatterwalk_advance(&gw->walk, n);
+ scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
+
+ if (gw->buf_bytes >= minbytesneeded) {
+ gw->ptr = gw->buf;
+ gw->nbytes = gw->buf_bytes;
+ goto out;
+ }
+
+ gw->walk_bytes = scatterwalk_clamp(&gw->walk,
+ gw->walk_bytes_remain);
+ if (!gw->walk_bytes) {
+ scatterwalk_start(&gw->walk, sg_next(gw->walk.sg));
+ gw->walk_bytes = scatterwalk_clamp(&gw->walk,
+ gw->walk_bytes_remain);
+ }
+ gw->walk_ptr = scatterwalk_map(&gw->walk);
+ }
+
+out:
+ return gw->nbytes;
+}
+
+static void gcm_sg_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
+{
+ int n;
+
+ if (gw->ptr == NULL)
+ return;
+
+ if (gw->ptr == gw->buf) {
+ n = gw->buf_bytes - bytesdone;
+ if (n > 0) {
+ memmove(gw->buf, gw->buf + bytesdone, n);
+ gw->buf_bytes -= n;
+ } else
+ gw->buf_bytes = 0;
+ } else {
+ gw->walk_bytes_remain -= bytesdone;
+ scatterwalk_unmap(&gw->walk);
+ scatterwalk_advance(&gw->walk, bytesdone);
+ scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
+ }
+}
+
+static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
+{
+ struct crypto_aead *tfm = crypto_aead_reqtfm(req);
+ struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
+ unsigned int ivsize = crypto_aead_ivsize(tfm);
+ unsigned int taglen = crypto_aead_authsize(tfm);
+ unsigned int aadlen = req->assoclen;
+ unsigned int pclen = req->cryptlen;
+ int ret = 0;
+
+ unsigned int len, in_bytes, out_bytes,
+ min_bytes, bytes, aad_bytes, pc_bytes;
+ struct gcm_sg_walk gw_in, gw_out;
+ u8 tag[GHASH_DIGEST_SIZE];
+
+ struct {
+ u32 _[3]; /* reserved */
+ u32 cv; /* Counter Value */
+ u8 t[GHASH_DIGEST_SIZE];/* Tag */
+ u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */
+ u64 taadl; /* Total AAD Length */
+ u64 tpcl; /* Total Plain-/Cipher-text Length */
+ u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
+ u8 k[AES_MAX_KEY_SIZE]; /* Key */
+ } param;
+
+ /*
+ * encrypt
+ * req->src: aad||plaintext
+ * req->dst: aad||ciphertext||tag
+ * decrypt
+ * req->src: aad||ciphertext||tag
+ * req->dst: aad||plaintext, return 0 or -EBADMSG
+ * aad, plaintext and ciphertext may be empty.
+ */
+ if (flags & CPACF_DECRYPT)
+ pclen -= taglen;
+ len = aadlen + pclen;
+
+ memset(&param, 0, sizeof(param));
+ param.cv = 1;
+ param.taadl = aadlen * 8;
+ param.tpcl = pclen * 8;
+ memcpy(param.j0, req->iv, ivsize);
+ *(u32 *)(param.j0 + ivsize) = 1;
+ memcpy(param.k, ctx->key, ctx->key_len);
+
+ gcm_sg_walk_start(&gw_in, req->src, len);
+ gcm_sg_walk_start(&gw_out, req->dst, len);
+
+ do {
+ min_bytes = min_t(unsigned int,
+ aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
+ in_bytes = gcm_sg_walk_go(&gw_in, min_bytes);
+ out_bytes = gcm_sg_walk_go(&gw_out, min_bytes);
+ bytes = min(in_bytes, out_bytes);
+
+ if (aadlen + pclen <= bytes) {
+ aad_bytes = aadlen;
+ pc_bytes = pclen;
+ flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
+ } else {
+ if (aadlen <= bytes) {
+ aad_bytes = aadlen;
+ pc_bytes = (bytes - aadlen) &
+ ~(AES_BLOCK_SIZE - 1);
+ flags |= CPACF_KMA_LAAD;
+ } else {
+ aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
+ pc_bytes = 0;
+ }
+ }
+
+ if (aad_bytes > 0)
+ memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
+
+ cpacf_kma(ctx->fc | flags, &param,
+ gw_out.ptr + aad_bytes,
+ gw_in.ptr + aad_bytes, pc_bytes,
+ gw_in.ptr, aad_bytes);
+
+ gcm_sg_walk_done(&gw_in, aad_bytes + pc_bytes);
+ gcm_sg_walk_done(&gw_out, aad_bytes + pc_bytes);
+ aadlen -= aad_bytes;
+ pclen -= pc_bytes;
+ } while (aadlen + pclen > 0);
+
+ if (flags & CPACF_DECRYPT) {
+ scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
+ if (crypto_memneq(tag, param.t, taglen))
+ ret = -EBADMSG;
+ } else
+ scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
+
+ memzero_explicit(&param, sizeof(param));
+ return ret;
+}
+
+static int gcm_aes_encrypt(struct aead_request *req)
+{
+ return gcm_aes_crypt(req, CPACF_ENCRYPT);
+}
+
+static int gcm_aes_decrypt(struct aead_request *req)
+{
+ return gcm_aes_crypt(req, CPACF_DECRYPT);
+}
+
+static struct aead_alg gcm_aes_aead = {
+ .setkey = gcm_aes_setkey,
+ .setauthsize = gcm_aes_setauthsize,
+ .encrypt = gcm_aes_encrypt,
+ .decrypt = gcm_aes_decrypt,
+
+ .ivsize = GHASH_BLOCK_SIZE - sizeof(u32),
+ .maxauthsize = GHASH_DIGEST_SIZE,
+ .chunksize = AES_BLOCK_SIZE,
+
+ .base = {
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct s390_aes_ctx),
+ .cra_priority = 900,
+ .cra_name = "gcm(aes)",
+ .cra_driver_name = "gcm-aes-s390",
+ .cra_module = THIS_MODULE,
+ },
+};
+
static struct crypto_alg *aes_s390_algs_ptr[5];
static int aes_s390_algs_num;
@@ -790,16 +1069,19 @@ static void aes_s390_fini(void)
crypto_unregister_alg(aes_s390_algs_ptr[aes_s390_algs_num]);
if (ctrblk)
free_page((unsigned long) ctrblk);
+
+ crypto_unregister_aead(&gcm_aes_aead);
}
static int __init aes_s390_init(void)
{
int ret;
- /* Query available functions for KM, KMC and KMCTR */
+ /* Query available functions for KM, KMC, KMCTR and KMA */
cpacf_query(CPACF_KM, &km_functions);
cpacf_query(CPACF_KMC, &kmc_functions);
cpacf_query(CPACF_KMCTR, &kmctr_functions);
+ cpacf_query(CPACF_KMA, &kma_functions);
if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
@@ -840,6 +1122,14 @@ static int __init aes_s390_init(void)
goto out_err;
}
+ if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
+ cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
+ cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
+ ret = crypto_register_aead(&gcm_aes_aead);
+ if (ret)
+ goto out_err;
+ }
+
return 0;
out_err:
aes_s390_fini();