diff options
Diffstat (limited to 'arch/s390/crypto/aes_s390.c')
| -rw-r--r-- | arch/s390/crypto/aes_s390.c | 1057 |
1 files changed, 1057 insertions, 0 deletions
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c new file mode 100644 index 000000000..c6fe5405d --- /dev/null +++ b/arch/s390/crypto/aes_s390.c @@ -0,0 +1,1057 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Cryptographic API. + * + * s390 implementation of the AES Cipher Algorithm. + * + * s390 Version: + * 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" + */ + +#define KMSG_COMPONENT "aes_s390" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <crypto/aes.h> +#include <crypto/algapi.h> +#include <crypto/ghash.h> +#include <crypto/internal/aead.h> +#include <crypto/internal/cipher.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/mutex.h> +#include <linux/fips.h> +#include <linux/string.h> +#include <crypto/xts.h> +#include <asm/cpacf.h> + +static u8 *ctrblk; +static DEFINE_MUTEX(ctrblk_lock); + +static cpacf_mask_t km_functions, kmc_functions, kmctr_functions, + kma_functions; + +struct s390_aes_ctx { + u8 key[AES_MAX_KEY_SIZE]; + int key_len; + unsigned long fc; + union { + struct crypto_skcipher *skcipher; + struct crypto_cipher *cip; + } fallback; +}; + +struct s390_xts_ctx { + u8 key[32]; + u8 pcc_key[32]; + int key_len; + unsigned long fc; + 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) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; + sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags & + CRYPTO_TFM_REQ_MASK); + + return crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len); +} + +static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + unsigned long fc; + + /* Pick the correct function code based on the key length */ + fc = (key_len == 16) ? CPACF_KM_AES_128 : + (key_len == 24) ? CPACF_KM_AES_192 : + (key_len == 32) ? CPACF_KM_AES_256 : 0; + + /* Check if the function code is available */ + sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; + if (!sctx->fc) + return setkey_fallback_cip(tfm, in_key, key_len); + + sctx->key_len = key_len; + memcpy(sctx->key, in_key, key_len); + return 0; +} + +static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + if (unlikely(!sctx->fc)) { + crypto_cipher_encrypt_one(sctx->fallback.cip, out, in); + return; + } + cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE); +} + +static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + if (unlikely(!sctx->fc)) { + crypto_cipher_decrypt_one(sctx->fallback.cip, out, in); + return; + } + cpacf_km(sctx->fc | CPACF_DECRYPT, + &sctx->key, out, in, AES_BLOCK_SIZE); +} + +static int fallback_init_cip(struct crypto_tfm *tfm) +{ + const char *name = tfm->__crt_alg->cra_name; + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + sctx->fallback.cip = crypto_alloc_cipher(name, 0, + CRYPTO_ALG_NEED_FALLBACK); + + if (IS_ERR(sctx->fallback.cip)) { + pr_err("Allocating AES fallback algorithm %s failed\n", + name); + return PTR_ERR(sctx->fallback.cip); + } + + return 0; +} + +static void fallback_exit_cip(struct crypto_tfm *tfm) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + crypto_free_cipher(sctx->fallback.cip); + sctx->fallback.cip = NULL; +} + +static struct crypto_alg aes_alg = { + .cra_name = "aes", + .cra_driver_name = "aes-s390", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER | + CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct s390_aes_ctx), + .cra_module = THIS_MODULE, + .cra_init = fallback_init_cip, + .cra_exit = fallback_exit_cip, + .cra_u = { + .cipher = { + .cia_min_keysize = AES_MIN_KEY_SIZE, + .cia_max_keysize = AES_MAX_KEY_SIZE, + .cia_setkey = aes_set_key, + .cia_encrypt = crypto_aes_encrypt, + .cia_decrypt = crypto_aes_decrypt, + } + } +}; + +static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key, + unsigned int len) +{ + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + + crypto_skcipher_clear_flags(sctx->fallback.skcipher, + CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(sctx->fallback.skcipher, + crypto_skcipher_get_flags(tfm) & + CRYPTO_TFM_REQ_MASK); + return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len); +} + +static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx, + struct skcipher_request *req, + unsigned long modifier) +{ + struct skcipher_request *subreq = skcipher_request_ctx(req); + + *subreq = *req; + skcipher_request_set_tfm(subreq, sctx->fallback.skcipher); + return (modifier & CPACF_DECRYPT) ? + crypto_skcipher_decrypt(subreq) : + crypto_skcipher_encrypt(subreq); +} + +static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + unsigned long fc; + + /* Pick the correct function code based on the key length */ + fc = (key_len == 16) ? CPACF_KM_AES_128 : + (key_len == 24) ? CPACF_KM_AES_192 : + (key_len == 32) ? CPACF_KM_AES_256 : 0; + + /* Check if the function code is available */ + sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; + if (!sctx->fc) + return setkey_fallback_skcipher(tfm, in_key, key_len); + + sctx->key_len = key_len; + memcpy(sctx->key, in_key, key_len); + return 0; +} + +static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int nbytes, n; + int ret; + + if (unlikely(!sctx->fc)) + return fallback_skcipher_crypt(sctx, req, modifier); + + ret = skcipher_walk_virt(&walk, req, false); + while ((nbytes = walk.nbytes) != 0) { + /* only use complete blocks */ + n = nbytes & ~(AES_BLOCK_SIZE - 1); + cpacf_km(sctx->fc | modifier, sctx->key, + walk.dst.virt.addr, walk.src.virt.addr, n); + ret = skcipher_walk_done(&walk, nbytes - n); + } + return ret; +} + +static int ecb_aes_encrypt(struct skcipher_request *req) +{ + return ecb_aes_crypt(req, 0); +} + +static int ecb_aes_decrypt(struct skcipher_request *req) +{ + return ecb_aes_crypt(req, CPACF_DECRYPT); +} + +static int fallback_init_skcipher(struct crypto_skcipher *tfm) +{ + const char *name = crypto_tfm_alg_name(&tfm->base); + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + + sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0, + CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); + + if (IS_ERR(sctx->fallback.skcipher)) { + pr_err("Allocating AES fallback algorithm %s failed\n", + name); + return PTR_ERR(sctx->fallback.skcipher); + } + + crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + + crypto_skcipher_reqsize(sctx->fallback.skcipher)); + return 0; +} + +static void fallback_exit_skcipher(struct crypto_skcipher *tfm) +{ + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + + crypto_free_skcipher(sctx->fallback.skcipher); +} + +static struct skcipher_alg ecb_aes_alg = { + .base.cra_name = "ecb(aes)", + .base.cra_driver_name = "ecb-aes-s390", + .base.cra_priority = 401, /* combo: aes + ecb + 1 */ + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = AES_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct s390_aes_ctx), + .base.cra_module = THIS_MODULE, + .init = fallback_init_skcipher, + .exit = fallback_exit_skcipher, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .setkey = ecb_aes_set_key, + .encrypt = ecb_aes_encrypt, + .decrypt = ecb_aes_decrypt, +}; + +static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + unsigned long fc; + + /* Pick the correct function code based on the key length */ + fc = (key_len == 16) ? CPACF_KMC_AES_128 : + (key_len == 24) ? CPACF_KMC_AES_192 : + (key_len == 32) ? CPACF_KMC_AES_256 : 0; + + /* Check if the function code is available */ + sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0; + if (!sctx->fc) + return setkey_fallback_skcipher(tfm, in_key, key_len); + + sctx->key_len = key_len; + memcpy(sctx->key, in_key, key_len); + return 0; +} + +static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int nbytes, n; + int ret; + struct { + u8 iv[AES_BLOCK_SIZE]; + u8 key[AES_MAX_KEY_SIZE]; + } param; + + if (unlikely(!sctx->fc)) + return fallback_skcipher_crypt(sctx, req, modifier); + + ret = skcipher_walk_virt(&walk, req, false); + if (ret) + return ret; + memcpy(param.iv, walk.iv, AES_BLOCK_SIZE); + memcpy(param.key, sctx->key, sctx->key_len); + while ((nbytes = walk.nbytes) != 0) { + /* only use complete blocks */ + n = nbytes & ~(AES_BLOCK_SIZE - 1); + cpacf_kmc(sctx->fc | modifier, ¶m, + walk.dst.virt.addr, walk.src.virt.addr, n); + memcpy(walk.iv, param.iv, AES_BLOCK_SIZE); + ret = skcipher_walk_done(&walk, nbytes - n); + } + memzero_explicit(¶m, sizeof(param)); + return ret; +} + +static int cbc_aes_encrypt(struct skcipher_request *req) +{ + return cbc_aes_crypt(req, 0); +} + +static int cbc_aes_decrypt(struct skcipher_request *req) +{ + return cbc_aes_crypt(req, CPACF_DECRYPT); +} + +static struct skcipher_alg cbc_aes_alg = { + .base.cra_name = "cbc(aes)", + .base.cra_driver_name = "cbc-aes-s390", + .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = AES_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct s390_aes_ctx), + .base.cra_module = THIS_MODULE, + .init = fallback_init_skcipher, + .exit = fallback_exit_skcipher, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = cbc_aes_set_key, + .encrypt = cbc_aes_encrypt, + .decrypt = cbc_aes_decrypt, +}; + +static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int len) +{ + struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); + + crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(xts_ctx->fallback, + crypto_skcipher_get_flags(tfm) & + CRYPTO_TFM_REQ_MASK); + return crypto_skcipher_setkey(xts_ctx->fallback, key, len); +} + +static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); + unsigned long fc; + int err; + + err = xts_fallback_setkey(tfm, in_key, key_len); + if (err) + return err; + + /* Pick the correct function code based on the key length */ + fc = (key_len == 32) ? CPACF_KM_XTS_128 : + (key_len == 64) ? CPACF_KM_XTS_256 : 0; + + /* Check if the function code is available */ + xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; + if (!xts_ctx->fc) + return 0; + + /* Split the XTS key into the two subkeys */ + key_len = key_len / 2; + xts_ctx->key_len = key_len; + memcpy(xts_ctx->key, in_key, key_len); + memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); + return 0; +} + +static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + unsigned int offset, nbytes, n; + int ret; + struct { + u8 key[32]; + u8 tweak[16]; + u8 block[16]; + u8 bit[16]; + u8 xts[16]; + } pcc_param; + struct { + u8 key[32]; + u8 init[16]; + } xts_param; + + if (req->cryptlen < AES_BLOCK_SIZE) + return -EINVAL; + + if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) { + struct skcipher_request *subreq = skcipher_request_ctx(req); + + *subreq = *req; + skcipher_request_set_tfm(subreq, xts_ctx->fallback); + return (modifier & CPACF_DECRYPT) ? + crypto_skcipher_decrypt(subreq) : + crypto_skcipher_encrypt(subreq); + } + + ret = skcipher_walk_virt(&walk, req, false); + if (ret) + return ret; + offset = xts_ctx->key_len & 0x10; + memset(pcc_param.block, 0, sizeof(pcc_param.block)); + memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); + memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); + memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak)); + memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); + cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); + + memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); + memcpy(xts_param.init, pcc_param.xts, 16); + + while ((nbytes = walk.nbytes) != 0) { + /* only use complete blocks */ + n = nbytes & ~(AES_BLOCK_SIZE - 1); + cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, + walk.dst.virt.addr, walk.src.virt.addr, n); + ret = skcipher_walk_done(&walk, nbytes - n); + } + memzero_explicit(&pcc_param, sizeof(pcc_param)); + memzero_explicit(&xts_param, sizeof(xts_param)); + return ret; +} + +static int xts_aes_encrypt(struct skcipher_request *req) +{ + return xts_aes_crypt(req, 0); +} + +static int xts_aes_decrypt(struct skcipher_request *req) +{ + return xts_aes_crypt(req, CPACF_DECRYPT); +} + +static int xts_fallback_init(struct crypto_skcipher *tfm) +{ + const char *name = crypto_tfm_alg_name(&tfm->base); + struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); + + xts_ctx->fallback = crypto_alloc_skcipher(name, 0, + CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); + + if (IS_ERR(xts_ctx->fallback)) { + pr_err("Allocating XTS fallback algorithm %s failed\n", + name); + return PTR_ERR(xts_ctx->fallback); + } + crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + + crypto_skcipher_reqsize(xts_ctx->fallback)); + return 0; +} + +static void xts_fallback_exit(struct crypto_skcipher *tfm) +{ + struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); + + crypto_free_skcipher(xts_ctx->fallback); +} + +static struct skcipher_alg xts_aes_alg = { + .base.cra_name = "xts(aes)", + .base.cra_driver_name = "xts-aes-s390", + .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = AES_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct s390_xts_ctx), + .base.cra_module = THIS_MODULE, + .init = xts_fallback_init, + .exit = xts_fallback_exit, + .min_keysize = 2 * AES_MIN_KEY_SIZE, + .max_keysize = 2 * AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = xts_aes_set_key, + .encrypt = xts_aes_encrypt, + .decrypt = xts_aes_decrypt, +}; + +static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + unsigned long fc; + + /* Pick the correct function code based on the key length */ + fc = (key_len == 16) ? CPACF_KMCTR_AES_128 : + (key_len == 24) ? CPACF_KMCTR_AES_192 : + (key_len == 32) ? CPACF_KMCTR_AES_256 : 0; + + /* Check if the function code is available */ + sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0; + if (!sctx->fc) + return setkey_fallback_skcipher(tfm, in_key, key_len); + + sctx->key_len = key_len; + memcpy(sctx->key, in_key, key_len); + return 0; +} + +static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes) +{ + unsigned int i, n; + + /* only use complete blocks, max. PAGE_SIZE */ + memcpy(ctrptr, iv, AES_BLOCK_SIZE); + n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1); + for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) { + memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE); + crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE); + ctrptr += AES_BLOCK_SIZE; + } + return n; +} + +static int ctr_aes_crypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); + u8 buf[AES_BLOCK_SIZE], *ctrptr; + struct skcipher_walk walk; + unsigned int n, nbytes; + int ret, locked; + + if (unlikely(!sctx->fc)) + return fallback_skcipher_crypt(sctx, req, 0); + + locked = mutex_trylock(&ctrblk_lock); + + ret = skcipher_walk_virt(&walk, req, false); + while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { + n = AES_BLOCK_SIZE; + + if (nbytes >= 2*AES_BLOCK_SIZE && locked) + n = __ctrblk_init(ctrblk, walk.iv, nbytes); + ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv; + cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr, + walk.src.virt.addr, n, ctrptr); + if (ctrptr == ctrblk) + memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE, + AES_BLOCK_SIZE); + crypto_inc(walk.iv, AES_BLOCK_SIZE); + ret = skcipher_walk_done(&walk, nbytes - n); + } + if (locked) + mutex_unlock(&ctrblk_lock); + /* + * final block may be < AES_BLOCK_SIZE, copy only nbytes + */ + if (nbytes) { + memset(buf, 0, AES_BLOCK_SIZE); + memcpy(buf, walk.src.virt.addr, nbytes); + cpacf_kmctr(sctx->fc, sctx->key, buf, buf, + AES_BLOCK_SIZE, walk.iv); + memcpy(walk.dst.virt.addr, buf, nbytes); + crypto_inc(walk.iv, AES_BLOCK_SIZE); + ret = skcipher_walk_done(&walk, 0); + } + + return ret; +} + +static struct skcipher_alg ctr_aes_alg = { + .base.cra_name = "ctr(aes)", + .base.cra_driver_name = "ctr-aes-s390", + .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ + .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct s390_aes_ctx), + .base.cra_module = THIS_MODULE, + .init = fallback_init_skcipher, + .exit = fallback_exit_skcipher, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = ctr_aes_set_key, + .encrypt = ctr_aes_crypt, + .decrypt = ctr_aes_crypt, + .chunksize = AES_BLOCK_SIZE, +}; + +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_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 inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw) +{ + struct scatterlist *nextsg; + + gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); + while (!gw->walk_bytes) { + nextsg = sg_next(gw->walk.sg); + if (!nextsg) + return 0; + scatterwalk_start(&gw->walk, nextsg); + gw->walk_bytes = scatterwalk_clamp(&gw->walk, + gw->walk_bytes_remain); + } + gw->walk_ptr = scatterwalk_map(&gw->walk); + return gw->walk_bytes; +} + +static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw, + unsigned int nbytes) +{ + gw->walk_bytes_remain -= nbytes; + scatterwalk_unmap(gw->walk_ptr); + scatterwalk_advance(&gw->walk, nbytes); + scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); + gw->walk_ptr = NULL; +} + +static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) +{ + int n; + + 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; + } + + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + } + + 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; + _gcm_sg_unmap_and_advance(gw, n); + if (gw->buf_bytes >= minbytesneeded) { + gw->ptr = gw->buf; + gw->nbytes = gw->buf_bytes; + goto out; + } + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + } + } + +out: + return gw->nbytes; +} + +static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) +{ + if (gw->walk_bytes_remain == 0) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + } + + if (!_gcm_sg_clamp_and_map(gw)) { + gw->ptr = NULL; + gw->nbytes = 0; + goto out; + } + + if (gw->walk_bytes >= minbytesneeded) { + gw->ptr = gw->walk_ptr; + gw->nbytes = gw->walk_bytes; + goto out; + } + + scatterwalk_unmap(gw->walk_ptr); + gw->walk_ptr = NULL; + + gw->ptr = gw->buf; + gw->nbytes = sizeof(gw->buf); + +out: + return gw->nbytes; +} + +static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) +{ + if (gw->ptr == NULL) + return 0; + + if (gw->ptr == gw->buf) { + int 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 + _gcm_sg_unmap_and_advance(gw, bytesdone); + + return bytesdone; +} + +static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) +{ + int i, n; + + if (gw->ptr == NULL) + return 0; + + if (gw->ptr == gw->buf) { + for (i = 0; i < bytesdone; i += n) { + if (!_gcm_sg_clamp_and_map(gw)) + return i; + n = min(gw->walk_bytes, bytesdone - i); + memcpy(gw->walk_ptr, gw->buf + i, n); + _gcm_sg_unmap_and_advance(gw, n); + } + } else + _gcm_sg_unmap_and_advance(gw, bytesdone); + + return bytesdone; +} + +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 n, 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(¶m, 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_walk_start(&gw_in, req->src, len); + gcm_walk_start(&gw_out, req->dst, len); + + do { + min_bytes = min_t(unsigned int, + aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); + in_bytes = gcm_in_walk_go(&gw_in, min_bytes); + out_bytes = gcm_out_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, ¶m, + gw_out.ptr + aad_bytes, + gw_in.ptr + aad_bytes, pc_bytes, + gw_in.ptr, aad_bytes); + + n = aad_bytes + pc_bytes; + if (gcm_in_walk_done(&gw_in, n) != n) + return -ENOMEM; + if (gcm_out_walk_done(&gw_out, n) != n) + return -ENOMEM; + 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(¶m, 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_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_alg; +static struct skcipher_alg *aes_s390_skcipher_algs[4]; +static int aes_s390_skciphers_num; +static struct aead_alg *aes_s390_aead_alg; + +static int aes_s390_register_skcipher(struct skcipher_alg *alg) +{ + int ret; + + ret = crypto_register_skcipher(alg); + if (!ret) + aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg; + return ret; +} + +static void aes_s390_fini(void) +{ + if (aes_s390_alg) + crypto_unregister_alg(aes_s390_alg); + while (aes_s390_skciphers_num--) + crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]); + if (ctrblk) + free_page((unsigned long) ctrblk); + + if (aes_s390_aead_alg) + crypto_unregister_aead(aes_s390_aead_alg); +} + +static int __init aes_s390_init(void) +{ + int ret; + + /* 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) || + cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { + ret = crypto_register_alg(&aes_alg); + if (ret) + goto out_err; + aes_s390_alg = &aes_alg; + ret = aes_s390_register_skcipher(&ecb_aes_alg); + if (ret) + goto out_err; + } + + if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || + cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || + cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { + ret = aes_s390_register_skcipher(&cbc_aes_alg); + if (ret) + goto out_err; + } + + if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || + cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { + ret = aes_s390_register_skcipher(&xts_aes_alg); + if (ret) + goto out_err; + } + + if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || + cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || + cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { + ctrblk = (u8 *) __get_free_page(GFP_KERNEL); + if (!ctrblk) { + ret = -ENOMEM; + goto out_err; + } + ret = aes_s390_register_skcipher(&ctr_aes_alg); + if (ret) + 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; + aes_s390_aead_alg = &gcm_aes_aead; + } + + return 0; +out_err: + aes_s390_fini(); + return ret; +} + +module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init); +module_exit(aes_s390_fini); + +MODULE_ALIAS_CRYPTO("aes-all"); + +MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(CRYPTO_INTERNAL); |