diff options
| -rw-r--r-- | arch/s390/crypto/aes_s390.c | 226 |
1 files changed, 205 insertions, 21 deletions
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c index 812511bbb540..85246112ab5e 100644 --- a/arch/s390/crypto/aes_s390.c +++ b/arch/s390/crypto/aes_s390.c @@ -6,6 +6,7 @@ * s390 Version: * Copyright IBM Corp. 2005,2007 * Author(s): Jan Glauber (jang@de.ibm.com) + * Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback * * Derived from "crypto/aes_generic.c" * @@ -18,6 +19,7 @@ #include <crypto/aes.h> #include <crypto/algapi.h> +#include <linux/err.h> #include <linux/module.h> #include <linux/init.h> #include "crypt_s390.h" @@ -34,45 +36,89 @@ struct s390_aes_ctx { long enc; long dec; int key_len; + union { + struct crypto_blkcipher *blk; + struct crypto_cipher *cip; + } fallback; }; -static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, - unsigned int key_len) +/* + * Check if the key_len is supported by the HW. + * Returns 0 if it is, a positive number if it is not and software fallback is + * required or a negative number in case the key size is not valid + */ +static int need_fallback(unsigned int key_len) { - struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); - u32 *flags = &tfm->crt_flags; - switch (key_len) { case 16: if (!(keylen_flag & AES_KEYLEN_128)) - goto fail; + return 1; break; case 24: if (!(keylen_flag & AES_KEYLEN_192)) - goto fail; - + return 1; break; case 32: if (!(keylen_flag & AES_KEYLEN_256)) - goto fail; + return 1; break; default: - goto fail; + return -1; break; } + return 0; +} + +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); + int ret; + + sctx->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; + sctx->fallback.blk->base.crt_flags |= (tfm->crt_flags & + CRYPTO_TFM_REQ_MASK); + + ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len); + if (ret) { + tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; + tfm->crt_flags |= (sctx->fallback.blk->base.crt_flags & + CRYPTO_TFM_RES_MASK); + } + return ret; +} + +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); + u32 *flags = &tfm->crt_flags; + int ret; + + ret = need_fallback(key_len); + if (ret < 0) { + *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } sctx->key_len = key_len; - memcpy(sctx->key, in_key, key_len); - return 0; -fail: - *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; - return -EINVAL; + if (!ret) { + memcpy(sctx->key, in_key, key_len); + return 0; + } + + return setkey_fallback_cip(tfm, in_key, key_len); } static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + if (unlikely(need_fallback(sctx->key_len))) { + crypto_cipher_encrypt_one(sctx->fallback.cip, out, in); + return; + } + switch (sctx->key_len) { case 16: crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in, @@ -93,6 +139,11 @@ static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + if (unlikely(need_fallback(sctx->key_len))) { + crypto_cipher_decrypt_one(sctx->fallback.cip, out, in); + return; + } + switch (sctx->key_len) { case 16: crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in, @@ -109,6 +160,29 @@ static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) } } +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_ASYNC | CRYPTO_ALG_NEED_FALLBACK); + + if (IS_ERR(sctx->fallback.cip)) { + printk(KERN_ERR "Error allocating fallback algo %s\n", name); + return PTR_ERR(sctx->fallback.blk); + } + + 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", @@ -120,6 +194,8 @@ static struct crypto_alg aes_alg = { .cra_ctxsize = sizeof(struct s390_aes_ctx), .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(aes_alg.cra_list), + .cra_init = fallback_init_cip, + .cra_exit = fallback_exit_cip, .cra_u = { .cipher = { .cia_min_keysize = AES_MIN_KEY_SIZE, @@ -131,10 +207,76 @@ static struct crypto_alg aes_alg = { } }; +static int setkey_fallback_blk(struct crypto_tfm *tfm, const u8 *key, + unsigned int len) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + unsigned int ret; + + sctx->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; + sctx->fallback.blk->base.crt_flags |= (tfm->crt_flags & + CRYPTO_TFM_REQ_MASK); + + ret = crypto_blkcipher_setkey(sctx->fallback.blk, key, len); + if (ret) { + tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; + tfm->crt_flags |= (sctx->fallback.blk->base.crt_flags & + CRYPTO_TFM_RES_MASK); + } + return ret; +} + +static int fallback_blk_dec(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + unsigned int ret; + struct crypto_blkcipher *tfm; + struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); + + memcpy(crypto_blkcipher_crt(sctx->fallback.blk)->iv, desc->info, + AES_BLOCK_SIZE); + + tfm = desc->tfm; + desc->tfm = sctx->fallback.blk; + + ret = crypto_blkcipher_decrypt(desc, dst, src, nbytes); + + desc->tfm = tfm; + return ret; +} + +static int fallback_blk_enc(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + unsigned int ret; + struct crypto_blkcipher *tfm; + struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); + + memcpy(crypto_blkcipher_crt(sctx->fallback.blk)->iv, desc->info, + AES_BLOCK_SIZE); + + tfm = desc->tfm; + desc->tfm = sctx->fallback.blk; + + ret = crypto_blkcipher_encrypt(desc, dst, src, nbytes); + + desc->tfm = tfm; + return ret; +} + static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len) { struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + int ret; + + ret = need_fallback(key_len); + if (ret > 0) { + sctx->key_len = key_len; + return setkey_fallback_blk(tfm, in_key, key_len); + } switch (key_len) { case 16: @@ -183,6 +325,9 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc, struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk walk; + if (unlikely(need_fallback(sctx->key_len))) + return fallback_blk_enc(desc, dst, src, nbytes); + blkcipher_walk_init(&walk, dst, src, nbytes); return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk); } @@ -194,10 +339,37 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc, struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk walk; + if (unlikely(need_fallback(sctx->key_len))) + return fallback_blk_dec(desc, dst, src, nbytes); + blkcipher_walk_init(&walk, dst, src, nbytes); return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk); } +static int fallback_init_blk(struct crypto_tfm *tfm) +{ + const char *name = tfm->__crt_alg->cra_name; + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + sctx->fallback.blk = crypto_alloc_blkcipher(name, 0, + CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK); + + if (IS_ERR(sctx->fallback.blk)) { + printk(KERN_ERR "Error allocating fallback algo %s\n", name); + return PTR_ERR(sctx->fallback.blk); + } + + return 0; +} + +static void fallback_exit_blk(struct crypto_tfm *tfm) +{ + struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + + crypto_free_blkcipher(sctx->fallback.blk); + sctx->fallback.blk = NULL; +} + static struct crypto_alg ecb_aes_alg = { .cra_name = "ecb(aes)", .cra_driver_name = "ecb-aes-s390", @@ -209,6 +381,8 @@ static struct crypto_alg ecb_aes_alg = { .cra_type = &crypto_blkcipher_type, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(ecb_aes_alg.cra_list), + .cra_init = fallback_init_blk, + .cra_exit = fallback_exit_blk, .cra_u = { .blkcipher = { .min_keysize = AES_MIN_KEY_SIZE, @@ -224,6 +398,13 @@ static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len) { struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); + int ret; + + ret = need_fallback(key_len); + if (ret > 0) { + sctx->key_len = key_len; + return setkey_fallback_blk(tfm, in_key, key_len); + } switch (key_len) { case 16: @@ -278,6 +459,9 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc, struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk walk; + if (unlikely(need_fallback(sctx->key_len))) + return fallback_blk_enc(desc, dst, src, nbytes); + blkcipher_walk_init(&walk, dst, src, nbytes); return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk); } @@ -289,6 +473,9 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc, struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); struct blkcipher_walk walk; + if (unlikely(need_fallback(sctx->key_len))) + return fallback_blk_dec(desc, dst, src, nbytes); + blkcipher_walk_init(&walk, dst, src, nbytes); return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk); } @@ -304,6 +491,8 @@ static struct crypto_alg cbc_aes_alg = { .cra_type = &crypto_blkcipher_type, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(cbc_aes_alg.cra_list), + .cra_init = fallback_init_blk, + .cra_exit = fallback_exit_blk, .cra_u = { .blkcipher = { .min_keysize = AES_MIN_KEY_SIZE, @@ -331,14 +520,10 @@ static int __init aes_init(void) return -EOPNOTSUPP; /* z9 109 and z9 BC/EC only support 128 bit key length */ - if (keylen_flag == AES_KEYLEN_128) { - aes_alg.cra_u.cipher.cia_max_keysize = AES_MIN_KEY_SIZE; - ecb_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE; - cbc_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE; + if (keylen_flag == AES_KEYLEN_128) printk(KERN_INFO "aes_s390: hardware acceleration only available for" "128 bit keys\n"); - } ret = crypto_register_alg(&aes_alg); if (ret) @@ -377,4 +562,3 @@ MODULE_ALIAS("aes"); MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); MODULE_LICENSE("GPL"); - |