/* * Cryptographic API. * * s390 implementation of the AES Cipher Algorithm. * * 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" * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #include <crypto/aes.h> #include <crypto/algapi.h> #include <linux/err.h> #include <linux/module.h> #include <linux/init.h> #include "crypt_s390.h" #define AES_KEYLEN_128 1 #define AES_KEYLEN_192 2 #define AES_KEYLEN_256 4 static char keylen_flag = 0; struct s390_aes_ctx { u8 iv[AES_BLOCK_SIZE]; u8 key[AES_MAX_KEY_SIZE]; long enc; long dec; int key_len; union { struct crypto_blkcipher *blk; struct crypto_cipher *cip; } fallback; }; /* * 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) { switch (key_len) { case 16: if (!(keylen_flag & AES_KEYLEN_128)) return 1; break; case 24: if (!(keylen_flag & AES_KEYLEN_192)) return 1; break; case 32: if (!(keylen_flag & AES_KEYLEN_256)) return 1; break; default: 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; 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, AES_BLOCK_SIZE); break; case 24: crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in, AES_BLOCK_SIZE); break; case 32: crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in, AES_BLOCK_SIZE); break; } } 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, AES_BLOCK_SIZE); break; case 24: crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in, AES_BLOCK_SIZE); break; case 32: crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in, AES_BLOCK_SIZE); break; } } 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", .cra_driver_name = "aes-s390", .cra_priority = CRYPT_S390_PRIORITY, .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_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, .cia_max_keysize = AES_MAX_KEY_SIZE, .cia_setkey = aes_set_key, .cia_encrypt = aes_encrypt, .cia_decrypt = aes_decrypt, } } }; 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: sctx->enc = KM_AES_128_ENCRYPT; sctx->dec = KM_AES_128_DECRYPT; break; case 24: sctx->enc = KM_AES_192_ENCRYPT; sctx->dec = KM_AES_192_DECRYPT; break; case 32: sctx->enc = KM_AES_256_ENCRYPT; sctx->dec = KM_AES_256_DECRYPT; break; } return aes_set_key(tfm, in_key, key_len); } static int ecb_aes_crypt(struct blkcipher_desc *desc, long func, void *param, struct blkcipher_walk *walk) { int ret = blkcipher_walk_virt(desc, walk); unsigned int nbytes; while ((nbytes = walk->nbytes)) { /* only use complete blocks */ unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1); u8 *out = walk->dst.virt.addr; u8 *in = walk->src.virt.addr; ret = crypt_s390_km(func, param, out, in, n); BUG_ON((ret < 0) || (ret != n)); nbytes &= AES_BLOCK_SIZE - 1; ret = blkcipher_walk_done(desc, walk, nbytes); } return ret; } static int ecb_aes_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { 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); } static int ecb_aes_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { 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", .cra_priority = CRYPT_S390_COMPOSITE_PRIORITY, .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct s390_aes_ctx), .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, .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_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: sctx->enc = KMC_AES_128_ENCRYPT; sctx->dec = KMC_AES_128_DECRYPT; break; case 24: sctx->enc = KMC_AES_192_ENCRYPT; sctx->dec = KMC_AES_192_DECRYPT; break; case 32: sctx->enc = KMC_AES_256_ENCRYPT; sctx->dec = KMC_AES_256_DECRYPT; break; } return aes_set_key(tfm, in_key, key_len); } static int cbc_aes_crypt(struct blkcipher_desc *desc, long func, void *param, struct blkcipher_walk *walk) { int ret = blkcipher_walk_virt(desc, walk); unsigned int nbytes = walk->nbytes; if (!nbytes) goto out; memcpy(param, walk->iv, AES_BLOCK_SIZE); do { /* only use complete blocks */ unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1); u8 *out = walk->dst.virt.addr; u8 *in = walk->src.virt.addr; ret = crypt_s390_kmc(func, param, out, in, n); BUG_ON((ret < 0) || (ret != n)); nbytes &= AES_BLOCK_SIZE - 1; ret = blkcipher_walk_done(desc, walk, nbytes); } while ((nbytes = walk->nbytes)); memcpy(walk->iv, param, AES_BLOCK_SIZE); out: return ret; } static int cbc_aes_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { 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); } static int cbc_aes_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { 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); } static struct crypto_alg cbc_aes_alg = { .cra_name = "cbc(aes)", .cra_driver_name = "cbc-aes-s390", .cra_priority = CRYPT_S390_COMPOSITE_PRIORITY, .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct s390_aes_ctx), .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, .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 __init aes_init(void) { int ret; if (crypt_s390_func_available(KM_AES_128_ENCRYPT)) keylen_flag |= AES_KEYLEN_128; if (crypt_s390_func_available(KM_AES_192_ENCRYPT)) keylen_flag |= AES_KEYLEN_192; if (crypt_s390_func_available(KM_AES_256_ENCRYPT)) keylen_flag |= AES_KEYLEN_256; if (!keylen_flag) return -EOPNOTSUPP; /* z9 109 and z9 BC/EC only support 128 bit key length */ 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) goto aes_err; ret = crypto_register_alg(&ecb_aes_alg); if (ret) goto ecb_aes_err; ret = crypto_register_alg(&cbc_aes_alg); if (ret) goto cbc_aes_err; out: return ret; cbc_aes_err: crypto_unregister_alg(&ecb_aes_alg); ecb_aes_err: crypto_unregister_alg(&aes_alg); aes_err: goto out; } static void __exit aes_fini(void) { crypto_unregister_alg(&cbc_aes_alg); crypto_unregister_alg(&ecb_aes_alg); crypto_unregister_alg(&aes_alg); } module_init(aes_init); module_exit(aes_fini); MODULE_ALIAS("aes"); MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); MODULE_LICENSE("GPL");