| /* |
| * Cryptographic API. |
| * |
| * Support for VIA PadLock hardware crypto engine. |
| * |
| * Copyright (c) 2004 Michal Ludvig <michal@logix.cz> |
| * |
| */ |
| |
| #include <crypto/algapi.h> |
| #include <crypto/aes.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/interrupt.h> |
| #include <linux/kernel.h> |
| #include <asm/byteorder.h> |
| #include "padlock.h" |
| |
| /* Control word. */ |
| struct cword { |
| unsigned int __attribute__ ((__packed__)) |
| rounds:4, |
| algo:3, |
| keygen:1, |
| interm:1, |
| encdec:1, |
| ksize:2; |
| } __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| |
| /* Whenever making any changes to the following |
| * structure *make sure* you keep E, d_data |
| * and cword aligned on 16 Bytes boundaries and |
| * the Hardware can access 16 * 16 bytes of E and d_data |
| * (only the first 15 * 16 bytes matter but the HW reads |
| * more). |
| */ |
| struct aes_ctx { |
| u32 E[AES_MAX_KEYLENGTH_U32] |
| __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| u32 d_data[AES_MAX_KEYLENGTH_U32] |
| __attribute__ ((__aligned__(PADLOCK_ALIGNMENT))); |
| struct { |
| struct cword encrypt; |
| struct cword decrypt; |
| } cword; |
| u32 *D; |
| }; |
| |
| /* Tells whether the ACE is capable to generate |
| the extended key for a given key_len. */ |
| static inline int |
| aes_hw_extkey_available(uint8_t key_len) |
| { |
| /* TODO: We should check the actual CPU model/stepping |
| as it's possible that the capability will be |
| added in the next CPU revisions. */ |
| if (key_len == 16) |
| return 1; |
| return 0; |
| } |
| |
| static inline struct aes_ctx *aes_ctx_common(void *ctx) |
| { |
| unsigned long addr = (unsigned long)ctx; |
| unsigned long align = PADLOCK_ALIGNMENT; |
| |
| if (align <= crypto_tfm_ctx_alignment()) |
| align = 1; |
| return (struct aes_ctx *)ALIGN(addr, align); |
| } |
| |
| static inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm) |
| { |
| return aes_ctx_common(crypto_tfm_ctx(tfm)); |
| } |
| |
| static inline struct aes_ctx *blk_aes_ctx(struct crypto_blkcipher *tfm) |
| { |
| return aes_ctx_common(crypto_blkcipher_ctx(tfm)); |
| } |
| |
| static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, |
| unsigned int key_len) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| const __le32 *key = (const __le32 *)in_key; |
| u32 *flags = &tfm->crt_flags; |
| struct crypto_aes_ctx gen_aes; |
| |
| if (key_len % 8) { |
| *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; |
| return -EINVAL; |
| } |
| |
| /* |
| * If the hardware is capable of generating the extended key |
| * itself we must supply the plain key for both encryption |
| * and decryption. |
| */ |
| ctx->D = ctx->E; |
| |
| ctx->E[0] = le32_to_cpu(key[0]); |
| ctx->E[1] = le32_to_cpu(key[1]); |
| ctx->E[2] = le32_to_cpu(key[2]); |
| ctx->E[3] = le32_to_cpu(key[3]); |
| |
| /* Prepare control words. */ |
| memset(&ctx->cword, 0, sizeof(ctx->cword)); |
| |
| ctx->cword.decrypt.encdec = 1; |
| ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4; |
| ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds; |
| ctx->cword.encrypt.ksize = (key_len - 16) / 8; |
| ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize; |
| |
| /* Don't generate extended keys if the hardware can do it. */ |
| if (aes_hw_extkey_available(key_len)) |
| return 0; |
| |
| ctx->D = ctx->d_data; |
| ctx->cword.encrypt.keygen = 1; |
| ctx->cword.decrypt.keygen = 1; |
| |
| if (crypto_aes_expand_key(&gen_aes, in_key, key_len)) { |
| *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; |
| return -EINVAL; |
| } |
| |
| memcpy(ctx->E, gen_aes.key_enc, AES_MAX_KEYLENGTH); |
| memcpy(ctx->D, gen_aes.key_dec, AES_MAX_KEYLENGTH); |
| return 0; |
| } |
| |
| /* ====== Encryption/decryption routines ====== */ |
| |
| /* These are the real call to PadLock. */ |
| static inline void padlock_reset_key(void) |
| { |
| asm volatile ("pushfl; popfl"); |
| } |
| |
| static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key, |
| void *control_word) |
| { |
| asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */ |
| : "+S"(input), "+D"(output) |
| : "d"(control_word), "b"(key), "c"(1)); |
| } |
| |
| static void aes_crypt_copy(const u8 *in, u8 *out, u32 *key, struct cword *cword) |
| { |
| u8 buf[AES_BLOCK_SIZE * 2 + PADLOCK_ALIGNMENT - 1]; |
| u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT); |
| |
| memcpy(tmp, in, AES_BLOCK_SIZE); |
| padlock_xcrypt(tmp, out, key, cword); |
| } |
| |
| static inline void aes_crypt(const u8 *in, u8 *out, u32 *key, |
| struct cword *cword) |
| { |
| /* padlock_xcrypt requires at least two blocks of data. */ |
| if (unlikely(!(((unsigned long)in ^ (PAGE_SIZE - AES_BLOCK_SIZE)) & |
| (PAGE_SIZE - 1)))) { |
| aes_crypt_copy(in, out, key, cword); |
| return; |
| } |
| |
| padlock_xcrypt(in, out, key, cword); |
| } |
| |
| static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key, |
| void *control_word, u32 count) |
| { |
| if (count == 1) { |
| aes_crypt(input, output, key, control_word); |
| return; |
| } |
| |
| asm volatile ("test $1, %%cl;" |
| "je 1f;" |
| "lea -1(%%ecx), %%eax;" |
| "mov $1, %%ecx;" |
| ".byte 0xf3,0x0f,0xa7,0xc8;" /* rep xcryptecb */ |
| "mov %%eax, %%ecx;" |
| "1:" |
| ".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */ |
| : "+S"(input), "+D"(output) |
| : "d"(control_word), "b"(key), "c"(count) |
| : "ax"); |
| } |
| |
| static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key, |
| u8 *iv, void *control_word, u32 count) |
| { |
| /* rep xcryptcbc */ |
| asm volatile (".byte 0xf3,0x0f,0xa7,0xd0" |
| : "+S" (input), "+D" (output), "+a" (iv) |
| : "d" (control_word), "b" (key), "c" (count)); |
| return iv; |
| } |
| |
| static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| padlock_reset_key(); |
| aes_crypt(in, out, ctx->E, &ctx->cword.encrypt); |
| } |
| |
| static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| struct aes_ctx *ctx = aes_ctx(tfm); |
| padlock_reset_key(); |
| aes_crypt(in, out, ctx->D, &ctx->cword.decrypt); |
| } |
| |
| static struct crypto_alg aes_alg = { |
| .cra_name = "aes", |
| .cra_driver_name = "aes-padlock", |
| .cra_priority = PADLOCK_CRA_PRIORITY, |
| .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| .cra_blocksize = AES_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct aes_ctx), |
| .cra_alignmask = PADLOCK_ALIGNMENT - 1, |
| .cra_module = THIS_MODULE, |
| .cra_list = LIST_HEAD_INIT(aes_alg.cra_list), |
| .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 ecb_aes_encrypt(struct blkcipher_desc *desc, |
| struct scatterlist *dst, struct scatterlist *src, |
| unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); |
| struct blkcipher_walk walk; |
| int err; |
| |
| padlock_reset_key(); |
| |
| blkcipher_walk_init(&walk, dst, src, nbytes); |
| err = blkcipher_walk_virt(desc, &walk); |
| |
| while ((nbytes = walk.nbytes)) { |
| padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr, |
| ctx->E, &ctx->cword.encrypt, |
| nbytes / AES_BLOCK_SIZE); |
| nbytes &= AES_BLOCK_SIZE - 1; |
| err = blkcipher_walk_done(desc, &walk, nbytes); |
| } |
| |
| return err; |
| } |
| |
| static int ecb_aes_decrypt(struct blkcipher_desc *desc, |
| struct scatterlist *dst, struct scatterlist *src, |
| unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); |
| struct blkcipher_walk walk; |
| int err; |
| |
| padlock_reset_key(); |
| |
| blkcipher_walk_init(&walk, dst, src, nbytes); |
| err = blkcipher_walk_virt(desc, &walk); |
| |
| while ((nbytes = walk.nbytes)) { |
| padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr, |
| ctx->D, &ctx->cword.decrypt, |
| nbytes / AES_BLOCK_SIZE); |
| nbytes &= AES_BLOCK_SIZE - 1; |
| err = blkcipher_walk_done(desc, &walk, nbytes); |
| } |
| |
| return err; |
| } |
| |
| static struct crypto_alg ecb_aes_alg = { |
| .cra_name = "ecb(aes)", |
| .cra_driver_name = "ecb-aes-padlock", |
| .cra_priority = PADLOCK_COMPOSITE_PRIORITY, |
| .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, |
| .cra_blocksize = AES_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct aes_ctx), |
| .cra_alignmask = PADLOCK_ALIGNMENT - 1, |
| .cra_type = &crypto_blkcipher_type, |
| .cra_module = THIS_MODULE, |
| .cra_list = LIST_HEAD_INIT(ecb_aes_alg.cra_list), |
| .cra_u = { |
| .blkcipher = { |
| .min_keysize = AES_MIN_KEY_SIZE, |
| .max_keysize = AES_MAX_KEY_SIZE, |
| .setkey = aes_set_key, |
| .encrypt = ecb_aes_encrypt, |
| .decrypt = ecb_aes_decrypt, |
| } |
| } |
| }; |
| |
| static int cbc_aes_encrypt(struct blkcipher_desc *desc, |
| struct scatterlist *dst, struct scatterlist *src, |
| unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); |
| struct blkcipher_walk walk; |
| int err; |
| |
| padlock_reset_key(); |
| |
| blkcipher_walk_init(&walk, dst, src, nbytes); |
| err = blkcipher_walk_virt(desc, &walk); |
| |
| while ((nbytes = walk.nbytes)) { |
| u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr, |
| walk.dst.virt.addr, ctx->E, |
| walk.iv, &ctx->cword.encrypt, |
| nbytes / AES_BLOCK_SIZE); |
| memcpy(walk.iv, iv, AES_BLOCK_SIZE); |
| nbytes &= AES_BLOCK_SIZE - 1; |
| err = blkcipher_walk_done(desc, &walk, nbytes); |
| } |
| |
| return err; |
| } |
| |
| static int cbc_aes_decrypt(struct blkcipher_desc *desc, |
| struct scatterlist *dst, struct scatterlist *src, |
| unsigned int nbytes) |
| { |
| struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); |
| struct blkcipher_walk walk; |
| int err; |
| |
| padlock_reset_key(); |
| |
| blkcipher_walk_init(&walk, dst, src, nbytes); |
| err = blkcipher_walk_virt(desc, &walk); |
| |
| while ((nbytes = walk.nbytes)) { |
| padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr, |
| ctx->D, walk.iv, &ctx->cword.decrypt, |
| nbytes / AES_BLOCK_SIZE); |
| nbytes &= AES_BLOCK_SIZE - 1; |
| err = blkcipher_walk_done(desc, &walk, nbytes); |
| } |
| |
| return err; |
| } |
| |
| static struct crypto_alg cbc_aes_alg = { |
| .cra_name = "cbc(aes)", |
| .cra_driver_name = "cbc-aes-padlock", |
| .cra_priority = PADLOCK_COMPOSITE_PRIORITY, |
| .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, |
| .cra_blocksize = AES_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct aes_ctx), |
| .cra_alignmask = PADLOCK_ALIGNMENT - 1, |
| .cra_type = &crypto_blkcipher_type, |
| .cra_module = THIS_MODULE, |
| .cra_list = LIST_HEAD_INIT(cbc_aes_alg.cra_list), |
| .cra_u = { |
| .blkcipher = { |
| .min_keysize = AES_MIN_KEY_SIZE, |
| .max_keysize = AES_MAX_KEY_SIZE, |
| .ivsize = AES_BLOCK_SIZE, |
| .setkey = aes_set_key, |
| .encrypt = cbc_aes_encrypt, |
| .decrypt = cbc_aes_decrypt, |
| } |
| } |
| }; |
| |
| static int __init padlock_init(void) |
| { |
| int ret; |
| |
| if (!cpu_has_xcrypt) { |
| printk(KERN_ERR PFX "VIA PadLock not detected.\n"); |
| return -ENODEV; |
| } |
| |
| if (!cpu_has_xcrypt_enabled) { |
| printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n"); |
| return -ENODEV; |
| } |
| |
| if ((ret = crypto_register_alg(&aes_alg))) |
| goto aes_err; |
| |
| if ((ret = crypto_register_alg(&ecb_aes_alg))) |
| goto ecb_aes_err; |
| |
| if ((ret = crypto_register_alg(&cbc_aes_alg))) |
| goto cbc_aes_err; |
| |
| printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n"); |
| |
| out: |
| return ret; |
| |
| cbc_aes_err: |
| crypto_unregister_alg(&ecb_aes_alg); |
| ecb_aes_err: |
| crypto_unregister_alg(&aes_alg); |
| aes_err: |
| printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n"); |
| goto out; |
| } |
| |
| static void __exit padlock_fini(void) |
| { |
| crypto_unregister_alg(&cbc_aes_alg); |
| crypto_unregister_alg(&ecb_aes_alg); |
| crypto_unregister_alg(&aes_alg); |
| } |
| |
| module_init(padlock_init); |
| module_exit(padlock_fini); |
| |
| MODULE_DESCRIPTION("VIA PadLock AES algorithm support"); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Michal Ludvig"); |
| |
| MODULE_ALIAS("aes"); |