/* * Copyright (C) 2016 Pengutronix, Steffen Trumtrar * * The driver is based on information gathered from * drivers/mxc/security/mxc_scc.c which can be found in * the Freescale linux-2.6-imx.git in the imx_2.6.35_maintain branch. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* Secure Memory (SCM) registers */ #define SCC_SCM_RED_START 0x0000 #define SCC_SCM_BLACK_START 0x0004 #define SCC_SCM_LENGTH 0x0008 #define SCC_SCM_CTRL 0x000C #define SCC_SCM_STATUS 0x0010 #define SCC_SCM_ERROR_STATUS 0x0014 #define SCC_SCM_INTR_CTRL 0x0018 #define SCC_SCM_CFG 0x001C #define SCC_SCM_INIT_VECTOR_0 0x0020 #define SCC_SCM_INIT_VECTOR_1 0x0024 #define SCC_SCM_RED_MEMORY 0x0400 #define SCC_SCM_BLACK_MEMORY 0x0800 /* Security Monitor (SMN) Registers */ #define SCC_SMN_STATUS 0x1000 #define SCC_SMN_COMMAND 0x1004 #define SCC_SMN_SEQ_START 0x1008 #define SCC_SMN_SEQ_END 0x100C #define SCC_SMN_SEQ_CHECK 0x1010 #define SCC_SMN_BIT_COUNT 0x1014 #define SCC_SMN_BITBANK_INC_SIZE 0x1018 #define SCC_SMN_BITBANK_DECREMENT 0x101C #define SCC_SMN_COMPARE_SIZE 0x1020 #define SCC_SMN_PLAINTEXT_CHECK 0x1024 #define SCC_SMN_CIPHERTEXT_CHECK 0x1028 #define SCC_SMN_TIMER_IV 0x102C #define SCC_SMN_TIMER_CONTROL 0x1030 #define SCC_SMN_DEBUG_DETECT_STAT 0x1034 #define SCC_SMN_TIMER 0x1038 #define SCC_SCM_CTRL_START_CIPHER BIT(2) #define SCC_SCM_CTRL_CBC_MODE BIT(1) #define SCC_SCM_CTRL_DECRYPT_MODE BIT(0) #define SCC_SCM_STATUS_LEN_ERR BIT(12) #define SCC_SCM_STATUS_SMN_UNBLOCKED BIT(11) #define SCC_SCM_STATUS_CIPHERING_DONE BIT(10) #define SCC_SCM_STATUS_ZEROIZING_DONE BIT(9) #define SCC_SCM_STATUS_INTR_STATUS BIT(8) #define SCC_SCM_STATUS_SEC_KEY BIT(7) #define SCC_SCM_STATUS_INTERNAL_ERR BIT(6) #define SCC_SCM_STATUS_BAD_SEC_KEY BIT(5) #define SCC_SCM_STATUS_ZEROIZE_FAIL BIT(4) #define SCC_SCM_STATUS_SMN_BLOCKED BIT(3) #define SCC_SCM_STATUS_CIPHERING BIT(2) #define SCC_SCM_STATUS_ZEROIZING BIT(1) #define SCC_SCM_STATUS_BUSY BIT(0) #define SCC_SMN_STATUS_STATE_MASK 0x0000001F #define SCC_SMN_STATE_START 0x0 /* The SMN is zeroizing its RAM during reset */ #define SCC_SMN_STATE_ZEROIZE_RAM 0x5 /* SMN has passed internal checks */ #define SCC_SMN_STATE_HEALTH_CHECK 0x6 /* Fatal Security Violation. SMN is locked, SCM is inoperative. */ #define SCC_SMN_STATE_FAIL 0x9 /* SCC is in secure state. SCM is using secret key. */ #define SCC_SMN_STATE_SECURE 0xA /* SCC is not secure. SCM is using default key. */ #define SCC_SMN_STATE_NON_SECURE 0xC #define SCC_SCM_INTR_CTRL_ZEROIZE_MEM BIT(2) #define SCC_SCM_INTR_CTRL_CLR_INTR BIT(1) #define SCC_SCM_INTR_CTRL_MASK_INTR BIT(0) /* Size, in blocks, of Red memory. */ #define SCC_SCM_CFG_BLACK_SIZE_MASK 0x07fe0000 #define SCC_SCM_CFG_BLACK_SIZE_SHIFT 17 /* Size, in blocks, of Black memory. */ #define SCC_SCM_CFG_RED_SIZE_MASK 0x0001ff80 #define SCC_SCM_CFG_RED_SIZE_SHIFT 7 /* Number of bytes per block. */ #define SCC_SCM_CFG_BLOCK_SIZE_MASK 0x0000007f #define SCC_SMN_COMMAND_TAMPER_LOCK BIT(4) #define SCC_SMN_COMMAND_CLR_INTR BIT(3) #define SCC_SMN_COMMAND_CLR_BIT_BANK BIT(2) #define SCC_SMN_COMMAND_EN_INTR BIT(1) #define SCC_SMN_COMMAND_SET_SOFTWARE_ALARM BIT(0) #define SCC_KEY_SLOTS 20 #define SCC_MAX_KEY_SIZE 32 #define SCC_KEY_SLOT_SIZE 32 #define SCC_CRC_CCITT_START 0xFFFF /* * Offset into each RAM of the base of the area which is not * used for Stored Keys. */ #define SCC_NON_RESERVED_OFFSET (SCC_KEY_SLOTS * SCC_KEY_SLOT_SIZE) /* Fixed padding for appending to plaintext to fill out a block */ static char scc_block_padding[8] = { 0x80, 0, 0, 0, 0, 0, 0, 0 }; enum mxc_scc_state { SCC_STATE_OK, SCC_STATE_UNIMPLEMENTED, SCC_STATE_FAILED }; struct mxc_scc { struct device *dev; void __iomem *base; struct clk *clk; bool hw_busy; spinlock_t lock; struct crypto_queue queue; struct crypto_async_request *req; int block_size_bytes; int black_ram_size_blocks; int memory_size_bytes; int bytes_remaining; void __iomem *red_memory; void __iomem *black_memory; }; struct mxc_scc_ctx { struct mxc_scc *scc; struct scatterlist *sg_src; size_t src_nents; struct scatterlist *sg_dst; size_t dst_nents; unsigned int offset; unsigned int size; unsigned int ctrl; }; struct mxc_scc_crypto_tmpl { struct mxc_scc *scc; struct crypto_alg alg; }; static int mxc_scc_get_data(struct mxc_scc_ctx *ctx, struct crypto_async_request *req) { struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req); struct mxc_scc *scc = ctx->scc; size_t len; void __iomem *from; if (ctx->ctrl & SCC_SCM_CTRL_DECRYPT_MODE) from = scc->red_memory; else from = scc->black_memory; dev_dbg(scc->dev, "pcopy: from 0x%p %d bytes\n", from, ctx->dst_nents * 8); len = sg_pcopy_from_buffer(ablkreq->dst, ctx->dst_nents, from, ctx->size, ctx->offset); if (!len) { dev_err(scc->dev, "pcopy err from 0x%p (len=%d)\n", from, len); return -EINVAL; } #ifdef DEBUG print_hex_dump(KERN_ERR, "red memory@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, scc->red_memory, ctx->size, 1); print_hex_dump(KERN_ERR, "black memory@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, scc->black_memory, ctx->size, 1); #endif ctx->offset += len; if (ctx->offset < ablkreq->nbytes) return -EINPROGRESS; return 0; } static int mxc_scc_ablkcipher_req_init(struct ablkcipher_request *req, struct mxc_scc_ctx *ctx) { struct mxc_scc *scc = ctx->scc; int nents; nents = sg_nents_for_len(req->src, req->nbytes); if (nents < 0) { dev_err(scc->dev, "Invalid number of src SC"); return nents; } ctx->src_nents = nents; nents = sg_nents_for_len(req->dst, req->nbytes); if (nents < 0) { dev_err(scc->dev, "Invalid number of dst SC"); return nents; } ctx->dst_nents = nents; ctx->size = 0; ctx->offset = 0; return 0; } static int mxc_scc_ablkcipher_req_complete(struct crypto_async_request *req, struct mxc_scc_ctx *ctx, int result) { struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req); struct mxc_scc *scc = ctx->scc; scc->req = NULL; scc->bytes_remaining = scc->memory_size_bytes; if (ctx->ctrl & SCC_SCM_CTRL_CBC_MODE) memcpy(ablkreq->info, scc->base + SCC_SCM_INIT_VECTOR_0, scc->block_size_bytes); req->complete(req, result); scc->hw_busy = false; return 0; } static int mxc_scc_put_data(struct mxc_scc_ctx *ctx, struct ablkcipher_request *req) { u8 padding_buffer[sizeof(u16) + sizeof(scc_block_padding)]; size_t len = min_t(size_t, req->nbytes - ctx->offset, ctx->scc->bytes_remaining); unsigned int padding_byte_count = 0; struct mxc_scc *scc = ctx->scc; void __iomem *to; if (ctx->ctrl & SCC_SCM_CTRL_DECRYPT_MODE) to = scc->black_memory; else to = scc->red_memory; if (ctx->ctrl & SCC_SCM_CTRL_CBC_MODE && req->info) memcpy(scc->base + SCC_SCM_INIT_VECTOR_0, req->info, scc->block_size_bytes); len = sg_pcopy_to_buffer(req->src, ctx->src_nents, to, len, ctx->offset); if (!len) { dev_err(scc->dev, "pcopy err to 0x%p (len=%d)\n", to, len); return -EINVAL; } ctx->size = len; #ifdef DEBUG dev_dbg(scc->dev, "copied %d bytes to 0x%p\n", len, to); print_hex_dump(KERN_ERR, "init vector0@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, scc->base + SCC_SCM_INIT_VECTOR_0, scc->block_size_bytes, 1); print_hex_dump(KERN_ERR, "red memory@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, scc->red_memory, ctx->size, 1); print_hex_dump(KERN_ERR, "black memory@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, scc->black_memory, ctx->size, 1); #endif scc->bytes_remaining -= len; padding_byte_count = len % scc->block_size_bytes; if (padding_byte_count) { memcpy(padding_buffer, scc_block_padding, padding_byte_count); memcpy(to + len, padding_buffer, padding_byte_count); ctx->size += padding_byte_count; } #ifdef DEBUG print_hex_dump(KERN_ERR, "data to encrypt@"__stringify(__LINE__)": ", DUMP_PREFIX_ADDRESS, 16, 4, to, ctx->size, 1); #endif return 0; } static void mxc_scc_ablkcipher_next(struct mxc_scc_ctx *ctx, struct crypto_async_request *req) { struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req); struct mxc_scc *scc = ctx->scc; int err; dev_dbg(scc->dev, "dispatch request (nbytes=%d, src=%p, dst=%p)\n", ablkreq->nbytes, ablkreq->src, ablkreq->dst); writel(0, scc->base + SCC_SCM_ERROR_STATUS); err = mxc_scc_put_data(ctx, ablkreq); if (err) { mxc_scc_ablkcipher_req_complete(req, ctx, err); return; } dev_dbg(scc->dev, "Start encryption (0x%p/0x%p)\n", (void *)readl(scc->base + SCC_SCM_RED_START), (void *)readl(scc->base + SCC_SCM_BLACK_START)); /* clear interrupt control registers */ writel(SCC_SCM_INTR_CTRL_CLR_INTR, scc->base + SCC_SCM_INTR_CTRL); writel((ctx->size / ctx->scc->block_size_bytes) - 1, scc->base + SCC_SCM_LENGTH); dev_dbg(scc->dev, "Process %d block(s) in 0x%p\n", ctx->size / ctx->scc->block_size_bytes, (ctx->ctrl & SCC_SCM_CTRL_DECRYPT_MODE) ? scc->black_memory : scc->red_memory); writel(ctx->ctrl, scc->base + SCC_SCM_CTRL); } static irqreturn_t mxc_scc_int(int irq, void *priv) { struct crypto_async_request *req; struct mxc_scc_ctx *ctx; struct mxc_scc *scc = priv; int status; int ret; status = readl(scc->base + SCC_SCM_STATUS); /* clear interrupt control registers */ writel(SCC_SCM_INTR_CTRL_CLR_INTR, scc->base + SCC_SCM_INTR_CTRL); if (status & SCC_SCM_STATUS_BUSY) return IRQ_NONE; req = scc->req; if (req) { ctx = crypto_tfm_ctx(req->tfm); ret = mxc_scc_get_data(ctx, req); if (ret != -EINPROGRESS) mxc_scc_ablkcipher_req_complete(req, ctx, ret); else mxc_scc_ablkcipher_next(ctx, req); } return IRQ_HANDLED; } static int mxc_scc_cra_init(struct crypto_tfm *tfm) { struct mxc_scc_ctx *ctx = crypto_tfm_ctx(tfm); struct crypto_alg *alg = tfm->__crt_alg; struct mxc_scc_crypto_tmpl *algt; algt = container_of(alg, struct mxc_scc_crypto_tmpl, alg); ctx->scc = algt->scc; return 0; } static void mxc_scc_dequeue_req_unlocked(struct mxc_scc_ctx *ctx) { struct crypto_async_request *req, *backlog; if (ctx->scc->hw_busy) return; spin_lock_bh(&ctx->scc->lock); backlog = crypto_get_backlog(&ctx->scc->queue); req = crypto_dequeue_request(&ctx->scc->queue); ctx->scc->req = req; ctx->scc->hw_busy = true; spin_unlock_bh(&ctx->scc->lock); if (!req) return; if (backlog) backlog->complete(backlog, -EINPROGRESS); mxc_scc_ablkcipher_next(ctx, req); } static int mxc_scc_queue_req(struct mxc_scc_ctx *ctx, struct crypto_async_request *req) { int ret; spin_lock_bh(&ctx->scc->lock); ret = crypto_enqueue_request(&ctx->scc->queue, req); spin_unlock_bh(&ctx->scc->lock); if (ret != -EINPROGRESS) return ret; mxc_scc_dequeue_req_unlocked(ctx); return -EINPROGRESS; } static int mxc_scc_des3_op(struct mxc_scc_ctx *ctx, struct ablkcipher_request *req) { int err; err = mxc_scc_ablkcipher_req_init(req, ctx); if (err) return err; return mxc_scc_queue_req(ctx, &req->base); } static int mxc_scc_ecb_des_encrypt(struct ablkcipher_request *req) { struct crypto_ablkcipher *cipher = crypto_ablkcipher_reqtfm(req); struct mxc_scc_ctx *ctx = crypto_ablkcipher_ctx(cipher); ctx->ctrl = SCC_SCM_CTRL_START_CIPHER; return mxc_scc_des3_op(ctx, req); } static int mxc_scc_ecb_des_decrypt(struct ablkcipher_request *req) { struct crypto_ablkcipher *cipher = crypto_ablkcipher_reqtfm(req); struct mxc_scc_ctx *ctx = crypto_ablkcipher_ctx(cipher); ctx->ctrl = SCC_SCM_CTRL_START_CIPHER; ctx->ctrl |= SCC_SCM_CTRL_DECRYPT_MODE; return mxc_scc_des3_op(ctx, req); } static int mxc_scc_cbc_des_encrypt(struct ablkcipher_request *req) { struct crypto_ablkcipher *cipher = crypto_ablkcipher_reqtfm(req); struct mxc_scc_ctx *ctx = crypto_ablkcipher_ctx(cipher); ctx->ctrl = SCC_SCM_CTRL_START_CIPHER; ctx->ctrl |= SCC_SCM_CTRL_CBC_MODE; return mxc_scc_des3_op(ctx, req); } static int mxc_scc_cbc_des_decrypt(struct ablkcipher_request *req) { struct crypto_ablkcipher *cipher = crypto_ablkcipher_reqtfm(req); struct mxc_scc_ctx *ctx = crypto_ablkcipher_ctx(cipher); ctx->ctrl = SCC_SCM_CTRL_START_CIPHER; ctx->ctrl |= SCC_SCM_CTRL_CBC_MODE; ctx->ctrl |= SCC_SCM_CTRL_DECRYPT_MODE; return mxc_scc_des3_op(ctx, req); } static void mxc_scc_hw_init(struct mxc_scc *scc) { int offset; offset = SCC_NON_RESERVED_OFFSET / scc->block_size_bytes; /* Fill the RED_START register */ writel(offset, scc->base + SCC_SCM_RED_START); /* Fill the BLACK_START register */ writel(offset, scc->base + SCC_SCM_BLACK_START); scc->red_memory = scc->base + SCC_SCM_RED_MEMORY + SCC_NON_RESERVED_OFFSET; scc->black_memory = scc->base + SCC_SCM_BLACK_MEMORY + SCC_NON_RESERVED_OFFSET; scc->bytes_remaining = scc->memory_size_bytes; } static int mxc_scc_get_config(struct mxc_scc *scc) { int config; config = readl(scc->base + SCC_SCM_CFG); scc->block_size_bytes = config & SCC_SCM_CFG_BLOCK_SIZE_MASK; scc->black_ram_size_blocks = config & SCC_SCM_CFG_BLACK_SIZE_MASK; scc->memory_size_bytes = (scc->block_size_bytes * scc->black_ram_size_blocks) - SCC_NON_RESERVED_OFFSET; return 0; } static enum mxc_scc_state mxc_scc_get_state(struct mxc_scc *scc) { enum mxc_scc_state state; int status; status = readl(scc->base + SCC_SMN_STATUS) & SCC_SMN_STATUS_STATE_MASK; /* If in Health Check, try to bringup to secure state */ if (status & SCC_SMN_STATE_HEALTH_CHECK) { /* * Write a simple algorithm to the Algorithm Sequence * Checker (ASC) */ writel(0xaaaa, scc->base + SCC_SMN_SEQ_START); writel(0x5555, scc->base + SCC_SMN_SEQ_END); writel(0x5555, scc->base + SCC_SMN_SEQ_CHECK); status = readl(scc->base + SCC_SMN_STATUS) & SCC_SMN_STATUS_STATE_MASK; } switch (status) { case SCC_SMN_STATE_NON_SECURE: case SCC_SMN_STATE_SECURE: state = SCC_STATE_OK; break; case SCC_SMN_STATE_FAIL: state = SCC_STATE_FAILED; break; default: state = SCC_STATE_UNIMPLEMENTED; break; } return state; } static struct mxc_scc_crypto_tmpl scc_ecb_des = { .alg = { .cra_name = "ecb(des3_ede)", .cra_driver_name = "ecb-des3-scc", .cra_priority = 300, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER, .cra_blocksize = DES3_EDE_BLOCK_SIZE, .cra_ctxsize = sizeof(struct mxc_scc_ctx), .cra_alignmask = 0, .cra_type = &crypto_ablkcipher_type, .cra_module = THIS_MODULE, .cra_init = mxc_scc_cra_init, .cra_u.ablkcipher = { .min_keysize = DES3_EDE_KEY_SIZE, .max_keysize = DES3_EDE_KEY_SIZE, .encrypt = mxc_scc_ecb_des_encrypt, .decrypt = mxc_scc_ecb_des_decrypt, } } }; static struct mxc_scc_crypto_tmpl scc_cbc_des = { .alg = { .cra_name = "cbc(des3_ede)", .cra_driver_name = "cbc-des3-scc", .cra_priority = 300, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER, .cra_blocksize = DES3_EDE_BLOCK_SIZE, .cra_ctxsize = sizeof(struct mxc_scc_ctx), .cra_alignmask = 0, .cra_type = &crypto_ablkcipher_type, .cra_module = THIS_MODULE, .cra_init = mxc_scc_cra_init, .cra_u.ablkcipher = { .min_keysize = DES3_EDE_KEY_SIZE, .max_keysize = DES3_EDE_KEY_SIZE, .encrypt = mxc_scc_cbc_des_encrypt, .decrypt = mxc_scc_cbc_des_decrypt, } } }; static struct mxc_scc_crypto_tmpl *scc_crypto_algs[] = { &scc_ecb_des, &scc_cbc_des, }; static int mxc_scc_crypto_register(struct mxc_scc *scc) { int i; int err = 0; for (i = 0; i < ARRAY_SIZE(scc_crypto_algs); i++) { scc_crypto_algs[i]->scc = scc; err = crypto_register_alg(&scc_crypto_algs[i]->alg); if (err) goto err_out; } return 0; err_out: while (--i >= 0) crypto_unregister_alg(&scc_crypto_algs[i]->alg); return err; } static void mxc_scc_crypto_unregister(void) { unsigned int i; for (i = 0; i < ARRAY_SIZE(scc_crypto_algs); i++) crypto_unregister_alg(&scc_crypto_algs[i]->alg); } static int mxc_scc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct resource *res; struct mxc_scc *scc; enum mxc_scc_state state; int irq; int ret; int i; scc = devm_kzalloc(dev, sizeof(*scc), GFP_KERNEL); if (!scc) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); scc->base = devm_ioremap_resource(dev, res); if (IS_ERR(scc->base)) return PTR_ERR(scc->base); scc->clk = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(scc->clk)) { dev_err(dev, "Could not get ipg clock\n"); return PTR_ERR(scc->clk); } ret = clk_prepare_enable(scc->clk); if (ret) return ret; /* clear error status register */ writel(0x0, scc->base + SCC_SCM_ERROR_STATUS); /* clear interrupt control registers */ writel(SCC_SCM_INTR_CTRL_CLR_INTR | SCC_SCM_INTR_CTRL_MASK_INTR, scc->base + SCC_SCM_INTR_CTRL); writel(SCC_SMN_COMMAND_CLR_INTR | SCC_SMN_COMMAND_EN_INTR, scc->base + SCC_SMN_COMMAND); scc->dev = dev; platform_set_drvdata(pdev, scc); ret = mxc_scc_get_config(scc); if (ret) goto err_out; state = mxc_scc_get_state(scc); if (state != SCC_STATE_OK) { dev_err(dev, "SCC in unusable state %d\n", state); ret = -EINVAL; goto err_out; } mxc_scc_hw_init(scc); spin_lock_init(&scc->lock); /* FIXME: calculate queue from RAM slots */ crypto_init_queue(&scc->queue, 50); for (i = 0; i < 2; i++) { irq = platform_get_irq(pdev, i); if (irq < 0) { dev_err(dev, "failed to get irq resource: %d\n", irq); ret = irq; goto err_out; } ret = devm_request_threaded_irq(dev, irq, NULL, mxc_scc_int, IRQF_ONESHOT, dev_name(dev), scc); if (ret) goto err_out; } ret = mxc_scc_crypto_register(scc); if (ret) { dev_err(dev, "could not register algorithms"); goto err_out; } dev_info(dev, "registered successfully.\n"); return 0; err_out: clk_disable_unprepare(scc->clk); return ret; } static int mxc_scc_remove(struct platform_device *pdev) { struct mxc_scc *scc = platform_get_drvdata(pdev); mxc_scc_crypto_unregister(); clk_disable_unprepare(scc->clk); return 0; } static const struct of_device_id mxc_scc_dt_ids[] = { { .compatible = "fsl,imx25-scc", .data = NULL, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mxc_scc_dt_ids); static struct platform_driver mxc_scc_driver = { .probe = mxc_scc_probe, .remove = mxc_scc_remove, .driver = { .name = "mxc-scc", .of_match_table = mxc_scc_dt_ids, }, }; module_platform_driver(mxc_scc_driver); MODULE_AUTHOR("Steffen Trumtrar "); MODULE_DESCRIPTION("Freescale i.MX25 SCC Crypto driver"); MODULE_LICENSE("GPL v2");