diff mbox series

[v4,4/5] crypto: caam - add in-kernel interface for blob generator

Message ID 3ea6e5c37559eddfdc51f26c4dff0abbbc894839.1633946449.git-series.a.fatoum@pengutronix.de (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show
Series KEYS: trusted: Introduce support for NXP CAAM-based trusted keys | expand

Commit Message

Ahmad Fatoum Oct. 11, 2021, 10:02 a.m. UTC
The CAAM can be used to protect user-defined data across system reboot:

  - When the system is fused and boots into secure state, the master
    key is a unique never-disclosed device-specific key
  - random key is encrypted by key derived from master key
  - data is encrypted using the random key
  - encrypted data and its encrypted random key are stored alongside
  - This blob can now be safely stored in non-volatile memory

On next power-on:
  - blob is loaded into CAAM
  - CAAM writes decrypted data either into memory or key register

Add functions to realize encrypting and decrypting into memory alongside
the CAAM driver.

They will be used in a later commit as a source for the trusted key
seal/unseal mechanism.

Reviewed-by: David Gstir <david@sigma-star.at>
Tested-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
To: "Horia Geantă" <horia.geanta@nxp.com>
To: Aymen Sghaier <aymen.sghaier@nxp.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
To: "David S. Miller" <davem@davemloft.net>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Udit Agarwal <udit.agarwal@nxp.com>
Cc: Jan Luebbe <j.luebbe@pengutronix.de>
Cc: David Gstir <david@sigma-star.at>
Cc: Richard Weinberger <richard@nod.at>
Cc: Franck LENORMAND <franck.lenormand@nxp.com>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
---
 drivers/crypto/caam/Kconfig    |   3 +-
 drivers/crypto/caam/Makefile   |   1 +-
 drivers/crypto/caam/blob_gen.c | 230 ++++++++++++++++++++++++++++++++++-
 include/soc/fsl/caam-blob.h    |  56 ++++++++-
 4 files changed, 290 insertions(+)
 create mode 100644 drivers/crypto/caam/blob_gen.c
 create mode 100644 include/soc/fsl/caam-blob.h

Comments

Ahmad Fatoum Nov. 1, 2021, 8 a.m. UTC | #1
Hello Horia, Aymen,

On 11.10.21 12:02, Ahmad Fatoum wrote:
> The CAAM can be used to protect user-defined data across system reboot:
> 
>   - When the system is fused and boots into secure state, the master
>     key is a unique never-disclosed device-specific key
>   - random key is encrypted by key derived from master key
>   - data is encrypted using the random key
>   - encrypted data and its encrypted random key are stored alongside
>   - This blob can now be safely stored in non-volatile memory
> 
> On next power-on:
>   - blob is loaded into CAAM
>   - CAAM writes decrypted data either into memory or key register
> 
> Add functions to realize encrypting and decrypting into memory alongside
> the CAAM driver.
> 
> They will be used in a later commit as a source for the trusted key
> seal/unseal mechanism.

Did you have time to look at this again?

I have incorporated the changes request in v1 and the
code has since been reviewed and tested by others.

Thanks,
Ahmad
 
> Reviewed-by: David Gstir <david@sigma-star.at>
> Tested-By: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> To: "Horia Geantă" <horia.geanta@nxp.com>
> To: Aymen Sghaier <aymen.sghaier@nxp.com>
> To: Herbert Xu <herbert@gondor.apana.org.au>
> To: "David S. Miller" <davem@davemloft.net>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jarkko Sakkinen <jarkko@kernel.org>
> Cc: Mimi Zohar <zohar@linux.ibm.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: "Serge E. Hallyn" <serge@hallyn.com>
> Cc: Udit Agarwal <udit.agarwal@nxp.com>
> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
> Cc: Sumit Garg <sumit.garg@linaro.org>
> Cc: linux-integrity@vger.kernel.org
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
> ---
>  drivers/crypto/caam/Kconfig    |   3 +-
>  drivers/crypto/caam/Makefile   |   1 +-
>  drivers/crypto/caam/blob_gen.c | 230 ++++++++++++++++++++++++++++++++++-
>  include/soc/fsl/caam-blob.h    |  56 ++++++++-
>  4 files changed, 290 insertions(+)
>  create mode 100644 drivers/crypto/caam/blob_gen.c
>  create mode 100644 include/soc/fsl/caam-blob.h
> 
> diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
> index 84ea7cba5ee5..ea9f8b1ae981 100644
> --- a/drivers/crypto/caam/Kconfig
> +++ b/drivers/crypto/caam/Kconfig
> @@ -151,6 +151,9 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API
>  	  Selecting this will register the SEC4 hardware rng to
>  	  the hw_random API for supplying the kernel entropy pool.
>  
> +config CRYPTO_DEV_FSL_CAAM_BLOB_GEN
> +	bool
> +
>  endif # CRYPTO_DEV_FSL_CAAM_JR
>  
>  endif # CRYPTO_DEV_FSL_CAAM
> diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile
> index 3570286eb9ce..25f7ae5a4642 100644
> --- a/drivers/crypto/caam/Makefile
> +++ b/drivers/crypto/caam/Makefile
> @@ -21,6 +21,7 @@ caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o
> +caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o
>  
>  caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o
>  ifneq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),)
> diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c
> new file mode 100644
> index 000000000000..513d3f90e438
> --- /dev/null
> +++ b/drivers/crypto/caam/blob_gen.c
> @@ -0,0 +1,230 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
> + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
> + */
> +
> +#include <linux/device.h>
> +#include <soc/fsl/caam-blob.h>
> +
> +#include "compat.h"
> +#include "desc_constr.h"
> +#include "desc.h"
> +#include "error.h"
> +#include "intern.h"
> +#include "jr.h"
> +#include "regs.h"
> +
> +struct caam_blob_priv {
> +	struct device jrdev;
> +};
> +
> +struct caam_blob_job_result {
> +	int err;
> +	struct completion completion;
> +};
> +
> +static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
> +{
> +	struct caam_blob_job_result *res = context;
> +	int ecode = 0;
> +
> +	dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
> +
> +	if (err)
> +		ecode = caam_jr_strstatus(dev, err);
> +
> +	res->err = ecode;
> +
> +	/*
> +	 * Upon completion, desc points to a buffer containing a CAAM job
> +	 * descriptor which encapsulates data into an externally-storable
> +	 * blob.
> +	 */
> +	complete(&res->completion);
> +}
> +
> +static u32 *caam_blob_alloc_desc(size_t keymod_len)
> +{
> +	size_t len;
> +
> +	/* header + (key mod immediate) + 2x pointers + op */
> +	len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 + CAAM_PTR_SZ_MAX) + 4;
> +
> +	if (len > CAAM_DESC_BYTES_MAX)
> +		return NULL;
> +
> +	return kzalloc(len, GFP_KERNEL | GFP_DMA);
> +}
> +
> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
> +		    void *input, void *output, size_t length)
> +{
> +	u32 *desc;
> +	struct device *jrdev = &priv->jrdev;
> +	dma_addr_t dma_in, dma_out;
> +	struct caam_blob_job_result testres;
> +	size_t keymod_len = strlen(keymod);
> +	int ret;
> +
> +	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
> +		return -EINVAL;
> +
> +	desc = caam_blob_alloc_desc(keymod_len);
> +	if (!desc) {
> +		dev_err(jrdev, "unable to allocate desc\n");
> +		return -ENOMEM;
> +	}
> +
> +	dma_in = dma_map_single(jrdev, input, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
> +	if (dma_mapping_error(jrdev, dma_in)) {
> +		dev_err(jrdev, "unable to map input DMA buffer\n");
> +		ret = -ENOMEM;
> +		goto out_free;
> +	}
> +
> +	dma_out = dma_map_single(jrdev, output, length,	DMA_FROM_DEVICE);
> +	if (dma_mapping_error(jrdev, dma_out)) {
> +		dev_err(jrdev, "unable to map output DMA buffer\n");
> +		ret = -ENOMEM;
> +		goto out_unmap_in;
> +	}
> +
> +	/*
> +	 * A data blob is encrypted using a blob key (BK); a random number.
> +	 * The BK is used as an AES-CCM key. The initial block (B0) and the
> +	 * initial counter (Ctr0) are generated automatically and stored in
> +	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
> +	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
> +	 */
> +
> +	init_job_desc(desc, 0);
> +	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
> +			  CLASS_2 | KEY_DEST_CLASS_REG);
> +	append_seq_in_ptr_intlen(desc, dma_in, length - CAAM_BLOB_OVERHEAD, 0);
> +	append_seq_out_ptr_intlen(desc, dma_out, length, 0);
> +	append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB);
> +
> +	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
> +			     DUMP_PREFIX_ADDRESS, 16, 1, input,
> +			     length - CAAM_BLOB_OVERHEAD, false);
> +	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
> +			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
> +			     desc_bytes(desc), false);
> +
> +	testres.err = 0;
> +	init_completion(&testres.completion);
> +
> +	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
> +	if (ret == -EINPROGRESS) {
> +		wait_for_completion(&testres.completion);
> +		ret = testres.err;
> +		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
> +				     DUMP_PREFIX_ADDRESS, 16, 1, output,
> +				     length, false);
> +	}
> +
> +	dma_unmap_single(jrdev, dma_out, length, DMA_FROM_DEVICE);
> +out_unmap_in:
> +	dma_unmap_single(jrdev, dma_in, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
> +out_free:
> +	kfree(desc);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(caam_encap_blob);
> +
> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
> +		    void *input, void *output, size_t length)
> +{
> +	u32 *desc;
> +	struct device *jrdev = &priv->jrdev;
> +	dma_addr_t dma_in, dma_out;
> +	struct caam_blob_job_result testres;
> +	size_t keymod_len = strlen(keymod);
> +	int ret;
> +
> +	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
> +		return -EINVAL;
> +
> +	desc = caam_blob_alloc_desc(keymod_len);
> +	if (!desc) {
> +		dev_err(jrdev, "unable to allocate desc\n");
> +		return -ENOMEM;
> +	}
> +
> +	dma_in = dma_map_single(jrdev, input, length, DMA_TO_DEVICE);
> +	if (dma_mapping_error(jrdev, dma_in)) {
> +		dev_err(jrdev, "unable to map input DMA buffer\n");
> +		ret = -ENOMEM;
> +		goto out_free;
> +	}
> +
> +	dma_out = dma_map_single(jrdev, output, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
> +	if (dma_mapping_error(jrdev, dma_out)) {
> +		dev_err(jrdev, "unable to map output DMA buffer\n");
> +		ret = -ENOMEM;
> +		goto out_unmap_in;
> +	}
> +
> +	/*
> +	 * A data blob is encrypted using a blob key (BK); a random number.
> +	 * The BK is used as an AES-CCM key. The initial block (B0) and the
> +	 * initial counter (Ctr0) are generated automatically and stored in
> +	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
> +	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
> +	 */
> +
> +	init_job_desc(desc, 0);
> +	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
> +			  CLASS_2 | KEY_DEST_CLASS_REG);
> +	append_seq_in_ptr(desc, dma_in, length, 0);
> +	append_seq_out_ptr(desc, dma_out, length - CAAM_BLOB_OVERHEAD, 0);
> +	append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB);
> +
> +	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
> +			     DUMP_PREFIX_ADDRESS, 16, 1, input,
> +			     length, false);
> +	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
> +			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
> +			     desc_bytes(desc), false);
> +
> +	testres.err = 0;
> +	init_completion(&testres.completion);
> +
> +	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
> +	if (ret == -EINPROGRESS) {
> +		wait_for_completion(&testres.completion);
> +		ret = testres.err;
> +		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
> +				     DUMP_PREFIX_ADDRESS, 16, 1, output,
> +				     length - CAAM_BLOB_OVERHEAD, false);
> +	}
> +
> +	dma_unmap_single(jrdev, dma_out, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
> +out_unmap_in:
> +	dma_unmap_single(jrdev, dma_in, length, DMA_TO_DEVICE);
> +out_free:
> +	kfree(desc);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(caam_decap_blob);
> +
> +struct caam_blob_priv *caam_blob_gen_init(void)
> +{
> +	struct device *jrdev;
> +
> +	jrdev = caam_jr_alloc();
> +	if (IS_ERR(jrdev))
> +		return ERR_CAST(jrdev);
> +
> +	return container_of(jrdev, struct caam_blob_priv, jrdev);
> +}
> +EXPORT_SYMBOL(caam_blob_gen_init);
> +
> +void caam_blob_gen_exit(struct caam_blob_priv *priv)
> +{
> +	caam_jr_free(&priv->jrdev);
> +}
> +EXPORT_SYMBOL(caam_blob_gen_exit);
> diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h
> new file mode 100644
> index 000000000000..83fd990ebdce
> --- /dev/null
> +++ b/include/soc/fsl/caam-blob.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
> + */
> +
> +#ifndef __CAAM_BLOB_GEN
> +#define __CAAM_BLOB_GEN
> +
> +#include <linux/types.h>
> +
> +#define CAAM_BLOB_KEYMOD_LENGTH		16
> +#define CAAM_BLOB_OVERHEAD		(32 + 16)
> +#define CAAM_BLOB_MAX_LEN		4096
> +
> +struct caam_blob_priv;
> +
> +/** caam_blob_gen_init - initialize blob generation
> + *
> + * returns either pointer to new caam_blob_priv instance
> + * or error pointer
> + */
> +struct caam_blob_priv *caam_blob_gen_init(void);
> +
> +/** caam_blob_gen_exit - free blob generation resources
> + *
> + * @priv: instance returned by caam_blob_gen_init
> + */
> +void caam_blob_gen_exit(struct caam_blob_priv *priv);
> +
> +/** caam_encap_blob - encapsulate blob
> + *
> + * @priv:   instance returned by caam_blob_gen_init
> + * @keymod: string to use as key modifier for blob encapsulation
> + *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
> + * @input:  buffer which CAAM will DMA from
> + * @output: buffer which CAAM will DMA to
> + * @length: buffer length including blob overhead
> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
> + */
> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
> +		    void *input, void *output, size_t length);
> +
> +/** caam_decap_blob - decapsulate blob
> + *
> + * @priv:   instance returned by caam_blob_gen_init
> + * @keymod: string to use as key modifier for blob decapsulation
> + *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
> + * @input:  buffer which CAAM will DMA from
> + * @output: buffer which CAAM will DMA to
> + * @length: buffer length including blob overhead
> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
> + */
> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
> +		    void *input, void *output, size_t length);
> +
> +#endif
>
Ahmad Fatoum Nov. 24, 2021, 7:48 a.m. UTC | #2
Hello again,

On 01.11.21 09:00, Ahmad Fatoum wrote:
> Hello Horia, Aymen,
> 
> On 11.10.21 12:02, Ahmad Fatoum wrote:
>> The CAAM can be used to protect user-defined data across system reboot:
>>
>>   - When the system is fused and boots into secure state, the master
>>     key is a unique never-disclosed device-specific key
>>   - random key is encrypted by key derived from master key
>>   - data is encrypted using the random key
>>   - encrypted data and its encrypted random key are stored alongside
>>   - This blob can now be safely stored in non-volatile memory
>>
>> On next power-on:
>>   - blob is loaded into CAAM
>>   - CAAM writes decrypted data either into memory or key register
>>
>> Add functions to realize encrypting and decrypting into memory alongside
>> the CAAM driver.
>>
>> They will be used in a later commit as a source for the trusted key
>> seal/unseal mechanism.
> 
> Did you have time to look at this again?

Ping.

> 
> I have incorporated the changes request in v1 and the
> code has since been reviewed and tested by others.
> 
> Thanks,
> Ahmad
>  
>> Reviewed-by: David Gstir <david@sigma-star.at>
>> Tested-By: Tim Harvey <tharvey@gateworks.com>
>> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>> ---
>> To: "Horia Geantă" <horia.geanta@nxp.com>
>> To: Aymen Sghaier <aymen.sghaier@nxp.com>
>> To: Herbert Xu <herbert@gondor.apana.org.au>
>> To: "David S. Miller" <davem@davemloft.net>
>> Cc: James Bottomley <jejb@linux.ibm.com>
>> Cc: Jarkko Sakkinen <jarkko@kernel.org>
>> Cc: Mimi Zohar <zohar@linux.ibm.com>
>> Cc: David Howells <dhowells@redhat.com>
>> Cc: James Morris <jmorris@namei.org>
>> Cc: Eric Biggers <ebiggers@kernel.org>
>> Cc: "Serge E. Hallyn" <serge@hallyn.com>
>> Cc: Udit Agarwal <udit.agarwal@nxp.com>
>> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
>> Cc: David Gstir <david@sigma-star.at>
>> Cc: Richard Weinberger <richard@nod.at>
>> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
>> Cc: Sumit Garg <sumit.garg@linaro.org>
>> Cc: linux-integrity@vger.kernel.org
>> Cc: keyrings@vger.kernel.org
>> Cc: linux-crypto@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-security-module@vger.kernel.org
>> ---
>>  drivers/crypto/caam/Kconfig    |   3 +-
>>  drivers/crypto/caam/Makefile   |   1 +-
>>  drivers/crypto/caam/blob_gen.c | 230 ++++++++++++++++++++++++++++++++++-
>>  include/soc/fsl/caam-blob.h    |  56 ++++++++-
>>  4 files changed, 290 insertions(+)
>>  create mode 100644 drivers/crypto/caam/blob_gen.c
>>  create mode 100644 include/soc/fsl/caam-blob.h
>>
>> diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
>> index 84ea7cba5ee5..ea9f8b1ae981 100644
>> --- a/drivers/crypto/caam/Kconfig
>> +++ b/drivers/crypto/caam/Kconfig
>> @@ -151,6 +151,9 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API
>>  	  Selecting this will register the SEC4 hardware rng to
>>  	  the hw_random API for supplying the kernel entropy pool.
>>  
>> +config CRYPTO_DEV_FSL_CAAM_BLOB_GEN
>> +	bool
>> +
>>  endif # CRYPTO_DEV_FSL_CAAM_JR
>>  
>>  endif # CRYPTO_DEV_FSL_CAAM
>> diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile
>> index 3570286eb9ce..25f7ae5a4642 100644
>> --- a/drivers/crypto/caam/Makefile
>> +++ b/drivers/crypto/caam/Makefile
>> @@ -21,6 +21,7 @@ caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o
>>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o
>>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o
>>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o
>> +caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o
>>  
>>  caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o
>>  ifneq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),)
>> diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c
>> new file mode 100644
>> index 000000000000..513d3f90e438
>> --- /dev/null
>> +++ b/drivers/crypto/caam/blob_gen.c
>> @@ -0,0 +1,230 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
>> + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <soc/fsl/caam-blob.h>
>> +
>> +#include "compat.h"
>> +#include "desc_constr.h"
>> +#include "desc.h"
>> +#include "error.h"
>> +#include "intern.h"
>> +#include "jr.h"
>> +#include "regs.h"
>> +
>> +struct caam_blob_priv {
>> +	struct device jrdev;
>> +};
>> +
>> +struct caam_blob_job_result {
>> +	int err;
>> +	struct completion completion;
>> +};
>> +
>> +static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
>> +{
>> +	struct caam_blob_job_result *res = context;
>> +	int ecode = 0;
>> +
>> +	dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
>> +
>> +	if (err)
>> +		ecode = caam_jr_strstatus(dev, err);
>> +
>> +	res->err = ecode;
>> +
>> +	/*
>> +	 * Upon completion, desc points to a buffer containing a CAAM job
>> +	 * descriptor which encapsulates data into an externally-storable
>> +	 * blob.
>> +	 */
>> +	complete(&res->completion);
>> +}
>> +
>> +static u32 *caam_blob_alloc_desc(size_t keymod_len)
>> +{
>> +	size_t len;
>> +
>> +	/* header + (key mod immediate) + 2x pointers + op */
>> +	len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 + CAAM_PTR_SZ_MAX) + 4;
>> +
>> +	if (len > CAAM_DESC_BYTES_MAX)
>> +		return NULL;
>> +
>> +	return kzalloc(len, GFP_KERNEL | GFP_DMA);
>> +}
>> +
>> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
>> +		    void *input, void *output, size_t length)
>> +{
>> +	u32 *desc;
>> +	struct device *jrdev = &priv->jrdev;
>> +	dma_addr_t dma_in, dma_out;
>> +	struct caam_blob_job_result testres;
>> +	size_t keymod_len = strlen(keymod);
>> +	int ret;
>> +
>> +	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
>> +		return -EINVAL;
>> +
>> +	desc = caam_blob_alloc_desc(keymod_len);
>> +	if (!desc) {
>> +		dev_err(jrdev, "unable to allocate desc\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	dma_in = dma_map_single(jrdev, input, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
>> +	if (dma_mapping_error(jrdev, dma_in)) {
>> +		dev_err(jrdev, "unable to map input DMA buffer\n");
>> +		ret = -ENOMEM;
>> +		goto out_free;
>> +	}
>> +
>> +	dma_out = dma_map_single(jrdev, output, length,	DMA_FROM_DEVICE);
>> +	if (dma_mapping_error(jrdev, dma_out)) {
>> +		dev_err(jrdev, "unable to map output DMA buffer\n");
>> +		ret = -ENOMEM;
>> +		goto out_unmap_in;
>> +	}
>> +
>> +	/*
>> +	 * A data blob is encrypted using a blob key (BK); a random number.
>> +	 * The BK is used as an AES-CCM key. The initial block (B0) and the
>> +	 * initial counter (Ctr0) are generated automatically and stored in
>> +	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
>> +	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
>> +	 */
>> +
>> +	init_job_desc(desc, 0);
>> +	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
>> +			  CLASS_2 | KEY_DEST_CLASS_REG);
>> +	append_seq_in_ptr_intlen(desc, dma_in, length - CAAM_BLOB_OVERHEAD, 0);
>> +	append_seq_out_ptr_intlen(desc, dma_out, length, 0);
>> +	append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB);
>> +
>> +	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
>> +			     DUMP_PREFIX_ADDRESS, 16, 1, input,
>> +			     length - CAAM_BLOB_OVERHEAD, false);
>> +	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
>> +			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
>> +			     desc_bytes(desc), false);
>> +
>> +	testres.err = 0;
>> +	init_completion(&testres.completion);
>> +
>> +	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
>> +	if (ret == -EINPROGRESS) {
>> +		wait_for_completion(&testres.completion);
>> +		ret = testres.err;
>> +		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
>> +				     DUMP_PREFIX_ADDRESS, 16, 1, output,
>> +				     length, false);
>> +	}
>> +
>> +	dma_unmap_single(jrdev, dma_out, length, DMA_FROM_DEVICE);
>> +out_unmap_in:
>> +	dma_unmap_single(jrdev, dma_in, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
>> +out_free:
>> +	kfree(desc);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL(caam_encap_blob);
>> +
>> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
>> +		    void *input, void *output, size_t length)
>> +{
>> +	u32 *desc;
>> +	struct device *jrdev = &priv->jrdev;
>> +	dma_addr_t dma_in, dma_out;
>> +	struct caam_blob_job_result testres;
>> +	size_t keymod_len = strlen(keymod);
>> +	int ret;
>> +
>> +	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
>> +		return -EINVAL;
>> +
>> +	desc = caam_blob_alloc_desc(keymod_len);
>> +	if (!desc) {
>> +		dev_err(jrdev, "unable to allocate desc\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	dma_in = dma_map_single(jrdev, input, length, DMA_TO_DEVICE);
>> +	if (dma_mapping_error(jrdev, dma_in)) {
>> +		dev_err(jrdev, "unable to map input DMA buffer\n");
>> +		ret = -ENOMEM;
>> +		goto out_free;
>> +	}
>> +
>> +	dma_out = dma_map_single(jrdev, output, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
>> +	if (dma_mapping_error(jrdev, dma_out)) {
>> +		dev_err(jrdev, "unable to map output DMA buffer\n");
>> +		ret = -ENOMEM;
>> +		goto out_unmap_in;
>> +	}
>> +
>> +	/*
>> +	 * A data blob is encrypted using a blob key (BK); a random number.
>> +	 * The BK is used as an AES-CCM key. The initial block (B0) and the
>> +	 * initial counter (Ctr0) are generated automatically and stored in
>> +	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
>> +	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
>> +	 */
>> +
>> +	init_job_desc(desc, 0);
>> +	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
>> +			  CLASS_2 | KEY_DEST_CLASS_REG);
>> +	append_seq_in_ptr(desc, dma_in, length, 0);
>> +	append_seq_out_ptr(desc, dma_out, length - CAAM_BLOB_OVERHEAD, 0);
>> +	append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB);
>> +
>> +	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
>> +			     DUMP_PREFIX_ADDRESS, 16, 1, input,
>> +			     length, false);
>> +	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
>> +			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
>> +			     desc_bytes(desc), false);
>> +
>> +	testres.err = 0;
>> +	init_completion(&testres.completion);
>> +
>> +	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
>> +	if (ret == -EINPROGRESS) {
>> +		wait_for_completion(&testres.completion);
>> +		ret = testres.err;
>> +		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
>> +				     DUMP_PREFIX_ADDRESS, 16, 1, output,
>> +				     length - CAAM_BLOB_OVERHEAD, false);
>> +	}
>> +
>> +	dma_unmap_single(jrdev, dma_out, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
>> +out_unmap_in:
>> +	dma_unmap_single(jrdev, dma_in, length, DMA_TO_DEVICE);
>> +out_free:
>> +	kfree(desc);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL(caam_decap_blob);
>> +
>> +struct caam_blob_priv *caam_blob_gen_init(void)
>> +{
>> +	struct device *jrdev;
>> +
>> +	jrdev = caam_jr_alloc();
>> +	if (IS_ERR(jrdev))
>> +		return ERR_CAST(jrdev);
>> +
>> +	return container_of(jrdev, struct caam_blob_priv, jrdev);
>> +}
>> +EXPORT_SYMBOL(caam_blob_gen_init);
>> +
>> +void caam_blob_gen_exit(struct caam_blob_priv *priv)
>> +{
>> +	caam_jr_free(&priv->jrdev);
>> +}
>> +EXPORT_SYMBOL(caam_blob_gen_exit);
>> diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h
>> new file mode 100644
>> index 000000000000..83fd990ebdce
>> --- /dev/null
>> +++ b/include/soc/fsl/caam-blob.h
>> @@ -0,0 +1,56 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
>> + */
>> +
>> +#ifndef __CAAM_BLOB_GEN
>> +#define __CAAM_BLOB_GEN
>> +
>> +#include <linux/types.h>
>> +
>> +#define CAAM_BLOB_KEYMOD_LENGTH		16
>> +#define CAAM_BLOB_OVERHEAD		(32 + 16)
>> +#define CAAM_BLOB_MAX_LEN		4096
>> +
>> +struct caam_blob_priv;
>> +
>> +/** caam_blob_gen_init - initialize blob generation
>> + *
>> + * returns either pointer to new caam_blob_priv instance
>> + * or error pointer
>> + */
>> +struct caam_blob_priv *caam_blob_gen_init(void);
>> +
>> +/** caam_blob_gen_exit - free blob generation resources
>> + *
>> + * @priv: instance returned by caam_blob_gen_init
>> + */
>> +void caam_blob_gen_exit(struct caam_blob_priv *priv);
>> +
>> +/** caam_encap_blob - encapsulate blob
>> + *
>> + * @priv:   instance returned by caam_blob_gen_init
>> + * @keymod: string to use as key modifier for blob encapsulation
>> + *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
>> + * @input:  buffer which CAAM will DMA from
>> + * @output: buffer which CAAM will DMA to
>> + * @length: buffer length including blob overhead
>> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
>> + */
>> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
>> +		    void *input, void *output, size_t length);
>> +
>> +/** caam_decap_blob - decapsulate blob
>> + *
>> + * @priv:   instance returned by caam_blob_gen_init
>> + * @keymod: string to use as key modifier for blob decapsulation
>> + *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
>> + * @input:  buffer which CAAM will DMA from
>> + * @output: buffer which CAAM will DMA to
>> + * @length: buffer length including blob overhead
>> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
>> + */
>> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
>> +		    void *input, void *output, size_t length);
>> +
>> +#endif
>>
> 
>
Jarkko Sakkinen Dec. 5, 2021, 12:18 a.m. UTC | #3
On Mon, Oct 11, 2021 at 12:02:37PM +0200, Ahmad Fatoum wrote:
> The CAAM can be used to protect user-defined data across system reboot:
> 
>   - When the system is fused and boots into secure state, the master
>     key is a unique never-disclosed device-specific key
>   - random key is encrypted by key derived from master key
>   - data is encrypted using the random key
>   - encrypted data and its encrypted random key are stored alongside
>   - This blob can now be safely stored in non-volatile memory
> 
> On next power-on:
>   - blob is loaded into CAAM
>   - CAAM writes decrypted data either into memory or key register
> 
> Add functions to realize encrypting and decrypting into memory alongside
> the CAAM driver.
> 
> They will be used in a later commit as a source for the trusted key
> seal/unseal mechanism.
> 
> Reviewed-by: David Gstir <david@sigma-star.at>
> Tested-By: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

What is CAAM? This is missing.

/Jarkko
Ahmad Fatoum Dec. 13, 2021, 10:34 a.m. UTC | #4
Hello Jarkko,

On 05.12.21 01:18, Jarkko Sakkinen wrote:
> On Mon, Oct 11, 2021 at 12:02:37PM +0200, Ahmad Fatoum wrote:
>> The CAAM can be used to protect user-defined data across system reboot:
>>
>>   - When the system is fused and boots into secure state, the master
>>     key is a unique never-disclosed device-specific key
>>   - random key is encrypted by key derived from master key
>>   - data is encrypted using the random key
>>   - encrypted data and its encrypted random key are stored alongside
>>   - This blob can now be safely stored in non-volatile memory
>>
>> On next power-on:
>>   - blob is loaded into CAAM
>>   - CAAM writes decrypted data either into memory or key register
>>
>> Add functions to realize encrypting and decrypting into memory alongside
>> the CAAM driver.
>>
>> They will be used in a later commit as a source for the trusted key
>> seal/unseal mechanism.
>>
>> Reviewed-by: David Gstir <david@sigma-star.at>
>> Tested-By: Tim Harvey <tharvey@gateworks.com>
>> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> 
> What is CAAM? This is missing.

That's Crypto Accelerator on NXP SoCs. There is a description in the cover
letter and in the follow-up patch wiring this into the new trusted key
source. I didn't elaborate on this here as this patch touches
drivers/crypto/caam and I assumed familiarity.

For v5, I can add some extra info:

"The NXP Cryptographic Acceleration and Assurance Module (CAAM)
 can be used to protect user-defined data across system reboot..."

Sounds good? Does the last patch in the series look ok to you?

Cheers,
Ahmad

> 
> /Jarkko
>
Pankaj Gupta (OSS) Dec. 23, 2021, 7:20 a.m. UTC | #5
Reviewed-by: Pankaj Gupta <pankaj.gupta@nxp.com>

> -----Original Message-----
> From: Ahmad Fatoum <a.fatoum@pengutronix.de>
> Sent: Monday, October 11, 2021 3:33 PM
> To: Horia Geanta <horia.geanta@nxp.com>; Aymen Sghaier
> <aymen.sghaier@nxp.com>; Herbert Xu <herbert@gondor.apana.org.au>;
> David S. Miller <davem@davemloft.net>
> Cc: kernel@pengutronix.de; David Gstir <david@sigma-star.at>;
> tharvey@gateworks.com; Ahmad Fatoum <a.fatoum@pengutronix.de>; James
> Bottomley <jejb@linux.ibm.com>; Jarkko Sakkinen <jarkko@kernel.org>; Mimi
> Zohar <zohar@linux.ibm.com>; David Howells <dhowells@redhat.com>; James
> Morris <jmorris@namei.org>; Eric Biggers <ebiggers@kernel.org>; Serge E.
> Hallyn <serge@hallyn.com>; Udit Agarwal <udit.agarwal@nxp.com>; Jan
> Luebbe <j.luebbe@pengutronix.de>; Richard Weinberger <richard@nod.at>;
> Franck Lenormand <franck.lenormand@nxp.com>; Sumit Garg
> <sumit.garg@linaro.org>; linux-integrity@vger.kernel.org;
> keyrings@vger.kernel.org; linux-crypto@vger.kernel.org; linux-
> kernel@vger.kernel.org; linux-security-module@vger.kernel.org
> Subject: [EXT] [PATCH v4 4/5] crypto: caam - add in-kernel interface for blob
> generator
> 
> Caution: EXT Email
> 
> The CAAM can be used to protect user-defined data across system reboot:
> 
>   - When the system is fused and boots into secure state, the master
>     key is a unique never-disclosed device-specific key
>   - random key is encrypted by key derived from master key
>   - data is encrypted using the random key
>   - encrypted data and its encrypted random key are stored alongside
>   - This blob can now be safely stored in non-volatile memory
> 
> On next power-on:
>   - blob is loaded into CAAM
>   - CAAM writes decrypted data either into memory or key register
> 
> Add functions to realize encrypting and decrypting into memory alongside the
> CAAM driver.
> 
> They will be used in a later commit as a source for the trusted key seal/unseal
> mechanism.
> 
> Reviewed-by: David Gstir <david@sigma-star.at>
> Tested-By: Tim Harvey <tharvey@gateworks.com>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> To: "Horia Geantă" <horia.geanta@nxp.com>
> To: Aymen Sghaier <aymen.sghaier@nxp.com>
> To: Herbert Xu <herbert@gondor.apana.org.au>
> To: "David S. Miller" <davem@davemloft.net>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jarkko Sakkinen <jarkko@kernel.org>
> Cc: Mimi Zohar <zohar@linux.ibm.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: "Serge E. Hallyn" <serge@hallyn.com>
> Cc: Udit Agarwal <udit.agarwal@nxp.com>
> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
> Cc: Sumit Garg <sumit.garg@linaro.org>
> Cc: linux-integrity@vger.kernel.org
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
> ---
>  drivers/crypto/caam/Kconfig    |   3 +-
>  drivers/crypto/caam/Makefile   |   1 +-
>  drivers/crypto/caam/blob_gen.c | 230
> ++++++++++++++++++++++++++++++++++-
>  include/soc/fsl/caam-blob.h    |  56 ++++++++-
>  4 files changed, 290 insertions(+)
>  create mode 100644 drivers/crypto/caam/blob_gen.c  create mode 100644
> include/soc/fsl/caam-blob.h
> 
> diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig index
> 84ea7cba5ee5..ea9f8b1ae981 100644
> --- a/drivers/crypto/caam/Kconfig
> +++ b/drivers/crypto/caam/Kconfig
> @@ -151,6 +151,9 @@ config CRYPTO_DEV_FSL_CAAM_RNG_API
>           Selecting this will register the SEC4 hardware rng to
>           the hw_random API for supplying the kernel entropy pool.
> 
> +config CRYPTO_DEV_FSL_CAAM_BLOB_GEN
> +       bool
> +
>  endif # CRYPTO_DEV_FSL_CAAM_JR
> 
>  endif # CRYPTO_DEV_FSL_CAAM
> diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile index
> 3570286eb9ce..25f7ae5a4642 100644
> --- a/drivers/crypto/caam/Makefile
> +++ b/drivers/crypto/caam/Makefile
> @@ -21,6 +21,7 @@ caam_jr-
> $(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o
>  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o
> pkc_desc.o
> +caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o
> 
>  caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o  ifneq
> ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),)
> diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c
> new file mode 100644 index 000000000000..513d3f90e438
> --- /dev/null
> +++ b/drivers/crypto/caam/blob_gen.c
> @@ -0,0 +1,230 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2015 Pengutronix, Steffen Trumtrar
> +<kernel@pengutronix.de>
> + * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
> +*/
> +
> +#include <linux/device.h>
> +#include <soc/fsl/caam-blob.h>
> +
> +#include "compat.h"
> +#include "desc_constr.h"
> +#include "desc.h"
> +#include "error.h"
> +#include "intern.h"
> +#include "jr.h"
> +#include "regs.h"
> +
> +struct caam_blob_priv {
> +       struct device jrdev;
> +};
> +
> +struct caam_blob_job_result {
> +       int err;
> +       struct completion completion;
> +};
> +
> +static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err,
> +void *context) {
> +       struct caam_blob_job_result *res = context;
> +       int ecode = 0;
> +
> +       dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
> +
> +       if (err)
> +               ecode = caam_jr_strstatus(dev, err);
> +
> +       res->err = ecode;
> +
> +       /*
> +        * Upon completion, desc points to a buffer containing a CAAM job
> +        * descriptor which encapsulates data into an externally-storable
> +        * blob.
> +        */
> +       complete(&res->completion);
> +}
> +
> +static u32 *caam_blob_alloc_desc(size_t keymod_len) {
> +       size_t len;
> +
> +       /* header + (key mod immediate) + 2x pointers + op */
> +       len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 +
> + CAAM_PTR_SZ_MAX) + 4;
> +
> +       if (len > CAAM_DESC_BYTES_MAX)
> +               return NULL;
> +
> +       return kzalloc(len, GFP_KERNEL | GFP_DMA); }
> +
> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
> +                   void *input, void *output, size_t length) {
> +       u32 *desc;
> +       struct device *jrdev = &priv->jrdev;
> +       dma_addr_t dma_in, dma_out;
> +       struct caam_blob_job_result testres;
> +       size_t keymod_len = strlen(keymod);
> +       int ret;
> +
> +       if (length <= CAAM_BLOB_OVERHEAD || keymod_len >
> CAAM_BLOB_KEYMOD_LENGTH)
> +               return -EINVAL;
> +
> +       desc = caam_blob_alloc_desc(keymod_len);
> +       if (!desc) {
> +               dev_err(jrdev, "unable to allocate desc\n");
> +               return -ENOMEM;
> +       }
> +
> +       dma_in = dma_map_single(jrdev, input, length - CAAM_BLOB_OVERHEAD,
> DMA_TO_DEVICE);
> +       if (dma_mapping_error(jrdev, dma_in)) {
> +               dev_err(jrdev, "unable to map input DMA buffer\n");
> +               ret = -ENOMEM;
> +               goto out_free;
> +       }
> +
> +       dma_out = dma_map_single(jrdev, output, length, DMA_FROM_DEVICE);
> +       if (dma_mapping_error(jrdev, dma_out)) {
> +               dev_err(jrdev, "unable to map output DMA buffer\n");
> +               ret = -ENOMEM;
> +               goto out_unmap_in;
> +       }
> +
> +       /*
> +        * A data blob is encrypted using a blob key (BK); a random number.
> +        * The BK is used as an AES-CCM key. The initial block (B0) and the
> +        * initial counter (Ctr0) are generated automatically and stored in
> +        * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
> +        * Class 1 Key Register. Operation Mode is set to AES-CCM.
> +        */
> +
> +       init_job_desc(desc, 0);
> +       append_key_as_imm(desc, keymod, keymod_len, keymod_len,
> +                         CLASS_2 | KEY_DEST_CLASS_REG);
> +       append_seq_in_ptr_intlen(desc, dma_in, length - CAAM_BLOB_OVERHEAD,
> 0);
> +       append_seq_out_ptr_intlen(desc, dma_out, length, 0);
> +       append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB);
> +
> +       print_hex_dump_debug("data@"__stringify(__LINE__)": ",
> +                            DUMP_PREFIX_ADDRESS, 16, 1, input,
> +                            length - CAAM_BLOB_OVERHEAD, false);
> +       print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
> +                            DUMP_PREFIX_ADDRESS, 16, 1, desc,
> +                            desc_bytes(desc), false);
> +
> +       testres.err = 0;
> +       init_completion(&testres.completion);
> +
> +       ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
> +       if (ret == -EINPROGRESS) {
> +               wait_for_completion(&testres.completion);
> +               ret = testres.err;
> +               print_hex_dump_debug("output@"__stringify(__LINE__)": ",
> +                                    DUMP_PREFIX_ADDRESS, 16, 1, output,
> +                                    length, false);
> +       }
> +
> +       dma_unmap_single(jrdev, dma_out, length, DMA_FROM_DEVICE);
> +out_unmap_in:
> +       dma_unmap_single(jrdev, dma_in, length - CAAM_BLOB_OVERHEAD,
> +DMA_TO_DEVICE);
> +out_free:
> +       kfree(desc);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL(caam_encap_blob);
> +
> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
> +                   void *input, void *output, size_t length) {
> +       u32 *desc;
> +       struct device *jrdev = &priv->jrdev;
> +       dma_addr_t dma_in, dma_out;
> +       struct caam_blob_job_result testres;
> +       size_t keymod_len = strlen(keymod);
> +       int ret;
> +
> +       if (length <= CAAM_BLOB_OVERHEAD || keymod_len >
> CAAM_BLOB_KEYMOD_LENGTH)
> +               return -EINVAL;
> +
> +       desc = caam_blob_alloc_desc(keymod_len);
> +       if (!desc) {
> +               dev_err(jrdev, "unable to allocate desc\n");
> +               return -ENOMEM;
> +       }
> +
> +       dma_in = dma_map_single(jrdev, input, length, DMA_TO_DEVICE);
> +       if (dma_mapping_error(jrdev, dma_in)) {
> +               dev_err(jrdev, "unable to map input DMA buffer\n");
> +               ret = -ENOMEM;
> +               goto out_free;
> +       }
> +
> +       dma_out = dma_map_single(jrdev, output, length -
> CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
> +       if (dma_mapping_error(jrdev, dma_out)) {
> +               dev_err(jrdev, "unable to map output DMA buffer\n");
> +               ret = -ENOMEM;
> +               goto out_unmap_in;
> +       }
> +
> +       /*
> +        * A data blob is encrypted using a blob key (BK); a random number.
> +        * The BK is used as an AES-CCM key. The initial block (B0) and the
> +        * initial counter (Ctr0) are generated automatically and stored in
> +        * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
> +        * Class 1 Key Register. Operation Mode is set to AES-CCM.
> +        */
> +
> +       init_job_desc(desc, 0);
> +       append_key_as_imm(desc, keymod, keymod_len, keymod_len,
> +                         CLASS_2 | KEY_DEST_CLASS_REG);
> +       append_seq_in_ptr(desc, dma_in, length, 0);
> +       append_seq_out_ptr(desc, dma_out, length - CAAM_BLOB_OVERHEAD, 0);
> +       append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB);
> +
> +       print_hex_dump_debug("data@"__stringify(__LINE__)": ",
> +                            DUMP_PREFIX_ADDRESS, 16, 1, input,
> +                            length, false);
> +       print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
> +                            DUMP_PREFIX_ADDRESS, 16, 1, desc,
> +                            desc_bytes(desc), false);
> +
> +       testres.err = 0;
> +       init_completion(&testres.completion);
> +
> +       ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
> +       if (ret == -EINPROGRESS) {
> +               wait_for_completion(&testres.completion);
> +               ret = testres.err;
> +               print_hex_dump_debug("output@"__stringify(__LINE__)": ",
> +                                    DUMP_PREFIX_ADDRESS, 16, 1, output,
> +                                    length - CAAM_BLOB_OVERHEAD, false);
> +       }
> +
> +       dma_unmap_single(jrdev, dma_out, length - CAAM_BLOB_OVERHEAD,
> +DMA_FROM_DEVICE);
> +out_unmap_in:
> +       dma_unmap_single(jrdev, dma_in, length, DMA_TO_DEVICE);
> +out_free:
> +       kfree(desc);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL(caam_decap_blob);
> +
> +struct caam_blob_priv *caam_blob_gen_init(void) {
> +       struct device *jrdev;
> +
> +       jrdev = caam_jr_alloc();
> +       if (IS_ERR(jrdev))
> +               return ERR_CAST(jrdev);
> +
> +       return container_of(jrdev, struct caam_blob_priv, jrdev); }
> +EXPORT_SYMBOL(caam_blob_gen_init);
> +
> +void caam_blob_gen_exit(struct caam_blob_priv *priv) {
> +       caam_jr_free(&priv->jrdev);
> +}
> +EXPORT_SYMBOL(caam_blob_gen_exit);
> diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h new file
> mode 100644 index 000000000000..83fd990ebdce
> --- /dev/null
> +++ b/include/soc/fsl/caam-blob.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
> +*/
> +
> +#ifndef __CAAM_BLOB_GEN
> +#define __CAAM_BLOB_GEN
> +
> +#include <linux/types.h>
> +
> +#define CAAM_BLOB_KEYMOD_LENGTH                16
> +#define CAAM_BLOB_OVERHEAD             (32 + 16)
> +#define CAAM_BLOB_MAX_LEN              4096
> +
> +struct caam_blob_priv;
> +
> +/** caam_blob_gen_init - initialize blob generation
> + *
> + * returns either pointer to new caam_blob_priv instance
> + * or error pointer
> + */
> +struct caam_blob_priv *caam_blob_gen_init(void);
> +
> +/** caam_blob_gen_exit - free blob generation resources
> + *
> + * @priv: instance returned by caam_blob_gen_init  */ void
> +caam_blob_gen_exit(struct caam_blob_priv *priv);
> +
> +/** caam_encap_blob - encapsulate blob
> + *
> + * @priv:   instance returned by caam_blob_gen_init
> + * @keymod: string to use as key modifier for blob encapsulation
> + *         can't be longer than CAAM_BLOB_KEYMOD_LENGTH
> + * @input:  buffer which CAAM will DMA from
> + * @output: buffer which CAAM will DMA to
> + * @length: buffer length including blob overhead
> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
> + */
> +int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
> +                   void *input, void *output, size_t length);
> +
> +/** caam_decap_blob - decapsulate blob
> + *
> + * @priv:   instance returned by caam_blob_gen_init
> + * @keymod: string to use as key modifier for blob decapsulation
> + *         can't be longer than CAAM_BLOB_KEYMOD_LENGTH
> + * @input:  buffer which CAAM will DMA from
> + * @output: buffer which CAAM will DMA to
> + * @length: buffer length including blob overhead
> + *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
> + */
> +int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
> +                   void *input, void *output, size_t length);
> +
> +#endif
> --
> git-series 0.9.1
diff mbox series

Patch

diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
index 84ea7cba5ee5..ea9f8b1ae981 100644
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -151,6 +151,9 @@  config CRYPTO_DEV_FSL_CAAM_RNG_API
 	  Selecting this will register the SEC4 hardware rng to
 	  the hw_random API for supplying the kernel entropy pool.
 
+config CRYPTO_DEV_FSL_CAAM_BLOB_GEN
+	bool
+
 endif # CRYPTO_DEV_FSL_CAAM_JR
 
 endif # CRYPTO_DEV_FSL_CAAM
diff --git a/drivers/crypto/caam/Makefile b/drivers/crypto/caam/Makefile
index 3570286eb9ce..25f7ae5a4642 100644
--- a/drivers/crypto/caam/Makefile
+++ b/drivers/crypto/caam/Makefile
@@ -21,6 +21,7 @@  caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += caamalg_qi.o
 caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_AHASH_API) += caamhash.o
 caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API) += caamrng.o
 caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_PKC_API) += caampkc.o pkc_desc.o
+caam_jr-$(CONFIG_CRYPTO_DEV_FSL_CAAM_BLOB_GEN) += blob_gen.o
 
 caam-$(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI) += qi.o
 ifneq ($(CONFIG_CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI),)
diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c
new file mode 100644
index 000000000000..513d3f90e438
--- /dev/null
+++ b/drivers/crypto/caam/blob_gen.c
@@ -0,0 +1,230 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
+ * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
+ */
+
+#include <linux/device.h>
+#include <soc/fsl/caam-blob.h>
+
+#include "compat.h"
+#include "desc_constr.h"
+#include "desc.h"
+#include "error.h"
+#include "intern.h"
+#include "jr.h"
+#include "regs.h"
+
+struct caam_blob_priv {
+	struct device jrdev;
+};
+
+struct caam_blob_job_result {
+	int err;
+	struct completion completion;
+};
+
+static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
+{
+	struct caam_blob_job_result *res = context;
+	int ecode = 0;
+
+	dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
+
+	if (err)
+		ecode = caam_jr_strstatus(dev, err);
+
+	res->err = ecode;
+
+	/*
+	 * Upon completion, desc points to a buffer containing a CAAM job
+	 * descriptor which encapsulates data into an externally-storable
+	 * blob.
+	 */
+	complete(&res->completion);
+}
+
+static u32 *caam_blob_alloc_desc(size_t keymod_len)
+{
+	size_t len;
+
+	/* header + (key mod immediate) + 2x pointers + op */
+	len = 4 + (4 + ALIGN(keymod_len, 4)) + 2*(4 + 4 + CAAM_PTR_SZ_MAX) + 4;
+
+	if (len > CAAM_DESC_BYTES_MAX)
+		return NULL;
+
+	return kzalloc(len, GFP_KERNEL | GFP_DMA);
+}
+
+int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
+		    void *input, void *output, size_t length)
+{
+	u32 *desc;
+	struct device *jrdev = &priv->jrdev;
+	dma_addr_t dma_in, dma_out;
+	struct caam_blob_job_result testres;
+	size_t keymod_len = strlen(keymod);
+	int ret;
+
+	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
+		return -EINVAL;
+
+	desc = caam_blob_alloc_desc(keymod_len);
+	if (!desc) {
+		dev_err(jrdev, "unable to allocate desc\n");
+		return -ENOMEM;
+	}
+
+	dma_in = dma_map_single(jrdev, input, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
+	if (dma_mapping_error(jrdev, dma_in)) {
+		dev_err(jrdev, "unable to map input DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	dma_out = dma_map_single(jrdev, output, length,	DMA_FROM_DEVICE);
+	if (dma_mapping_error(jrdev, dma_out)) {
+		dev_err(jrdev, "unable to map output DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_unmap_in;
+	}
+
+	/*
+	 * A data blob is encrypted using a blob key (BK); a random number.
+	 * The BK is used as an AES-CCM key. The initial block (B0) and the
+	 * initial counter (Ctr0) are generated automatically and stored in
+	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
+	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
+	 */
+
+	init_job_desc(desc, 0);
+	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
+			  CLASS_2 | KEY_DEST_CLASS_REG);
+	append_seq_in_ptr_intlen(desc, dma_in, length - CAAM_BLOB_OVERHEAD, 0);
+	append_seq_out_ptr_intlen(desc, dma_out, length, 0);
+	append_operation(desc, OP_TYPE_ENCAP_PROTOCOL | OP_PCLID_BLOB);
+
+	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, input,
+			     length - CAAM_BLOB_OVERHEAD, false);
+	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
+			     desc_bytes(desc), false);
+
+	testres.err = 0;
+	init_completion(&testres.completion);
+
+	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&testres.completion);
+		ret = testres.err;
+		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
+				     DUMP_PREFIX_ADDRESS, 16, 1, output,
+				     length, false);
+	}
+
+	dma_unmap_single(jrdev, dma_out, length, DMA_FROM_DEVICE);
+out_unmap_in:
+	dma_unmap_single(jrdev, dma_in, length - CAAM_BLOB_OVERHEAD, DMA_TO_DEVICE);
+out_free:
+	kfree(desc);
+
+	return ret;
+}
+EXPORT_SYMBOL(caam_encap_blob);
+
+int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
+		    void *input, void *output, size_t length)
+{
+	u32 *desc;
+	struct device *jrdev = &priv->jrdev;
+	dma_addr_t dma_in, dma_out;
+	struct caam_blob_job_result testres;
+	size_t keymod_len = strlen(keymod);
+	int ret;
+
+	if (length <= CAAM_BLOB_OVERHEAD || keymod_len > CAAM_BLOB_KEYMOD_LENGTH)
+		return -EINVAL;
+
+	desc = caam_blob_alloc_desc(keymod_len);
+	if (!desc) {
+		dev_err(jrdev, "unable to allocate desc\n");
+		return -ENOMEM;
+	}
+
+	dma_in = dma_map_single(jrdev, input, length, DMA_TO_DEVICE);
+	if (dma_mapping_error(jrdev, dma_in)) {
+		dev_err(jrdev, "unable to map input DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	dma_out = dma_map_single(jrdev, output, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
+	if (dma_mapping_error(jrdev, dma_out)) {
+		dev_err(jrdev, "unable to map output DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_unmap_in;
+	}
+
+	/*
+	 * A data blob is encrypted using a blob key (BK); a random number.
+	 * The BK is used as an AES-CCM key. The initial block (B0) and the
+	 * initial counter (Ctr0) are generated automatically and stored in
+	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
+	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
+	 */
+
+	init_job_desc(desc, 0);
+	append_key_as_imm(desc, keymod, keymod_len, keymod_len,
+			  CLASS_2 | KEY_DEST_CLASS_REG);
+	append_seq_in_ptr(desc, dma_in, length, 0);
+	append_seq_out_ptr(desc, dma_out, length - CAAM_BLOB_OVERHEAD, 0);
+	append_operation(desc, OP_TYPE_DECAP_PROTOCOL | OP_PCLID_BLOB);
+
+	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, input,
+			     length, false);
+	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
+			     desc_bytes(desc), false);
+
+	testres.err = 0;
+	init_completion(&testres.completion);
+
+	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&testres.completion);
+		ret = testres.err;
+		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
+				     DUMP_PREFIX_ADDRESS, 16, 1, output,
+				     length - CAAM_BLOB_OVERHEAD, false);
+	}
+
+	dma_unmap_single(jrdev, dma_out, length - CAAM_BLOB_OVERHEAD, DMA_FROM_DEVICE);
+out_unmap_in:
+	dma_unmap_single(jrdev, dma_in, length, DMA_TO_DEVICE);
+out_free:
+	kfree(desc);
+
+	return ret;
+}
+EXPORT_SYMBOL(caam_decap_blob);
+
+struct caam_blob_priv *caam_blob_gen_init(void)
+{
+	struct device *jrdev;
+
+	jrdev = caam_jr_alloc();
+	if (IS_ERR(jrdev))
+		return ERR_CAST(jrdev);
+
+	return container_of(jrdev, struct caam_blob_priv, jrdev);
+}
+EXPORT_SYMBOL(caam_blob_gen_init);
+
+void caam_blob_gen_exit(struct caam_blob_priv *priv)
+{
+	caam_jr_free(&priv->jrdev);
+}
+EXPORT_SYMBOL(caam_blob_gen_exit);
diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h
new file mode 100644
index 000000000000..83fd990ebdce
--- /dev/null
+++ b/include/soc/fsl/caam-blob.h
@@ -0,0 +1,56 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
+ */
+
+#ifndef __CAAM_BLOB_GEN
+#define __CAAM_BLOB_GEN
+
+#include <linux/types.h>
+
+#define CAAM_BLOB_KEYMOD_LENGTH		16
+#define CAAM_BLOB_OVERHEAD		(32 + 16)
+#define CAAM_BLOB_MAX_LEN		4096
+
+struct caam_blob_priv;
+
+/** caam_blob_gen_init - initialize blob generation
+ *
+ * returns either pointer to new caam_blob_priv instance
+ * or error pointer
+ */
+struct caam_blob_priv *caam_blob_gen_init(void);
+
+/** caam_blob_gen_exit - free blob generation resources
+ *
+ * @priv: instance returned by caam_blob_gen_init
+ */
+void caam_blob_gen_exit(struct caam_blob_priv *priv);
+
+/** caam_encap_blob - encapsulate blob
+ *
+ * @priv:   instance returned by caam_blob_gen_init
+ * @keymod: string to use as key modifier for blob encapsulation
+ *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
+ * @input:  buffer which CAAM will DMA from
+ * @output: buffer which CAAM will DMA to
+ * @length: buffer length including blob overhead
+ *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
+ */
+int caam_encap_blob(struct caam_blob_priv *priv, const char *keymod,
+		    void *input, void *output, size_t length);
+
+/** caam_decap_blob - decapsulate blob
+ *
+ * @priv:   instance returned by caam_blob_gen_init
+ * @keymod: string to use as key modifier for blob decapsulation
+ *	    can't be longer than CAAM_BLOB_KEYMOD_LENGTH
+ * @input:  buffer which CAAM will DMA from
+ * @output: buffer which CAAM will DMA to
+ * @length: buffer length including blob overhead
+ *          CAAM_BLOB_OVERHEAD < length <= CAAM_BLOB_MAX_LEN
+ */
+int caam_decap_blob(struct caam_blob_priv *priv, const char *keymod,
+		    void *input, void *output, size_t length);
+
+#endif