/** \file psa_crypto_random_impl.h

 *

 * \brief PSA crypto random generator implementation abstraction.

 */

/*

 *  Copyright The Mbed TLS Contributors

 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later

 */

#ifndef PSA_CRYPTO_RANDOM_IMPL_H

#define PSA_CRYPTO_RANDOM_IMPL_H

#include "psa_util_internal.h"

#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)

typedef mbedtls_psa_external_random_context_t mbedtls_psa_random_context_t;

#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */

#include "mbedtls/entropy.h"

/* Choose a DRBG based on configuration and availability */

#if defined(MBEDTLS_CTR_DRBG_C)

#include "mbedtls/ctr_drbg.h"

#undef MBEDTLS_PSA_HMAC_DRBG_MD_TYPE

#elif defined(MBEDTLS_HMAC_DRBG_C)

#include "mbedtls/hmac_drbg.h"

#if defined(MBEDTLS_MD_CAN_SHA512) && defined(MBEDTLS_MD_CAN_SHA256)

#include <limits.h>

#if SIZE_MAX > 0xffffffff

/* Looks like a 64-bit system, so prefer SHA-512. */

#define MBEDTLS_PSA_HMAC_DRBG_MD_TYPE MBEDTLS_MD_SHA512

#else

/* Looks like a 32-bit system, so prefer SHA-256. */

#define MBEDTLS_PSA_HMAC_DRBG_MD_TYPE MBEDTLS_MD_SHA256

#endif

#elif defined(MBEDTLS_MD_CAN_SHA512)

#define MBEDTLS_PSA_HMAC_DRBG_MD_TYPE MBEDTLS_MD_SHA512

#elif defined(MBEDTLS_MD_CAN_SHA256)

#define MBEDTLS_PSA_HMAC_DRBG_MD_TYPE MBEDTLS_MD_SHA256

#else

#error "No hash algorithm available for HMAC_DBRG."

#endif

#else /* !MBEDTLS_CTR_DRBG_C && !MBEDTLS_HMAC_DRBG_C*/

#error "No DRBG module available for the psa_crypto module."

#endif /* !MBEDTLS_CTR_DRBG_C && !MBEDTLS_HMAC_DRBG_C*/

/* The maximum number of bytes that mbedtls_psa_get_random() is expected to return. */

#if defined(MBEDTLS_CTR_DRBG_C)

#define MBEDTLS_PSA_RANDOM_MAX_REQUEST MBEDTLS_CTR_DRBG_MAX_REQUEST

#elif defined(MBEDTLS_HMAC_DRBG_C)

#define MBEDTLS_PSA_RANDOM_MAX_REQUEST MBEDTLS_HMAC_DRBG_MAX_REQUEST

#endif

#if defined(MBEDTLS_CTR_DRBG_C)

typedef mbedtls_ctr_drbg_context            mbedtls_psa_drbg_context_t;

#elif defined(MBEDTLS_HMAC_DRBG_C)

typedef mbedtls_hmac_drbg_context           mbedtls_psa_drbg_context_t;

#endif /* !MBEDTLS_CTR_DRBG_C && !MBEDTLS_HMAC_DRBG_C */

typedef struct {

    void (* entropy_init)(mbedtls_entropy_context *ctx);

    void (* entropy_free)(mbedtls_entropy_context *ctx);

    mbedtls_entropy_context entropy;

    mbedtls_psa_drbg_context_t drbg;

} mbedtls_psa_random_context_t;

/** Initialize the PSA DRBG.

 *

 * \param p_rng        Pointer to the Mbed TLS DRBG state.

 */

static inline void mbedtls_psa_drbg_init(mbedtls_psa_drbg_context_t *p_rng)

{

#if defined(MBEDTLS_CTR_DRBG_C)

    mbedtls_ctr_drbg_init(p_rng);

#elif defined(MBEDTLS_HMAC_DRBG_C)

    mbedtls_hmac_drbg_init(p_rng);

#endif

}

psa_crypto.c:mbedtls_psa_drbg_init

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{

81

10

#if defined(MBEDTLS_CTR_DRBG_C)

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10

    mbedtls_ctr_drbg_init(p_rng);

83

#elif defined(MBEDTLS_HMAC_DRBG_C)

84

    mbedtls_hmac_drbg_init(p_rng);

85

#endif

86

10

}

Unexecuted instantiation: psa_crypto_cipher.c:mbedtls_psa_drbg_init

Unexecuted instantiation: psa_crypto_ecp.c:mbedtls_psa_drbg_init

Unexecuted instantiation: psa_crypto_ffdh.c:mbedtls_psa_drbg_init

Unexecuted instantiation: psa_crypto_rsa.c:mbedtls_psa_drbg_init

/** Deinitialize the PSA DRBG.

 *

 * \param p_rng        Pointer to the Mbed TLS DRBG state.

 */

static inline void mbedtls_psa_drbg_free(mbedtls_psa_drbg_context_t *p_rng)

{

#if defined(MBEDTLS_CTR_DRBG_C)

    mbedtls_ctr_drbg_free(p_rng);

#elif defined(MBEDTLS_HMAC_DRBG_C)

    mbedtls_hmac_drbg_free(p_rng);

#endif

}

Unexecuted instantiation: psa_crypto.c:mbedtls_psa_drbg_free

Unexecuted instantiation: psa_crypto_cipher.c:mbedtls_psa_drbg_free

Unexecuted instantiation: psa_crypto_ecp.c:mbedtls_psa_drbg_free

Unexecuted instantiation: psa_crypto_ffdh.c:mbedtls_psa_drbg_free

Unexecuted instantiation: psa_crypto_rsa.c:mbedtls_psa_drbg_free

/** Seed the PSA DRBG.

 *

 * \param entropy       An entropy context to read the seed from.

 * \param custom        The personalization string.

 *                      This can be \c NULL, in which case the personalization

 *                      string is empty regardless of the value of \p len.

 * \param len           The length of the personalization string.

 *

 * \return              \c 0 on success.

 * \return              An Mbed TLS error code (\c MBEDTLS_ERR_xxx) on failure.

 */

static inline int mbedtls_psa_drbg_seed(mbedtls_psa_drbg_context_t *drbg_ctx,

                                        mbedtls_entropy_context *entropy,

                                        const unsigned char *custom, size_t len)

{

#if defined(MBEDTLS_CTR_DRBG_C)

    return mbedtls_ctr_drbg_seed(drbg_ctx, mbedtls_entropy_func, entropy, custom, len);

#elif defined(MBEDTLS_HMAC_DRBG_C)

    const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE);

    return mbedtls_hmac_drbg_seed(drbg_ctx, md_info, mbedtls_entropy_func, entropy, custom, len);

#endif

}

psa_crypto.c:mbedtls_psa_drbg_seed

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{

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#if defined(MBEDTLS_CTR_DRBG_C)

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    return mbedtls_ctr_drbg_seed(drbg_ctx, mbedtls_entropy_func, entropy, custom, len);

118

#elif defined(MBEDTLS_HMAC_DRBG_C)

119

    const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE);

120

    return mbedtls_hmac_drbg_seed(drbg_ctx, md_info, mbedtls_entropy_func, entropy, custom, len);

121

#endif

122

10

}

Unexecuted instantiation: psa_crypto_cipher.c:mbedtls_psa_drbg_seed

Unexecuted instantiation: psa_crypto_ecp.c:mbedtls_psa_drbg_seed

Unexecuted instantiation: psa_crypto_ffdh.c:mbedtls_psa_drbg_seed

Unexecuted instantiation: psa_crypto_rsa.c:mbedtls_psa_drbg_seed

#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */

#endif /* PSA_CRYPTO_RANDOM_IMPL_H */