initial commit, 4.5 stable

thirdparty/mbedtls/library/psa_crypto_random_impl.h

@@ -0,0 +1,126 @@
+/** \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
+}
+
+/** 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
+}
+
+/** 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
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+
+#endif /* PSA_CRYPTO_RANDOM_IMPL_H */