tests/suites/test_suite_entropy.function - mirror/mbed-tls.git - TrustedFirmware Git Browser

 /* BEGIN_HEADER */
 #include "mbedtls/entropy.h"
 #include "entropy_poll.h"
 #include "mbedtls/md.h"
 #include "string.h"

 typedef enum {
     DUMMY_CONSTANT_LENGTH, /* Output context->length bytes */
     DUMMY_REQUESTED_LENGTH, /* Output whatever length was requested */
     DUMMY_FAIL, /* Return an error code */
 } entropy_dummy_instruction;

 typedef struct {
     entropy_dummy_instruction instruction;
     size_t length; /* Length to return for DUMMY_CONSTANT_LENGTH */
     size_t calls; /* Incremented at each call */
 } entropy_dummy_context;

 /*
  * Dummy entropy source
  *
  * If data is NULL, write exactly the requested length.
  * Otherwise, write the length indicated by data or error if negative
  */
 static int entropy_dummy_source(void *arg, unsigned char *output,
                                 size_t len, size_t *olen)
 {
     entropy_dummy_context *context = arg;
     ++context->calls;

     switch (context->instruction) {
         case DUMMY_CONSTANT_LENGTH:
             *olen = context->length;
             break;
         case DUMMY_REQUESTED_LENGTH:
             *olen = len;
             break;
         case DUMMY_FAIL:
             return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
     }

     memset(output, 0x2a, *olen);
     return 0;
 }

 /*
  * Ability to clear entropy sources to allow testing with just predefined
  * entropy sources. This function or tests depending on it might break if there
  * are internal changes to how entropy sources are registered.
  *
  * To be called immediately after mbedtls_entropy_init().
  *
  * Just resetting the counter. New sources will overwrite existing ones.
  * This might break memory checks in the future if sources need 'free-ing' then
  * as well.
  */
 static void entropy_clear_sources(mbedtls_entropy_context *ctx)
 {
     ctx->source_count = 0;
 }

 #if defined(MBEDTLS_ENTROPY_NV_SEED)
 /*
  * NV seed read/write functions that use a buffer instead of a file
  */
 static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];

 int buffer_nv_seed_read(unsigned char *buf, size_t buf_len)
 {
     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     memcpy(buf, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE);
     return 0;
 }

 int buffer_nv_seed_write(unsigned char *buf, size_t buf_len)
 {
     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     memcpy(buffer_seed, buf, MBEDTLS_ENTROPY_BLOCK_SIZE);
     return 0;
 }

 /*
  * NV seed read/write helpers that fill the base seedfile
  */
 static int write_nv_seed(unsigned char *buf, size_t buf_len)
 {
     FILE *f;

     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     if ((f = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w")) == NULL) {
         return -1;
     }

     if (fwrite(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) !=
         MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     fclose(f);

     return 0;
 }

 int read_nv_seed(unsigned char *buf, size_t buf_len)
 {
     FILE *f;

     if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     if ((f = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb")) == NULL) {
         return -1;
     }

     if (fread(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) !=
         MBEDTLS_ENTROPY_BLOCK_SIZE) {
         return -1;
     }

     fclose(f);

     return 0;
 }
 #endif /* MBEDTLS_ENTROPY_NV_SEED */
 /* END_HEADER */

 /* BEGIN_DEPENDENCIES
  * depends_on:MBEDTLS_ENTROPY_C:!MBEDTLS_PSA_INJECT_ENTROPY
  * END_DEPENDENCIES
  */

 /* BEGIN_CASE */
 void entropy_init_free(int reinit)
 {
     mbedtls_entropy_context ctx;

     /* Double free is not explicitly documented to work, but it is convenient
      * to call mbedtls_entropy_free() unconditionally on an error path without
      * checking whether it has already been called in the success path. */

     mbedtls_entropy_init(&ctx);
     mbedtls_entropy_free(&ctx);

     if (reinit) {
         mbedtls_entropy_init(&ctx);
     }
     mbedtls_entropy_free(&ctx);

     /* This test case always succeeds, functionally speaking. A plausible
      * bug might trigger an invalid pointer dereference or a memory leak. */
     goto exit;
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
 void entropy_seed_file(char *path, int ret)
 {
     mbedtls_entropy_context ctx;

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);

     TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, path) == ret);
     TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, path) == ret);

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
 void entropy_write_base_seed_file(int ret)
 {
     mbedtls_entropy_context ctx;

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);

     TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE) == ret);
     TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE) == ret);

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE */
 void entropy_no_sources()
 {
     mbedtls_entropy_context ctx;
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];

     mbedtls_entropy_init(&ctx);
     entropy_clear_sources(&ctx);
     TEST_EQUAL(mbedtls_entropy_func(&ctx, buf, sizeof(buf)),
                MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED);

 exit:
     mbedtls_entropy_free(&ctx);
 }
 /* END_CASE */

 /* BEGIN_CASE */
 void entropy_too_many_sources()
 {
     mbedtls_entropy_context ctx;
     size_t i;
     entropy_dummy_context dummy = { DUMMY_REQUESTED_LENGTH, 0, 0 };

     mbedtls_entropy_init(&ctx);

     /*
      * It's hard to tell precisely when the error will occur,
      * since we don't know how many sources were automatically added.
      */
     for (i = 0; i < MBEDTLS_ENTROPY_MAX_SOURCES; i++) {
         (void) mbedtls_entropy_add_source(&ctx, entropy_dummy_source, &dummy,
                                           16, MBEDTLS_ENTROPY_SOURCE_WEAK);
     }

     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source, &dummy,
                                            16, MBEDTLS_ENTROPY_SOURCE_WEAK)
                 == MBEDTLS_ERR_ENTROPY_MAX_SOURCES);

 exit:
     mbedtls_entropy_free(&ctx);
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG */
 void entropy_func_len(int len, int ret)
 {
     mbedtls_entropy_context ctx;
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
     unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
     size_t i, j;

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);

     /*
      * See comments in mbedtls_entropy_self_test()
      */
     for (i = 0; i < 8; i++) {
         TEST_ASSERT(mbedtls_entropy_func(&ctx, buf, len) == ret);
         for (j = 0; j < sizeof(buf); j++) {
             acc[j] |= buf[j];
         }
     }

     if (ret == 0) {
         for (j = 0; j < (size_t) len; j++) {
             TEST_ASSERT(acc[j] != 0);
         }
     }

     for (j = len; j < sizeof(buf); j++) {
         TEST_ASSERT(acc[j] == 0);
     }

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE */
 void entropy_source_fail(char *path)
 {
     mbedtls_entropy_context ctx;
     unsigned char buf[16];
     entropy_dummy_context dummy = { DUMMY_FAIL, 0, 0 };

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);

     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
                                            &dummy, 16,
                                            MBEDTLS_ENTROPY_SOURCE_WEAK)
                 == 0);

     TEST_ASSERT(mbedtls_entropy_func(&ctx, buf, sizeof(buf))
                 == MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
     TEST_ASSERT(mbedtls_entropy_gather(&ctx)
                 == MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
 #if defined(MBEDTLS_FS_IO) && defined(MBEDTLS_ENTROPY_NV_SEED)
     TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, path)
                 == MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
     TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, path)
                 == MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
 #else
     ((void) path);
 #endif

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE */
 void entropy_threshold(int threshold, int chunk_size, int result)
 {
     mbedtls_entropy_context ctx;
     entropy_dummy_context strong =
     { DUMMY_CONSTANT_LENGTH, MBEDTLS_ENTROPY_BLOCK_SIZE, 0 };
     entropy_dummy_context weak = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
     int ret;

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);
     entropy_clear_sources(&ctx);

     /* Set strong source that reaches its threshold immediately and
      * a weak source whose threshold is a test parameter. */
     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
                                            &strong, 1,
                                            MBEDTLS_ENTROPY_SOURCE_STRONG) == 0);
     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
                                            &weak, threshold,
                                            MBEDTLS_ENTROPY_SOURCE_WEAK) == 0);

     ret = mbedtls_entropy_func(&ctx, buf, sizeof(buf));

     if (result >= 0) {
         TEST_ASSERT(ret == 0);
 #if defined(MBEDTLS_ENTROPY_NV_SEED)
         /* If the NV seed functionality is enabled, there are two entropy
          * updates: before and after updating the NV seed. */
         result *= 2;
 #endif
         TEST_ASSERT(weak.calls == (size_t) result);
     } else {
         TEST_ASSERT(ret == result);
     }

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE */
 void entropy_calls(int strength1, int strength2,
                    int threshold, int chunk_size,
                    int result)
 {
     /*
      * if result >= 0: result = expected number of calls to source 1
      * if result < 0: result = expected return code from mbedtls_entropy_func()
      */

     mbedtls_entropy_context ctx;
     entropy_dummy_context dummy1 = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
     entropy_dummy_context dummy2 = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
     int ret;

     MD_PSA_INIT();

     mbedtls_entropy_init(&ctx);
     entropy_clear_sources(&ctx);

     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
                                            &dummy1, threshold,
                                            strength1) == 0);
     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
                                            &dummy2, threshold,
                                            strength2) == 0);

     ret = mbedtls_entropy_func(&ctx, buf, sizeof(buf));

     if (result >= 0) {
         TEST_ASSERT(ret == 0);
 #if defined(MBEDTLS_ENTROPY_NV_SEED)
         /* If the NV seed functionality is enabled, there are two entropy
          * updates: before and after updating the NV seed. */
         result *= 2;
 #endif
         TEST_ASSERT(dummy1.calls == (size_t) result);
     } else {
         TEST_ASSERT(ret == result);
     }

 exit:
     mbedtls_entropy_free(&ctx);
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
 void nv_seed_file_create()
 {
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];

     memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

     TEST_ASSERT(write_nv_seed(buf, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO:MBEDTLS_PLATFORM_NV_SEED_ALT */
 void entropy_nv_seed_std_io()
 {
     unsigned char io_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
     unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];

     memset(io_seed, 1, MBEDTLS_ENTROPY_BLOCK_SIZE);
     memset(check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

     mbedtls_platform_set_nv_seed(mbedtls_platform_std_nv_seed_read,
                                  mbedtls_platform_std_nv_seed_write);

     /* Check if platform NV read and write manipulate the same data */
     TEST_ASSERT(write_nv_seed(io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
     TEST_ASSERT(mbedtls_nv_seed_read(check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) ==
                 MBEDTLS_ENTROPY_BLOCK_SIZE);

     TEST_ASSERT(memcmp(io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

     memset(check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

     /* Check if platform NV write and raw read manipulate the same data */
     TEST_ASSERT(mbedtls_nv_seed_write(io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) ==
                 MBEDTLS_ENTROPY_BLOCK_SIZE);
     TEST_ASSERT(read_nv_seed(check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

     TEST_ASSERT(memcmp(io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:MBEDTLS_MD_C:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT */
 void entropy_nv_seed(data_t *read_seed)
 {
 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
     const mbedtls_md_info_t *md_info =
         mbedtls_md_info_from_type(MBEDTLS_MD_SHA512);
 #elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR)
     const mbedtls_md_info_t *md_info =
         mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
 #else
 #error "Unsupported entropy accumulator"
 #endif
     mbedtls_md_context_t accumulator;
     mbedtls_entropy_context ctx;
     int (*original_mbedtls_nv_seed_read)(unsigned char *buf, size_t buf_len) =
         mbedtls_nv_seed_read;
     int (*original_mbedtls_nv_seed_write)(unsigned char *buf, size_t buf_len) =
         mbedtls_nv_seed_write;

     unsigned char header[2];
     unsigned char entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
     unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
     unsigned char empty[MBEDTLS_ENTROPY_BLOCK_SIZE];
     unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
     unsigned char check_entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];

     MD_PSA_INIT();

     memset(entropy, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
     memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
     memset(empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
     memset(check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE);
     memset(check_entropy, 3, MBEDTLS_ENTROPY_BLOCK_SIZE);

     // Make sure we read/write NV seed from our buffers
     mbedtls_platform_set_nv_seed(buffer_nv_seed_read, buffer_nv_seed_write);

     mbedtls_md_init(&accumulator);
     mbedtls_entropy_init(&ctx);
     entropy_clear_sources(&ctx);

     TEST_ASSERT(mbedtls_entropy_add_source(&ctx, mbedtls_nv_seed_poll, NULL,
                                            MBEDTLS_ENTROPY_BLOCK_SIZE,
                                            MBEDTLS_ENTROPY_SOURCE_STRONG) == 0);

     // Set the initial NV seed to read
     TEST_ASSERT(read_seed->len >= MBEDTLS_ENTROPY_BLOCK_SIZE);
     memcpy(buffer_seed, read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE);

     // Do an entropy run
     TEST_ASSERT(mbedtls_entropy_func(&ctx, entropy, sizeof(entropy)) == 0);
     // Determine what should have happened with manual entropy internal logic

     // Init accumulator
     header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE;
     TEST_ASSERT(mbedtls_md_setup(&accumulator, md_info, 0) == 0);

     // First run for updating write_seed
     header[0] = 0;
     TEST_ASSERT(mbedtls_md_starts(&accumulator) == 0);
     TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
     TEST_ASSERT(mbedtls_md_update(&accumulator,
                                   read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
     TEST_ASSERT(mbedtls_md_finish(&accumulator, buf) == 0);

     TEST_ASSERT(mbedtls_md_starts(&accumulator) == 0);
     TEST_ASSERT(mbedtls_md_update(&accumulator,
                                   buf, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

     TEST_ASSERT(mbedtls_md(md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
                            check_seed) == 0);

     // Second run for actual entropy (triggers mbedtls_entropy_update_nv_seed)
     header[0] = MBEDTLS_ENTROPY_SOURCE_MANUAL;
     TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
     TEST_ASSERT(mbedtls_md_update(&accumulator,
                                   empty, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

     header[0] = 0;
     TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
     TEST_ASSERT(mbedtls_md_update(&accumulator,
                                   check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
     TEST_ASSERT(mbedtls_md_finish(&accumulator, buf) == 0);

     TEST_ASSERT(mbedtls_md(md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
                            check_entropy) == 0);

     // Check result of both NV file and entropy received with the manual calculations
     TEST_ASSERT(memcmp(check_seed, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
     TEST_ASSERT(memcmp(check_entropy, entropy, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

 exit:
     mbedtls_md_free(&accumulator);
     mbedtls_entropy_free(&ctx);
     mbedtls_nv_seed_read = original_mbedtls_nv_seed_read;
     mbedtls_nv_seed_write = original_mbedtls_nv_seed_write;
     MD_PSA_DONE();
 }
 /* END_CASE */

 /* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG:MBEDTLS_SELF_TEST */
 void entropy_selftest(int result)
 {
     MD_PSA_INIT();

     TEST_ASSERT(mbedtls_entropy_self_test(1) == result);

 exit:
     MD_PSA_DONE();
 }
 /* END_CASE */
	/* BEGIN_HEADER */
	#include "mbedtls/entropy.h"
	#include "entropy_poll.h"
	#include "mbedtls/md.h"
	#include "string.h"

	typedef enum {
	DUMMY_CONSTANT_LENGTH, /* Output context->length bytes */
	DUMMY_REQUESTED_LENGTH, /* Output whatever length was requested */
	DUMMY_FAIL, /* Return an error code */
	} entropy_dummy_instruction;

	typedef struct {
	entropy_dummy_instruction instruction;
	size_t length; /* Length to return for DUMMY_CONSTANT_LENGTH */
	size_t calls; /* Incremented at each call */
	} entropy_dummy_context;

	/*
	* Dummy entropy source
	*
	* If data is NULL, write exactly the requested length.
	* Otherwise, write the length indicated by data or error if negative
	*/
	static int entropy_dummy_source(void arg, unsigned char output,
	size_t len, size_t *olen)
	{
	entropy_dummy_context *context = arg;
	++context->calls;

	switch (context->instruction) {
	case DUMMY_CONSTANT_LENGTH:
	*olen = context->length;
	break;
	case DUMMY_REQUESTED_LENGTH:
	*olen = len;
	break;
	case DUMMY_FAIL:
	return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
	}

	memset(output, 0x2a, *olen);
	return 0;
	}

	/*
	* Ability to clear entropy sources to allow testing with just predefined
	* entropy sources. This function or tests depending on it might break if there
	* are internal changes to how entropy sources are registered.
	*
	* To be called immediately after mbedtls_entropy_init().
	*
	* Just resetting the counter. New sources will overwrite existing ones.
	* This might break memory checks in the future if sources need 'free-ing' then
	* as well.
	*/
	static void entropy_clear_sources(mbedtls_entropy_context *ctx)
	{
	ctx->source_count = 0;
	}

	#if defined(MBEDTLS_ENTROPY_NV_SEED)
	/*
	* NV seed read/write functions that use a buffer instead of a file
	*/
	static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];

	int buffer_nv_seed_read(unsigned char *buf, size_t buf_len)
	{
	if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	memcpy(buf, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE);
	return 0;
	}

	int buffer_nv_seed_write(unsigned char *buf, size_t buf_len)
	{
	if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	memcpy(buffer_seed, buf, MBEDTLS_ENTROPY_BLOCK_SIZE);
	return 0;
	}

	/*
	* NV seed read/write helpers that fill the base seedfile
	*/
	static int write_nv_seed(unsigned char *buf, size_t buf_len)
	{
	FILE *f;

	if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	if ((f = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w")) == NULL) {
	return -1;
	}

	if (fwrite(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) !=
	MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	fclose(f);

	return 0;
	}

	int read_nv_seed(unsigned char *buf, size_t buf_len)
	{
	FILE *f;

	if (buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	if ((f = fopen(MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb")) == NULL) {
	return -1;
	}

	if (fread(buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f) !=
	MBEDTLS_ENTROPY_BLOCK_SIZE) {
	return -1;
	}

	fclose(f);

	return 0;
	}
	#endif /* MBEDTLS_ENTROPY_NV_SEED */
	/* END_HEADER */

	/* BEGIN_DEPENDENCIES
	* depends_on:MBEDTLS_ENTROPY_C:!MBEDTLS_PSA_INJECT_ENTROPY
	* END_DEPENDENCIES
	*/

	/* BEGIN_CASE */
	void entropy_init_free(int reinit)
	{
	mbedtls_entropy_context ctx;

	/* Double free is not explicitly documented to work, but it is convenient
	* to call mbedtls_entropy_free() unconditionally on an error path without
	* checking whether it has already been called in the success path. */

	mbedtls_entropy_init(&ctx);
	mbedtls_entropy_free(&ctx);

	if (reinit) {
	mbedtls_entropy_init(&ctx);
	}
	mbedtls_entropy_free(&ctx);

	/* This test case always succeeds, functionally speaking. A plausible
	* bug might trigger an invalid pointer dereference or a memory leak. */
	goto exit;
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
	void entropy_seed_file(char *path, int ret)
	{
	mbedtls_entropy_context ctx;

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);

	TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, path) == ret);
	TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, path) == ret);

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
	void entropy_write_base_seed_file(int ret)
	{
	mbedtls_entropy_context ctx;

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);

	TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE) == ret);
	TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, MBEDTLS_PLATFORM_STD_NV_SEED_FILE) == ret);

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE */
	void entropy_no_sources()
	{
	mbedtls_entropy_context ctx;
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];

	mbedtls_entropy_init(&ctx);
	entropy_clear_sources(&ctx);
	TEST_EQUAL(mbedtls_entropy_func(&ctx, buf, sizeof(buf)),
	MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED);

	exit:
	mbedtls_entropy_free(&ctx);
	}
	/* END_CASE */

	/* BEGIN_CASE */
	void entropy_too_many_sources()
	{
	mbedtls_entropy_context ctx;
	size_t i;
	entropy_dummy_context dummy = { DUMMY_REQUESTED_LENGTH, 0, 0 };

	mbedtls_entropy_init(&ctx);

	/*
	* It's hard to tell precisely when the error will occur,
	* since we don't know how many sources were automatically added.
	*/
	for (i = 0; i < MBEDTLS_ENTROPY_MAX_SOURCES; i++) {
	(void) mbedtls_entropy_add_source(&ctx, entropy_dummy_source, &dummy,
	16, MBEDTLS_ENTROPY_SOURCE_WEAK);
	}

	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source, &dummy,
	16, MBEDTLS_ENTROPY_SOURCE_WEAK)
	== MBEDTLS_ERR_ENTROPY_MAX_SOURCES);

	exit:
	mbedtls_entropy_free(&ctx);
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG */
	void entropy_func_len(int len, int ret)
	{
	mbedtls_entropy_context ctx;
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
	unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE + 10] = { 0 };
	size_t i, j;

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);

	/*
	* See comments in mbedtls_entropy_self_test()
	*/
	for (i = 0; i < 8; i++) {
	TEST_ASSERT(mbedtls_entropy_func(&ctx, buf, len) == ret);
	for (j = 0; j < sizeof(buf); j++) {
	acc[j] \|= buf[j];
	}
	}

	if (ret == 0) {
	for (j = 0; j < (size_t) len; j++) {
	TEST_ASSERT(acc[j] != 0);
	}
	}

	for (j = len; j < sizeof(buf); j++) {
	TEST_ASSERT(acc[j] == 0);
	}

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE */
	void entropy_source_fail(char *path)
	{
	mbedtls_entropy_context ctx;
	unsigned char buf[16];
	entropy_dummy_context dummy = { DUMMY_FAIL, 0, 0 };

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);

	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
	&dummy, 16,
	MBEDTLS_ENTROPY_SOURCE_WEAK)
	== 0);

	TEST_ASSERT(mbedtls_entropy_func(&ctx, buf, sizeof(buf))
	== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
	TEST_ASSERT(mbedtls_entropy_gather(&ctx)
	== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
	#if defined(MBEDTLS_FS_IO) && defined(MBEDTLS_ENTROPY_NV_SEED)
	TEST_ASSERT(mbedtls_entropy_write_seed_file(&ctx, path)
	== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
	TEST_ASSERT(mbedtls_entropy_update_seed_file(&ctx, path)
	== MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
	#else
	((void) path);
	#endif

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE */
	void entropy_threshold(int threshold, int chunk_size, int result)
	{
	mbedtls_entropy_context ctx;
	entropy_dummy_context strong =
	{ DUMMY_CONSTANT_LENGTH, MBEDTLS_ENTROPY_BLOCK_SIZE, 0 };
	entropy_dummy_context weak = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
	int ret;

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);
	entropy_clear_sources(&ctx);

	/* Set strong source that reaches its threshold immediately and
	* a weak source whose threshold is a test parameter. */
	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
	&strong, 1,
	MBEDTLS_ENTROPY_SOURCE_STRONG) == 0);
	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
	&weak, threshold,
	MBEDTLS_ENTROPY_SOURCE_WEAK) == 0);

	ret = mbedtls_entropy_func(&ctx, buf, sizeof(buf));

	if (result >= 0) {
	TEST_ASSERT(ret == 0);
	#if defined(MBEDTLS_ENTROPY_NV_SEED)
	/* If the NV seed functionality is enabled, there are two entropy
	* updates: before and after updating the NV seed. */
	result *= 2;
	#endif
	TEST_ASSERT(weak.calls == (size_t) result);
	} else {
	TEST_ASSERT(ret == result);
	}

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE */
	void entropy_calls(int strength1, int strength2,
	int threshold, int chunk_size,
	int result)
	{
	/*
	* if result >= 0: result = expected number of calls to source 1
	* if result < 0: result = expected return code from mbedtls_entropy_func()
	*/

	mbedtls_entropy_context ctx;
	entropy_dummy_context dummy1 = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
	entropy_dummy_context dummy2 = { DUMMY_CONSTANT_LENGTH, chunk_size, 0 };
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
	int ret;

	MD_PSA_INIT();

	mbedtls_entropy_init(&ctx);
	entropy_clear_sources(&ctx);

	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
	&dummy1, threshold,
	strength1) == 0);
	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, entropy_dummy_source,
	&dummy2, threshold,
	strength2) == 0);

	ret = mbedtls_entropy_func(&ctx, buf, sizeof(buf));

	if (result >= 0) {
	TEST_ASSERT(ret == 0);
	#if defined(MBEDTLS_ENTROPY_NV_SEED)
	/* If the NV seed functionality is enabled, there are two entropy
	* updates: before and after updating the NV seed. */
	result *= 2;
	#endif
	TEST_ASSERT(dummy1.calls == (size_t) result);
	} else {
	TEST_ASSERT(ret == result);
	}

	exit:
	mbedtls_entropy_free(&ctx);
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
	void nv_seed_file_create()
	{
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];

	memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

	TEST_ASSERT(write_nv_seed(buf, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO:MBEDTLS_PLATFORM_NV_SEED_ALT */
	void entropy_nv_seed_std_io()
	{
	unsigned char io_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
	unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];

	memset(io_seed, 1, MBEDTLS_ENTROPY_BLOCK_SIZE);
	memset(check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

	mbedtls_platform_set_nv_seed(mbedtls_platform_std_nv_seed_read,
	mbedtls_platform_std_nv_seed_write);

	/* Check if platform NV read and write manipulate the same data */
	TEST_ASSERT(write_nv_seed(io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	TEST_ASSERT(mbedtls_nv_seed_read(check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) ==
	MBEDTLS_ENTROPY_BLOCK_SIZE);

	TEST_ASSERT(memcmp(io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

	memset(check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);

	/* Check if platform NV write and raw read manipulate the same data */
	TEST_ASSERT(mbedtls_nv_seed_write(io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) ==
	MBEDTLS_ENTROPY_BLOCK_SIZE);
	TEST_ASSERT(read_nv_seed(check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

	TEST_ASSERT(memcmp(io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:MBEDTLS_MD_C:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT */
	void entropy_nv_seed(data_t *read_seed)
	{
	#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
	const mbedtls_md_info_t *md_info =
	mbedtls_md_info_from_type(MBEDTLS_MD_SHA512);
	#elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR)
	const mbedtls_md_info_t *md_info =
	mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
	#else
	#error "Unsupported entropy accumulator"
	#endif
	mbedtls_md_context_t accumulator;
	mbedtls_entropy_context ctx;
	int (original_mbedtls_nv_seed_read)(unsigned char buf, size_t buf_len) =
	mbedtls_nv_seed_read;
	int (original_mbedtls_nv_seed_write)(unsigned char buf, size_t buf_len) =
	mbedtls_nv_seed_write;

	unsigned char header[2];
	unsigned char entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
	unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
	unsigned char empty[MBEDTLS_ENTROPY_BLOCK_SIZE];
	unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
	unsigned char check_entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];

	MD_PSA_INIT();

	memset(entropy, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
	memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
	memset(empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
	memset(check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE);
	memset(check_entropy, 3, MBEDTLS_ENTROPY_BLOCK_SIZE);

	// Make sure we read/write NV seed from our buffers
	mbedtls_platform_set_nv_seed(buffer_nv_seed_read, buffer_nv_seed_write);

	mbedtls_md_init(&accumulator);
	mbedtls_entropy_init(&ctx);
	entropy_clear_sources(&ctx);

	TEST_ASSERT(mbedtls_entropy_add_source(&ctx, mbedtls_nv_seed_poll, NULL,
	MBEDTLS_ENTROPY_BLOCK_SIZE,
	MBEDTLS_ENTROPY_SOURCE_STRONG) == 0);

	// Set the initial NV seed to read
	TEST_ASSERT(read_seed->len >= MBEDTLS_ENTROPY_BLOCK_SIZE);
	memcpy(buffer_seed, read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE);

	// Do an entropy run
	TEST_ASSERT(mbedtls_entropy_func(&ctx, entropy, sizeof(entropy)) == 0);
	// Determine what should have happened with manual entropy internal logic

	// Init accumulator
	header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE;
	TEST_ASSERT(mbedtls_md_setup(&accumulator, md_info, 0) == 0);

	// First run for updating write_seed
	header[0] = 0;
	TEST_ASSERT(mbedtls_md_starts(&accumulator) == 0);
	TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
	TEST_ASSERT(mbedtls_md_update(&accumulator,
	read_seed->x, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	TEST_ASSERT(mbedtls_md_finish(&accumulator, buf) == 0);

	TEST_ASSERT(mbedtls_md_starts(&accumulator) == 0);
	TEST_ASSERT(mbedtls_md_update(&accumulator,
	buf, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

	TEST_ASSERT(mbedtls_md(md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
	check_seed) == 0);

	// Second run for actual entropy (triggers mbedtls_entropy_update_nv_seed)
	header[0] = MBEDTLS_ENTROPY_SOURCE_MANUAL;
	TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
	TEST_ASSERT(mbedtls_md_update(&accumulator,
	empty, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

	header[0] = 0;
	TEST_ASSERT(mbedtls_md_update(&accumulator, header, 2) == 0);
	TEST_ASSERT(mbedtls_md_update(&accumulator,
	check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	TEST_ASSERT(mbedtls_md_finish(&accumulator, buf) == 0);

	TEST_ASSERT(mbedtls_md(md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE,
	check_entropy) == 0);

	// Check result of both NV file and entropy received with the manual calculations
	TEST_ASSERT(memcmp(check_seed, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);
	TEST_ASSERT(memcmp(check_entropy, entropy, MBEDTLS_ENTROPY_BLOCK_SIZE) == 0);

	exit:
	mbedtls_md_free(&accumulator);
	mbedtls_entropy_free(&ctx);
	mbedtls_nv_seed_read = original_mbedtls_nv_seed_read;
	mbedtls_nv_seed_write = original_mbedtls_nv_seed_write;
	MD_PSA_DONE();
	}
	/* END_CASE */

	/* BEGIN_CASE depends_on:ENTROPY_HAVE_STRONG:MBEDTLS_SELF_TEST */
	void entropy_selftest(int result)
	{
	MD_PSA_INIT();

	TEST_ASSERT(mbedtls_entropy_self_test(1) == result);

	exit:
	MD_PSA_DONE();
	}
	/* END_CASE */