diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 815b5bb..1dc31c9 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -678,7 +678,6 @@
 static inline unsigned int mbedtls_cipher_get_block_size(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return 0;
     }
@@ -698,7 +697,6 @@
 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, MBEDTLS_MODE_NONE);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return MBEDTLS_MODE_NONE;
     }
@@ -719,7 +717,6 @@
 static inline int mbedtls_cipher_get_iv_size(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return 0;
     }
@@ -743,8 +740,6 @@
 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx != NULL, MBEDTLS_CIPHER_NONE);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return MBEDTLS_CIPHER_NONE;
     }
@@ -764,7 +759,6 @@
 static inline const char *mbedtls_cipher_get_name(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return 0;
     }
@@ -784,8 +778,6 @@
 static inline int mbedtls_cipher_get_key_bitlen(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx != NULL, MBEDTLS_KEY_LENGTH_NONE);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return MBEDTLS_KEY_LENGTH_NONE;
     }
@@ -805,8 +797,6 @@
 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
     const mbedtls_cipher_context_t *ctx)
 {
-    MBEDTLS_INTERNAL_VALIDATE_RET(
-        ctx != NULL, MBEDTLS_OPERATION_NONE);
     if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
         return MBEDTLS_OPERATION_NONE;
     }
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index cba02ab..1b371ef 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -23,10 +23,6 @@
 extern "C" {
 #endif
 
-/* Internal macros meant to be called only from within the library. */
-#define MBEDTLS_INTERNAL_VALIDATE_RET(cond, ret)  do { } while (0)
-#define MBEDTLS_INTERNAL_VALIDATE(cond)           do { } while (0)
-
 /* Internal helper macros for deprecating API constants. */
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 #if defined(MBEDTLS_DEPRECATED_WARNING)
diff --git a/library/aria.c b/library/aria.c
index ba12578..d9f84cc 100644
--- a/library/aria.c
+++ b/library/aria.c
@@ -25,12 +25,6 @@
 
 #include "mbedtls/platform_util.h"
 
-/* Parameter validation macros */
-#define ARIA_VALIDATE_RET(cond)                                       \
-    MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_ARIA_BAD_INPUT_DATA)
-#define ARIA_VALIDATE(cond)                                           \
-    MBEDTLS_INTERNAL_VALIDATE(cond)
-
 /*
  * modify byte order: ( A B C D ) -> ( B A D C ), i.e. swap pairs of bytes
  *
@@ -363,8 +357,6 @@
 
     int i;
     uint32_t w[4][4], *w2;
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(key != NULL);
 
     if (keybits != 128 && keybits != 192 && keybits != 256) {
         return MBEDTLS_ERR_ARIA_BAD_INPUT_DATA;
@@ -418,8 +410,6 @@
                             const unsigned char *key, unsigned int keybits)
 {
     int i, j, k, ret;
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(key != NULL);
 
     ret = mbedtls_aria_setkey_enc(ctx, key, keybits);
     if (ret != 0) {
@@ -455,9 +445,6 @@
     int i;
 
     uint32_t a, b, c, d;
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(input != NULL);
-    ARIA_VALIDATE_RET(output != NULL);
 
     a = MBEDTLS_GET_UINT32_LE(input,  0);
     b = MBEDTLS_GET_UINT32_LE(input,  4);
@@ -505,7 +492,6 @@
 /* Initialize context */
 void mbedtls_aria_init(mbedtls_aria_context *ctx)
 {
-    ARIA_VALIDATE(ctx != NULL);
     memset(ctx, 0, sizeof(mbedtls_aria_context));
 }
 
@@ -532,12 +518,9 @@
 {
     unsigned char temp[MBEDTLS_ARIA_BLOCKSIZE];
 
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(mode == MBEDTLS_ARIA_ENCRYPT ||
-                      mode == MBEDTLS_ARIA_DECRYPT);
-    ARIA_VALIDATE_RET(length == 0 || input  != NULL);
-    ARIA_VALIDATE_RET(length == 0 || output != NULL);
-    ARIA_VALIDATE_RET(iv != NULL);
+    if ((mode != MBEDTLS_ARIA_ENCRYPT) && (mode != MBEDTLS_ARIA_DECRYPT)) {
+        return MBEDTLS_ERR_ARIA_BAD_INPUT_DATA;
+    }
 
     if (length % MBEDTLS_ARIA_BLOCKSIZE) {
         return MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH;
@@ -588,19 +571,14 @@
     unsigned char c;
     size_t n;
 
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(mode == MBEDTLS_ARIA_ENCRYPT ||
-                      mode == MBEDTLS_ARIA_DECRYPT);
-    ARIA_VALIDATE_RET(length == 0 || input  != NULL);
-    ARIA_VALIDATE_RET(length == 0 || output != NULL);
-    ARIA_VALIDATE_RET(iv != NULL);
-    ARIA_VALIDATE_RET(iv_off != NULL);
+    if ((mode != MBEDTLS_ARIA_ENCRYPT) && (mode != MBEDTLS_ARIA_DECRYPT)) {
+        return MBEDTLS_ERR_ARIA_BAD_INPUT_DATA;
+    }
 
     n = *iv_off;
 
     /* An overly large value of n can lead to an unlimited
-     * buffer overflow. Therefore, guard against this
-     * outside of parameter validation. */
+     * buffer overflow. */
     if (n >= MBEDTLS_ARIA_BLOCKSIZE) {
         return MBEDTLS_ERR_ARIA_BAD_INPUT_DATA;
     }
@@ -650,17 +628,9 @@
     int c, i;
     size_t n;
 
-    ARIA_VALIDATE_RET(ctx != NULL);
-    ARIA_VALIDATE_RET(length == 0 || input  != NULL);
-    ARIA_VALIDATE_RET(length == 0 || output != NULL);
-    ARIA_VALIDATE_RET(nonce_counter != NULL);
-    ARIA_VALIDATE_RET(stream_block  != NULL);
-    ARIA_VALIDATE_RET(nc_off != NULL);
-
     n = *nc_off;
     /* An overly large value of n can lead to an unlimited
-     * buffer overflow. Therefore, guard against this
-     * outside of parameter validation. */
+     * buffer overflow. */
     if (n >= MBEDTLS_ARIA_BLOCKSIZE) {
         return MBEDTLS_ERR_ARIA_BAD_INPUT_DATA;
     }
diff --git a/library/bignum.c b/library/bignum.c
index 1869137..d3d72ab 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -37,11 +37,6 @@
 
 #include "mbedtls/platform.h"
 
-#define MPI_VALIDATE_RET(cond)                                       \
-    MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_MPI_BAD_INPUT_DATA)
-#define MPI_VALIDATE(cond)                                           \
-    MBEDTLS_INTERNAL_VALIDATE(cond)
-
 /*
  * Compare signed values in constant time
  */
@@ -51,10 +46,6 @@
 {
     mbedtls_ct_condition_t different_sign, X_is_negative, Y_is_negative, result;
 
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
-    MPI_VALIDATE_RET(ret != NULL);
-
     if (X->n != Y->n) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
     }
@@ -115,8 +106,6 @@
                                  unsigned char assign)
 {
     int ret = 0;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
 
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(X, Y->n));
 
@@ -149,8 +138,6 @@
 {
     int ret = 0;
     int s;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
 
     if (X == Y) {
         return 0;
@@ -179,8 +166,6 @@
  */
 void mbedtls_mpi_init(mbedtls_mpi *X)
 {
-    MPI_VALIDATE(X != NULL);
-
     X->s = 1;
     X->n = 0;
     X->p = NULL;
@@ -210,7 +195,6 @@
 int mbedtls_mpi_grow(mbedtls_mpi *X, size_t nblimbs)
 {
     mbedtls_mpi_uint *p;
-    MPI_VALIDATE_RET(X != NULL);
 
     if (nblimbs > MBEDTLS_MPI_MAX_LIMBS) {
         return MBEDTLS_ERR_MPI_ALLOC_FAILED;
@@ -243,7 +227,6 @@
 {
     mbedtls_mpi_uint *p;
     size_t i;
-    MPI_VALIDATE_RET(X != NULL);
 
     if (nblimbs > MBEDTLS_MPI_MAX_LIMBS) {
         return MBEDTLS_ERR_MPI_ALLOC_FAILED;
@@ -312,8 +295,6 @@
 {
     int ret = 0;
     size_t i;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
 
     if (X == Y) {
         return 0;
@@ -355,8 +336,6 @@
 void mbedtls_mpi_swap(mbedtls_mpi *X, mbedtls_mpi *Y)
 {
     mbedtls_mpi T;
-    MPI_VALIDATE(X != NULL);
-    MPI_VALIDATE(Y != NULL);
 
     memcpy(&T,  X, sizeof(mbedtls_mpi));
     memcpy(X,  Y, sizeof(mbedtls_mpi));
@@ -385,7 +364,6 @@
 int mbedtls_mpi_lset(mbedtls_mpi *X, mbedtls_mpi_sint z)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    MPI_VALIDATE_RET(X != NULL);
 
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(X, 1));
     memset(X->p, 0, X->n * ciL);
@@ -403,8 +381,6 @@
  */
 int mbedtls_mpi_get_bit(const mbedtls_mpi *X, size_t pos)
 {
-    MPI_VALIDATE_RET(X != NULL);
-
     if (X->n * biL <= pos) {
         return 0;
     }
@@ -420,7 +396,6 @@
     int ret = 0;
     size_t off = pos / biL;
     size_t idx = pos % biL;
-    MPI_VALIDATE_RET(X != NULL);
 
     if (val != 0 && val != 1) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
@@ -448,7 +423,6 @@
 size_t mbedtls_mpi_lsb(const mbedtls_mpi *X)
 {
     size_t i;
-    MBEDTLS_INTERNAL_VALIDATE_RET(X != NULL, 0);
 
 #if defined(__has_builtin)
 #if (MBEDTLS_MPI_UINT_MAX == UINT_MAX) && __has_builtin(__builtin_ctz)
@@ -530,8 +504,6 @@
     int sign = 1;
     mbedtls_mpi_uint d;
     mbedtls_mpi T;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(s != NULL);
 
     if (radix < 2 || radix > 16) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
@@ -634,9 +606,6 @@
     size_t n;
     char *p;
     mbedtls_mpi T;
-    MPI_VALIDATE_RET(X    != NULL);
-    MPI_VALIDATE_RET(olen != NULL);
-    MPI_VALIDATE_RET(buflen == 0 || buf != NULL);
 
     if (radix < 2 || radix > 16) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
@@ -726,9 +695,6 @@
      */
     char s[MBEDTLS_MPI_RW_BUFFER_SIZE];
 
-    MPI_VALIDATE_RET(X   != NULL);
-    MPI_VALIDATE_RET(fin != NULL);
-
     if (radix < 2 || radix > 16) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
     }
@@ -772,7 +738,6 @@
      * newline characters and '\0'
      */
     char s[MBEDTLS_MPI_RW_BUFFER_SIZE];
-    MPI_VALIDATE_RET(X != NULL);
 
     if (radix < 2 || radix > 16) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
@@ -844,9 +809,6 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const size_t limbs = CHARS_TO_LIMBS(buflen);
 
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(buflen == 0 || buf != NULL);
-
     /* Ensure that target MPI has exactly the necessary number of limbs */
     MBEDTLS_MPI_CHK(mbedtls_mpi_resize_clear(X, limbs));
 
@@ -887,7 +849,6 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;
-    MPI_VALIDATE_RET(X != NULL);
 
     i = mbedtls_mpi_bitlen(X) + count;
 
@@ -908,7 +869,6 @@
  */
 int mbedtls_mpi_shift_r(mbedtls_mpi *X, size_t count)
 {
-    MPI_VALIDATE_RET(X != NULL);
     if (X->n != 0) {
         mbedtls_mpi_core_shift_r(X->p, X->n, count);
     }
@@ -921,8 +881,6 @@
 int mbedtls_mpi_cmp_abs(const mbedtls_mpi *X, const mbedtls_mpi *Y)
 {
     size_t i, j;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
 
     for (i = X->n; i > 0; i--) {
         if (X->p[i - 1] != 0) {
@@ -964,8 +922,6 @@
 int mbedtls_mpi_cmp_mpi(const mbedtls_mpi *X, const mbedtls_mpi *Y)
 {
     size_t i, j;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(Y != NULL);
 
     for (i = X->n; i > 0; i--) {
         if (X->p[i - 1] != 0) {
@@ -1016,7 +972,6 @@
 {
     mbedtls_mpi Y;
     mbedtls_mpi_uint p[1];
-    MPI_VALIDATE_RET(X != NULL);
 
     *p  = mpi_sint_abs(z);
     Y.s = TO_SIGN(z);
@@ -1035,9 +990,6 @@
     size_t j;
     mbedtls_mpi_uint *p;
     mbedtls_mpi_uint c;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     if (X == B) {
         const mbedtls_mpi *T = A; A = X; B = T;
@@ -1098,9 +1050,6 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t n;
     mbedtls_mpi_uint carry;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     for (n = B->n; n > 0; n--) {
         if (B->p[n - 1] != 0) {
@@ -1152,9 +1101,6 @@
                        int flip_B)
 {
     int ret, s;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     s = A->s;
     if (A->s * B->s * flip_B < 0) {
@@ -1203,8 +1149,6 @@
 {
     mbedtls_mpi B;
     mbedtls_mpi_uint p[1];
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
 
     p[0] = mpi_sint_abs(b);
     B.s = TO_SIGN(b);
@@ -1221,8 +1165,6 @@
 {
     mbedtls_mpi B;
     mbedtls_mpi_uint p[1];
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
 
     p[0] = mpi_sint_abs(b);
     B.s = TO_SIGN(b);
@@ -1241,9 +1183,6 @@
     size_t i, j;
     mbedtls_mpi TA, TB;
     int result_is_zero = 0;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     mbedtls_mpi_init(&TA);
     mbedtls_mpi_init(&TB);
@@ -1300,9 +1239,6 @@
  */
 int mbedtls_mpi_mul_int(mbedtls_mpi *X, const mbedtls_mpi *A, mbedtls_mpi_uint b)
 {
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-
     size_t n = A->n;
     while (n > 0 && A->p[n - 1] == 0) {
         --n;
@@ -1448,8 +1384,6 @@
     size_t i, n, t, k;
     mbedtls_mpi X, Y, Z, T1, T2;
     mbedtls_mpi_uint TP2[3];
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     if (mbedtls_mpi_cmp_int(B, 0) == 0) {
         return MBEDTLS_ERR_MPI_DIVISION_BY_ZERO;
@@ -1572,7 +1506,6 @@
 {
     mbedtls_mpi B;
     mbedtls_mpi_uint p[1];
-    MPI_VALIDATE_RET(A != NULL);
 
     p[0] = mpi_sint_abs(b);
     B.s = TO_SIGN(b);
@@ -1588,9 +1521,6 @@
 int mbedtls_mpi_mod_mpi(mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    MPI_VALIDATE_RET(R != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
 
     if (mbedtls_mpi_cmp_int(B, 0) < 0) {
         return MBEDTLS_ERR_MPI_NEGATIVE_VALUE;
@@ -1618,8 +1548,6 @@
 {
     size_t i;
     mbedtls_mpi_uint x, y, z;
-    MPI_VALIDATE_RET(r != NULL);
-    MPI_VALIDATE_RET(A != NULL);
 
     if (b == 0) {
         return MBEDTLS_ERR_MPI_DIVISION_BY_ZERO;
@@ -1763,11 +1691,6 @@
     mbedtls_mpi RR, T, W[(size_t) 1 << MBEDTLS_MPI_WINDOW_SIZE], WW, Apos;
     int neg;
 
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(E != NULL);
-    MPI_VALIDATE_RET(N != NULL);
-
     if (mbedtls_mpi_cmp_int(N, 0) <= 0 || (N->p[0] & 1) == 0) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
     }
@@ -2054,10 +1977,6 @@
     size_t lz, lzt;
     mbedtls_mpi TA, TB;
 
-    MPI_VALIDATE_RET(G != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(B != NULL);
-
     mbedtls_mpi_init(&TA); mbedtls_mpi_init(&TB);
 
     MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&TA, A));
@@ -2168,9 +2087,6 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const size_t limbs = CHARS_TO_LIMBS(size);
 
-    MPI_VALIDATE_RET(X     != NULL);
-    MPI_VALIDATE_RET(f_rng != NULL);
-
     /* Ensure that target MPI has exactly the necessary number of limbs */
     MBEDTLS_MPI_CHK(mbedtls_mpi_resize_clear(X, limbs));
     if (size == 0) {
@@ -2214,9 +2130,6 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_mpi G, TA, TU, U1, U2, TB, TV, V1, V2;
-    MPI_VALIDATE_RET(X != NULL);
-    MPI_VALIDATE_RET(A != NULL);
-    MPI_VALIDATE_RET(N != NULL);
 
     if (mbedtls_mpi_cmp_int(N, 1) <= 0) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
@@ -2372,9 +2285,6 @@
     size_t i, j, k, s;
     mbedtls_mpi W, R, T, A, RR;
 
-    MPI_VALIDATE_RET(X     != NULL);
-    MPI_VALIDATE_RET(f_rng != NULL);
-
     mbedtls_mpi_init(&W); mbedtls_mpi_init(&R);
     mbedtls_mpi_init(&T); mbedtls_mpi_init(&A);
     mbedtls_mpi_init(&RR);
@@ -2462,8 +2372,6 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_mpi XX;
-    MPI_VALIDATE_RET(X     != NULL);
-    MPI_VALIDATE_RET(f_rng != NULL);
 
     XX.s = 1;
     XX.n = X->n;
@@ -2513,9 +2421,6 @@
     mbedtls_mpi_uint r;
     mbedtls_mpi Y;
 
-    MPI_VALIDATE_RET(X     != NULL);
-    MPI_VALIDATE_RET(f_rng != NULL);
-
     if (nbits < 3 || nbits > MBEDTLS_MPI_MAX_BITS) {
         return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
     }
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 577e23b..d295709 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -23,12 +23,6 @@
 
 #if !defined(MBEDTLS_ECP_ALT)
 
-/* Parameter validation macros based on platform_util.h */
-#define ECP_VALIDATE_RET(cond)    \
-    MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA)
-#define ECP_VALIDATE(cond)        \
-    MBEDTLS_INTERNAL_VALIDATE(cond)
-
 #define ECP_MPI_INIT(_p, _n) { .p = (mbedtls_mpi_uint *) (_p), .s = 1, .n = (_n) }
 
 #define ECP_MPI_INIT_ARRAY(x)   \
@@ -4722,7 +4716,6 @@
  */
 int mbedtls_ecp_group_load(mbedtls_ecp_group *grp, mbedtls_ecp_group_id id)
 {
-    ECP_VALIDATE_RET(grp != NULL);
     mbedtls_ecp_group_free(grp);
 
     mbedtls_ecp_group_init(grp);
diff --git a/library/ecp_curves_new.c b/library/ecp_curves_new.c
index 4ee0f58..035b23a 100644
--- a/library/ecp_curves_new.c
+++ b/library/ecp_curves_new.c
@@ -28,12 +28,6 @@
 
 #if !defined(MBEDTLS_ECP_ALT)
 
-/* Parameter validation macros based on platform_util.h */
-#define ECP_VALIDATE_RET(cond)    \
-    MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_ECP_BAD_INPUT_DATA)
-#define ECP_VALIDATE(cond)        \
-    MBEDTLS_INTERNAL_VALIDATE(cond)
-
 #define ECP_MPI_INIT(_p, _n) { .p = (mbedtls_mpi_uint *) (_p), .s = 1, .n = (_n) }
 
 #define ECP_MPI_INIT_ARRAY(x)   \
@@ -4764,7 +4758,6 @@
  */
 int mbedtls_ecp_group_load(mbedtls_ecp_group *grp, mbedtls_ecp_group_id id)
 {
-    ECP_VALIDATE_RET(grp != NULL);
     mbedtls_ecp_group_free(grp);
 
     mbedtls_ecp_group_init(grp);
diff --git a/library/platform_util.c b/library/platform_util.c
index eafb0aa..0741bf5 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -93,8 +93,6 @@
 
 void mbedtls_platform_zeroize(void *buf, size_t len)
 {
-    MBEDTLS_INTERNAL_VALIDATE(len == 0 || buf != NULL);
-
     if (len > 0) {
 #if defined(MBEDTLS_PLATFORM_HAS_EXPLICIT_BZERO)
         explicit_bzero(buf, len);
diff --git a/tests/suites/test_suite_aria.function b/tests/suites/test_suite_aria.function
index f1748d1..a454eba 100644
--- a/tests/suites/test_suite_aria.function
+++ b/tests/suites/test_suite_aria.function
@@ -16,7 +16,7 @@
  * END_DEPENDENCIES
  */
 
-/* BEGIN_CASE depends_on:NOT_DEFINED */
+/* BEGIN_CASE */
 void aria_invalid_param()
 {
     mbedtls_aria_context ctx;
@@ -52,8 +52,10 @@
                                          output));
 #endif /* MBEDTLS_CIPHER_MODE_CFB */
 
+#if defined(MBEDTLS_CIPHER_MODE_CBC) || defined(MBEDTLS_CIPHER_MODE_CFB)
 exit:
     return;
+#endif
 
 }
 /* END_CASE */
diff --git a/tests/suites/test_suite_bignum.function b/tests/suites/test_suite_bignum.function
index c90f1bb..2305f48 100644
--- a/tests/suites/test_suite_bignum.function
+++ b/tests/suites/test_suite_bignum.function
@@ -144,6 +144,26 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
+void mpi_zero_length_buffer_is_null()
+{
+    mbedtls_mpi X;
+    size_t olen;
+
+    mbedtls_mpi_init(&X);
+
+    /* Simply test that the following functions do not crash when a NULL buffer
+     * pointer and 0 length is passed. We don't care much about the return value. */
+    TEST_EQUAL(mbedtls_mpi_read_binary(&X, NULL, 0), 0);
+    TEST_EQUAL(mbedtls_mpi_read_binary_le(&X, NULL, 0), 0);
+    TEST_EQUAL(mbedtls_mpi_write_string(&X, 16, NULL, 0, &olen), MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL);
+    TEST_EQUAL(mbedtls_mpi_write_binary(&X, NULL, 0), 0);
+
+exit:
+    mbedtls_mpi_free(&X);
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void mpi_read_binary(data_t *buf, char *input_A)
 {
     mbedtls_mpi X;
diff --git a/tests/suites/test_suite_bignum.misc.data b/tests/suites/test_suite_bignum.misc.data
index 9d068f1..c53e42a 100644
--- a/tests/suites/test_suite_bignum.misc.data
+++ b/tests/suites/test_suite_bignum.misc.data
@@ -82,6 +82,9 @@
 Test mpi_write_string #10 (Negative hex with odd number of digits)
 mpi_read_write_string:16:"-1":16:"":3:0:MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL
 
+Provide NULL buffer with 0 length
+mpi_zero_length_buffer_is_null
+
 Base test mbedtls_mpi_read_binary #1
 mpi_read_binary:"0941379d00fed1491fe15df284dfde4a142f68aa8d412023195cee66883e6290ffe703f4ea5963bf212713cee46b107c09182b5edcd955adac418bf4918e2889af48e1099d513830cec85c26ac1e158b52620e33ba8692f893efbb2f958b4424":"0941379D00FED1491FE15DF284DFDE4A142F68AA8D412023195CEE66883E6290FFE703F4EA5963BF212713CEE46B107C09182B5EDCD955ADAC418BF4918E2889AF48E1099D513830CEC85C26AC1E158B52620E33BA8692F893EFBB2F958B4424"