diff --git a/boot/bootutil/src/encrypted.c b/boot/bootutil/src/encrypted.c
index 12c0a9c..73e1f1f 100644
--- a/boot/bootutil/src/encrypted.c
+++ b/boot/bootutil/src/encrypted.c
@@ -2,7 +2,7 @@
  * SPDX-License-Identifier: Apache-2.0
  *
  * Copyright (c) 2018-2019 JUUL Labs
- * Copyright (c) 2019 Arm Limited
+ * Copyright (c) 2019-2021 Arm Limited
  */
 
 #include "mcuboot_config/mcuboot_config.h"
@@ -14,7 +14,11 @@
 
 #if defined(MCUBOOT_ENCRYPT_RSA)
 #include "mbedtls/rsa.h"
+#if MBEDTLS_VERSION_NUMBER >= 0x03000000
+#include "rsa_alt_helpers.h"
+#else
 #include "mbedtls/rsa_internal.h"
+#endif
 #include "mbedtls/asn1.h"
 #endif
 
@@ -40,6 +44,7 @@
 #include "bootutil/image.h"
 #include "bootutil/enc_key.h"
 #include "bootutil/sign_key.h"
+#include "bootutil/crypto/common.h"
 
 #include "bootutil_priv.h"
 
@@ -74,15 +79,11 @@
 
     bootutil_aes_kw_init(&aes_kw);
     rc = bootutil_aes_kw_set_unwrap_key(&aes_kw, bootutil_enc_key.key, *bootutil_enc_key.len);
-    if (rc != 0) {
-        goto done;
-    }
-    rc = bootutil_aes_kw_unwrap(&aes_kw, wrapped, TLV_ENC_KW_SZ, enckey, BOOT_ENC_KEY_SIZE);
-    if (rc != 0) {
-        goto done;
+
+    if (rc == 0) {
+        rc = bootutil_aes_kw_unwrap(&aes_kw, wrapped, TLV_ENC_KW_SZ, enckey, BOOT_ENC_KEY_SIZE);
     }
 
-done:
     bootutil_aes_kw_drop(&aes_kw);
     return rc;
 }
@@ -105,16 +106,16 @@
 
     /* Non-optional fields. */
     if ( /* version */
-        mbedtls_asn1_get_int(p, end, &ctx->ver) != 0 ||
+        mbedtls_asn1_get_int(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(ver)) != 0 ||
          /* public modulus */
-        mbedtls_asn1_get_mpi(p, end, &ctx->N) != 0 ||
+        mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(N)) != 0 ||
          /* public exponent */
-        mbedtls_asn1_get_mpi(p, end, &ctx->E) != 0 ||
+        mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(E)) != 0 ||
          /* private exponent */
-        mbedtls_asn1_get_mpi(p, end, &ctx->D) != 0 ||
+        mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(D)) != 0 ||
          /* primes */
-        mbedtls_asn1_get_mpi(p, end, &ctx->P) != 0 ||
-        mbedtls_asn1_get_mpi(p, end, &ctx->Q) != 0) {
+        mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(P)) != 0 ||
+        mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(Q)) != 0) {
 
         return -3;
     }
@@ -127,22 +128,26 @@
      */
     if (*p < end) {
         if ( /* d mod (p-1) and d mod (q-1) */
-            mbedtls_asn1_get_mpi(p, end, &ctx->DP) != 0 ||
-            mbedtls_asn1_get_mpi(p, end, &ctx->DQ) != 0 ||
+            mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(DP)) != 0 ||
+            mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(DQ)) != 0 ||
              /* q ^ (-1) mod p */
-            mbedtls_asn1_get_mpi(p, end, &ctx->QP) != 0) {
+            mbedtls_asn1_get_mpi(p, end, &ctx->MBEDTLS_CONTEXT_MEMBER(QP)) != 0) {
 
             return -4;
         }
     } else {
-        if (mbedtls_rsa_deduce_crt(&ctx->P, &ctx->Q, &ctx->D,
-                    &ctx->DP, &ctx->DQ, &ctx->QP) != 0) {
+        if (mbedtls_rsa_deduce_crt(&ctx->MBEDTLS_CONTEXT_MEMBER(P),
+                                   &ctx->MBEDTLS_CONTEXT_MEMBER(Q),
+                                   &ctx->MBEDTLS_CONTEXT_MEMBER(D),
+                                   &ctx->MBEDTLS_CONTEXT_MEMBER(DP),
+                                   &ctx->MBEDTLS_CONTEXT_MEMBER(DQ),
+                                   &ctx->MBEDTLS_CONTEXT_MEMBER(QP)) != 0) {
             return -5;
         }
     }
 #endif
 
-    ctx->len = mbedtls_mpi_size(&ctx->N);
+    ctx->MBEDTLS_CONTEXT_MEMBER(len) = mbedtls_mpi_size(&ctx->MBEDTLS_CONTEXT_MEMBER(N));
 
     if (mbedtls_rsa_check_privkey(ctx) != 0) {
         return -6;
@@ -190,12 +195,12 @@
         return -5;
     }
 
-    if (alg.len != sizeof(ec_pubkey_oid) - 1 ||
-        memcmp(alg.p, ec_pubkey_oid, sizeof(ec_pubkey_oid) - 1)) {
+    if (alg.MBEDTLS_CONTEXT_MEMBER(len) != sizeof(ec_pubkey_oid) - 1 ||
+        memcmp(alg.MBEDTLS_CONTEXT_MEMBER(p), ec_pubkey_oid, sizeof(ec_pubkey_oid) - 1)) {
         return -6;
     }
-    if (param.len != sizeof(ec_secp256r1_oid) - 1 ||
-        memcmp(param.p, ec_secp256r1_oid, sizeof(ec_secp256r1_oid) - 1)) {
+    if (param.MBEDTLS_CONTEXT_MEMBER(len) != sizeof(ec_secp256r1_oid) - 1 ||
+        memcmp(param.MBEDTLS_CONTEXT_MEMBER(p), ec_secp256r1_oid, sizeof(ec_secp256r1_oid) - 1)) {
         return -7;
     }
 
@@ -267,8 +272,8 @@
         return -4;
     }
 
-    if (alg.len != sizeof(ec_pubkey_oid) - 1 ||
-        memcmp(alg.p, ec_pubkey_oid, sizeof(ec_pubkey_oid) - 1)) {
+    if (alg.MBEDTLS_CONTEXT_MEMBER(len) != sizeof(ec_pubkey_oid) - 1 ||
+        memcmp(alg.MBEDTLS_CONTEXT_MEMBER(p), ec_pubkey_oid, sizeof(ec_pubkey_oid) - 1)) {
         return -5;
     }
 
@@ -433,25 +438,22 @@
 
 #if defined(MCUBOOT_ENCRYPT_RSA)
 #    define EXPECTED_ENC_TLV        IMAGE_TLV_ENC_RSA2048
-#    define EXPECTED_ENC_EXT_LEN    EXPECTED_ENC_TLV
 #elif defined(MCUBOOT_ENCRYPT_KW)
-#    define EXPECTED_ENC_TLV        IMAGE_TLV_ENC_KW128
-#    define EXPECTED_ENC_EXT_LEN    EXPECTED_ENC_TLV
+#    define EXPECTED_ENC_TLV    IMAGE_TLV_ENC_KW
 #elif defined(MCUBOOT_ENCRYPT_EC256)
 #    define EXPECTED_ENC_TLV     IMAGE_TLV_ENC_EC256
 #    define EXPECTED_ENC_EXT_LEN (EXPECTED_ENC_LEN + BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE)
 #    define EC_PUBK_INDEX       (0)
 #    define EC_TAG_INDEX        (65)
 #    define EC_CIPHERKEY_INDEX  (65 + 32)
-_Static_assert(EC_CIPHERKEY_INDEX + 16 == EXPECTED_ENC_LEN,
+_Static_assert(EC_CIPHERKEY_INDEX + BOOT_ENC_KEY_SIZE == EXPECTED_ENC_LEN,
         "Please fix ECIES-P256 component indexes");
 #elif defined(MCUBOOT_ENCRYPT_X25519)
 #    define EXPECTED_ENC_TLV        IMAGE_TLV_ENC_X25519
-#    define EXPECTED_ENC_EXT_LEN    EXPECTED_ENC_TLV
 #    define EC_PUBK_INDEX       (0)
 #    define EC_TAG_INDEX        (32)
 #    define EC_CIPHERKEY_INDEX  (32 + 32)
-_Static_assert(EC_CIPHERKEY_INDEX + 16 == EXPECTED_ENC_LEN,
+_Static_assert(EC_CIPHERKEY_INDEX + BOOT_ENC_KEY_SIZE == EXPECTED_ENC_LEN,
         "Please fix ECIES-X25519 component indexes");
 #endif
 
@@ -459,12 +461,30 @@
 #define EXPECTED_ENC_EXT_LEN        EXPECTED_ENC_LEN
 #endif
 
+#if defined(MCUBOOT_ENCRYPT_RSA) || \
+    (defined(MCUBOOT_ENCRYPT_EC256) && defined(MCUBOOT_USE_MBED_TLS))
+#if MBEDTLS_VERSION_NUMBER >= 0x03000000
+static int fake_rng(void *p_rng, unsigned char *output, size_t len)
+{
+    size_t i;
+
+    (void)p_rng;
+    for (i = 0; i < len; i++) {
+        output[i] = (char)i;
+    }
+
+    return 0;
+}
+#endif
+#endif /* defined(MCUBOOT_ENCRYPT_RSA) ||
+          defined(MCUBOOT_ENCRYPT_EC256) && defined(MCUBOOT_USE_MBED_TLS) */
+
 /*
  * Decrypt an encryption key TLV.
  *
- * @param buf An encryption TLV buffer red from flash
+ * @param buf An encryption TLV read from flash (build time fixed length)
  * @param sz An encryption TLV buffer data size
- * @param enckey An AES-128 key sized buffer to store to plain key.
+ * @param enckey An AES-128 or AES-256 key sized buffer to store to plain key.
  */
 int
 boot_enc_decrypt(const uint8_t *buf, uint8_t *enckey, uint32_t sz, uint8_t *enciv)
@@ -505,8 +525,12 @@
 
 #if defined(MCUBOOT_ENCRYPT_RSA)
 
+#if MBEDTLS_VERSION_NUMBER >= 0x03000000
+    mbedtls_rsa_init(&rsa);
+    mbedtls_rsa_set_padding(&rsa, MBEDTLS_RSA_PKCS_V21, MBEDTLS_MD_SHA256);
+#else
     mbedtls_rsa_init(&rsa, MBEDTLS_RSA_PKCS_V21, MBEDTLS_MD_SHA256);
-
+#endif
     cp = (uint8_t *)bootutil_enc_key.key;
     cpend = cp + *bootutil_enc_key.len;
 
@@ -515,16 +539,20 @@
         mbedtls_rsa_free(&rsa);
         return rc;
     }
-
+#if MBEDTLS_VERSION_NUMBER >= 0x03000000
+    rc = mbedtls_rsa_rsaes_oaep_decrypt(&rsa, fake_rng, NULL,
+            NULL, 0, &olen, buf, enckey, BOOT_ENC_KEY_SIZE);
+#else
     rc = mbedtls_rsa_rsaes_oaep_decrypt(&rsa, NULL, NULL, MBEDTLS_RSA_PRIVATE,
             NULL, 0, &olen, buf, enckey, BOOT_ENC_KEY_SIZE);
+#endif
     mbedtls_rsa_free(&rsa);
 
 #endif /* defined(MCUBOOT_ENCRYPT_RSA) */
 
 #if defined(MCUBOOT_ENCRYPT_KW)
 
-    assert(*bootutil_enc_key.len == 16);
+    assert(*bootutil_enc_key.len == BOOT_ENC_KEY_SIZE);
     rc = key_unwrap(buf, enckey);
 
 #endif /* defined(MCUBOOT_ENCRYPT_KW) */
@@ -592,8 +620,8 @@
      */
 
     /* Prepare for default encryption scheme with zero salt and AES IVs */
-    memset(counter, 0, BOOTUTIL_CRYPTO_AES_CTR_BLOCK_SIZE);
-    memset(salt, 0, BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE);
+    (void)memset(counter, 0, BOOTUTIL_CRYPTO_AES_CTR_BLOCK_SIZE);
+    (void)memset(salt, 0, BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE);
 
     len = BOOTUTIL_CRYPTO_AES_CTR_KEY_SIZE + BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE;
 
@@ -625,13 +653,13 @@
 
     bootutil_hmac_sha256_init(&hmac);
 
-    rc = bootutil_hmac_sha256_set_key(&hmac, &derived_key[BOOTUTIL_CRYPTO_AES_CTR_BLOCK_SIZE], BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE);
+    rc = bootutil_hmac_sha256_set_key(&hmac, &derived_key[BOOT_ENC_KEY_SIZE], BOOTUTIL_CRYPTO_SHA256_DIGEST_SIZE);
     if (rc != 0) {
         (void)bootutil_hmac_sha256_drop(&hmac);
         return -1;
     }
 
-    rc = bootutil_hmac_sha256_update(&hmac, &buf[EC_CIPHERKEY_INDEX], BOOTUTIL_CRYPTO_AES_CTR_BLOCK_SIZE);
+    rc = bootutil_hmac_sha256_update(&hmac, &buf[EC_CIPHERKEY_INDEX], BOOT_ENC_KEY_SIZE);
     if (rc != 0) {
         (void)bootutil_hmac_sha256_drop(&hmac);
         return -1;
@@ -699,16 +727,18 @@
     uint8_t slot;
     int rc;
 
-    rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
+    rc = flash_area_id_to_multi_image_slot(image_index, flash_area_get_id(fap));
     if (rc < 0) {
         return rc;
     }
     slot = rc;
 
+#ifndef MCUBOOT_ENC_IMAGES_XIP
     /* Already loaded... */
     if (enc_state[slot].valid) {
         return 1;
     }
+#endif
 
     /* Initialize the AES context */
     boot_enc_init(enc_state, slot);
@@ -729,11 +759,11 @@
 
 #if MCUBOOT_SWAP_SAVE_ENCTLV
     buf = bs->enctlv[slot];
-    memset(buf, 0xff, BOOT_ENC_TLV_ALIGN_SIZE);
+    (void)memset(buf, BOOT_UNINITIALIZED_TLV_FILL, BOOT_ENC_TLV_ALIGN_SIZE);
 #endif
 
     rc = flash_area_read(fap, off, buf, len);
-    if (rc) {
+    if (rc != 0) {
         return -1;
     }
 
@@ -746,7 +776,7 @@
 {
     int rc;
 
-    rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
+    rc = flash_area_id_to_multi_image_slot(image_index, flash_area_get_id(fap));
     if (rc < 0) {
         /* can't get proper slot number - skip encryption, */
         /* postpone the error for a upper layer */
@@ -756,7 +786,7 @@
     return enc_state[rc].valid;
 }
 
-void
+int
 boot_encrypt(struct enc_key_data *enc_state, int image_index,
         const struct flash_area *fap, uint32_t off, uint32_t sz,
         uint32_t blk_off, uint8_t *buf)
@@ -768,13 +798,23 @@
     /* boot_copy_region will call boot_encrypt with sz = 0 when skipping over
        the TLVs. */
     if (sz == 0) {
-       return;
+        return 0;
     }
 
-    rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
-    if (rc < 0) {
-        assert(0);
-        return;
+#if MCUBOOT_SWAP_USING_SCRATCH
+/* in this case scratch area contains encrypted source block that was copied
+from secondary slot */
+    if (fap->fa_id == FLASH_AREA_IMAGE_SCRATCH) {
+        rc = 1;
+    }
+    else
+#endif
+    {
+        rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
+        if (rc < 0) {
+            assert(0);
+            return rc;
+        }
     }
 
     enc = &enc_state[rc];
@@ -788,7 +828,7 @@
     nonce[14] = (uint8_t)(off >> 8);
     nonce[15] = (uint8_t)off;
 
-    bootutil_aes_ctr_encrypt(&enc->aes_ctr, nonce, buf, sz, blk_off, buf);
+    return bootutil_aes_ctr_encrypt(&enc->aes_ctr, nonce, buf, sz, blk_off, buf);
 }
 
 /**
@@ -801,7 +841,7 @@
     for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
         (void)boot_enc_drop(enc_state, slot);
     }
-    memset(enc_state, 0, sizeof(struct enc_key_data) * BOOT_NUM_SLOTS);
+    (void)memset(enc_state, 0, sizeof(struct enc_key_data) * BOOT_NUM_SLOTS);
 }
 
 #endif /* MCUBOOT_ENC_IMAGES */