diff --git a/configs/config-symmetric-only.h b/configs/config-symmetric-only.h
new file mode 100644
index 0000000..94e80ab
--- /dev/null
+++ b/configs/config-symmetric-only.h
@@ -0,0 +1,99 @@
+/**
+ * \file config-symmetric-only.h
+ *
+ * \brief Configuration without any asymmetric cryptography.
+ */
+/*
+ *  Copyright (C) 2019, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#ifndef MBEDTLS_CONFIG_H
+#define MBEDTLS_CONFIG_H
+
+/* System support */
+//#define MBEDTLS_HAVE_ASM
+#define MBEDTLS_HAVE_TIME
+#define MBEDTLS_HAVE_TIME_DATE
+
+/* Mbed Crypto feature support */
+#define MBEDTLS_CIPHER_MODE_CBC
+#define MBEDTLS_CIPHER_MODE_CFB
+#define MBEDTLS_CIPHER_MODE_CTR
+#define MBEDTLS_CIPHER_MODE_OFB
+#define MBEDTLS_CIPHER_MODE_XTS
+#define MBEDTLS_CIPHER_PADDING_PKCS7
+#define MBEDTLS_CIPHER_PADDING_ONE_AND_ZEROS
+#define MBEDTLS_CIPHER_PADDING_ZEROS_AND_LEN
+#define MBEDTLS_CIPHER_PADDING_ZEROS
+#define MBEDTLS_ERROR_STRERROR_DUMMY
+#define MBEDTLS_FS_IO
+#define MBEDTLS_ENTROPY_NV_SEED
+#define MBEDTLS_SELF_TEST
+#define MBEDTLS_USE_PSA_CRYPTO
+#define MBEDTLS_VERSION_FEATURES
+
+/* Mbed Crypto modules */
+#define MBEDTLS_AES_C
+#define MBEDTLS_ARC4_C
+#define MBEDTLS_ASN1_PARSE_C
+#define MBEDTLS_ASN1_WRITE_C
+#define MBEDTLS_BASE64_C
+#define MBEDTLS_BLOWFISH_C
+#define MBEDTLS_CAMELLIA_C
+#define MBEDTLS_ARIA_C
+#define MBEDTLS_CCM_C
+#define MBEDTLS_CHACHA20_C
+#define MBEDTLS_CHACHAPOLY_C
+#define MBEDTLS_CIPHER_C
+#define MBEDTLS_CMAC_C
+#define MBEDTLS_CTR_DRBG_C
+#define MBEDTLS_DES_C
+#define MBEDTLS_ENTROPY_C
+#define MBEDTLS_ERROR_C
+#define MBEDTLS_GCM_C
+//#define MBEDTLS_HAVEGE_C
+#define MBEDTLS_HKDF_C
+#define MBEDTLS_HMAC_DRBG_C
+#define MBEDTLS_NIST_KW_C
+#define MBEDTLS_MD_C
+#define MBEDTLS_MD2_C
+#define MBEDTLS_MD4_C
+#define MBEDTLS_MD5_C
+#define MBEDTLS_OID_C
+#define MBEDTLS_PEM_PARSE_C
+#define MBEDTLS_PEM_WRITE_C
+#define MBEDTLS_PKCS5_C
+#define MBEDTLS_PKCS12_C
+#define MBEDTLS_PLATFORM_C
+#define MBEDTLS_POLY1305_C
+#define MBEDTLS_PSA_CRYPTO_C
+#define MBEDTLS_PSA_CRYPTO_SE_C
+#define MBEDTLS_PSA_CRYPTO_STORAGE_C
+#define MBEDTLS_PSA_ITS_FILE_C
+#define MBEDTLS_RIPEMD160_C
+#define MBEDTLS_SHA1_C
+#define MBEDTLS_SHA256_C
+#define MBEDTLS_SHA512_C
+//#define MBEDTLS_THREADING_C
+#define MBEDTLS_TIMING_C
+#define MBEDTLS_VERSION_C
+#define MBEDTLS_XTEA_C
+
+#include "check_config.h"
+
+#endif /* MBEDTLS_CONFIG_H */
diff --git a/docs/getting_started.md b/docs/getting_started.md
index 236c1a2..9938909 100644
--- a/docs/getting_started.md
+++ b/docs/getting_started.md
@@ -72,9 +72,10 @@
 
 This example shows how to import a key:
 ```C
+void import_a_key(const uint8_t *key, size_t key_len)
+{
     psa_status_t status;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
-    uint8_t data[] = AES_KEY;
     psa_key_handle_t handle;
 
     printf("Import an AES key...\t");
@@ -94,7 +95,7 @@
     psa_set_key_bits(&attributes, 128);
 
     /* Import the key */
-    status = psa_import_key(&attributes, data, sizeof(data), &handle);
+    status = psa_import_key(&attributes, key, key_len, &handle);
     if (status != PSA_SUCCESS) {
         printf("Failed to import key\n");
         return;
@@ -108,6 +109,7 @@
     psa_destroy_key(handle);
 
     mbedtls_psa_crypto_free();
+}
 ```
 
 ### Signing a message using RSA
@@ -123,9 +125,10 @@
 
 This example shows how to sign a hash that has already been calculated:
 ```C
+void sign_a_message_using_rsa(const uint8_t *key, size_t key_len)
+{
     psa_status_t status;
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
-    uint8_t key[] = RSA_KEY;
     uint8_t hash[32] = {0x50, 0xd8, 0x58, 0xe0, 0x98, 0x5e, 0xcc, 0x7f,
                         0x60, 0x41, 0x8a, 0xaf, 0x0c, 0xc5, 0xab, 0x58,
                         0x7f, 0x42, 0xc2, 0x57, 0x0a, 0x88, 0x40, 0x95,
@@ -151,7 +154,7 @@
     psa_set_key_bits(&attributes, 1024);
 
     /* Import the key */
-    status = psa_import_key(&attributes, key, sizeof(key), &handle);
+    status = psa_import_key(&attributes, key, key_len, &handle);
     if (status != PSA_SUCCESS) {
         printf("Failed to import key\n");
         return;
@@ -176,6 +179,7 @@
     psa_destroy_key(handle);
 
     mbedtls_psa_crypto_free();
+}
 ```
 
 ### Using symmetric ciphers
@@ -196,6 +200,8 @@
 
 This example shows how to encrypt data using an AES (Advanced Encryption Standard) key in CBC (Cipher Block Chaining) mode with no padding (assuming all prerequisites have been fulfilled):
 ```c
+void encrypt_with_symmetric_ciphers(const uint8_t *key, size_t key_len)
+{
     enum {
         block_size = PSA_BLOCK_CIPHER_BLOCK_SIZE(PSA_KEY_TYPE_AES),
     };
@@ -205,7 +211,6 @@
     uint8_t plaintext[block_size] = SOME_PLAINTEXT;
     uint8_t iv[block_size];
     size_t iv_len;
-    uint8_t key[] = AES_KEY;
     uint8_t output[block_size];
     size_t output_len;
     psa_key_handle_t handle;
@@ -227,7 +232,7 @@
     psa_set_key_algorithm(&attributes, alg);
     psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
     psa_set_key_bits(&attributes, 128);
-    status = psa_import_key(&attributes, key, sizeof(key), &handle);
+    status = psa_import_key(&attributes, key, key_len, &handle);
     if (status != PSA_SUCCESS) {
         printf("Failed to import a key\n");
         return;
@@ -266,6 +271,7 @@
     psa_destroy_key(handle);
 
     mbedtls_psa_crypto_free();
+}
 ```
 
 **To decrypt a message with a symmetric cipher:**
@@ -279,6 +285,8 @@
 This example shows how to decrypt encrypted data using an AES key in CBC mode with no padding
 (assuming all prerequisites have been fulfilled):
 ```c
+void decrypt_with_symmetric_ciphers(const uint8_t *key, size_t key_len)
+{
     enum {
         block_size = PSA_BLOCK_CIPHER_BLOCK_SIZE(PSA_KEY_TYPE_AES),
     };
@@ -288,7 +296,6 @@
     psa_cipher_operation_t operation = PSA_CIPHER_OPERATION_INIT;
     uint8_t ciphertext[block_size] = SOME_CIPHERTEXT;
     uint8_t iv[block_size] = ENCRYPTED_WITH_IV;
-    uint8_t key[] = AES_KEY;
     uint8_t output[block_size];
     size_t output_len;
     psa_key_handle_t handle;
@@ -309,7 +316,7 @@
     psa_set_key_algorithm(&attributes, alg);
     psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
     psa_set_key_bits(&attributes, 128);
-    status = psa_import_key(&attributes, key, sizeof(key), &handle);
+    status = psa_import_key(&attributes, key, key_len, &handle);
     if (status != PSA_SUCCESS) {
         printf("Failed to import a key\n");
         return;
@@ -348,6 +355,7 @@
     psa_destroy_key(handle);
 
     mbedtls_psa_crypto_free();
+}
 ```
 
 #### Handling cipher operation contexts
diff --git a/include/mbedtls/psa_util.h b/include/mbedtls/psa_util.h
index 8d18fcc..a87ca81 100644
--- a/include/mbedtls/psa_util.h
+++ b/include/mbedtls/psa_util.h
@@ -230,9 +230,11 @@
             *oid_len = MBEDTLS_OID_SIZE( MBEDTLS_OID_EC_GRP_BP512R1 );
             return( 0 );
 #endif /* MBEDTLS_ECP_DP_BP512R1_ENABLED */
+        default:
+            (void) oid;
+            (void) oid_len;
+            return( -1 );
     }
-
-     return( -1 );
 }
 
 #define MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH 1
diff --git a/library/entropy.c b/library/entropy.c
index f8db1a5..d7091cb 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -258,7 +258,9 @@
  */
 static int entropy_gather_internal( mbedtls_entropy_context *ctx )
 {
-    int ret, i, have_one_strong = 0;
+    int ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
+    int i;
+    int have_one_strong = 0;
     unsigned char buf[MBEDTLS_ENTROPY_MAX_GATHER];
     size_t olen;
 
diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
index 284c9b4..f71c95c 100644
--- a/library/hmac_drbg.c
+++ b/library/hmac_drbg.c
@@ -74,7 +74,7 @@
     unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
     unsigned char sep[1];
     unsigned char K[MBEDTLS_MD_MAX_SIZE];
-    int ret;
+    int ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
 
     for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
     {
diff --git a/library/pkwrite.c b/library/pkwrite.c
index 4388160..c2c5623 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -38,7 +38,9 @@
 #include "mbedtls/rsa.h"
 #endif
 #if defined(MBEDTLS_ECP_C)
+#include "mbedtls/bignum.h"
 #include "mbedtls/ecp.h"
+#include "mbedtls/platform_util.h"
 #endif
 #if defined(MBEDTLS_ECDSA_C)
 #include "mbedtls/ecdsa.h"
@@ -154,6 +156,26 @@
 
     return( (int) len );
 }
+
+/*
+ * privateKey  OCTET STRING -- always of length ceil(log2(n)/8)
+ */
+static int pk_write_ec_private( unsigned char **p, unsigned char *start,
+                                mbedtls_ecp_keypair *ec )
+{
+    int ret;
+    size_t byte_length = ( ec->grp.pbits + 7 ) / 8;
+    unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
+
+    ret = mbedtls_mpi_write_binary( &ec->d, tmp, byte_length );
+    if( ret != 0 )
+        goto exit;
+    ret = mbedtls_asn1_write_octet_string( p, start, tmp, byte_length );
+
+exit:
+    mbedtls_platform_zeroize( tmp, byte_length );
+    return( ret );
+}
 #endif /* MBEDTLS_ECP_C */
 
 int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
@@ -424,9 +446,8 @@
                             MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
         len += par_len;
 
-        /* privateKey: write as MPI then fix tag */
-        MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &ec->d ) );
-        *c = MBEDTLS_ASN1_OCTET_STRING;
+        /* privateKey */
+        MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_private( &c, buf, ec ) );
 
         /* version */
         MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 1 ) );
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 42c2969..e4d4924 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2006,6 +2006,7 @@
 /* Message digests */
 /****************************************************************/
 
+#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_DETERMINISTIC)
 static const mbedtls_md_info_t *mbedtls_md_info_from_psa( psa_algorithm_t alg )
 {
     switch( alg )
@@ -2046,6 +2047,7 @@
             return( NULL );
     }
 }
+#endif
 
 psa_status_t psa_hash_abort( psa_hash_operation_t *operation )
 {
diff --git a/library/psa_crypto_storage.c b/library/psa_crypto_storage.c
index a27442c..1389fd4 100644
--- a/library/psa_crypto_storage.c
+++ b/library/psa_crypto_storage.c
@@ -419,7 +419,7 @@
 {
     struct psa_storage_info_t p_info;
     psa_status_t status;
-    status = psa_its_get_info( PSA_CRYPTO_ITS_RANDOM_SEED_UID, &p_info );
+    status = psa_its_get_info( PSA_CRYPTO_ITS_TRANSACTION_UID, &p_info );
     if( status == PSA_SUCCESS )
     {
         /* This shouldn't happen: we're trying to start a transaction while
diff --git a/tests/data_files/ec_256_long_prv.pem b/tests/data_files/ec_256_long_prv.pem
new file mode 100644
index 0000000..5141e30
--- /dev/null
+++ b/tests/data_files/ec_256_long_prv.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIIcex4mqXsQamUKTVf8vXmTAJrQvGjh5mXG8p9+OR4xAoAoGCCqGSM49
+AwEHoUQDQgAEqJ2HQjPpc6fDwE/vSa6U35USXawkTo98y4U6NsAl+rOGuqMPEFXf
+P1Srm/Jrzwa/RuppRL5kgyAsGJTUmwZEzQ==
+-----END EC PRIVATE KEY-----
diff --git a/tests/data_files/ec_521_short_prv.pem b/tests/data_files/ec_521_short_prv.pem
new file mode 100644
index 0000000..427b7ad
--- /dev/null
+++ b/tests/data_files/ec_521_short_prv.pem
@@ -0,0 +1,7 @@
+-----BEGIN EC PRIVATE KEY-----
+MIHcAgEBBEIAOXdk7W+Hf5L7Hc9fKe44wmpaRNs5ERFTkv5CrlXv/Bu3y28M673q
+vBNo7a/UE/6NNQHu2pQODEYFpMg6R34b5SigBwYFK4EEACOhgYkDgYYABAFUMHXV
+KPA4vkMgq+pFgDoH96XoM517gF2GJFV6h2gLhykzIHL/otAyEpAStw7MBvbU0V21
+ixB+hjqzO7Snxaj9mwB8g87OKxm5eGfsqvJNPdJ0RZ/EKy06Ukg6KThlhQeyrtIk
+g5PTCrPnNszlffAy6/jCOe3Moi59g15H13sSzwfX6g==
+-----END EC PRIVATE KEY-----
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 2414f45..282c513 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -879,6 +879,8 @@
 
 component_test_se_full () {
     msg "build: full config + MBEDTLS_PSA_CRYPTO_SE_C"
+    scripts/config.pl full
+    scripts/config.pl unset MBEDTLS_MEMORY_BUFFER_ALLOC_C
     scripts/config.pl set MBEDTLS_PSA_CRYPTO_SE_C
     make CC=gcc CFLAGS="$ASAN_CFLAGS -O2" LDFLAGS="$ASAN_CFLAGS"
 
diff --git a/tests/scripts/test-ref-configs.pl b/tests/scripts/test-ref-configs.pl
index 09baebb..1e65969 100755
--- a/tests/scripts/test-ref-configs.pl
+++ b/tests/scripts/test-ref-configs.pl
@@ -17,6 +17,8 @@
 use strict;
 
 my %configs = (
+    'config-symmetric-only.h' => {
+    },
     'config-suite-b.h' => {
     },
 );
@@ -48,6 +50,15 @@
     exit 1;
 }
 
+# Create a seedfile for configurations that enable MBEDTLS_ENTROPY_NV_SEED.
+# For test purposes, this doesn't have to be cryptographically random.
+if (!-e "tests/seedfile" || -s "tests/seedfile" < 64) {
+    local *SEEDFILE;
+    open SEEDFILE, ">tests/seedfile" or die;
+    print SEEDFILE "*" x 64 or die;
+    close SEEDFILE or die;
+}
+
 while( my ($conf, $data) = each %configs ) {
     system( "cp $config_h.bak $config_h" ) and die;
     system( "make clean" ) and die;
diff --git a/tests/suites/test_suite_pkwrite.data b/tests/suites/test_suite_pkwrite.data
index c8ff177..e0101cc 100644
--- a/tests/suites/test_suite_pkwrite.data
+++ b/tests/suites/test_suite_pkwrite.data
@@ -30,10 +30,18 @@
 depends_on:MBEDTLS_ECP_C:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_SECP192R1_ENABLED
 pk_write_key_check:"data_files/ec_prv.sec1.pem"
 
+Private key write check EC 256 bits (top bit set)
+depends_on:MBEDTLS_ECP_C:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+pk_write_key_check:"data_files/ec_256_long_prv.pem"
+
 Private key write check EC 521 bits
 depends_on:MBEDTLS_ECP_C:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_SECP521R1_ENABLED
 pk_write_key_check:"data_files/ec_521_prv.pem"
 
+Private key write check EC 521 bits (top byte is 0)
+depends_on:MBEDTLS_ECP_C:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_SECP521R1_ENABLED
+pk_write_key_check:"data_files/ec_521_short_prv.pem"
+
 Private key write check EC Brainpool 512 bits
 depends_on:MBEDTLS_ECP_C:MBEDTLS_BASE64_C:MBEDTLS_ECP_DP_BP512R1_ENABLED
 pk_write_key_check:"data_files/ec_bp512_prv.pem"
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 2fd70c6..f3f79ab 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -899,6 +899,8 @@
                               "No sanity check for public key type=0x%08lx",
                               (unsigned long) type );
             test_fail( message, __LINE__, __FILE__ );
+            (void) p;
+            (void) end;
             return( 0 );
         }
     }