Add __attribute__ ((nonstring)) to remove unterminated-string-initialization warning

Signed-off-by: Felix Conway <felix.conway@arm.com>
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index dbc703a..51afb04 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -80,7 +80,8 @@
  *            the HkdfLabel structure on success.
  */
 
-static const char tls13_label_prefix[6] = "tls13 ";
+/* We need to tell the compiler that we meant to leave out the null character. */
+static const char tls13_label_prefix[6] __attribute__ ((nonstring)) = "tls13 ";
 
 #define SSL_TLS1_3_KEY_SCHEDULE_HKDF_LABEL_LEN(label_len, context_len) \
     (2                     /* expansion length           */ \
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index 14f6e48..f6d02b5 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -40,8 +40,9 @@
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
 
+/* We need to tell the compiler that we meant to leave out the null character. */
 #define MBEDTLS_SSL_TLS1_3_LABEL(name, string)       \
-    const unsigned char name    [sizeof(string) - 1];
+    const unsigned char name    [sizeof(string) - 1] __attribute__ ((nonstring));
 
 union mbedtls_ssl_tls13_labels_union {
     MBEDTLS_SSL_TLS1_3_LABEL_LIST
diff --git a/tests/psa-client-server/psasim/src/aut_psa_aead_encrypt_decrypt.c b/tests/psa-client-server/psasim/src/aut_psa_aead_encrypt_decrypt.c
index ca090cc..83cd3c0 100644
--- a/tests/psa-client-server/psasim/src/aut_psa_aead_encrypt_decrypt.c
+++ b/tests/psa-client-server/psasim/src/aut_psa_aead_encrypt_decrypt.c
@@ -25,7 +25,8 @@
     uint8_t encrypt[BUFFER_SIZE] = { 0 };
     uint8_t decrypt[BUFFER_SIZE] = { 0 };
     const uint8_t plaintext[] = "Hello World!";
-    const uint8_t key_bytes[32] = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const uint8_t key_bytes[32] __attribute__ ((nonstring)) = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     uint8_t nonce[PSA_AEAD_NONCE_LENGTH(PSA_KEY_TYPE_AES, PSA_ALG_CCM)];
     size_t nonce_length = sizeof(nonce);
     size_t ciphertext_length;
diff --git a/tests/psa-client-server/psasim/src/aut_psa_cipher_encrypt_decrypt.c b/tests/psa-client-server/psasim/src/aut_psa_cipher_encrypt_decrypt.c
index a923feb..22d0bfb 100644
--- a/tests/psa-client-server/psasim/src/aut_psa_cipher_encrypt_decrypt.c
+++ b/tests/psa-client-server/psasim/src/aut_psa_cipher_encrypt_decrypt.c
@@ -25,7 +25,8 @@
     uint8_t original[BUFFER_SIZE] = { 0 };
     uint8_t encrypt[BUFFER_SIZE] = { 0 };
     uint8_t decrypt[BUFFER_SIZE] = { 0 };
-    const uint8_t key_bytes[32] = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const uint8_t key_bytes[32] __attribute__ ((nonstring)) = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     size_t encrypted_length;
     size_t decrypted_length;
 
diff --git a/tests/suites/test_suite_ssl_decrypt.function b/tests/suites/test_suite_ssl_decrypt.function
index 909e6cf..7282416 100644
--- a/tests/suites/test_suite_ssl_decrypt.function
+++ b/tests/suites/test_suite_ssl_decrypt.function
@@ -37,7 +37,8 @@
     mbedtls_ssl_write_version(rec_good.ver,
                               MBEDTLS_SSL_TRANSPORT_STREAM,
                               version);
-    const char sample_plaintext[3] = "ABC";
+    /* We need to tell the compiler that we meant to leave out the null character. */
+    const char sample_plaintext[3] __attribute__ ((nonstring)) = "ABC";
     mbedtls_ssl_context ssl;
     mbedtls_ssl_init(&ssl);
     uint8_t *buf = NULL;