PKCS5: always use MD

As a consequence, MD_C is now enabled in component accel_hash_use_psa.

Fix guards in X.509 info function to avoid this causing a failure now.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>

include/mbedtls/build_info.h

@@ -80,6 +80,13 @@
 #include MBEDTLS_USER_CONFIG_FILE
 #endif
 
+/* Auto-enable MBEDTLS_MD_C if needed by a module that didn't require it
+ * in a previous release, to ensure backwards compatibility.
+ */
+#if defined(MBEDTLS_PKCS5_C)
+#define MBEDTLS_MD_C
+#endif
+
 /* Auto-enable MBEDTLS_MD_LIGHT based on MBEDTLS_MD_C.
  * This allows checking for MD_LIGHT rather than MD_LIGHT || MD_C.
  */
@@ -87,7 +94,8 @@
 #define MBEDTLS_MD_LIGHT
 #endif
 
-/* Auto-enable MBEDTLS_MD_LIGHT if some module needs it.
+/* Auto-enable MBEDTLS_MD_LIGHT if needed by a module that didn't require it
+ * in a previous release, to ensure backwards compatibility.
  */
 #if defined(MBEDTLS_ECJPAKE_C) || \
     defined(MBEDTLS_PEM_PARSE_C) || \

include/mbedtls/check_config.h

@@ -169,8 +169,7 @@
 #endif
 
 #if defined(MBEDTLS_PKCS5_C) && \
-    ( !( defined(MBEDTLS_MD_C) || defined(MBEDTLS_PSA_CRYPTO_C) ) || \
+    !defined(MBEDTLS_CIPHER_C)
-        !defined(MBEDTLS_CIPHER_C) )
 #error "MBEDTLS_PKCS5_C defined, but not all prerequisites"
 #endif
 

include/mbedtls/mbedtls_config.h

@@ -2849,15 +2849,11 @@
  *
  * Module:  library/pkcs5.c
  *
- * Requires: MBEDTLS_CIPHER_C and either MBEDTLS_MD_C or MBEDTLS_PSA_CRYPTO_C.
+ * Requires: MBEDTLS_CIPHER_C
+ *           (auto-enables MBEDTLS_MD_C)
  *
- * \warning If building without MBEDTLS_MD_C, you must call psa_crypto_init()
+ * \warning If using a hash that is only provided by PSA drivers, you must
- * before doing any PKCS5 operation.
+ * call psa_crypto_init() before doing any PKCS5 operations.
- *
- * \warning When building with MBEDTLS_MD_C, all hashes used with this
- * need to be available as built-ins (that is, for SHA-256, MBEDTLS_SHA256_C,
- * etc.) as opposed to just PSA drivers. So far, PSA drivers are only used by
- * this module in builds where MBEDTLS_MD_C is disabled.
  *
  * This module adds support for the PKCS#5 functions.
  */

library/pkcs5.c

@@ -47,12 +47,6 @@
 #include "hash_info.h"
 #include "mbedtls/psa_util.h"
 
-#if !defined(MBEDTLS_MD_C)
-#define PSA_TO_MBEDTLS_ERR(status) PSA_TO_MBEDTLS_ERR_LIST(status,   \
-                                                           psa_to_md_errors,              \
-                                                           psa_generic_status_to_mbedtls)
-#endif
-
 #if defined(MBEDTLS_ASN1_PARSE_C)
 static int pkcs5_parse_pbkdf2_params(const mbedtls_asn1_buf *params,
                                      mbedtls_asn1_buf *salt, int *iterations,
@@ -221,7 +215,6 @@ exit:
 }
 #endif /* MBEDTLS_ASN1_PARSE_C */
 
-#if defined(MBEDTLS_MD_C)
 static int pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx,
                              const unsigned char *password,
                              size_t plen, const unsigned char *salt, size_t slen,
@@ -322,7 +315,6 @@ int mbedtls_pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx,
                              key_length, output);
 }
 #endif
-#endif /* MBEDTLS_MD_C */
 
 int mbedtls_pkcs5_pbkdf2_hmac_ext(mbedtls_md_type_t md_alg,
                                   const unsigned char *password,
@@ -330,7 +322,6 @@ int mbedtls_pkcs5_pbkdf2_hmac_ext(mbedtls_md_type_t md_alg,
                                   unsigned int iteration_count,
                                   uint32_t key_length, unsigned char *output)
 {
-#if defined(MBEDTLS_MD_C)
     mbedtls_md_context_t md_ctx;
     const mbedtls_md_info_t *md_info = NULL;
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -350,116 +341,6 @@ int mbedtls_pkcs5_pbkdf2_hmac_ext(mbedtls_md_type_t md_alg,
 exit:
     mbedtls_md_free(&md_ctx);
     return ret;
-#else
-    unsigned int i;
-    unsigned char md1[PSA_HASH_MAX_SIZE];
-    unsigned char work[PSA_HASH_MAX_SIZE];
-    const unsigned char md_size = mbedtls_hash_info_get_size(md_alg);
-    psa_mac_operation_t operation = PSA_MAC_OPERATION_INIT;
-
-    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
-    psa_status_t status_destruction = PSA_ERROR_CORRUPTION_DETECTED;
-    size_t use_len, out_len;
-    unsigned char *out_p = output;
-    unsigned char counter[4];
-    mbedtls_svc_key_id_t psa_hmac_key = MBEDTLS_SVC_KEY_ID_INIT;
-    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
-    const psa_algorithm_t alg = PSA_ALG_HMAC(mbedtls_hash_info_psa_from_md(md_alg));
-    const size_t out_size = PSA_MAC_LENGTH(PSA_KEY_TYPE_HMAC, 0, alg);
-
-    memset(counter, 0, sizeof(counter));
-    counter[3] = 1;
-
-    psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_MESSAGE);
-    psa_set_key_algorithm(&attributes,  alg);
-    psa_set_key_type(&attributes, PSA_KEY_TYPE_HMAC);
-
-    if (key_length == 0) {
-        return 0;
-    }
-    if ((status = psa_import_key(&attributes,
-                                 password, plen,
-                                 &psa_hmac_key)) != PSA_SUCCESS) {
-        return MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA;
-    }
-
-#if UINT_MAX > 0xFFFFFFFF
-    if (iteration_count > 0xFFFFFFFF) {
-        return MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA;
-    }
-#endif
-
-    while (key_length) {
-        status = psa_mac_sign_setup(&operation, psa_hmac_key,
-                                    PSA_ALG_HMAC(alg));
-        if (status != PSA_SUCCESS) {
-            goto cleanup;
-        }
-        // U1 ends up in work
-        if ((status = psa_mac_update(&operation, salt, slen)) != PSA_SUCCESS) {
-            goto cleanup;
-        }
-
-        if ((status = psa_mac_update(&operation, counter, sizeof(counter))) != PSA_SUCCESS) {
-            goto cleanup;
-        }
-
-        if ((status = psa_mac_sign_finish(&operation, work, out_size, &out_len))
-            != PSA_SUCCESS) {
-            goto cleanup;
-        }
-
-        memcpy(md1, work, out_len);
-
-        for (i = 1; i < iteration_count; i++) {
-            // U2 ends up in md1
-            //
-            status = psa_mac_sign_setup(&operation, psa_hmac_key,
-                                        PSA_ALG_HMAC(alg));
-            if (status != PSA_SUCCESS) {
-                goto cleanup;
-            }
-            if ((status = psa_mac_update(&operation, md1, md_size)) != PSA_SUCCESS) {
-                goto cleanup;
-            }
-            if ((status =
-                     psa_mac_sign_finish(&operation, md1, out_size, &out_len)) != PSA_SUCCESS) {
-                goto cleanup;
-            }
-
-            // U1 xor U2
-            //
-            mbedtls_xor(work, work, md1, md_size);
-        }
-
-        use_len = (key_length < md_size) ? key_length : md_size;
-        memcpy(out_p, work, use_len);
-
-        key_length -= (uint32_t) use_len;
-        out_p += use_len;
-
-        for (i = 4; i > 0; i--) {
-            if (++counter[i - 1] != 0) {
-                break;
-            }
-        }
-    }
-
-cleanup:
-    /* Zeroise buffers to clear sensitive data from memory. */
-    mbedtls_platform_zeroize(work, PSA_HASH_MAX_SIZE);
-    mbedtls_platform_zeroize(md1, PSA_HASH_MAX_SIZE);
-    status_destruction = psa_destroy_key(psa_hmac_key);
-    if (status == PSA_SUCCESS && status_destruction != PSA_SUCCESS) {
-        status = status_destruction;
-    }
-    status_destruction = psa_mac_abort(&operation);
-    if (status == PSA_SUCCESS && status_destruction != PSA_SUCCESS) {
-        status = status_destruction;
-    }
-
-    return PSA_TO_MBEDTLS_ERR(status);
-#endif /* !MBEDTLS_MD_C */
 }
 
 #if defined(MBEDTLS_SELF_TEST)

library/x509.c

@@ -135,31 +135,31 @@ int mbedtls_x509_get_alg(unsigned char **p, const unsigned char *end,
 static inline const char *md_type_to_string(mbedtls_md_type_t md_alg)
 {
     switch (md_alg) {
-#if defined(MBEDTLS_HAS_ALG_MD5_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_MD5)
         case MBEDTLS_MD_MD5:
             return "MD5";
 #endif
-#if defined(MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_SHA1)
         case MBEDTLS_MD_SHA1:
             return "SHA1";
 #endif
-#if defined(MBEDTLS_HAS_ALG_SHA_224_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_SHA224)
         case MBEDTLS_MD_SHA224:
             return "SHA224";
 #endif
-#if defined(MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_SHA256)
         case MBEDTLS_MD_SHA256:
             return "SHA256";
 #endif
-#if defined(MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_SHA384)
         case MBEDTLS_MD_SHA384:
             return "SHA384";
 #endif
-#if defined(MBEDTLS_HAS_ALG_SHA_512_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_SHA512)
         case MBEDTLS_MD_SHA512:
             return "SHA512";
 #endif
-#if defined(MBEDTLS_HAS_ALG_RIPEMD160_VIA_MD_OR_PSA)
+#if defined(MBEDTLS_MD_CAN_RIPEMD160)
         case MBEDTLS_MD_RIPEMD160:
             return "RIPEMD160";
 #endif

tests/scripts/all.sh

@@ -1224,12 +1224,15 @@ component_test_crypto_full_md_light_only () {
     scripts/config.py crypto_full
     # Disable MD
     scripts/config.py unset MBEDTLS_MD_C
-    # Disable direct dependencies of MD
+    # Disable direct dependencies of MD_C
     scripts/config.py unset MBEDTLS_HKDF_C
     scripts/config.py unset MBEDTLS_HMAC_DRBG_C
     scripts/config.py unset MBEDTLS_PKCS7_C
-    # Disable indirect dependencies of MD
+    # Disable indirect dependencies of MD_C
     scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC # needs HMAC_DRBG
+    # Disable things that would auto-enable MD_C
+    scripts/config.py unset MBEDTLS_PKCS5_C
+
     # Note: MD-light is auto-enabled in build_info.h by modules that need it,
     # which we haven't disabled, so no need to explicitly enable it.
     make CFLAGS="$ASAN_CFLAGS" LDFLAGS="$ASAN_CFLAGS"
@@ -2671,9 +2674,7 @@ component_test_psa_crypto_config_accel_hash_use_psa () {
     make CFLAGS="$ASAN_CFLAGS -Werror -I../tests/include -I../tests -I../../tests -DPSA_CRYPTO_DRIVER_TEST -DMBEDTLS_TEST_LIBTESTDRIVER1 $loc_accel_flags" LDFLAGS="-ltestdriver1 $ASAN_CFLAGS" all
 
     # There's a risk of something getting re-enabled via config_psa.h;
-    # make sure it did not happen. Note: it's OK for MD_LIGHT to be enabled,
+    # make sure it did not happen. Note: it's OK for MD_C to be enabled.
-    # but not the full MD_C (for now), so check mbedtls_md_hmac for that.
-    not grep mbedtls_md_hmac library/md.o
     not grep mbedtls_md5 library/md5.o
     not grep mbedtls_sha1 library/sha1.o
     not grep mbedtls_sha256 library/sha256.o

tests/suites/test_suite_pkcs5.function

@@ -14,14 +14,16 @@ void pbkdf2_hmac(int hash, data_t *pw_str, data_t *salt_str,
 {
     unsigned char key[100];
 
-    PSA_INIT_IF_NO_MD();
+    MD_PSA_INIT();
     TEST_ASSERT(mbedtls_pkcs5_pbkdf2_hmac_ext(hash, pw_str->x, pw_str->len,
                                               salt_str->x, salt_str->len,
                                               it_cnt, key_len, key) == 0);
 
     TEST_ASSERT(mbedtls_test_hexcmp(key, result_key_string->x,
                                     key_len, result_key_string->len) == 0);
-    PSA_DONE_IF_NO_MD();
+
+exit:
+    MD_PSA_DONE();
 }
 /* END_CASE */
 
@@ -33,7 +35,7 @@ void mbedtls_pkcs5_pbes2(int params_tag, data_t *params_hex, data_t *pw,
     mbedtls_asn1_buf params;
     unsigned char *my_out = NULL;
 
-    PSA_INIT_IF_NO_MD();
+    MD_PSA_INIT();
 
     params.tag = params_tag;
     params.p = params_hex->x;
@@ -51,13 +53,17 @@ void mbedtls_pkcs5_pbes2(int params_tag, data_t *params_hex, data_t *pw,
 
 exit:
     mbedtls_free(my_out);
-    PSA_DONE_IF_NO_MD();
+    MD_PSA_DONE();
 }
 /* END_CASE */
 
 /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
 void pkcs5_selftest()
 {
+    MD_PSA_INIT();
     TEST_ASSERT(mbedtls_pkcs5_self_test(1) == 0);
+
+exit:
+    MD_PSA_DONE();
 }
 /* END_CASE */