Mbed-TLS · ronald-cron-arm · Sep 5, 2024 · Nov 14, 2024 · Nov 15, 2024
diff --git a/ChangeLog.d/psa-crypto-config-always-on.txt b/ChangeLog.d/psa-crypto-config-always-on.txt
@@ -0,0 +1,7 @@
+Default behavior changes
+   * The `PSA_WANT_XXX` symbols as defined in
+     tf-psa-crypto/include/psa/crypto_config.h are now always used in the
+     configuration of the cryptographic mechanisms exposed by the PSA API.
+     This corresponds to the configuration behavior of Mbed TLS 3.x when
+     MBEDTLS_PSA_CRYPTO_CONFIG is enabled. In effect, MBEDTLS_PSA_CRYPTO_CONFIG
+     is now always enabled and the configuration option has been removed.
diff --git a/README.md b/README.md
@@ -303,11 +303,6 @@ Mbed TLS supports drivers for cryptographic accelerators, secure elements and ra
 
 Please see the [PSA driver example and guide](docs/psa-driver-example-and-guide.md) for information on writing a driver.
 
-When using drivers, you will generally want to enable two compilation options (see the reference manual for more information):
-
-* `MBEDTLS_USE_PSA_CRYPTO` is necessary so that the X.509 and TLS code calls the PSA drivers rather than the built-in software implementation.
-* `MBEDTLS_PSA_CRYPTO_CONFIG` allows you to enable PSA cryptographic mechanisms without including the code of the corresponding software implementation. This is not yet supported for all mechanisms.
-
 License
 -------
 

diff --git a/configs/config-ccm-psk-dtls1_2.h b/configs/config-ccm-psk-dtls1_2.h
@@ -26,7 +26,6 @@
 #define MBEDTLS_PSA_CRYPTO_CONFIG_FILE "../configs/crypto-config-ccm-psk-tls1_2.h"
 
 #define MBEDTLS_PSA_CRYPTO_C
-#define MBEDTLS_PSA_CRYPTO_CONFIG
 #define MBEDTLS_USE_PSA_CRYPTO
 
 /* System support */

diff --git a/configs/config-ccm-psk-tls1_2.h b/configs/config-ccm-psk-tls1_2.h
@@ -25,7 +25,6 @@
 #define MBEDTLS_PSA_CRYPTO_CONFIG_FILE "../configs/crypto-config-ccm-psk-tls1_2.h"
 
 #define MBEDTLS_PSA_CRYPTO_C
-#define MBEDTLS_PSA_CRYPTO_CONFIG
 #define MBEDTLS_USE_PSA_CRYPTO
 
 /* System support */

diff --git a/configs/config-suite-b.h b/configs/config-suite-b.h
@@ -24,7 +24,6 @@
 #define MBEDTLS_PSA_CRYPTO_CONFIG_FILE "../configs/crypto-config-suite-b.h"
 
 #define MBEDTLS_PSA_CRYPTO_C
-#define MBEDTLS_PSA_CRYPTO_CONFIG
 #define MBEDTLS_USE_PSA_CRYPTO
 
 /* System support */

diff --git a/configs/config-symmetric-only.h b/configs/config-symmetric-only.h
@@ -11,7 +11,6 @@
 #define MBEDTLS_PSA_CRYPTO_CONFIG_FILE "../configs/crypto-config-symmetric-only.h"
 
 #define MBEDTLS_PSA_CRYPTO_C
-#define MBEDTLS_PSA_CRYPTO_CONFIG
 #define MBEDTLS_USE_PSA_CRYPTO
 
 /* System support */

diff --git a/configs/config-thread.h b/configs/config-thread.h
@@ -24,7 +24,6 @@
 #define MBEDTLS_PSA_CRYPTO_CONFIG_FILE "../configs/crypto-config-thread.h"
 
 #define MBEDTLS_PSA_CRYPTO_C
-#define MBEDTLS_PSA_CRYPTO_CONFIG
 #define MBEDTLS_USE_PSA_CRYPTO
 
 /* System support */

diff --git a/docs/architecture/psa-crypto-implementation-structure.md b/docs/architecture/psa-crypto-implementation-structure.md
@@ -124,9 +124,7 @@ New constants must have a test case in `tests/suites/test_suite_psa_crypto_metad
 
 Each cryptographic mechanism is optional and can be selected by the application at build time. For each feature `PSA_ttt_xxx`:
 
-* The feature is available to applications when the preprocessor symbol `PSA_WANT_ttt_xxx` is defined. These symbols are set:
-    * If `MBEDTLS_PSA_CRYPTO_CONFIG` is disabled: based on the available mechanisms in Mbed TLS, deduced from `mbedtls/mbedtls_config.h` by code in `include/mbedtls/config_psa.h`.
-    * if `MBEDTLS_PSA_CRYPTO_CONFIG` is enabled: in the application configuration file `include/psa/crypto_config.h` (or `MBEDTLS_PSA_CRYPTO_CONFIG_FILE`, plus `MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE`), with code in `include/mbedtls/config_psa.h` deducing the necessary underlying `MBEDTLS_xxx` symbols.
+* The feature is available to applications when the preprocessor symbol `PSA_WANT_ttt_xxx` is defined. These symbols are set in the application configuration file `include/psa/crypto_config.h` (or `MBEDTLS_PSA_CRYPTO_CONFIG_FILE`, plus `MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE`), with code in `include/mbedtls/config_psa.h` deducing the necessary underlying `MBEDTLS_xxx` symbols.
 *  For transparent keys (keys that are not in a secure element), the feature is implemented by Mbed TLS if `MBEDTLS_PSA_BUILTIN_ttt_xxx` is defined, and by an accelerator driver if `MBEDTLS_PSA_ACCEL_ttt_xxx` is defined. `MBEDTLS_PSA_BUILTIN_ttt_xxx` constants are set in `include/mbedtls/config_psa.h` based on the application requests `PSA_WANT_ttt_xxx` and the accelerator driver declarations `MBEDTLS_PSA_ACCEL_ttt_xxx`.
 * For the testing of the driver dispatch code, `tests/include/test/drivers/crypto_config_test_driver_extension.h` sets additional `MBEDTLS_PSA_ACCEL_xxx` symbols.
 

diff --git a/docs/architecture/psa-migration/md-cipher-dispatch.md b/docs/architecture/psa-migration/md-cipher-dispatch.md
@@ -73,7 +73,6 @@ The following configuration options are described as experimental, and are likel
 
 * `MBEDTLS_PSA_CRYPTO_CLIENT`: “This interface is experimental and may change or be removed without notice.” In practice we don't want to remove this, but we may constrain how it's used.
 * `MBEDTLS_PSA_CRYPTO_DRIVERS`: “This interface is experimental. We intend to maintain backward compatibility with application code that relies on drivers, but the driver interfaces may change without notice.” In practice, this may mean constraints not only on how to write drivers, but also on how to integrate drivers into code that is platform code more than application code.
-* `MBEDTLS_PSA_CRYPTO_CONFIG`: “This feature is still experimental and is not ready for production since it is not completed.” We may want to change this, for example, to automatically enable more mechanisms (although this wouldn't be considered a backward compatibility break anyway, since we don't promise that you will not get a feature if you don't enable its `PSA_WANT_xxx`).
 
 ### Non-goals
 
@@ -285,8 +284,7 @@ We could go further and make PSA accelerators available to legacy callers that c
 
 #### Implications between legacy availability and PSA availability
 
-* When `MBEDTLS_PSA_CRYPTO_CONFIG` is disabled, all legacy mechanisms are automatically enabled through PSA. Users can manually enable PSA mechanisms that are available through accelerators but not through legacy, but this is not officially supported (users are not supposed to manually define PSA configuration symbols when `MBEDTLS_PSA_CRYPTO_CONFIG` is disabled).
-* When `MBEDTLS_PSA_CRYPTO_CONFIG` is enabled, there is no mandatory relationship between PSA support and legacy support for a mechanism. Users can configure legacy support and PSA support independently. Legacy support is automatically enabled if PSA support is requested, but only if there is no accelerator.
+There is no mandatory relationship between PSA support and legacy support for a mechanism. Users can configure legacy support and PSA support independently. Legacy support is automatically enabled if PSA support is requested, but only if there is no accelerator.
 
 It is strongly desirable to allow mechanisms available through PSA but not legacy: this allows saving code size when an accelerator is present.
 
@@ -522,8 +520,6 @@ As discussed in [“Implications between legacy availability and PSA availabilit
 
 > If an algorithm has a legacy implementation, it is also available through PSA.
 
-When `MBEDTLS_PSA_CRYPTO_CONFIG` is disabled, this is already the case. When is enabled, we will now make it so as well. Change `include/mbedtls/config_psa.h` accordingly.
-
 ### MD light optimizations
 
 This section is not necessary to implement MD light, but will cut down its code size.

diff --git a/docs/driver-only-builds.md b/docs/driver-only-builds.md
@@ -22,11 +22,6 @@ the following compile-time configuration options enabled:
   TLS use PSA Crypto. You need to enable this if you're using PK, X.509 or TLS
 and want them to have access to the algorithms provided by your driver. (See
 [the dedicated document](use-psa-crypto.md) for details.)
-- `MBEDTLS_PSA_CRYPTO_CONFIG` (disabled by default) - this enables
-  configuration of cryptographic algorithms using `PSA_WANT` macros in
-`include/psa/crypto_config.h`. See [Conditional inclusion of cryptographic
-mechanism through the PSA API in Mbed
-TLS](proposed/psa-conditional-inclusion-c.md) for details.
 
 In addition, for each mechanism you want provided only by your driver:
 

diff --git a/docs/proposed/config-split.md b/docs/proposed/config-split.md
@@ -347,7 +347,6 @@ PSA_WANT_\* macros as in current `crypto_config.h`.
 #define MBEDTLS_PKCS1_V15
 #define MBEDTLS_PKCS1_V21
 #define MBEDTLS_POLY1305_C
-//#define MBEDTLS_PSA_CRYPTO_CONFIG
 //#define MBEDTLS_PSA_CRYPTO_SE_C
 #define MBEDTLS_RIPEMD160_C
 #define MBEDTLS_RSA_C

diff --git a/docs/proposed/psa-conditional-inclusion-c.md b/docs/proposed/psa-conditional-inclusion-c.md
@@ -50,11 +50,7 @@ The current model is difficult to adapt to the PSA interface for several reasons
 ### PSA Crypto configuration file
 
 The PSA Crypto configuration file `psa/crypto_config.h` defines a series of symbols of the form `PSA_WANT_xxx` where `xxx` describes the feature that the symbol enables. The symbols are documented in the section [“PSA Crypto configuration symbols”](#psa-crypto-configuration-symbols) below.
-
-The symbol `MBEDTLS_PSA_CRYPTO_CONFIG` in `mbedtls/mbedtls_config.h` determines whether `psa/crypto_config.h` is used.
-
-* If `MBEDTLS_PSA_CRYPTO_CONFIG` is unset, which is the default at least in Mbed TLS 2.x versions, things are as they are today: the PSA subsystem includes generic code unconditionally, and includes support for specific mechanisms conditionally based on the existing `MBEDTLS_xxx_` symbols.
-* If `MBEDTLS_PSA_CRYPTO_CONFIG` is set, the necessary software implementations of cryptographic algorithms are included based on both the content of the PSA Crypto configuration file and the Mbed TLS configuration file. For example, the code in `aes.c` is enabled if either `mbedtls/mbedtls_config.h` contains `MBEDTLS_AES_C` or `psa/crypto_config.h` contains `PSA_WANT_KEY_TYPE_AES`.
+The necessary software implementations of cryptographic algorithms are included based on the content of the PSA Crypto configuration file. For example, the code in `aes.c` is enabled if `psa/crypto_config.h` contains `PSA_WANT_KEY_TYPE_AES`.
 
 ### PSA Crypto configuration symbols
 
@@ -130,37 +126,29 @@ These symbols are not part of the public interface of Mbed TLS towards applicati
 
 ### Architecture of symbol definitions
 
-#### New-style definition of configuration symbols
+#### Definition of configuration symbols
 
-When `MBEDTLS_PSA_CRYPTO_CONFIG` is set, the header file `mbedtls/mbedtls_config.h` needs to define all the `MBEDTLS_xxx_C` configuration symbols, including the ones deduced from the PSA Crypto configuration. It does this by including the new header file **`mbedtls/config_psa.h`**, which defines the `MBEDTLS_PSA_BUILTIN_xxx` symbols and deduces the corresponding `MBEDTLS_xxx_C` (and other) symbols.
+The header file `mbedtls/mbedtls_config.h` defines all the `MBEDTLS_xxx_C` configuration symbols, including the ones deduced from the PSA Crypto configuration. It does this by including the new header file **`mbedtls/config_psa.h`**, which defines the `MBEDTLS_PSA_BUILTIN_xxx` symbols and deduces the corresponding `MBEDTLS_xxx_C` (and other) symbols.
 
 `mbedtls/config_psa.h` includes `psa/crypto_config.h`, the user-editable file that defines application requirements.
 
-#### Old-style definition of configuration symbols
-
-When `MBEDTLS_PSA_CRYPTO_CONFIG` is not set, the configuration of Mbed TLS works as before, and the inclusion of non-PSA code only depends on `MBEDTLS_xxx` symbols defined (or not) in `mbedtls/mbedtls_config.h`. Furthermore, the new header file **`mbedtls/config_psa.h`** deduces PSA configuration symbols (`PSA_WANT_xxx`, `MBEDTLS_PSA_BUILTIN_xxx`) from classic configuration symbols (`MBEDTLS_xxx`).
-
-The `PSA_WANT_xxx` definitions in `mbedtls/config_psa.h` are needed not only to build the PSA parts of the library, but also to build code that uses these parts. This includes structure definitions in `psa/crypto_struct.h`, size calculations in `psa/crypto_sizes.h`, and application code that's specific to a given cryptographic mechanism. In Mbed TLS itself, code under `MBEDTLS_USE_PSA_CRYPTO` and conditional compilation guards in tests and sample programs need `PSA_WANT_xxx`.
-
-Since some existing applications use a handwritten `mbedtls/mbedtls_config.h` or an edited copy of `mbedtls/mbedtls_config.h` from an earlier version of Mbed TLS, `mbedtls/config_psa.h` must be included via an already existing header that is not `mbedtls/mbedtls_config.h`, so it is included via `psa/crypto.h` (for example from `psa/crypto_platform.h`).
-
 #### Summary of definitions of configuration symbols
 
-Whether `MBEDTLS_PSA_CRYPTO_CONFIG` is set or not, `mbedtls/config_psa.h` includes `mbedtls/crypto_drivers.h`, a header file generated by the transpilation of the driver descriptions. It defines `MBEDTLS_PSA_ACCEL_xxx` symbols according to the availability of transparent drivers without fallback.
+`mbedtls/config_psa.h` includes `mbedtls/crypto_drivers.h`, a header file generated by the transpilation of the driver descriptions. It defines `MBEDTLS_PSA_ACCEL_xxx` symbols according to the availability of transparent drivers without fallback.
 
 The following table summarizes where symbols are defined depending on the configuration mode.
 
 * (U) indicates a symbol that is defined by the user (application).
 * (D) indicates a symbol that is deduced from other symbols by code that ships with Mbed TLS.
 * (G) indicates a symbol that is generated from driver descriptions.
 
-| Symbols                   | With `MBEDTLS_PSA_CRYPTO_CONFIG`  | Without `MBEDTLS_PSA_CRYPTO_CONFIG` |
-| ------------------------- | --------------------------------- | ----------------------------------- |
-| `MBEDTLS_xxx_C`           | `mbedtls/mbedtls_config.h` (U) or | `mbedtls/mbedtls_config.h` (U)      |
-|                           | `mbedtls/config_psa.h` (D)        |                                     |
-| `PSA_WANT_xxx`            | `psa/crypto_config.h` (U)         | `mbedtls/config_psa.h` (D)          |
-| `MBEDTLS_PSA_BUILTIN_xxx` | `mbedtls/config_psa.h` (D)        | `mbedtls/config_psa.h` (D)          |
-| `MBEDTLS_PSA_ACCEL_xxx`   | `mbedtls/crypto_drivers.h` (G)    | N/A                                 |
+| Symbols                   |                                   |
+| ------------------------- | --------------------------------- |
+| `MBEDTLS_xxx_C`           | `mbedtls/mbedtls_config.h` (U) or |
+|                           | `mbedtls/config_psa.h` (D)        |
+| `PSA_WANT_xxx`            | `psa/crypto_config.h` (U)         |
+| `MBEDTLS_PSA_BUILTIN_xxx` | `mbedtls/config_psa.h` (D)        |
+| `MBEDTLS_PSA_ACCEL_xxx`   | `mbedtls/crypto_drivers.h` (G)    |
 
 #### Visibility of internal symbols
 

diff --git a/docs/psa-driver-example-and-guide.md b/docs/psa-driver-example-and-guide.md
@@ -142,7 +142,6 @@ This guide assumes you are building Mbed TLS from source alongside your project.
 
 The Mbed TLS build system includes the instructions needed to build p256-m. To build with and use p256-m, set the macro `MBEDTLS_PSA_P256M_DRIVER_ENABLED` using `config.py`, then build as usual using make/cmake. From the root of the `mbedtls/` directory, run:
 
-    python3 scripts/config.py set MBEDTLS_PSA_CRYPTO_CONFIG
     python3 scripts/config.py set MBEDTLS_PSA_P256M_DRIVER_ENABLED
     make
 

diff --git a/docs/psa-transition.md b/docs/psa-transition.md
@@ -175,9 +175,7 @@ Note that a key consumes a key store entry, which is distinct from heap memory,
 
 ### Cryptographic mechanism availability
 
-**This section only applies if `MBEDTLS_PSA_CRYPTO_CONFIG` is enabled.** This option is disabled in the default configuration.
-
-When the configuration option [`MBEDTLS_PSA_CRYPTO_CONFIG`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/file/mbedtls__config_8h/#mbedtls__config_8h_1a5aca5ddcffb586acad82f9aef26db056) is enabled, the cryptographic mechanisms available through the PSA API are determined by the contents of the header file `"psa/crypto_config.h"`. You can override the file location with the macro [`MBEDTLS_PSA_CRYPTO_CONFIG_FILE`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/file/mbedtls__config_8h/#mbedtls__config_8h_1a25f7e358caa101570cb9519705c2b873), and you can set [`MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/file/mbedtls__config_8h/#mbedtls__config_8h_1abd1870cc0d2681183a3018a7247cb137) to the path of an additional file (similar to `MBEDTLS_CONFIG_FILE` and `MBEDTLS_USER_CONFIG_FILE` for legacy configuration symbols).
+The cryptographic mechanisms available through the PSA API are determined by the contents of the header file `"psa/crypto_config.h"`. You can override the file location with the macro [`MBEDTLS_PSA_CRYPTO_CONFIG_FILE`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/file/mbedtls__config_8h/#mbedtls__config_8h_1a25f7e358caa101570cb9519705c2b873), and you can set [`MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/file/mbedtls__config_8h/#mbedtls__config_8h_1abd1870cc0d2681183a3018a7247cb137) to the path of an additional file (similar to `MBEDTLS_CONFIG_FILE` and `MBEDTLS_USER_CONFIG_FILE` for legacy configuration symbols).
 
 The availability of cryptographic mechanisms in the PSA API is based on a systematic pattern:
 

diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
@@ -131,7 +131,6 @@
 #endif
 
 /* PSA crypto configuration */
-#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
 #if defined(MBEDTLS_PSA_CRYPTO_CONFIG_FILE)
 #include MBEDTLS_PSA_CRYPTO_CONFIG_FILE
 #else
@@ -140,7 +139,6 @@
 #if defined(MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE)
 #include MBEDTLS_PSA_CRYPTO_USER_CONFIG_FILE
 #endif
-#endif /* defined(MBEDTLS_PSA_CRYPTO_CONFIG) */
 
 /* Indicate that all configuration files have been read.
  * It is now time to adjust the configuration (follow through on dependencies,
@@ -170,11 +168,7 @@
  *   this symbol should be consulted after its inclusion.
  *   (e.g. MBEDTLS_MD_LIGHT)
  */
-#if defined(MBEDTLS_PSA_CRYPTO_CONFIG) /* PSA_WANT_xxx influences MBEDTLS_xxx */ || \
-    defined(MBEDTLS_PSA_CRYPTO_C) /* MBEDTLS_xxx influences PSA_WANT_xxx */ || \
-    defined(MBEDTLS_PSA_CRYPTO_CLIENT) /* The same as the previous, but with separation only */
 #include "mbedtls/config_psa.h"
-#endif
 
 #include "mbedtls/config_adjust_legacy_crypto.h"
 

diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
@@ -118,7 +118,7 @@
 #error "MBEDTLS_NIST_KW_C defined, but not all prerequisites"
 #endif
 
-#if defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT) && defined(MBEDTLS_PSA_CRYPTO_CONFIG)
+#if defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
 #if defined(PSA_WANT_ALG_CBC_NO_PADDING)
 #error "MBEDTLS_BLOCK_CIPHER_NO_DECRYPT and PSA_WANT_ALG_CBC_NO_PADDING cannot be defined simultaneously"
 #endif