jwt: remove TinyCrypt usage

As part of TinyCrypt deprecation process (#79566) this commit
removes usage of this library from the JWT subsystem and its
related tests.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>

doc/releases/migration-guide-4.0.rst

@@ -576,11 +576,21 @@ Shell
 JWT (JSON Web Token)
 ====================
 
-* By default, the signature is now computed through PSA Crypto API for both RSA and ECDSA.
+* By default, the signature is now computed using the PSA Crypto API for both RSA and ECDSA
-  The newly-added :kconfig:option:`CONFIG_JWT_USE_LEGACY` can be used to switch
+  (:github:`78243`). The conversion to the PSA Crypto API is part of the adoption
-  back to previous libraries (TinyCrypt for ECDSA and Mbed TLS for RSA).
+  of a standard interface for crypto operations (:github:`43712`). Moreover,
-  The conversion to the PSA Crypto API is being done in preparation for the
+  following the deprecation of the TinyCrypt library (:github:`79566`), usage
-  deprecation of TinyCrypt. (:github:`78243` and :github:`43712`)
+  of TinyCrypt was removed from the JWT subsystem (:github:`79653`).
+
+* The following new symbols were added to allow specifying both the signature
+  algorithm and crypto library:
+
+  * :kconfig:option:`CONFIG_JWT_SIGN_RSA_PSA` (default) RSA signature using the PSA Crypto API;
+  * :kconfig:option:`CONFIG_JWT_SIGN_RSA_LEGACY` RSA signature using Mbed TLS;
+  * :kconfig:option:`CONFIG_JWT_SIGN_ECDSA_PSA` ECDSA signature using the PSA Crypto API.
+
+  They replace the previously-existing Kconfigs ``CONFIG_JWT_SIGN_RSA`` and
+  ``CONFIG_JWT_SIGN_ECDSA``. (:github:`79653`)
 
 Architectures
 *************

doc/releases/release-notes-4.0.rst

@@ -608,12 +608,14 @@ Libraries / Subsystems
 
 * JWT (JSON Web Token)
 
-  * The following new Kconfigs were added to specify which library to use for the
+  * The following new symbols were added to allow specifying both the signature
-    signature:
+    algorithm and crypto library:
 
-    * :kconfig:option:`CONFIG_JWT_USE_PSA` (default) use the PSA Crypto API;
+    * :kconfig:option:`CONFIG_JWT_SIGN_RSA_PSA` (default) RSA signature using the PSA Crypto API;
-    * :kconfig:option:`CONFIG_JWT_USE_LEGACY` use legacy libraries, i.e. TinyCrypt
+    * :kconfig:option:`CONFIG_JWT_SIGN_RSA_LEGACY` RSA signature using Mbed TLS;
-      for ECDSA and Mbed TLS for RSA.
+    * :kconfig:option:`CONFIG_JWT_SIGN_ECDSA_PSA` ECDSA signature using the PSA Crypto API.
+
+    (:github:`79653`)
 
 HALs
 ****

subsys/jwt/CMakeLists.txt

@@ -3,8 +3,10 @@
 zephyr_library()
 zephyr_library_sources(jwt.c)
 
-zephyr_library_sources_ifdef(CONFIG_JWT_SIGN_ECDSA_LEGACY jwt_legacy_ecdsa.c)
 zephyr_library_sources_ifdef(CONFIG_JWT_SIGN_RSA_LEGACY jwt_legacy_rsa.c)
-zephyr_library_sources_ifdef(CONFIG_JWT_USE_PSA jwt_psa.c)
+
+if (CONFIG_JWT_SIGN_RSA_PSA OR CONFIG_JWT_SIGN_ECDSA_PSA)
+  zephyr_library_sources(jwt_psa.c)
+endif()
 
 zephyr_library_link_libraries_ifdef(CONFIG_MBEDTLS mbedTLS)

subsys/jwt/Kconfig

@@ -12,69 +12,34 @@ if JWT
 
 choice
 	prompt "JWT signature algorithm"
-	default JWT_SIGN_RSA
+	default JWT_SIGN_RSA_PSA
 	help
 	  Select which algorithm to use for signing JWT tokens.
 
-config JWT_SIGN_RSA
+config JWT_SIGN_RSA_LEGACY
-	bool "Use RSA signature (RS-256)"
+	bool "Use RSA signature (RS-256). Use Mbed TLS as crypto library."
-
+	depends on CSPRNG_ENABLED
-config JWT_SIGN_ECDSA
+	select MBEDTLS
-	bool "Use ECDSA signature (ES-256)"
+	select MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
-
-endchoice
-
-choice
-	default JWT_USE_PSA
-	prompt "Select crypto library to be used"
-
-config JWT_USE_PSA
-	bool "PSA crypto API library"
-	select MBEDTLS if !BUILD_WITH_TFM
-	select MBEDTLS_PSA_CRYPTO_C if !BUILD_WITH_TFM
-
-config JWT_USE_LEGACY
-	bool "Legacy library: TinyCrypt for ECDSA, Mbed TLS for RSA"
-
-endchoice
-
-# Prompless Kconfigs to effectively select which algorithm and library will be used
-# to sign the JWT. User's selections on the above choices will determine which
-# element will be picked here.
-config JWT_SIGN_ECDSA_PSA
-	bool
-	default y
-	depends on JWT_SIGN_ECDSA && JWT_USE_PSA
-	select PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_IMPORT
-	select PSA_WANT_ALG_ECDSA
-	select PSA_WANT_ECC_SECP_R1_256
-	select PSA_WANT_ALG_SHA_256
-
-config JWT_SIGN_ECDSA_LEGACY
-	bool
-	default y
-	depends on JWT_SIGN_ECDSA && JWT_USE_LEGACY
-	select TINYCRYPT
-	select TINYCRYPT_SHA256
-	select TINYCRYPT_ECC_DSA
-	select TINYCRYPT_CTR_PRNG
-	select TINYCRYPT_AES
 
 config JWT_SIGN_RSA_PSA
-	bool
+	bool "Use RSA signature (RS-256). Use PSA Crypto API."
-	default y
+	select MBEDTLS if !BUILD_WITH_TFM
-	depends on JWT_SIGN_RSA && JWT_USE_PSA
+	select MBEDTLS_PSA_CRYPTO_C if !BUILD_WITH_TFM
 	select PSA_WANT_KEY_TYPE_RSA_PUBLIC_KEY
 	select PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_IMPORT
 	select PSA_WANT_ALG_RSA_PKCS1V15_SIGN
 	select PSA_WANT_ALG_SHA_256
 
-config JWT_SIGN_RSA_LEGACY
+config JWT_SIGN_ECDSA_PSA
-	bool
+	bool "Use ECDSA signature (ES-256). Use PSA Crypto API."
-	default y
+	select MBEDTLS if !BUILD_WITH_TFM
-	depends on JWT_SIGN_RSA && JWT_USE_LEGACY
+	select MBEDTLS_PSA_CRYPTO_C if !BUILD_WITH_TFM
-	depends on CSPRNG_ENABLED
+	select PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_IMPORT
-	select MBEDTLS
+	select PSA_WANT_ALG_ECDSA
-	select MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+	select PSA_WANT_ECC_SECP_R1_256
+	select PSA_WANT_ALG_SHA_256
+
+endchoice
 
 endif # JWT

subsys/jwt/jwt.c

@@ -14,9 +14,9 @@
 
 #include "jwt.h"
 
-#if defined(CONFIG_JWT_SIGN_RSA)
+#if defined(CONFIG_JWT_SIGN_RSA_PSA) || defined(JWT_SIGN_RSA_LEGACY)
 #define JWT_SIGNATURE_LEN 256
-#else /* CONFIG_JWT_SIGN_ECDSA */
+#else /* CONFIG_JWT_SIGN_ECDSA_PSA */
 #define JWT_SIGNATURE_LEN 64
 #endif
 
@@ -143,10 +143,10 @@ static int jwt_add_header(struct jwt_builder *builder)
 	 * Use https://www.base64encode.org/ for update
 	 */
 	const char jwt_header[] =
-#ifdef CONFIG_JWT_SIGN_RSA
+#if defined(CONFIG_JWT_SIGN_RSA_PSA) || defined(CONFIG_JWT_SIGN_RSA_LEGACY)
 		/* {"alg":"RS256","typ":"JWT"} */
 		"eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9";
-#else /* CONFIG_JWT_SIGN_ECDSA */
+#else /* CONFIG_JWT_SIGN_ECDSA_PSA */
 		/* {"alg":"ES256","typ":"JWT"} */
 		"eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9";
 #endif

subsys/jwt/jwt_legacy_ecdsa.c

@@ -1,82 +0,0 @@
-/*
- * Copyright (C) 2024 BayLibre SAS
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#include <string.h>
-#include <zephyr/types.h>
-#include <errno.h>
-
-#include <zephyr/data/jwt.h>
-#include <zephyr/data/json.h>
-#include <zephyr/random/random.h>
-
-#include <tinycrypt/ctr_prng.h>
-#include <tinycrypt/sha256.h>
-#include <tinycrypt/ecc_dsa.h>
-#include <tinycrypt/constants.h>
-
-#include "jwt.h"
-
-static TCCtrPrng_t prng_state;
-static bool prng_init;
-
-static const char personalize[] = "zephyr:drivers/jwt/jwt.c";
-
-static int setup_prng(void)
-{
-	if (prng_init) {
-		return 0;
-	}
-	prng_init = true;
-
-	uint8_t entropy[TC_AES_KEY_SIZE + TC_AES_BLOCK_SIZE];
-
-	sys_rand_get(entropy, sizeof(entropy));
-
-	int res = tc_ctr_prng_init(&prng_state, (const uint8_t *)&entropy, sizeof(entropy),
-				   personalize, sizeof(personalize));
-
-	return res == TC_CRYPTO_SUCCESS ? 0 : -EINVAL;
-}
-
-/* This function is declared in
- * modules/crypto/tinycrypt/lib/include/tinycrypt/ecc_platform_specific.h.
- *
- * TinyCrypt expects this function to be implemented somewhere when using the
- * ECC module.
- */
-int default_CSPRNG(uint8_t *dest, unsigned int size)
-{
-	int res = tc_ctr_prng_generate(&prng_state, NULL, 0, dest, size);
-	return res;
-}
-
-int jwt_sign_impl(struct jwt_builder *builder, const unsigned char *der_key, size_t der_key_len,
-		  unsigned char *sig, size_t sig_size)
-{
-	struct tc_sha256_state_struct ctx;
-	uint8_t hash[32];
-	int res;
-
-	ARG_UNUSED(sig_size);
-
-	tc_sha256_init(&ctx);
-	tc_sha256_update(&ctx, builder->base, builder->buf - builder->base);
-	tc_sha256_final(hash, &ctx);
-
-	res = setup_prng();
-
-	if (res != 0) {
-		return res;
-	}
-
-	/* Note that tinycrypt only supports P-256. */
-	res = uECC_sign(der_key, hash, sizeof(hash), sig, &curve_secp256r1);
-	if (res != TC_CRYPTO_SUCCESS) {
-		return -EINVAL;
-	}
-
-	return 0;
-}

subsys/jwt/jwt_psa.c

@@ -24,15 +24,15 @@ int jwt_sign_impl(struct jwt_builder *builder, const unsigned char *der_key, siz
 	psa_algorithm_t alg;
 	int ret;
 
-#if defined(CONFIG_JWT_SIGN_ECDSA)
+#if defined(CONFIG_JWT_SIGN_ECDSA_PSA)
 	psa_set_key_type(&attr, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_SECP_R1));
 	psa_set_key_algorithm(&attr, PSA_ALG_ECDSA(PSA_ALG_SHA_256));
 	alg = PSA_ALG_ECDSA(PSA_ALG_SHA_256);
-#else  /* CONFIG_JWT_SIGN_RSA */
+#else
 	psa_set_key_type(&attr, PSA_KEY_TYPE_RSA_KEY_PAIR);
 	psa_set_key_algorithm(&attr, PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_256));
 	alg = PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_256);
-#endif /* CONFIG_JWT_SIGN_ECDSA || CONFIG_JWT_SIGN_RSA */
+#endif
 	psa_set_key_usage_flags(&attr, PSA_KEY_USAGE_SIGN_MESSAGE);
 
 	status = psa_import_key(&attr, der_key, der_key_len, &key_id);

tests/subsys/jwt/src/jwt-test-private.c

@@ -4,7 +4,7 @@
  *
  */
 
-#if defined(CONFIG_JWT_SIGN_RSA)
+#if defined(CONFIG_JWT_SIGN_RSA_PSA) || defined(CONFIG_JWT_SIGN_RSA_LEGACY)
 
 /* To generate the key in the correct format use the following command:
  * $ openssl genrsa 2048 | openssl rsa -outform DER | xxd -i
@@ -113,7 +113,7 @@ unsigned char jwt_test_private_der[] = {
 	0x05, 0xfd, 0x71, 0xb0, 0x3e
 };
 
-#else /* CONFIG_JWT_SIGN_ECDSA */
+#else /* CONFIG_JWT_SIGN_ECDSA_PSA */
 
 /* Here's how to generate the key in the correct format:
  * - generate the key using OpenSSL:

tests/subsys/jwt/testcase.yaml

@@ -9,24 +9,17 @@ common:
   extra_configs:
     - CONFIG_TEST_RANDOM_GENERATOR=y
 tests:
-  libraries.encoding.jwt.ecdsa.legacy:
-    extra_configs:
-      - CONFIG_JWT_SIGN_ECDSA=y
-      - CONFIG_JWT_USE_LEGACY=y
   libraries.encoding.jwt.ecdsa.psa:
     extra_configs:
-      - CONFIG_JWT_SIGN_ECDSA=y
+      - CONFIG_JWT_SIGN_ECDSA_PSA=y
-      - CONFIG_JWT_USE_PSA=y
       - CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG=y
       - CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG_ALLOW_NON_CSPRNG=y
   libraries.encoding.jwt.rsa.legacy:
     filter: CSPRNG_ENABLED
     extra_configs:
-      - CONFIG_JWT_SIGN_RSA=y
+      - CONFIG_JWT_SIGN_RSA_LEGACY=y
-      - CONFIG_JWT_USE_LEGACY=y
   libraries.encoding.jwt.rsa.psa:
     extra_configs:
-      - CONFIG_JWT_SIGN_RSA=y
+      - CONFIG_JWT_SIGN_RSA_PSA=y
-      - CONFIG_JWT_USE_PSA=y
       - CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG=y
       - CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG_ALLOW_NON_CSPRNG=y