commit 08d34b8693a03727e6731ae5adf44a8e081dfbf9
author Andrzej Kurek <andrzej.kurek@arm.com> Fri Jul 29 10:00:16 2022 -0400
committer Andrzej Kurek <andrzej.kurek@arm.com> Wed Sep 14 08:39:26 2022 -0400
tree f8e09c89ed1fd6c1ce2cc105fd88d7b9105c0d31
parent f6a6a2d8154209886fc89e3f300108ff41e82efb

Add an EC J-PAKE KDF to transform K -> SHA256(K.X) for TLS 1.2

TLS uses it to derive the session secret. The algorithm takes a serialized
point in an uncompressed form, extracts the X coordinate and computes
SHA256 of it. It is only expected to work with P-256.
Fixes #5978.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>

include/psa/crypto_struct.h

diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index 957b4c6..afba325 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -202,6 +202,12 @@
 #endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF ||
           MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT ||
           MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+typedef struct
+{
+    uint8_t MBEDTLS_PRIVATE(data)[PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE];
+} psa_tls12_ecjpake_to_pms_t;
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS */
 
 #if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
     defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
@@ -267,6 +273,9 @@
     defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
         psa_tls12_prf_key_derivation_t MBEDTLS_PRIVATE(tls12_prf);
 #endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+        psa_tls12_ecjpake_to_pms_t MBEDTLS_PRIVATE(tls12_ecjpake_to_pms);
+#endif
     } MBEDTLS_PRIVATE(ctx);
 };