Merge remote-tracking branch 'upstream-public/pr/1046' into development

ChangeLog

@@ -28,6 +28,12 @@ Features
      The following functions from the ECDSA module can be replaced
      with alternative implementation:
      mbedtls_ecdsa_sign(), mbedtls_ecdsa_verify() and mbedtls_ecdsa_genkey().
+   * Add support for alternative implementation for ECDH, controlled by new
+     configuration flags MBEDTLS_ECDH_COMPUTE_SHARED_ALT and
+     MBEDTLS_ECDH_GEN_PUBLIC_ALT in config.h.
+     The following functions from the ECDH module can be replaced
+     with an alternative implementation:
+     mbedtls_ecdh_gen_public() and mbedtls_ecdh_compute_shared().
 
 New deprecations
    * Deprecate usage of RSA primitives with non-matching key-type

include/mbedtls/config.h

@@ -332,6 +332,8 @@
 //#define MBEDTLS_AES_SETKEY_DEC_ALT
 //#define MBEDTLS_AES_ENCRYPT_ALT
 //#define MBEDTLS_AES_DECRYPT_ALT
+//#define MBEDTLS_ECDH_GEN_PUBLIC_ALT
+//#define MBEDTLS_ECDH_COMPUTE_SHARED_ALT
 //#define MBEDTLS_ECDSA_VERIFY_ALT
 //#define MBEDTLS_ECDSA_SIGN_ALT
 //#define MBEDTLS_ECDSA_GENKEY_ALT

library/ecdh.c

@@ -38,6 +38,7 @@
 
 #include <string.h>
 
+#if !defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)
 /*
  * Generate public key: simple wrapper around mbedtls_ecp_gen_keypair
  */
@@ -47,7 +48,9 @@ int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp
 {
     return mbedtls_ecp_gen_keypair( grp, d, Q, f_rng, p_rng );
 }
+#endif /* MBEDTLS_ECDH_GEN_PUBLIC_ALT */
 
+#if !defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT)
 /*
  * Compute shared secret (SEC1 3.3.1)
  */
@@ -81,6 +84,7 @@ cleanup:
 
     return( ret );
 }
+#endif /* MBEDTLS_ECDH_COMPUTE_SHARED_ALT */
 
 /*
  * Initialize context

library/version_features.c

@@ -177,6 +177,12 @@ static const char *features[] = {
 #if defined(MBEDTLS_AES_DECRYPT_ALT)
     "MBEDTLS_AES_DECRYPT_ALT",
 #endif /* MBEDTLS_AES_DECRYPT_ALT */
+#if defined(MBEDTLS_ECDH_GEN_PUBLIC_ALT)
+    "MBEDTLS_ECDH_GEN_PUBLIC_ALT",
+#endif /* MBEDTLS_ECDH_GEN_PUBLIC_ALT */
+#if defined(MBEDTLS_ECDH_COMPUTE_SHARED_ALT)
+    "MBEDTLS_ECDH_COMPUTE_SHARED_ALT",
+#endif /* MBEDTLS_ECDH_COMPUTE_SHARED_ALT */
 #if defined(MBEDTLS_ECDSA_VERIFY_ALT)
     "MBEDTLS_ECDSA_VERIFY_ALT",
 #endif /* MBEDTLS_ECDSA_VERIFY_ALT */