Deprecate the old deterministic ECDSA function
The current interface does not allow passing an RNG, which is needed for
blinding. Using the scheme's internal HMAC-DRBG results the same
blinding values for the same key and message, diminishing the
effectiveness of the countermeasure. A new function
`mbedtls_ecdsa_det_ext` is available to address this problem.
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 6a54132..3ae8eed 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -503,6 +503,8 @@
/*
* Deterministic signature wrappers
*/
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
@@ -517,6 +519,7 @@
return( ecdsa_sign_det_restartable( grp, r, s, d, buf, blen, md_alg,
NULL, NULL, NULL ) );
}
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
int mbedtls_ecdsa_sign_det_ext( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,