Also check curve in verify()
This is the only function that performs computations without calling
EccPoint_mult_safer() and that didn't have that guard yet.
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index b3a08cf..04b1bfa 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -220,6 +220,9 @@
wordcount_t num_words = curve->num_words;
wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
+ if (curve != uECC_secp256r1())
+ return 0;
+
rx[num_n_words - 1] = 0;
r[num_n_words - 1] = 0;
s[num_n_words - 1] = 0;