[bssl] Implement nostd bssl wrapper for ECDSA sign/verify

Bug: 310634099
Test: atest rialto_test libbssl_avf_nostd.test
Change-Id: I817bce28a73fd49c218fa14d9c7ff69eb2e0674d
diff --git a/libs/bssl/src/lib.rs b/libs/bssl/src/lib.rs
index de81368..8e3abcf 100644
--- a/libs/bssl/src/lib.rs
+++ b/libs/bssl/src/lib.rs
@@ -27,9 +27,10 @@
 mod hkdf;
 mod hmac;
 mod rand;
+mod sha;
 mod util;
 
-pub use bssl_avf_error::{ApiName, CipherError, Error, ReasonCode, Result};
+pub use bssl_avf_error::{ApiName, CipherError, EcError, EcdsaError, Error, ReasonCode, Result};
 
 pub use aead::{Aead, AeadContext, AES_GCM_NONCE_LENGTH};
 pub use cbb::CbbFixed;
@@ -39,3 +40,4 @@
 pub use hkdf::hkdf;
 pub use hmac::hmac_sha256;
 pub use rand::rand_bytes;
+pub use sha::sha256;