[PATCH 6/9] tls: Add helper to find hash function by id

[Denis Kenzior <denkenz@gmail.com>]

Instead of open-coding a loop to map the hash id from
SignatureAndHashAlgorithm structure to a supported hash function.
---
 ell/tls-suites.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/ell/tls-suites.c b/ell/tls-suites.c
index d5d2ec8f741f..bc6a756422b3 100644
--- a/ell/tls-suites.c
+++ b/ell/tls-suites.c
@@ -47,6 +47,17 @@ enum signature_algorithm {
 	SIGNATURE_ALGORITHM_ECDSA = 3,
 };
 
+static enum handshake_hash_type find_hash_by_id(uint8_t id)
+{
+	enum handshake_hash_type hash;
+
+	for (hash = 0; hash < __HANDSHAKE_HASH_COUNT; hash++)
+		if (tls_handshake_hash_data[hash].tls_id == id)
+			break;
+
+	return hash;
+}
+
 /*
  * Sanitize DigitallySigned struct input, making sure the lengths
  * are valid and correspond to what we expect.
@@ -182,11 +193,7 @@ static bool tls_rsa_verify(struct l_tls *tls, const uint8_t *in, size_t in_len,
 	}
 
 	if (tls->negotiated_version >= L_TLS_V12) {
-		enum handshake_hash_type hash;
-
-		for (hash = 0; hash < __HANDSHAKE_HASH_COUNT; hash++)
-			if (tls_handshake_hash_data[hash].tls_id == in[0])
-				break;
+		enum handshake_hash_type hash = find_hash_by_id(in[0]);
 
 		if (hash == __HANDSHAKE_HASH_COUNT) {
 			TLS_DISCONNECT(TLS_ALERT_DECRYPT_ERROR, 0,
-- 
2.35.1