diff --git a/hs20/client/est.c b/hs20/client/est.c
index db65334..97f9132 100644
--- a/hs20/client/est.c
+++ b/hs20/client/est.c
@@ -158,7 +158,7 @@
 		return -1;
 	}
 
-	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
+	pkcs7 = base64_decode(resp, resp_len, &pkcs7_len);
 	if (pkcs7 && pkcs7_len < resp_len / 2) {
 		wpa_printf(MSG_INFO, "Too short base64 decode (%u bytes; downloaded %u bytes) - assume this was binary",
 			   (unsigned int) pkcs7_len, (unsigned int) resp_len);
@@ -639,8 +639,7 @@
 			return -1;
 		}
 
-		attrs = base64_decode((unsigned char *) resp, resp_len,
-				      &attrs_len);
+		attrs = base64_decode(resp, resp_len, &attrs_len);
 		os_free(resp);
 
 		if (attrs == NULL) {
@@ -734,7 +733,7 @@
 	}
 	wpa_printf(MSG_DEBUG, "EST simpleenroll response: %s", resp);
 
-	pkcs7 = base64_decode((unsigned char *) resp, resp_len, &pkcs7_len);
+	pkcs7 = base64_decode(resp, resp_len, &pkcs7_len);
 	if (pkcs7 == NULL) {
 		wpa_printf(MSG_INFO, "EST workaround - Could not decode base64, assume this is DER encoded PKCS7");
 		pkcs7 = os_malloc(resp_len);
diff --git a/hs20/client/osu_client.c b/hs20/client/osu_client.c
index fd99600..a94f40c 100644
--- a/hs20/client/osu_client.c
+++ b/hs20/client/osu_client.c
@@ -310,7 +310,7 @@
 	size_t len;
 	u8 digest1[SHA256_MAC_LEN], digest2[SHA256_MAC_LEN];
 	int res;
-	unsigned char *b64;
+	char *b64;
 	FILE *f;
 
 	url_node = get_node(ctx->xml, params, "CertURL");
@@ -364,7 +364,7 @@
 		return -1;
 	}
 
-	b64 = base64_encode((unsigned char *) cert, len, NULL);
+	b64 = base64_encode(cert, len, NULL);
 	os_free(cert);
 	if (b64 == NULL)
 		return -1;
diff --git a/hs20/server/spp_server.c b/hs20/server/spp_server.c
index 4bef0ff..a50e907 100644
--- a/hs20/server/spp_server.c
+++ b/hs20/server/spp_server.c
@@ -633,7 +633,7 @@
 
 	add_text_node(ctx, node, "Username", user);
 
-	b64 = (char *) base64_encode((unsigned char *) pw, strlen(pw), NULL);
+	b64 = base64_encode(pw, strlen(pw), NULL);
 	if (b64 == NULL)
 		return NULL;
 	len = os_strlen(b64);
@@ -1602,8 +1602,7 @@
 
 	xml_node_create_text(ctx->xml, enroll, ns, "estUserID", user);
 
-	b64 = (char *) base64_encode((unsigned char *) password,
-				     strlen(password), NULL);
+	b64 = base64_encode(password, strlen(password), NULL);
 	if (b64 == NULL) {
 		xml_node_free(ctx->xml, spp_node);
 		return NULL;