+
+static char hex_digit(char val)
+{
+ val += val > 9 ? 'a' - 10 : '0';
+ return val;
+}
+
+void bin_to_hex(char *dest, const void *buf, int len)
+{
+ const uint8_t *data = buf;
+ int i;
+
+ for (i = 0; i < len; i++) {
+ *(dest++) = hex_digit(data[i] >> 4);
+ *(dest++) = hex_digit(data[i] & 0xf);
+ }
+ *dest = 0;
+}
+
+static void http_create_hash(char *dest, const char * const * str, int n_str)
+{
+ uint32_t hash[4];
+ md5_ctx_t md5;
+ int i;
+
+ md5_begin(&md5);
+ for (i = 0; i < n_str; i++) {
+ if (i)
+ md5_hash(":", 1, &md5);
+ md5_hash(str[i], strlen(str[i]), &md5);
+ }
+ md5_end(hash, &md5);
+ bin_to_hex(dest, &hash, sizeof(hash));
+}
+
+void http_digest_calculate_auth_hash(char *dest, const char *user, const char *realm, const char *password)
+{
+ const char *hash_str[] = {
+ user,
+ realm,
+ password
+ };
+
+ http_create_hash(dest, hash_str, ARRAY_SIZE(hash_str));
+}
+
+void http_digest_calculate_response(char *dest, const struct http_digest_data *data)
+{
+ const char *h_a2_strings[] = {
+ data->method,
+ data->uri,
+ };
+ const char *resp_strings[] = {
+ data->auth_hash,
+ data->nonce,
+ data->nc,
+ data->cnonce,
+ data->qop,
+ dest, /* initialized to H(A2) first */
+ };
+
+ http_create_hash(dest, h_a2_strings, ARRAY_SIZE(h_a2_strings));
+ http_create_hash(dest, resp_strings, ARRAY_SIZE(resp_strings));
+}