http: decode Content-MD5 headers/trailers

This means we'll eventually be able to reject
uploads if the Content-MD5 trailer doesn't match
the contents of the upload.

1 files changed, 15 insertions, 2 deletions

diff --git a/http_common.rl b/http_common.rl
index b2ccd03..cb5bc8b 100644
--- a/http_common.rl
+++ b/http_common.rl
@@ -13,6 +13,19 @@
         header_value = (any -- CTL)*;
         sep = LWS+|LWS*"\r\n"LWS+;
         b64_val = ([a-zA-Z0-9/+]{22}) > { http->tmp_tip = to_u16(fpc - buf); }
-                  "=="; # TODO
-        content_md5 = "Content-MD5:"i sep b64_val eor;
+                  "=="
+                  eor > {
+                        uint16_t tmp_end = to_u16(fpc - buf);
+                        char *in = buf + http->tmp_tip;
+                        size_t inlen = tmp_end - http->tmp_tip;
+                        char *out = (char *)http->expect_md5;
+                        size_t outlen = sizeof(http->expect_md5);
+                        bool rc;
+
+                        rc = base64_decode_ctx(NULL, in, inlen, out, &outlen);
+                        assert(rc == true && outlen == 16
+                               && "base64_decoder broke for HTTP");
+                        http->has_expect_md5 = 1;
+                  };
+        content_md5 = "Content-MD5:"i sep b64_val;
 }%%