Merge branch 'master' of https://github.com/grpc/grpc into caching_with_uri
diff --git a/BUILD b/BUILD
index 33daa2b..c91c147 100644
--- a/BUILD
+++ b/BUILD
@@ -510,6 +510,7 @@
         "src/core/lib/json/json_reader.c",
         "src/core/lib/json/json_string.c",
         "src/core/lib/json/json_writer.c",
+        "src/core/lib/security/util/b64.c",
         "src/core/lib/slice/percent_encoding.c",
         "src/core/lib/slice/slice.c",
         "src/core/lib/slice/slice_buffer.c",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f73d76d..0ebd610 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -951,6 +951,7 @@
   src/core/lib/json/json_reader.c
   src/core/lib/json/json_string.c
   src/core/lib/json/json_writer.c
+  src/core/lib/security/util/b64.c
   src/core/lib/slice/percent_encoding.c
   src/core/lib/slice/slice.c
   src/core/lib/slice/slice_buffer.c
@@ -1032,7 +1033,6 @@
   src/core/lib/security/transport/security_handshaker.c
   src/core/lib/security/transport/server_auth_filter.c
   src/core/lib/security/transport/tsi_error.c
-  src/core/lib/security/util/b64.c
   src/core/lib/security/util/json_util.c
   src/core/lib/surface/init_secure.c
   src/core/lib/tsi/fake_transport_security.c
@@ -1263,6 +1263,7 @@
   src/core/lib/json/json_reader.c
   src/core/lib/json/json_string.c
   src/core/lib/json/json_writer.c
+  src/core/lib/security/util/b64.c
   src/core/lib/slice/percent_encoding.c
   src/core/lib/slice/slice.c
   src/core/lib/slice/slice_buffer.c
@@ -1367,7 +1368,6 @@
   src/core/lib/security/transport/security_handshaker.c
   src/core/lib/security/transport/server_auth_filter.c
   src/core/lib/security/transport/tsi_error.c
-  src/core/lib/security/util/b64.c
   src/core/lib/security/util/json_util.c
   src/core/lib/surface/init_secure.c
   src/core/lib/tsi/fake_transport_security.c
@@ -1566,6 +1566,7 @@
   src/core/lib/json/json_reader.c
   src/core/lib/json/json_string.c
   src/core/lib/json/json_writer.c
+  src/core/lib/security/util/b64.c
   src/core/lib/slice/percent_encoding.c
   src/core/lib/slice/slice.c
   src/core/lib/slice/slice_buffer.c
@@ -1816,6 +1817,7 @@
   src/core/lib/json/json_reader.c
   src/core/lib/json/json_string.c
   src/core/lib/json/json_writer.c
+  src/core/lib/security/util/b64.c
   src/core/lib/slice/percent_encoding.c
   src/core/lib/slice/slice.c
   src/core/lib/slice/slice_buffer.c
@@ -2426,6 +2428,7 @@
   src/core/lib/json/json_reader.c
   src/core/lib/json/json_string.c
   src/core/lib/json/json_writer.c
+  src/core/lib/security/util/b64.c
   src/core/lib/slice/percent_encoding.c
   src/core/lib/slice/slice.c
   src/core/lib/slice/slice_buffer.c
diff --git a/Makefile b/Makefile
index 9d3aee8..63cd93c 100644
--- a/Makefile
+++ b/Makefile
@@ -2842,6 +2842,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -2923,7 +2924,6 @@
     src/core/lib/security/transport/security_handshaker.c \
     src/core/lib/security/transport/server_auth_filter.c \
     src/core/lib/security/transport/tsi_error.c \
-    src/core/lib/security/util/b64.c \
     src/core/lib/security/util/json_util.c \
     src/core/lib/surface/init_secure.c \
     src/core/lib/tsi/fake_transport_security.c \
@@ -3157,6 +3157,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -3261,7 +3262,6 @@
     src/core/lib/security/transport/security_handshaker.c \
     src/core/lib/security/transport/server_auth_filter.c \
     src/core/lib/security/transport/tsi_error.c \
-    src/core/lib/security/util/b64.c \
     src/core/lib/security/util/json_util.c \
     src/core/lib/surface/init_secure.c \
     src/core/lib/tsi/fake_transport_security.c \
@@ -3463,6 +3463,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -3693,6 +3694,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -4305,6 +4307,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -18675,7 +18678,6 @@
 src/core/lib/security/transport/security_handshaker.c: $(OPENSSL_DEP)
 src/core/lib/security/transport/server_auth_filter.c: $(OPENSSL_DEP)
 src/core/lib/security/transport/tsi_error.c: $(OPENSSL_DEP)
-src/core/lib/security/util/b64.c: $(OPENSSL_DEP)
 src/core/lib/security/util/json_util.c: $(OPENSSL_DEP)
 src/core/lib/surface/init_secure.c: $(OPENSSL_DEP)
 src/core/lib/tsi/fake_transport_security.c: $(OPENSSL_DEP)
diff --git a/binding.gyp b/binding.gyp
index ced23e2..4c6e149 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -693,6 +693,7 @@
         'src/core/lib/json/json_reader.c',
         'src/core/lib/json/json_string.c',
         'src/core/lib/json/json_writer.c',
+        'src/core/lib/security/util/b64.c',
         'src/core/lib/slice/percent_encoding.c',
         'src/core/lib/slice/slice.c',
         'src/core/lib/slice/slice_buffer.c',
@@ -774,7 +775,6 @@
         'src/core/lib/security/transport/security_handshaker.c',
         'src/core/lib/security/transport/server_auth_filter.c',
         'src/core/lib/security/transport/tsi_error.c',
-        'src/core/lib/security/util/b64.c',
         'src/core/lib/security/util/json_util.c',
         'src/core/lib/surface/init_secure.c',
         'src/core/lib/tsi/fake_transport_security.c',
diff --git a/build.yaml b/build.yaml
index 63f22fd..de032e7 100644
--- a/build.yaml
+++ b/build.yaml
@@ -368,6 +368,7 @@
   - src/core/lib/json/json_reader.c
   - src/core/lib/json/json_string.c
   - src/core/lib/json/json_writer.c
+  - src/core/lib/security/util/b64.c
   - src/core/lib/slice/percent_encoding.c
   - src/core/lib/slice/slice.c
   - src/core/lib/slice/slice_buffer.c
diff --git a/config.m4 b/config.m4
index 96ac558..5ddd77a 100644
--- a/config.m4
+++ b/config.m4
@@ -168,6 +168,7 @@
     src/core/lib/json/json_reader.c \
     src/core/lib/json/json_string.c \
     src/core/lib/json/json_writer.c \
+    src/core/lib/security/util/b64.c \
     src/core/lib/slice/percent_encoding.c \
     src/core/lib/slice/slice.c \
     src/core/lib/slice/slice_buffer.c \
@@ -249,7 +250,6 @@
     src/core/lib/security/transport/security_handshaker.c \
     src/core/lib/security/transport/server_auth_filter.c \
     src/core/lib/security/transport/tsi_error.c \
-    src/core/lib/security/util/b64.c \
     src/core/lib/security/util/json_util.c \
     src/core/lib/surface/init_secure.c \
     src/core/lib/tsi/fake_transport_security.c \
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index e45631e..1d37b91 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -539,6 +539,7 @@
                       'src/core/lib/json/json_reader.c',
                       'src/core/lib/json/json_string.c',
                       'src/core/lib/json/json_writer.c',
+                      'src/core/lib/security/util/b64.c',
                       'src/core/lib/slice/percent_encoding.c',
                       'src/core/lib/slice/slice.c',
                       'src/core/lib/slice/slice_buffer.c',
@@ -620,7 +621,6 @@
                       'src/core/lib/security/transport/security_handshaker.c',
                       'src/core/lib/security/transport/server_auth_filter.c',
                       'src/core/lib/security/transport/tsi_error.c',
-                      'src/core/lib/security/util/b64.c',
                       'src/core/lib/security/util/json_util.c',
                       'src/core/lib/surface/init_secure.c',
                       'src/core/lib/tsi/fake_transport_security.c',
diff --git a/grpc.gemspec b/grpc.gemspec
index c7d9bfb..0e4452d 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -456,6 +456,7 @@
   s.files += %w( src/core/lib/json/json_reader.c )
   s.files += %w( src/core/lib/json/json_string.c )
   s.files += %w( src/core/lib/json/json_writer.c )
+  s.files += %w( src/core/lib/security/util/b64.c )
   s.files += %w( src/core/lib/slice/percent_encoding.c )
   s.files += %w( src/core/lib/slice/slice.c )
   s.files += %w( src/core/lib/slice/slice_buffer.c )
@@ -537,7 +538,6 @@
   s.files += %w( src/core/lib/security/transport/security_handshaker.c )
   s.files += %w( src/core/lib/security/transport/server_auth_filter.c )
   s.files += %w( src/core/lib/security/transport/tsi_error.c )
-  s.files += %w( src/core/lib/security/util/b64.c )
   s.files += %w( src/core/lib/security/util/json_util.c )
   s.files += %w( src/core/lib/surface/init_secure.c )
   s.files += %w( src/core/lib/tsi/fake_transport_security.c )
diff --git a/package.xml b/package.xml
index a47f1b9..2a3705c 100644
--- a/package.xml
+++ b/package.xml
@@ -465,6 +465,7 @@
     <file baseinstalldir="/" name="src/core/lib/json/json_reader.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/json/json_string.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/json/json_writer.c" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/security/util/b64.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/percent_encoding.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_buffer.c" role="src" />
@@ -546,7 +547,6 @@
     <file baseinstalldir="/" name="src/core/lib/security/transport/security_handshaker.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/transport/server_auth_filter.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/transport/tsi_error.c" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/security/util/b64.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/security/util/json_util.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/surface/init_secure.c" role="src" />
     <file baseinstalldir="/" name="src/core/lib/tsi/fake_transport_security.c" role="src" />
diff --git a/src/core/lib/channel/http_client_filter.c b/src/core/lib/channel/http_client_filter.c
index 028e9a5..51f2d84 100644
--- a/src/core/lib/channel/http_client_filter.c
+++ b/src/core/lib/channel/http_client_filter.c
@@ -36,6 +36,7 @@
 #include <grpc/support/string_util.h>
 #include <string.h>
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/security/util/b64.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
@@ -56,7 +57,6 @@
   grpc_linked_mdelem te_trailers;
   grpc_linked_mdelem content_type;
   grpc_linked_mdelem user_agent;
-  grpc_linked_mdelem payload_bin;
 
   grpc_metadata_batch *recv_initial_metadata;
   grpc_metadata_batch *recv_trailing_metadata;
@@ -292,19 +292,57 @@
       continue_send_message(exec_ctx, elem);
 
       if (calld->send_message_blocked == false) {
-        /* when all the send_message data is available, then create a MDELEM and
-        append to headers */
-        grpc_mdelem payload_bin = grpc_mdelem_from_slices(
-            exec_ctx, GRPC_MDSTR_GRPC_PAYLOAD_BIN,
-            grpc_slice_from_copied_buffer((const char *)calld->payload_bytes,
-                                          op->send_message->length));
-        error =
-            grpc_metadata_batch_add_tail(exec_ctx, op->send_initial_metadata,
-                                         &calld->payload_bin, payload_bin);
+        /* when all the send_message data is available, then modify the path
+         * MDELEM by appending base64 encoded query to the path */
+        const int k_url_safe = 1;
+        const int k_multi_line = 0;
+        const char *k_query_separator = "?";
+        const size_t k_query_separator_len = 1; /* strlen(k_query_separator) */
+
+        grpc_slice path_slice =
+            GRPC_MDVALUE(op->send_initial_metadata->idx.named.path->md);
+        /* sum up individual component's lengths and allocate enough memory to
+         * hold combined path+query */
+        size_t estimated_len = GRPC_SLICE_LENGTH(path_slice);
+        estimated_len += k_query_separator_len;
+        estimated_len += grpc_base64_estimate_encoded_size(
+            op->send_message->length, k_url_safe, k_multi_line);
+        estimated_len += 1; /* for the trailing 0 */
+        grpc_slice path_with_query_slice = grpc_slice_malloc(estimated_len);
+
+        /* memcopy individual pieces into this slice */
+        uint8_t *write_ptr = (uint8_t *)GRPC_SLICE_START_PTR(path_with_query_slice);
+        uint8_t *original_path = (uint8_t *)GRPC_SLICE_START_PTR(path_slice);
+        memcpy(write_ptr, original_path, GRPC_SLICE_LENGTH(path_slice));
+        write_ptr += GRPC_SLICE_LENGTH(path_slice);
+
+        memcpy(write_ptr, k_query_separator, k_query_separator_len);
+        write_ptr += k_query_separator_len;
+
+        grpc_base64_encode_core((char *)write_ptr, calld->payload_bytes,
+                                op->send_message->length, k_url_safe,
+                                k_multi_line);
+
+        /* remove trailing unused memory and add trailing 0 to terminate string
+         */
+        char *t = (char *)GRPC_SLICE_START_PTR(path_with_query_slice);
+        size_t path_length = strlen(t) + 1;
+        *(t + path_length) = '\0';
+        path_with_query_slice =
+            grpc_slice_sub(path_with_query_slice, 0, path_length);
+
+        /* substitute previous path with the new path+query */
+        grpc_mdelem mdelem_path_and_query = grpc_mdelem_from_slices(
+            exec_ctx, GRPC_MDSTR_PATH, path_with_query_slice);
+        grpc_metadata_batch *b = op->send_initial_metadata;
+        error = grpc_metadata_batch_substitute(exec_ctx, b, b->idx.named.path,
+                                               mdelem_path_and_query);
         if (error != GRPC_ERROR_NONE) return error;
+
         calld->on_complete = op->on_complete;
         op->on_complete = &calld->hc_on_complete;
         op->send_message = NULL;
+        grpc_slice_unref_internal(exec_ctx, path_with_query_slice);
       } else {
         /* Not all data is available. Fall back to POST. */
         gpr_log(GPR_DEBUG,
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index 41a325b..dbe41d3 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -37,6 +37,7 @@
 #include <grpc/support/log.h>
 #include <string.h>
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/security/util/b64.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
@@ -51,8 +52,8 @@
   grpc_linked_mdelem status;
   grpc_linked_mdelem content_type;
 
-  /* did this request come with payload-bin */
-  bool seen_payload_bin;
+  /* did this request come with path query containing request payload */
+  bool seen_path_with_query;
   /* flag to ensure payload_bin is delivered only once */
   bool payload_bin_delivered;
 
@@ -61,7 +62,7 @@
   bool *recv_cacheable_request;
   /** Closure to call when finished with the hs_on_recv hook */
   grpc_closure *on_done_recv;
-  /** Closure to call when we retrieve read message from the payload-bin header
+  /** Closure to call when we retrieve read message from the path URI
    */
   grpc_closure *recv_message_ready;
   grpc_closure *on_complete;
@@ -205,6 +206,42 @@
               grpc_error_set_str(
                   GRPC_ERROR_CREATE_FROM_STATIC_STRING("Missing header"),
                   GRPC_ERROR_STR_KEY, grpc_slice_from_static_string(":path")));
+  } else if (*calld->recv_cacheable_request == true) {
+    /* We have a cacheable request made with GET verb. The path contains the
+     * query parameter which is base64 encoded request payload. */
+    const char *k_query_separator = "?";
+    grpc_slice path_slice = GRPC_MDVALUE(b->idx.named.path->md);
+    uint8_t *path_ptr = (uint8_t *)GRPC_SLICE_START_PTR(path_slice);
+    size_t path_length = GRPC_SLICE_LENGTH(path_slice);
+    /* offset of the character '?' */
+    size_t offset = 0;
+    for (offset = 0; *path_ptr != k_query_separator[0] && offset < path_length;
+         path_ptr++, offset++)
+      ;
+    if (offset < path_length) {
+      grpc_slice query_slice =
+          grpc_slice_sub(path_slice, offset + 1, path_length);
+
+      /* substitute path metadata with just the path (not query) */
+      grpc_mdelem mdelem_path_without_query = grpc_mdelem_from_slices(
+          exec_ctx, GRPC_MDSTR_PATH, grpc_slice_sub(path_slice, 0, offset));
+
+      grpc_metadata_batch_substitute(exec_ctx, b, b->idx.named.path,
+                                     mdelem_path_without_query);
+
+      /* decode payload from query and add to the slice buffer to be returned */
+      const int k_url_safe = 1;
+      grpc_slice_buffer_add(
+          &calld->read_slice_buffer,
+          grpc_base64_decode(exec_ctx,
+                             (const char *)GRPC_SLICE_START_PTR(query_slice),
+                             k_url_safe));
+      grpc_slice_buffer_stream_init(&calld->read_stream,
+                                    &calld->read_slice_buffer, 0);
+      calld->seen_path_with_query = true;
+    } else {
+      gpr_log(GPR_ERROR, "GET request without QUERY");
+    }
   }
 
   if (b->idx.named.host != NULL && b->idx.named.authority == NULL) {
@@ -228,16 +265,6 @@
             GRPC_ERROR_STR_KEY, grpc_slice_from_static_string(":authority")));
   }
 
-  if (b->idx.named.grpc_payload_bin != NULL) {
-    calld->seen_payload_bin = true;
-    grpc_slice_buffer_add(&calld->read_slice_buffer,
-                          grpc_slice_ref_internal(
-                              GRPC_MDVALUE(b->idx.named.grpc_payload_bin->md)));
-    grpc_slice_buffer_stream_init(&calld->read_stream,
-                                  &calld->read_slice_buffer, 0);
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_payload_bin);
-  }
-
   return error;
 }
 
@@ -258,8 +285,8 @@
                            grpc_error *err) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
-  /* Call recv_message_ready if we got the payload via the header field */
-  if (calld->seen_payload_bin && calld->recv_message_ready != NULL) {
+  /* Call recv_message_ready if we got the payload via the path field */
+  if (calld->seen_path_with_query && calld->recv_message_ready != NULL) {
     *calld->pp_recv_message = calld->payload_bin_delivered
                                   ? NULL
                                   : (grpc_byte_stream *)&calld->read_stream;
@@ -274,7 +301,7 @@
                                   grpc_error *err) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
-  if (calld->seen_payload_bin) {
+  if (calld->seen_path_with_query) {
     /* do nothing. This is probably a GET request, and payload will be returned
     in hs_on_complete callback. */
   } else {
diff --git a/src/core/lib/security/util/b64.c b/src/core/lib/security/util/b64.c
index 09c8213..a84e42b 100644
--- a/src/core/lib/security/util/b64.c
+++ b/src/core/lib/security/util/b64.c
@@ -71,15 +71,31 @@
 
 char *grpc_base64_encode(const void *vdata, size_t data_size, int url_safe,
                          int multiline) {
-  const unsigned char *data = vdata;
-  const char *base64_chars =
-      url_safe ? base64_url_safe_chars : base64_url_unsafe_chars;
+  size_t result_projected_size =
+      grpc_base64_estimate_encoded_size(data_size, url_safe, multiline);
+  char *result = gpr_malloc(result_projected_size);
+  grpc_base64_encode_core(result, vdata, data_size, url_safe, multiline);
+  return result;
+}
+
+size_t grpc_base64_estimate_encoded_size(size_t data_size, int url_safe,
+                                         int multiline) {
   size_t result_projected_size =
       4 * ((data_size + 3) / 3) +
       2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS))
                      : 0) +
       1;
-  char *result = gpr_malloc(result_projected_size);
+  return result_projected_size;
+}
+
+void grpc_base64_encode_core(char *result, const void *vdata, size_t data_size,
+                             int url_safe, int multiline) {
+  const unsigned char *data = vdata;
+  const char *base64_chars =
+      url_safe ? base64_url_safe_chars : base64_url_unsafe_chars;
+  size_t result_projected_size =
+      grpc_base64_estimate_encoded_size(data_size, url_safe, multiline);
+
   char *current = result;
   size_t num_blocks = 0;
   size_t i = 0;
@@ -119,7 +135,6 @@
   GPR_ASSERT(current >= result);
   GPR_ASSERT((uintptr_t)(current - result) < result_projected_size);
   result[current - result] = '\0';
-  return result;
 }
 
 grpc_slice grpc_base64_decode(grpc_exec_ctx *exec_ctx, const char *b64,
diff --git a/src/core/lib/security/util/b64.h b/src/core/lib/security/util/b64.h
index d42a136..e84c502 100644
--- a/src/core/lib/security/util/b64.h
+++ b/src/core/lib/security/util/b64.h
@@ -41,6 +41,17 @@
 char *grpc_base64_encode(const void *data, size_t data_size, int url_safe,
                          int multiline);
 
+/* estimate the upper bound on size of base64 encoded data. The actual size
+ * is guaranteed to be less than or equal to the size returned here. */
+size_t grpc_base64_estimate_encoded_size(size_t data_size, int url_safe,
+                                         int multiline);
+
+/* Encodes data using base64 and write it to memory pointed to by result. It is
+ * the caller's responsiblity to allocate enough memory in |result| to fit the
+ * encoded data. */
+void grpc_base64_encode_core(char *result, const void *vdata, size_t data_size,
+                             int url_safe, int multiline);
+
 /* Decodes data according to the base64 specification. Returns an empty
    slice in case of failure. */
 grpc_slice grpc_base64_decode(grpc_exec_ctx *exec_ctx, const char *b64,
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 249d63d..0e4e41c 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -162,6 +162,7 @@
   'src/core/lib/json/json_reader.c',
   'src/core/lib/json/json_string.c',
   'src/core/lib/json/json_writer.c',
+  'src/core/lib/security/util/b64.c',
   'src/core/lib/slice/percent_encoding.c',
   'src/core/lib/slice/slice.c',
   'src/core/lib/slice/slice_buffer.c',
@@ -243,7 +244,6 @@
   'src/core/lib/security/transport/security_handshaker.c',
   'src/core/lib/security/transport/server_auth_filter.c',
   'src/core/lib/security/transport/tsi_error.c',
-  'src/core/lib/security/util/b64.c',
   'src/core/lib/security/util/json_util.c',
   'src/core/lib/surface/init_secure.c',
   'src/core/lib/tsi/fake_transport_security.c',
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 81dbd02..e7e8d3c 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -7749,6 +7749,7 @@
       "src/core/lib/json/json_string.c", 
       "src/core/lib/json/json_writer.c", 
       "src/core/lib/json/json_writer.h", 
+      "src/core/lib/security/util/b64.c", 
       "src/core/lib/slice/percent_encoding.c", 
       "src/core/lib/slice/percent_encoding.h", 
       "src/core/lib/slice/slice.c", 
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj b/vsprojects/vcxproj/grpc/grpc.vcxproj
index ccf0d4d..557a3b6 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj
@@ -672,6 +672,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\slice.c">
@@ -834,8 +836,6 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\transport\tsi_error.c">
     </ClCompile>
-    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
-    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\json_util.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\surface\init_secure.c">
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
index e9d950a..c0ef364 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
@@ -259,6 +259,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
       <Filter>src\core\lib\json</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+      <Filter>src\core\lib\security\util</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
       <Filter>src\core\lib\slice</Filter>
     </ClCompile>
@@ -502,9 +505,6 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\transport\tsi_error.c">
       <Filter>src\core\lib\security\transport</Filter>
     </ClCompile>
-    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
-      <Filter>src\core\lib\security\util</Filter>
-    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\json_util.c">
       <Filter>src\core\lib\security\util</Filter>
     </ClCompile>
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
index 734ce1b..b6056b9 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
@@ -515,6 +515,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\slice.c">
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
index 63eb9a0..3d9fd85 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
@@ -316,6 +316,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
       <Filter>src\core\lib\json</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+      <Filter>src\core\lib\security\util</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
       <Filter>src\core\lib\slice</Filter>
     </ClCompile>
@@ -935,6 +938,12 @@
     <Filter Include="src\core\lib\json">
       <UniqueIdentifier>{89bc8f83-e29a-ddab-8f6b-22df11cdc867}</UniqueIdentifier>
     </Filter>
+    <Filter Include="src\core\lib\security">
+      <UniqueIdentifier>{83d9c8a0-c579-769e-e2df-270c67b8c159}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="src\core\lib\security\util">
+      <UniqueIdentifier>{d55417ff-35a3-ef69-80c4-e6a95673728b}</UniqueIdentifier>
+    </Filter>
     <Filter Include="src\core\lib\slice">
       <UniqueIdentifier>{4d172bbc-20c4-6e7d-872a-2d287b589aa0}</UniqueIdentifier>
     </Filter>
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
index a077f0e..688a23d 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
@@ -639,6 +639,8 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\slice.c">
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
index e8b381c..ed32667 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
@@ -262,6 +262,9 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\json\json_writer.c">
       <Filter>src\core\lib\json</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\security\util\b64.c">
+      <Filter>src\core\lib\security\util</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\slice\percent_encoding.c">
       <Filter>src\core\lib\slice</Filter>
     </ClCompile>
@@ -1328,6 +1331,12 @@
     <Filter Include="src\core\lib\json">
       <UniqueIdentifier>{681cdaeb-c47f-8853-d985-bf13c2873947}</UniqueIdentifier>
     </Filter>
+    <Filter Include="src\core\lib\security">
+      <UniqueIdentifier>{02c849c5-66eb-e42f-c9f7-2cf7cc9db06a}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="src\core\lib\security\util">
+      <UniqueIdentifier>{c22aef1f-8b7b-6b5c-9e22-321b11f6352d}</UniqueIdentifier>
+    </Filter>
     <Filter Include="src\core\lib\slice">
       <UniqueIdentifier>{74c81ab7-e329-a362-3890-4c41b90f0511}</UniqueIdentifier>
     </Filter>