Convert payload to base64

edenhill · Aug 3, 2023 · 2cbfdf6 · 2cbfdf6
1 parent ab6ce81
commit 2cbfdf6
Showing 1 changed file with 52 additions and 4 deletions.
diff --git a/json.c b/json.c
@@ -30,12 +30,58 @@
 
 #include <yajl/yajl_gen.h>
 
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+
 #define JS_STR(G, STR) do {                                             \
                 const char *_s = (STR);                                 \
                 yajl_gen_string(G, (const unsigned char *)_s, strlen(_s)); \
         } while (0)
 #define JS_INT(G, INT) yajl_gen_integer(g, INT)
 
+static char encoding_table[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+                                'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+                                'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+                                'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+                                'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+                                'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+                                'w', 'x', 'y', 'z', '0', '1', '2', '3',
+                                '4', '5', '6', '7', '8', '9', '+', '/'};
+static int mod_table[] = {0, 2, 1};
+
+
+char *base64_encode(const unsigned char *data,
+                    size_t input_length,
+                    size_t *output_length) {
+
+    *output_length = 4 * ((input_length + 2) / 3);
+
+    char *encoded_data = malloc(*output_length);
+    if (encoded_data == NULL) return NULL;
+
+    for (size_t i = 0, j = 0; i < input_length;) {
+
+        uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
+        uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
+        uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;
+
+        uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;
+
+        encoded_data[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
+        encoded_data[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
+        encoded_data[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
+        encoded_data[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
+    }
+
+    for (int i = 0; i < mod_table[input_length % 3]; i++)
+        encoded_data[*output_length - 1 - i] = '=';
+
+    printf(encoded_data, output_length);
+
+    return encoded_data;
+}
+
 void fmt_msg_output_json (FILE *fp, const rd_kafka_message_t *rkmessage) {
         yajl_gen g;
         const char *topic = rd_kafka_topic_name(rkmessage->rkt);
@@ -178,12 +224,14 @@ void fmt_msg_output_json (FILE *fp, const rd_kafka_message_t *rkmessage) {
                         }
 
                         free(json);
-                } else
+                } else {
 #endif
+                        size_t output_len = 0;
+                        unsigned char* base64Payload = (unsigned char *)base64_encode((const unsigned char *) rkmessage->payload, rkmessage->len, &output_len);
                         yajl_gen_string(g,
-                                        (const unsigned char *)
-                                        rkmessage->payload,
-                                        rkmessage->len);
+                                        base64Payload,
+                                        output_len);
+                }
         } else
                 yajl_gen_null(g);