completed set2, challenge 10

1 files changed, 51 insertions, 0 deletions

diff --git a/lib/lib.c b/lib/lib.c
index c2ee753..0eb5be8 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -471,3 +471,54 @@ char brute_force_single_byte_xor(char *string, int length, struct key_and_freq *
 
 	return key;
 }
+
+
+/**
+ * reads a base64 an decode it
+ * @param file path of the file
+ * @param out writes file in this buffer, allocated by this method
+ */
+int read_base64_file(const char *file, char **out)
+{
+	char ch;
+	FILE *fp;
+	int file_size = 60;
+	char *new_file_content;
+	int file_pos = 0;
+
+	fp = fopen(file, "r");
+
+	if (fp == NULL) {
+		printf("Error open file\n");
+		exit(1);
+	}
+	
+	*out = malloc(file_size);
+
+	if (*out == NULL) {
+		perror("out of memory");
+		exit(1);
+	}
+
+	// read data and decode it from base64
+	while ( (ch = fgetc(fp)) != EOF) {
+		// ignore new lines as this is part of base64
+		if (ch == '\n' || ch == '\r')
+			continue;
+
+		if (file_pos+1 >= file_size) {
+			new_file_content = realloc(*out, (file_size+60));
+			if (new_file_content != NULL) {
+				*out = new_file_content;
+				file_size += 60;
+			}
+			else {
+				printf("error allocating memory\n");
+				exit(1);
+			}
+		}
+		(*out)[file_pos++] = ch;
+	}
+	return file_pos;
+
+}