--- a/libidav/utils.c Sun Dec 03 13:09:14 2017 +0100
+++ b/libidav/utils.c Wed Dec 13 19:48:44 2017 +0100
@@ -466,41 +466,139 @@
return util_base64decode_len(in, &len);
}
+#define WHITESPACE 64
+#define EQUALS 65
+#define INVALID 66
+static char b64dectable[] = {
+ 66,66,66,66,66,66,66,66,66,66,64,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,62,66,66,66,63,52,53,
+ 54,55,56,57,58,59,60,61,66,66,66,65,66,66,66, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
+ 10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,66,66,66,66,66,66,26,27,28,
+ 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,66,
+ 66,66,66,66,66,66
+};
char* util_base64decode_len(char* in, int *outlen) {
- size_t len = strlen(in);
- char *out = calloc(1, len);
+ /* code is mostly from wikibooks */
+
+ size_t inlen = strlen(in);
+ size_t bufsize = (inlen*3) / 4;
+ char *outbuf = malloc(bufsize+1);
+ *outlen = -1;
+
+ unsigned char *out = outbuf;
+
+ char *end = in + inlen;
+ char iter = 0;
+ uint32_t buf = 0;
+ size_t len = 0;
- BIO *b = BIO_new_mem_buf(in, len);
- BIO *d = BIO_new(BIO_f_base64());
- BIO_set_flags(d, BIO_FLAGS_BASE64_NO_NL);
- b = BIO_push(d, b);
+ while (in < end) {
+ unsigned char c = b64dectable[*in++];
+
+ switch (c) {
+ case WHITESPACE: continue; /* skip whitespace */
+ case INVALID: {
+ /* invalid input */
+ outbuf[0] = 0;
+ return outbuf;
+ }
+ case EQUALS: {
+ /* pad character, end of data */
+ in = end;
+ continue;
+ }
+ default: {
+ buf = buf << 6 | c;
+ iter++; // increment the number of iteration
+ /* If the buffer is full, split it into bytes */
+ if (iter == 4) {
+ if ((len += 3) > bufsize) {
+ /* buffer overflow */
+ outbuf[0] = 0;
+ return outbuf;
+ }
+ *(out++) = (buf >> 16) & 255;
+ *(out++) = (buf >> 8) & 255;
+ *(out++) = buf & 255;
+ buf = 0; iter = 0;
- *outlen = BIO_read(b, out, len);
- BIO_free_all(b);
-
- return out;
+ }
+ }
+ }
+ }
+
+ if (iter == 3) {
+ if ((len += 2) > bufsize) {
+ /* buffer overflow */
+ outbuf[0] = 0;
+ return outbuf;
+ }
+ *(out++) = (buf >> 10) & 255;
+ *(out++) = (buf >> 2) & 255;
+ }
+ else if (iter == 2) {
+ if (++len > bufsize) {
+ /* buffer overflow */
+ outbuf[0] = 0;
+ return outbuf;
+ }
+ *(out++) = (buf >> 4) & 255;
+ }
+
+ *outlen = len; /* modify to reflect the actual output size */
+ outbuf[len] = 0;
+ return outbuf;
}
-char* util_base64encode(char *in, size_t len) {
- BIO *b;
- BIO *e;
- BUF_MEM *mem;
- e = BIO_new(BIO_f_base64());
- b = BIO_new(BIO_s_mem());
- BIO_set_flags(e, BIO_FLAGS_BASE64_NO_NL);
+static char* b64enctable = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+char* util_base64encode(char *in, size_t len) {
+ // calculate length of base64 output and create buffer
+ size_t outlen = 4 * ((len + 2) / 3);
+ int pad = len % 3;
+
+ char *out = malloc(outlen + 1);
+ out[outlen] = 0;
+ size_t pos = 0;
- e = BIO_push(e, b);
- BIO_write(e, in, len);
- BIO_flush(e);
+ // encode blocks of 3 bytes
+ size_t i;
+ size_t blockend = len - pad;
+ for(i=0;i<blockend;i++) {
+ unsigned char b1 = in[i++];
+ unsigned char b2 = in[i++];
+ unsigned char b3 = in[i];
+ uint32_t inb = b1 << 16 | (b2 << 8) | b3;
+ out[pos++] = b64enctable[(inb >> 18) & 63];
+ out[pos++] = b64enctable[(inb >> 12) & 63];
+ out[pos++] = b64enctable[(inb >> 6) & 63];
+ out[pos++] = b64enctable[(inb) & 63];
+ }
- BIO_get_mem_ptr(e, &mem);
- char *out = malloc(mem->length + 1);
- memcpy(out, mem->data, mem->length);
- out[mem->length] = '\0';
-
- BIO_free_all(e);
-
+ // encode last bytes
+ if(pad > 0) {
+ char p[3] = {0, 0, 0};
+ for(int j=0;i<len;i++) {
+ p[j++] = in[i];
+ }
+ unsigned char b1 = p[0];
+ unsigned char b2 = p[1];
+ unsigned char b3 = p[2];
+ uint32_t inb = (b1 << 16) | (b2 << 8) | b3;
+ out[pos++] = b64enctable[(inb >> 18) & 63];
+ out[pos++] = b64enctable[(inb >> 12) & 63];
+ out[pos++] = b64enctable[(inb >> 6) & 63];
+ out[pos++] = b64enctable[(inb) & 63];
+ for(int k=outlen-1;k>=outlen-(3-pad);k--) {
+ out[k] = '=';
+ }
+ }
+
return out;
}
