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/* base64 encoder/decoder based on public domain implementation
* by Chris Venter */
#include <arpa/inet.h>
#include <stdlib.h>
#include "rpmio/base64.h"
static char base64_encode_value(char value_in)
{
static const char encoding[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
if (value_in > 63) return '=';
return encoding[(int)value_in];
}
static char *base64_encode_block(const char *plaintext_in, int length_in, char *codechar)
{
const char *plainchar = plaintext_in;
const char *const plaintextend = plaintext_in + length_in;
char result;
char fragment;
while (1) {
if (plainchar == plaintextend) {
return codechar;
}
fragment = *plainchar++;
result = (fragment & 0x0fc) >> 2;
*codechar++ = base64_encode_value(result);
result = (fragment & 0x003) << 4;
if (plainchar == plaintextend)
{
*codechar++ = base64_encode_value(result);
*codechar++ = '=';
*codechar++ = '=';
return codechar;
}
fragment = *plainchar++;
result |= (fragment & 0x0f0) >> 4;
*codechar++ = base64_encode_value(result);
result = (fragment & 0x00f) << 2;
if (plainchar == plaintextend)
{
*codechar++ = base64_encode_value(result);
*codechar++ = '=';
return codechar;
}
fragment = *plainchar++;
result |= (fragment & 0x0c0) >> 6;
*codechar++ = base64_encode_value(result);
result = (fragment & 0x03f) >> 0;
*codechar++ = base64_encode_value(result);
}
/* control should not reach here */
return codechar;
}
#define BASE64_DEFAULT_LINE_LENGTH 64
char *b64encode(const void *data, size_t len, int linelen)
{
size_t encodedlen;
const char *dataptr = data;
char *output;
char *outptr;
if (data == NULL)
return NULL;
if (linelen < 0)
linelen = BASE64_DEFAULT_LINE_LENGTH;
linelen /= 4;
encodedlen = ((len + 2) / 3) * 4;
if (linelen > 0) {
encodedlen += encodedlen/(linelen * 4) + 1;
}
++encodedlen; /* for zero termination */
output = malloc(encodedlen);
if (output == NULL)
return NULL;
outptr = output;
while (len > 0) {
if (linelen > 0 && len > linelen * 3) {
outptr = base64_encode_block(dataptr, linelen * 3, outptr);
len -= linelen * 3;
dataptr += linelen * 3;
} else {
outptr = base64_encode_block(dataptr, len, outptr);
len = 0;
}
if (linelen > 0) {
*outptr++ = '\n';
}
}
*outptr = '\0';
return output;
}
static int base64_decode_value(unsigned char value_in)
{
static const int decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
value_in -= 43;
if (value_in > sizeof(decoding)/sizeof(int))
return -1;
return decoding[value_in];
}
static size_t base64_decode_block(const char *code_in, const size_t length_in, char *plaintext_out)
{
const char *codechar = code_in;
char *plainchar = plaintext_out;
int fragment;
*plainchar = 0;
while (1)
{
do {
if (codechar == code_in+length_in)
{
return plainchar - plaintext_out;
}
fragment = base64_decode_value(*codechar++);
} while (fragment < 0);
*plainchar = (char)((fragment & 0x03f) << 2);
do {
if (codechar == code_in+length_in)
{
return plainchar - plaintext_out;
}
fragment = base64_decode_value(*codechar++);
} while (fragment < 0);
*plainchar++ |= (char)((fragment & 0x030) >> 4);
*plainchar = (char)((fragment & 0x00f) << 4);
do {
if (codechar == code_in+length_in)
{
return plainchar - plaintext_out;
}
fragment = base64_decode_value(*codechar++);
} while (fragment < 0);
*plainchar++ |= (char)((fragment & 0x03c) >> 2);
*plainchar = (char)((fragment & 0x003) << 6);
do {
if (codechar == code_in+length_in)
{
return plainchar - plaintext_out;
}
fragment = base64_decode_value(*codechar++);
} while (fragment < 0);
*plainchar++ |= (char)(fragment & 0x03f);
}
/* control should not reach here */
return plainchar - plaintext_out;
}
int b64decode(const char *in, void **out, size_t *outlen)
{
size_t outcnt = 0;
const char *inptr = in;
*out = NULL;
if (in == NULL) {
return 1;
}
while (*inptr != '\0') {
/* assume all ASCII control chars as whitespace */
if (*inptr > 32) {
if (base64_decode_value(*inptr) != -1) {
++outcnt;
} else {
return 3;
}
}
++inptr;
}
if (outcnt % 4 != 0)
return 2;
outcnt = (outcnt / 4) * 3;
*out = malloc(outcnt + 1); /* base64_decode_block can write one extra character */
if (*out == NULL)
return 4;
*outlen = base64_decode_block(in, inptr - in, *out);
return 0;
}
#define CRC24_INIT 0xb704ce
#define CRC24_POLY 0x1864cfb
char *b64crc(const unsigned char *data, size_t len)
{
uint32_t crc = CRC24_INIT;
int i;
while (len--) {
crc ^= (*data++) << 16;
for (i = 0; i < 8; i++) {
crc <<= 1;
if (crc & 0x1000000)
crc ^= CRC24_POLY;
}
}
crc = htonl(crc & 0xffffff);
data = (unsigned char *)&crc;
++data;
return b64encode(data, 3, 0);
}
#ifdef BASE64_TEST
#include <stdio.h>
#include <string.h>
int main(int argc, char *argv[])
{
static char tst[]="wtrt8122čLýáj\x20s ~ýhž\t4\x02šjjmBvž^%$RTš#á.íěj\x1hčýčŤc+";
char *encoded;
void *decoded;
size_t size;
int err;
printf("Original: %lu\n%s\n", sizeof(tst)-1, tst);
encoded = b64encode(tst, sizeof(tst)-1, 64);
printf("Encoded: %lu\n%s\n", strlen(encoded), encoded);
if ((err = b64decode(encoded, &decoded, &size)) != 0) {
fprintf(stderr, "Error in decode: %d\n", err);
return 1;
}
printf("Decoded:\n%.*s\n", (int)size, (char *)decoded);
if (size != sizeof(tst)-1) {
fprintf(stderr, "Size differs orig: %lu new: %lu\n", sizeof(tst)-1, size);
return 1;
}
if (memcmp(tst, decoded, size) != 0) {
fprintf(stderr, "Decoded data differs.\n");
return 1;
}
fprintf(stderr, "OK\n");
return 0;
}
#endif
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