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commit c781b566414ba4ad22f2018c57f6876c23e5e0d9
parent efa917d9e3ed2304b728d4263944ecc86120656d
Author: z3bra <willyatmailoodotorg>
Date:   Sat May  7 11:42:29 2016

base64_encode() working

Diffstat:
 base64.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 base64.h | 15 +++++++++++++++-
 2 files changed, 82 insertions(+), 0 deletions(-)

diff --git a/base64.c b/base64.c @@ -0,0 +1,67 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <unistd.h> + +#include "base64.h" + +size_t +base64_encode(char **buf, const unsigned char *msg, size_t len) +{ + int i, j; + uint64_t b64; + size_t size; + + /* calculate size needed for the base64 buffer */ + size = 1 + (len / 3) * 4 + (len % 3 ? 4 : 0); + + *buf = malloc(size); + memset(*buf, 0, size); + + for (i = j = 0; i < len; i+=3) { + /* concatenate 3 bytes into one 24 bits quantum, or 0 */ + b64 = 0 | (msg[i]<<16); + b64 |= ((i+1 < len ? msg[i+1] : 0) << 8); + b64 |= i+2 < len ? msg[i+2] : 0; + + /* extract 4 base64 values from it */ + (*buf)[j++] = base64_table[63 & (b64>>18)]; + (*buf)[j++] = base64_table[63 & (b64>>12)]; + (*buf)[j++] = i+1 < len ? base64_table[63 & (b64>>6)] : '='; + (*buf)[j++] = i+2 < len ? base64_table[63 & b64] : '='; + } + + return size; +} + +size_t +base64_decode(char **buf, const unsigned char *msg, size_t len) +{ + size_t size; + + size = 1 + (len / 4 ) * 3; + size -= msg[len - 1] == '=' ? 1 : 0; + size -= msg[len - 2] == '=' ? 1 : 0; + + printf("base64: %lu bytes\n", len); + printf("clear : %lu bytes\n", size); + + return size; +} + +int +main(int argc, char *argv[]) +{ + int i; + size_t len, n; + char *buf = NULL, in[59]; + + while ((n = read(0, in, 57)) > 0) { + in[58] = 0; + len = base64_encode(&buf, in, n); + puts(buf); + free(buf); + } + return 0; +} diff --git a/base64.h b/base64.h @@ -0,0 +1,15 @@ +#ifndef BASE64_H__ +#define BASE64_H__ + +size_t base64_encode(char **buf, const unsigned char *msg, size_t len); +size_t base64_decode(char **buf, const unsigned char *msg, size_t len); + +const char base64_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','+','/' +}; + +#endif