1189251Ssam/* 2189251Ssam * Base64 encoding/decoding (RFC1341) 3252726Srpaulo * Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi> 4189251Ssam * 5252726Srpaulo * This software may be distributed under the terms of the BSD license. 6252726Srpaulo * See README for more details. 7189251Ssam */ 8189251Ssam 9189251Ssam#include "includes.h" 10189251Ssam 11189251Ssam#include "os.h" 12189251Ssam#include "base64.h" 13189251Ssam 14189251Ssamstatic const unsigned char base64_table[65] = 15189251Ssam "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 16189251Ssam 17189251Ssam/** 18189251Ssam * base64_encode - Base64 encode 19189251Ssam * @src: Data to be encoded 20189251Ssam * @len: Length of the data to be encoded 21189251Ssam * @out_len: Pointer to output length variable, or %NULL if not used 22189251Ssam * Returns: Allocated buffer of out_len bytes of encoded data, 23189251Ssam * or %NULL on failure 24189251Ssam * 25189251Ssam * Caller is responsible for freeing the returned buffer. Returned buffer is 26189251Ssam * nul terminated to make it easier to use as a C string. The nul terminator is 27189251Ssam * not included in out_len. 28189251Ssam */ 29189251Ssamunsigned char * base64_encode(const unsigned char *src, size_t len, 30189251Ssam size_t *out_len) 31189251Ssam{ 32189251Ssam unsigned char *out, *pos; 33189251Ssam const unsigned char *end, *in; 34189251Ssam size_t olen; 35189251Ssam int line_len; 36189251Ssam 37189251Ssam olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */ 38189251Ssam olen += olen / 72; /* line feeds */ 39189251Ssam olen++; /* nul termination */ 40209158Srpaulo if (olen < len) 41209158Srpaulo return NULL; /* integer overflow */ 42189251Ssam out = os_malloc(olen); 43189251Ssam if (out == NULL) 44189251Ssam return NULL; 45189251Ssam 46189251Ssam end = src + len; 47189251Ssam in = src; 48189251Ssam pos = out; 49189251Ssam line_len = 0; 50189251Ssam while (end - in >= 3) { 51189251Ssam *pos++ = base64_table[in[0] >> 2]; 52189251Ssam *pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)]; 53189251Ssam *pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)]; 54189251Ssam *pos++ = base64_table[in[2] & 0x3f]; 55189251Ssam in += 3; 56189251Ssam line_len += 4; 57189251Ssam if (line_len >= 72) { 58189251Ssam *pos++ = '\n'; 59189251Ssam line_len = 0; 60189251Ssam } 61189251Ssam } 62189251Ssam 63189251Ssam if (end - in) { 64189251Ssam *pos++ = base64_table[in[0] >> 2]; 65189251Ssam if (end - in == 1) { 66189251Ssam *pos++ = base64_table[(in[0] & 0x03) << 4]; 67189251Ssam *pos++ = '='; 68189251Ssam } else { 69189251Ssam *pos++ = base64_table[((in[0] & 0x03) << 4) | 70189251Ssam (in[1] >> 4)]; 71189251Ssam *pos++ = base64_table[(in[1] & 0x0f) << 2]; 72189251Ssam } 73189251Ssam *pos++ = '='; 74189251Ssam line_len += 4; 75189251Ssam } 76189251Ssam 77189251Ssam if (line_len) 78189251Ssam *pos++ = '\n'; 79189251Ssam 80189251Ssam *pos = '\0'; 81189251Ssam if (out_len) 82189251Ssam *out_len = pos - out; 83189251Ssam return out; 84189251Ssam} 85189251Ssam 86189251Ssam 87189251Ssam/** 88189251Ssam * base64_decode - Base64 decode 89189251Ssam * @src: Data to be decoded 90189251Ssam * @len: Length of the data to be decoded 91189251Ssam * @out_len: Pointer to output length variable 92189251Ssam * Returns: Allocated buffer of out_len bytes of decoded data, 93189251Ssam * or %NULL on failure 94189251Ssam * 95189251Ssam * Caller is responsible for freeing the returned buffer. 96189251Ssam */ 97189251Ssamunsigned char * base64_decode(const unsigned char *src, size_t len, 98189251Ssam size_t *out_len) 99189251Ssam{ 100252726Srpaulo unsigned char dtable[256], *out, *pos, block[4], tmp; 101189251Ssam size_t i, count, olen; 102252726Srpaulo int pad = 0; 103189251Ssam 104189251Ssam os_memset(dtable, 0x80, 256); 105189251Ssam for (i = 0; i < sizeof(base64_table) - 1; i++) 106189251Ssam dtable[base64_table[i]] = (unsigned char) i; 107189251Ssam dtable['='] = 0; 108189251Ssam 109189251Ssam count = 0; 110189251Ssam for (i = 0; i < len; i++) { 111189251Ssam if (dtable[src[i]] != 0x80) 112189251Ssam count++; 113189251Ssam } 114189251Ssam 115189251Ssam if (count == 0 || count % 4) 116189251Ssam return NULL; 117189251Ssam 118189251Ssam olen = count / 4 * 3; 119189251Ssam pos = out = os_malloc(olen); 120189251Ssam if (out == NULL) 121189251Ssam return NULL; 122189251Ssam 123189251Ssam count = 0; 124189251Ssam for (i = 0; i < len; i++) { 125189251Ssam tmp = dtable[src[i]]; 126189251Ssam if (tmp == 0x80) 127189251Ssam continue; 128189251Ssam 129252726Srpaulo if (src[i] == '=') 130252726Srpaulo pad++; 131189251Ssam block[count] = tmp; 132189251Ssam count++; 133189251Ssam if (count == 4) { 134189251Ssam *pos++ = (block[0] << 2) | (block[1] >> 4); 135189251Ssam *pos++ = (block[1] << 4) | (block[2] >> 2); 136189251Ssam *pos++ = (block[2] << 6) | block[3]; 137189251Ssam count = 0; 138252726Srpaulo if (pad) { 139252726Srpaulo if (pad == 1) 140252726Srpaulo pos--; 141252726Srpaulo else if (pad == 2) 142252726Srpaulo pos -= 2; 143252726Srpaulo else { 144252726Srpaulo /* Invalid padding */ 145252726Srpaulo os_free(out); 146252726Srpaulo return NULL; 147252726Srpaulo } 148252726Srpaulo break; 149252726Srpaulo } 150189251Ssam } 151189251Ssam } 152189251Ssam 153189251Ssam *out_len = pos - out; 154189251Ssam return out; 155189251Ssam} 156