source: libcf/trunk/src/cf_codec.c@ 129

/**
 * \file cf_codec.c
 *
 * \author myusgun <myusgun@gmail.com>
 *
 * \brief 데이터 변환 구현
 */
#include "cf_codec.h"
#include "cf_type.h"
#include "cf_error.h"

#include <string.h>
#include <stdio.h>

#define ASSERT_ARGS(x)  \
    if ((x))            \
        return CF_ERROR_CODEC_INVALID_ARGS

const static cf_byte g_ascii_HexDecode[] = {
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  00 -  15 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  16 -  31 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  32 -  47 */
     '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',0x00,0x00,0x00,0x00,0x00,0x00,    /*  48 -  63 */
    0x00, 'A', 'A', 'A', 'A', 'A', 'A',0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  64 -  79 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  80 -  95 */
    0x00, 'a', 'a', 'a', 'a', 'a', 'a',0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /*  96 - 111 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 112 - 127 */
    /* end of ascii character */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 128 - 143 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 144 - 159 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 160 - 175 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 176 - 191 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 192 - 207 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 208 - 223 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 224 - 239 */
    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,    /* 240 - 255 */
};

const static char g_table_Base64Encode[] = {
#define BASE64_PADDING_CHAR_INDEX   64
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',     /* 00 - 07 */
    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',     /* 08 - 15 */
    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',     /* 16 - 23 */
    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',     /* 24 - 31 */
    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',     /* 32 - 39 */
    'o', 'p', 'q', 'r', 's', 't', 'u', 'v',     /* 40 - 47 */
    'w', 'x', 'y', 'z', '0', '1', '2', '3',     /* 48 - 55 */
    '4', '5', '6', '7', '8', '9', '+', '/',     /* 56 - 63 */
    '='                                         /* padding */
};

const static cf_byte g_ascii_Base64Decode[] = {
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /*  00 -  15 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /*  16 -  31 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,  62,0xff,0xff,0xff,  63,    /*  32 -  47 */
      52,  53,  54,  55,  56,  57,  58,  59,  60,  61,0xff,0xff,0xff,  64,0xff,0xff,    /*  48 -  63 */
    0xff,   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,    /*  64 -  79 */
      15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,0xff,0xff,0xff,0xff,0xff,    /*  80 -  95 */
    0xff,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,    /*  96 - 111 */
      41,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51,0xff,0xff,0xff,0xff,0xff,    /* 112 - 127 */
    /* end of ascii character */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 128 - 143 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 144 - 159 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 160 - 175 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 176 - 191 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 192 - 207 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 208 - 223 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 224 - 239 */
    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,    /* 240 - 255 */
};


/**
 * hex-encode
 *
 * \return 성공 시, CF_OK; 실패 시, 오류 코드
 *
 * \param bin   바이너리 데이터
 * \param len   바이너리 데이터의 길이
 * \param hex   16진수 문자열을 저장할 주소
 *
 * \remarks
 * hex는 할당된 메모리이며, 크기는 '\0'를 제외하고 len * 2
 */
int
CF_Codec_Hex_Encode (const cf_byte  * bin,
                     const size_t   len,
                     char           * hex)
{
    size_t  iter = 0;
    size_t  hexlen = len * 2 + 1;

    const cf_byte   * ptr = bin;

    const static char   hexchar[] = {'0', '1', '2', '3',
                                     '4', '5', '6', '7',
                                     '8', '9', 'a', 'b',
                                     'c', 'd', 'e', 'f'};

    ASSERT_ARGS (bin == NULL);
    ASSERT_ARGS (hex == NULL);

    for (iter = 0 ; iter < hexlen ; iter += 2, ptr++)
    {
        hex[iter    ] = hexchar[((*(ptr)) >> 4) & 0x0f];
        hex[iter + 1] = hexchar[((*(ptr))     ) & 0x0f];
    }
    hex[hexlen - 1] = '\0';

    return CF_OK;
}

/**
 * hex-decode
 *
 * \return 성공 시, 디코딩된 바이너리 데이터의 길이; 실패 시, 오류 코드
 *
 * \param hex   16진수 문자열
 * \param bin   바이너리 데이터를 저장할 주소
 * \param len   바이너리 데이터의 길이를 저장할 주소
 *
 * \remarks
 * bin는 할당된 메모리이며, 크기는 strlen (hex) / 2
 */
int
CF_Codec_Hex_Decode (const char * hex,
                     cf_byte    * bin,
                     size_t     * len)
{
    size_t      length = 0; /* absolutely even-number */
    size_t      iter = 0;
    size_t      binlen = 0;

    const char  * ptr = hex;
    char        buf = 0;
    cf_byte     val = 0;
    cf_byte     asciiHex = 0;

    ASSERT_ARGS (hex == NULL);
    ASSERT_ARGS (bin == NULL);
    ASSERT_ARGS (len == NULL);

    *len = 0;

    for ( ; g_ascii_HexDecode[(int)*ptr] && *ptr ; ptr++, length++);

    if (*ptr)
        return CF_ERROR_CODEC_NOT_HEXSTRING;

    binlen = length / 2;

    for (iter = 0, ptr = hex ; *ptr ; iter++)
    {
        val = 0;    /* init/re-init docoding-buffer */

        /* decode one character */
#define DECODE_HEX(x)                               \
        do {                                        \
        buf = *(x);                                 \
        val = (cf_byte)(val << 4);          \
        asciiHex = g_ascii_HexDecode[(int)buf];     \
                                                    \
        val |=  (cf_byte)                       \
                (buf - asciiHex + (asciiHex == '0' ? 0 : 10));  \
        } while (0)

        /* decode one byte by decode two character */
        DECODE_HEX (ptr++);
        DECODE_HEX (ptr++);

        bin[iter] = val;
    }

    * len = binlen;

    return CF_OK;
}

/**
 * Base64-encode
 *
 * \return 성공 시, CF_OK; 실패 시, 오류 코드
 *
 * \param bin       바이너리 데이터
 * \param len       바이너리 데이터 길이
 * \param base64    base64 문자열을 저장할 주소
 *
 * \remarks
 * base64는 할당된 메모리이며, 크기는 '\0'를 제외하고 ((len + 2) / 3) * 4
 */
int
CF_Codec_Base64_Encode (const cf_byte   * bin,
                        const size_t    len,
                        char            * base64)
{
    const cf_byte   * src = bin;
    char            * dst = base64;

    ASSERT_ARGS (src == NULL);
    ASSERT_ARGS (dst == NULL);

#define SEXTUPLE_E_1(__x)   (((__x[0]) >> 2) & 0x3f)
#define SEXTUPLE_E_2(__x)   (((__x[0]) << 4) & 0x30)
#define SEXTUPLE_E_3(__x)   (((__x[1]) >> 4) & 0x0f)
#define SEXTUPLE_E_4(__x)   (((__x[1]) << 2) & 0x3c)
#define SEXTUPLE_E_5(__x)   (((__x[2]) >> 6) & 0x03)
#define SEXTUPLE_E_6(__x)   (((__x[2])     ) & 0x3f)

    for ( ; src - bin < len - 2 ; src += 3)
    {
        *dst++ = g_table_Base64Encode[SEXTUPLE_E_1 (src)];
        *dst++ = g_table_Base64Encode[SEXTUPLE_E_2 (src)|
                                      SEXTUPLE_E_3 (src)];
        *dst++ = g_table_Base64Encode[SEXTUPLE_E_4 (src)|
                                      SEXTUPLE_E_5 (src)];
        *dst++ = g_table_Base64Encode[SEXTUPLE_E_6 (src)];
    }

    if (src - bin < len)
    {
        *dst++ = g_table_Base64Encode[SEXTUPLE_E_1 (src)];

        if (src - bin == len - 1)
        {
            *dst++ = g_table_Base64Encode[SEXTUPLE_E_2 (src)];
            *dst++ = g_table_Base64Encode[BASE64_PADDING_CHAR_INDEX];
        }
        else
        {
            *dst++ = g_table_Base64Encode[SEXTUPLE_E_2 (src)|
                                          SEXTUPLE_E_3 (src)];
            *dst++ = g_table_Base64Encode[SEXTUPLE_E_4 (src)];
        }

        *dst++ = g_table_Base64Encode[BASE64_PADDING_CHAR_INDEX];
    }
    *dst = '\0';

    return CF_OK;
}

/**
 * Base64-decode
 *
 * \return 성공 시, 디코딩된 바이너리 데이터의 길이; 실패 시, 오류 코드
 *
 * \param base64    base64 문자열
 * \param bin       바이너리 데이터를 저장할 주소
 * \param len       바이너리 데이터의 길이를 저장할 주소
 *
 * \remarks
 * base64는 할당된 메모리이며, 크기는 (strlen (base64)) / 4 * 3
 */
int
CF_Codec_Base64_Decode (const char  * base64,
                        cf_byte     * bin,
                        size_t      * len)
{
    const char  * src = base64;
    cf_byte     * dst = bin;
    int         remain = 0;
    int         binlen = 0;

    ASSERT_ARGS (src == NULL);
    ASSERT_ARGS (dst == NULL);
    ASSERT_ARGS (len == NULL);

    *len = 0;

    while (g_ascii_Base64Decode[(int)*src] < BASE64_PADDING_CHAR_INDEX) src++;

    if (*src == 0xff)
        return CF_ERROR_CODEC_NOT_BASE64;

    remain = (int)(src - base64);
    binlen = ((remain + 2/* max padding length */) / 4) * 3;

#define SEXTUPLE_D_1(src)   (g_ascii_Base64Decode[(int)src[0]] << 2)
#define SEXTUPLE_D_2(src)   (g_ascii_Base64Decode[(int)src[1]] >> 4)
#define SEXTUPLE_D_3(src)   (g_ascii_Base64Decode[(int)src[1]] << 4)
#define SEXTUPLE_D_4(src)   (g_ascii_Base64Decode[(int)src[2]] >> 2)
#define SEXTUPLE_D_5(src)   (g_ascii_Base64Decode[(int)src[2]] << 6)
#define SEXTUPLE_D_6(src)   (g_ascii_Base64Decode[(int)src[3]]     )

    for (src = base64 ; remain > 4 ; remain -= 4, src += 4)
    {
        *dst++ = (cf_byte)(SEXTUPLE_D_1 (src) | SEXTUPLE_D_2 (src));
        *dst++ = (cf_byte)(SEXTUPLE_D_3 (src) | SEXTUPLE_D_4 (src));
        *dst++ = (cf_byte)(SEXTUPLE_D_5 (src) | SEXTUPLE_D_6 (src));
    }

    if (remain > 1)
        *dst++ = (cf_byte)(SEXTUPLE_D_1 (src) | SEXTUPLE_D_2 (src));
    if (remain > 2)
        *dst++ = (cf_byte)(SEXTUPLE_D_3 (src) | SEXTUPLE_D_4 (src));
    if (remain > 3)
        *dst++ = (cf_byte)(SEXTUPLE_D_5 (src) | SEXTUPLE_D_6 (src));

    return binlen - (4 - remain);
}