root / libsylph / base64.c @ aebfd4cc
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| 1 | /*
|
|---|---|
| 2 | * LibSylph -- E-Mail client library |
| 3 | * Copyright (C) 1999-2011 Hiroyuki Yamamoto |
| 4 | */ |
| 5 | |
| 6 | #include <glib.h> |
| 7 | #include <ctype.h> |
| 8 | #include <string.h> |
| 9 | |
| 10 | #include "base64.h" |
| 11 | |
| 12 | static const gchar base64char[64] = |
| 13 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
|
| 14 | |
| 15 | static const gchar base64val[128] = { |
| 16 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 17 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 18 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, |
| 19 | 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, |
| 20 | -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, |
| 21 | 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, |
| 22 | -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, |
| 23 | 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 |
| 24 | }; |
| 25 | |
| 26 | #define BASE64VAL(c) (isascii((guchar)c) ? base64val[(gint)(c)] : -1) |
| 27 | |
| 28 | void base64_encode(gchar *out, const guchar *in, gint inlen) |
| 29 | {
|
| 30 | const guchar *inp = in;
|
| 31 | gchar *outp = out; |
| 32 | |
| 33 | while (inlen >= 3) { |
| 34 | *outp++ = base64char[(inp[0] >> 2) & 0x3f]; |
| 35 | *outp++ = base64char[((inp[0] & 0x03) << 4) | |
| 36 | ((inp[1] >> 4) & 0x0f)]; |
| 37 | *outp++ = base64char[((inp[1] & 0x0f) << 2) | |
| 38 | ((inp[2] >> 6) & 0x03)]; |
| 39 | *outp++ = base64char[inp[2] & 0x3f]; |
| 40 | |
| 41 | inp += 3;
|
| 42 | inlen -= 3;
|
| 43 | } |
| 44 | |
| 45 | if (inlen > 0) { |
| 46 | *outp++ = base64char[(inp[0] >> 2) & 0x3f]; |
| 47 | if (inlen == 1) { |
| 48 | *outp++ = base64char[(inp[0] & 0x03) << 4]; |
| 49 | *outp++ = '=';
|
| 50 | } else {
|
| 51 | *outp++ = base64char[((inp[0] & 0x03) << 4) | |
| 52 | ((inp[1] >> 4) & 0x0f)]; |
| 53 | *outp++ = base64char[((inp[1] & 0x0f) << 2)]; |
| 54 | } |
| 55 | *outp++ = '=';
|
| 56 | } |
| 57 | |
| 58 | *outp = '\0';
|
| 59 | } |
| 60 | |
| 61 | gint base64_decode(guchar *out, const gchar *in, gint inlen)
|
| 62 | {
|
| 63 | const gchar *inp = in;
|
| 64 | guchar *outp = out; |
| 65 | gchar buf[4];
|
| 66 | |
| 67 | if (inlen < 0) |
| 68 | inlen = G_MAXINT; |
| 69 | |
| 70 | while (inlen >= 4 && *inp != '\0') { |
| 71 | buf[0] = *inp++;
|
| 72 | inlen--; |
| 73 | if (BASE64VAL(buf[0]) == -1) break; |
| 74 | |
| 75 | buf[1] = *inp++;
|
| 76 | inlen--; |
| 77 | if (BASE64VAL(buf[1]) == -1) break; |
| 78 | |
| 79 | buf[2] = *inp++;
|
| 80 | inlen--; |
| 81 | if (buf[2] != '=' && BASE64VAL(buf[2]) == -1) break; |
| 82 | |
| 83 | buf[3] = *inp++;
|
| 84 | inlen--; |
| 85 | if (buf[3] != '=' && BASE64VAL(buf[3]) == -1) break; |
| 86 | |
| 87 | *outp++ = ((BASE64VAL(buf[0]) << 2) & 0xfc) | |
| 88 | ((BASE64VAL(buf[1]) >> 4) & 0x03); |
| 89 | if (buf[2] != '=') { |
| 90 | *outp++ = ((BASE64VAL(buf[1]) & 0x0f) << 4) | |
| 91 | ((BASE64VAL(buf[2]) >> 2) & 0x0f); |
| 92 | if (buf[3] != '=') { |
| 93 | *outp++ = ((BASE64VAL(buf[2]) & 0x03) << 6) | |
| 94 | (BASE64VAL(buf[3]) & 0x3f); |
| 95 | } |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | return outp - out;
|
| 100 | } |
| 101 | |
| 102 | Base64Decoder *base64_decoder_new(void)
|
| 103 | {
|
| 104 | Base64Decoder *decoder; |
| 105 | |
| 106 | decoder = g_new0(Base64Decoder, 1);
|
| 107 | return decoder;
|
| 108 | } |
| 109 | |
| 110 | void base64_decoder_free(Base64Decoder *decoder)
|
| 111 | {
|
| 112 | g_free(decoder); |
| 113 | } |
| 114 | |
| 115 | gint base64_decoder_decode(Base64Decoder *decoder, |
| 116 | const gchar *in, guchar *out)
|
| 117 | {
|
| 118 | gint len, total_len = 0;
|
| 119 | gint buf_len; |
| 120 | gchar buf[4];
|
| 121 | |
| 122 | g_return_val_if_fail(decoder != NULL, -1); |
| 123 | g_return_val_if_fail(in != NULL, -1); |
| 124 | g_return_val_if_fail(out != NULL, -1); |
| 125 | |
| 126 | buf_len = decoder->buf_len; |
| 127 | memcpy(buf, decoder->buf, sizeof(buf));
|
| 128 | |
| 129 | for (;;) {
|
| 130 | while (buf_len < 4) { |
| 131 | gchar c = *in; |
| 132 | |
| 133 | in++; |
| 134 | if (c == '\0') break; |
| 135 | if (c == '\r' || c == '\n') continue; |
| 136 | if (c != '=' && BASE64VAL(c) == -1) |
| 137 | return -1; |
| 138 | buf[buf_len++] = c; |
| 139 | } |
| 140 | if (buf_len < 4 || buf[0] == '=' || buf[1] == '=') { |
| 141 | decoder->buf_len = buf_len; |
| 142 | memcpy(decoder->buf, buf, sizeof(buf));
|
| 143 | return total_len;
|
| 144 | } |
| 145 | len = base64_decode(out, buf, 4);
|
| 146 | out += len; |
| 147 | total_len += len; |
| 148 | buf_len = 0;
|
| 149 | if (len < 3) { |
| 150 | decoder->buf_len = 0;
|
| 151 | return total_len;
|
| 152 | } |
| 153 | } |
| 154 | } |