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| author | June McEnroe <june@causal.agency> | 2020-04-29 19:01:10 -0400 |
|---|---|---|
| committer | June McEnroe <june@causal.agency> | 2020-04-29 19:04:52 -0400 |
| commit | 10d9be50e919b6e7d5814b579eeabfa617dc801e (patch) | |
| tree | 8aed562716b64bb3040082456ee4f197e21dca05 /decode.c | |
| parent | Fix infinite loop if exportAtom can't find a text part (diff) | |
| download | bubger-10d9be50e919b6e7d5814b579eeabfa617dc801e.tar.gz bubger-10d9be50e919b6e7d5814b579eeabfa617dc801e.zip | |
Use a table to decode base64
Diffstat (limited to 'decode.c')
| -rw-r--r-- | decode.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/decode.c b/decode.c index 8578c41..8fd005d 100644 --- a/decode.c +++ b/decode.c @@ -86,20 +86,30 @@ static void convertCharset( iconv_close(conv); } -static const char Base64[64] = { +static const uint8_t Base64[64] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" }; +static uint8_t Table64[256]; + +static uint8_t unbase64(char ch) { + if (!Table64[Base64[1]]) { + for (size_t i = 0; i < sizeof(Base64); ++i) { + Table64[Base64[i]] = i; + } + } + return Table64[(uint8_t)ch]; +} static void decodeBase64(struct Buffer *dst, const char *src) { while (src[0] && src[1] && src[2] && src[3]) { - if (!strchr(Base64, src[0])) { + if (!unbase64(src[0]) && src[0] != Base64[0]) { src++; continue; } uint32_t bits = 0; for (int i = 0; i < 4; ++i) { bits <<= 6; - bits |= strchr(Base64, src[i]) - Base64; + bits |= unbase64(src[i]); } *bufferDest(dst, 1) = bits >> 16; if (src[2] != '=') *bufferDest(dst, 1) = bits >> 8; |