From 706e6990bfe2a447dda68094425d35e3c9c43519 Mon Sep 17 00:00:00 2001 From: Eugene Ostroukhov Date: Fri, 20 May 2016 15:42:29 -0700 Subject: string_bytes: Make base64 encode/decode reusable Node already has support for base64 encoding and decoding that is not visible outside the string_bytes.cc file. Our work on providing a support for the Chrome inspector protocol (https://github.com/nodejs/node/pull/6792) requires base64 encoding support. Rather then introducing a second copy of the base64 encoder, we suggest moving this code into a separate header. PR-URL: https://github.com/nodejs/node/pull/6910 Reviewed-By: bnoordhuis - Ben Noordhuis Reviewed-By: indutny - Fedor Indutny Reviewed-By: ofrobots - Ali Ijaz Sheikh --- src/string_bytes.cc | 180 +--------------------------------------------------- 1 file changed, 2 insertions(+), 178 deletions(-) (limited to 'src/string_bytes.cc') diff --git a/src/string_bytes.cc b/src/string_bytes.cc index 5bd3a21176..8a327deac2 100644 --- a/src/string_bytes.cc +++ b/src/string_bytes.cc @@ -1,5 +1,6 @@ #include "string_bytes.h" +#include "base64.h" #include "node.h" #include "node_buffer.h" #include "v8.h" @@ -121,45 +122,8 @@ MaybeLocal ExternTwoByteString::NewExternal( } -//// Base 64 //// - -#define base64_encoded_size(size) ((size + 2 - ((size + 2) % 3)) / 3 * 4) - - -// Doesn't check for padding at the end. Can be 1-2 bytes over. -static inline size_t base64_decoded_size_fast(size_t size) { - size_t remainder = size % 4; - - size = (size / 4) * 3; - if (remainder) { - if (size == 0 && remainder == 1) { - // special case: 1-byte input cannot be decoded - size = 0; - } else { - // non-padded input, add 1 or 2 extra bytes - size += 1 + (remainder == 3); - } - } - - return size; -} - -template -size_t base64_decoded_size(const TypeName* src, size_t size) { - if (size == 0) - return 0; - - if (src[size - 1] == '=') - size--; - if (size > 0 && src[size - 1] == '=') - size--; - - return base64_decoded_size_fast(size); -} - - // supports regular and URL-safe base64 -static const int8_t unbase64_table[] = +const int8_t unbase64_table[256] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -1, -1, -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, @@ -177,82 +141,6 @@ static const int8_t unbase64_table[] = -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 }; -#define unbase64(x) \ - static_cast(unbase64_table[static_cast(x)]) - - -template -size_t base64_decode_slow(char* dst, size_t dstlen, - const TypeName* src, size_t srclen) { - uint8_t hi; - uint8_t lo; - size_t i = 0; - size_t k = 0; - for (;;) { -#define V(expr) \ - while (i < srclen) { \ - const uint8_t c = src[i]; \ - lo = unbase64(c); \ - i += 1; \ - if (lo < 64) \ - break; /* Legal character. */ \ - if (c == '=') \ - return k; \ - } \ - expr; \ - if (i >= srclen) \ - return k; \ - if (k >= dstlen) \ - return k; \ - hi = lo; - V(/* Nothing. */); - V(dst[k++] = ((hi & 0x3F) << 2) | ((lo & 0x30) >> 4)); - V(dst[k++] = ((hi & 0x0F) << 4) | ((lo & 0x3C) >> 2)); - V(dst[k++] = ((hi & 0x03) << 6) | ((lo & 0x3F) >> 0)); -#undef V - } - UNREACHABLE(); -} - - -template -size_t base64_decode_fast(char* const dst, const size_t dstlen, - const TypeName* const src, const size_t srclen, - const size_t decoded_size) { - const size_t available = dstlen < decoded_size ? dstlen : decoded_size; - const size_t max_i = srclen / 4 * 4; - const size_t max_k = available / 3 * 3; - size_t i = 0; - size_t k = 0; - while (i < max_i && k < max_k) { - const uint32_t v = - unbase64(src[i + 0]) << 24 | - unbase64(src[i + 1]) << 16 | - unbase64(src[i + 2]) << 8 | - unbase64(src[i + 3]); - // If MSB is set, input contains whitespace or is not valid base64. - if (v & 0x80808080) { - break; - } - dst[k + 0] = ((v >> 22) & 0xFC) | ((v >> 20) & 0x03); - dst[k + 1] = ((v >> 12) & 0xF0) | ((v >> 10) & 0x0F); - dst[k + 2] = ((v >> 2) & 0xC0) | ((v >> 0) & 0x3F); - i += 4; - k += 3; - } - if (i < srclen && k < dstlen) { - return k + base64_decode_slow(dst + k, dstlen - k, src + i, srclen - i); - } - return k; -} - - -template -size_t base64_decode(char* const dst, const size_t dstlen, - const TypeName* const src, const size_t srclen) { - const size_t decoded_size = base64_decoded_size(src, srclen); - return base64_decode_fast(dst, dstlen, src, srclen, decoded_size); -} template @@ -685,70 +573,6 @@ static void force_ascii(const char* src, char* dst, size_t len) { } -static size_t base64_encode(const char* src, - size_t slen, - char* dst, - size_t dlen) { - // We know how much we'll write, just make sure that there's space. - CHECK(dlen >= base64_encoded_size(slen) && - "not enough space provided for base64 encode"); - - dlen = base64_encoded_size(slen); - - unsigned a; - unsigned b; - unsigned c; - unsigned i; - unsigned k; - unsigned n; - - static const char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" - "abcdefghijklmnopqrstuvwxyz" - "0123456789+/"; - - i = 0; - k = 0; - n = slen / 3 * 3; - - while (i < n) { - a = src[i + 0] & 0xff; - b = src[i + 1] & 0xff; - c = src[i + 2] & 0xff; - - dst[k + 0] = table[a >> 2]; - dst[k + 1] = table[((a & 3) << 4) | (b >> 4)]; - dst[k + 2] = table[((b & 0x0f) << 2) | (c >> 6)]; - dst[k + 3] = table[c & 0x3f]; - - i += 3; - k += 4; - } - - if (n != slen) { - switch (slen - n) { - case 1: - a = src[i + 0] & 0xff; - dst[k + 0] = table[a >> 2]; - dst[k + 1] = table[(a & 3) << 4]; - dst[k + 2] = '='; - dst[k + 3] = '='; - break; - - case 2: - a = src[i + 0] & 0xff; - b = src[i + 1] & 0xff; - dst[k + 0] = table[a >> 2]; - dst[k + 1] = table[((a & 3) << 4) | (b >> 4)]; - dst[k + 2] = table[(b & 0x0f) << 2]; - dst[k + 3] = '='; - break; - } - } - - return dlen; -} - - static size_t hex_encode(const char* src, size_t slen, char* dst, size_t dlen) { // We know how much we'll write, just make sure that there's space. CHECK(dlen >= slen * 2 && -- cgit v1.2.3