diff options
author | redpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f> | 2010-08-11 02:37:10 +0000 |
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committer | redpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f> | 2010-08-11 02:37:10 +0000 |
commit | 80686d4e567bae579ea39e009826a2de92cd4ace (patch) | |
tree | c3c35fcba57dde423a248f38aa121ad197c79734 /utils/b64tools.cc | |
parent | 3c85c407c333899f6b4bc26632d312b8e568b638 (diff) |
major refactor, break bad circular deps
git-svn-id: https://ws10smt.googlecode.com/svn/trunk@509 ec762483-ff6d-05da-a07a-a48fb63a330f
Diffstat (limited to 'utils/b64tools.cc')
-rw-r--r-- | utils/b64tools.cc | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/utils/b64tools.cc b/utils/b64tools.cc new file mode 100644 index 00000000..5512f975 --- /dev/null +++ b/utils/b64tools.cc @@ -0,0 +1,59 @@ +#include <iostream> +#include <cassert> + +using namespace std; + +namespace B64 { + +static const char cb64[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +static const char cd64[]="|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq"; + +static void encodeblock(const unsigned char* in, ostream* os, int len) { + char out[4]; + out[0] = cb64[ in[0] >> 2 ]; + out[1] = cb64[ ((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4) ]; + out[2] = (len > 1 ? cb64[ ((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6) ] : '='); + out[3] = (len > 2 ? cb64[ in[2] & 0x3f ] : '='); + os->write(out, 4); +} + +void b64encode(const char* data, const size_t size, ostream* out) { + size_t cur = 0; + while(cur < size) { + int len = min(static_cast<size_t>(3), size - cur); + encodeblock(reinterpret_cast<const unsigned char*>(&data[cur]), out, len); + cur += len; + } +} + +static void decodeblock(const unsigned char* in, unsigned char* out) { + out[0] = (unsigned char ) (in[0] << 2 | in[1] >> 4); + out[1] = (unsigned char ) (in[1] << 4 | in[2] >> 2); + out[2] = (unsigned char ) (((in[2] << 6) & 0xc0) | in[3]); +} + +bool b64decode(const unsigned char* data, const size_t insize, char* out, const size_t outsize) { + size_t cur = 0; + size_t ocur = 0; + unsigned char in[4]; + while(cur < insize) { + assert(ocur < outsize); + for (int i = 0; i < 4; ++i) { + unsigned char v = data[cur]; + v = (unsigned char) ((v < 43 || v > 122) ? '\0' : cd64[ v - 43 ]); + if (!v) { + cerr << "B64 decode error at offset " << cur << " offending character: " << (int)data[cur] << endl; + return false; + } + v = (unsigned char) ((v == '$') ? '\0' : v - 61); + if (v) in[i] = v - 1; else in[i] = 0; + ++cur; + } + decodeblock(in, reinterpret_cast<unsigned char*>(&out[ocur])); + ocur += 3; + } + return true; +} + +} + |