diff options
Diffstat (limited to 'third_party/bearssl/src/i15_encode.c')
-rw-r--r-- | third_party/bearssl/src/i15_encode.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/third_party/bearssl/src/i15_encode.c b/third_party/bearssl/src/i15_encode.c new file mode 100644 index 0000000..50668f4 --- /dev/null +++ b/third_party/bearssl/src/i15_encode.c @@ -0,0 +1,56 @@ +/* + * Copyright (c) 2017 Thomas Pornin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "inner.h" + +/* see inner.h */ +void +br_i15_encode(void *dst, size_t len, const uint16_t *x) +{ + unsigned char *buf; + size_t u, xlen; + uint32_t acc; + int acc_len; + + xlen = (x[0] + 15) >> 4; + if (xlen == 0) { + memset(dst, 0, len); + return; + } + u = 1; + acc = 0; + acc_len = 0; + buf = dst; + while (len -- > 0) { + if (acc_len < 8) { + if (u <= xlen) { + acc += (uint32_t)x[u ++] << acc_len; + } + acc_len += 15; + } + buf[len] = (unsigned char)acc; + acc >>= 8; + acc_len -= 8; + } +} |