diff options
Diffstat (limited to 'test/monniaux/BearSSL/src/codec/pemenc.c')
| -rw-r--r-- | test/monniaux/BearSSL/src/codec/pemenc.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/test/monniaux/BearSSL/src/codec/pemenc.c b/test/monniaux/BearSSL/src/codec/pemenc.c new file mode 100644 index 00000000..236601e6 --- /dev/null +++ b/test/monniaux/BearSSL/src/codec/pemenc.c @@ -0,0 +1,173 @@ +/* + * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org> + * + * 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" + +/* + * Get the appropriate Base64 character for a numeric value in the + * 0..63 range. This is constant-time. + */ +static char +b64char(uint32_t x) +{ + /* + * Values 0 to 25 map to 0x41..0x5A ('A' to 'Z') + * Values 26 to 51 map to 0x61..0x7A ('a' to 'z') + * Values 52 to 61 map to 0x30..0x39 ('0' to '9') + * Value 62 maps to 0x2B ('+') + * Value 63 maps to 0x2F ('/') + */ + uint32_t a, b, c; + + a = x - 26; + b = x - 52; + c = x - 62; + + /* + * Looking at bits 8..15 of values a, b and c: + * + * x a b c + * --------------------- + * 0..25 FF FF FF + * 26..51 00 FF FF + * 52..61 00 00 FF + * 62..63 00 00 00 + */ + return (char)(((x + 0x41) & ((a & b & c) >> 8)) + | ((x + (0x61 - 26)) & ((~a & b & c) >> 8)) + | ((x - (52 - 0x30)) & ((~a & ~b & c) >> 8)) + | ((0x2B + ((x & 1) << 2)) & (~(a | b | c) >> 8))); +} + +/* see bearssl_pem.h */ +size_t +br_pem_encode(void *dest, const void *data, size_t len, + const char *banner, unsigned flags) +{ + size_t dlen, banner_len, lines; + char *d; + unsigned char *buf; + size_t u; + int off, lim; + + banner_len = strlen(banner); + /* FIXME: try to avoid divisions here, as they may pull + an extra libc function. */ + if ((flags & BR_PEM_LINE64) != 0) { + lines = (len + 47) / 48; + } else { + lines = (len + 56) / 57; + } + dlen = (banner_len << 1) + 30 + (((len + 2) / 3) << 2) + + lines + 2; + if ((flags & BR_PEM_CRLF) != 0) { + dlen += lines + 2; + } + + if (dest == NULL) { + return dlen; + } + + d = dest; + + /* + * We always move the source data to the end of output buffer; + * the encoding process never "catches up" except at the very + * end. This also handles all conditions of partial or total + * overlap. + */ + buf = (unsigned char *)d + dlen - len; + memmove(buf, data, len); + + memcpy(d, "-----BEGIN ", 11); + d += 11; + memcpy(d, banner, banner_len); + d += banner_len; + memcpy(d, "-----", 5); + d += 5; + if ((flags & BR_PEM_CRLF) != 0) { + *d ++ = 0x0D; + } + *d ++ = 0x0A; + + off = 0; + lim = (flags & BR_PEM_LINE64) != 0 ? 16 : 19; + for (u = 0; (u + 2) < len; u += 3) { + uint32_t w; + + w = ((uint32_t)buf[u] << 16) + | ((uint32_t)buf[u + 1] << 8) + | (uint32_t)buf[u + 2]; + *d ++ = b64char(w >> 18); + *d ++ = b64char((w >> 12) & 0x3F); + *d ++ = b64char((w >> 6) & 0x3F); + *d ++ = b64char(w & 0x3F); + if (++ off == lim) { + off = 0; + if ((flags & BR_PEM_CRLF) != 0) { + *d ++ = 0x0D; + } + *d ++ = 0x0A; + } + } + if (u < len) { + uint32_t w; + + w = (uint32_t)buf[u] << 16; + if (u + 1 < len) { + w |= (uint32_t)buf[u + 1] << 8; + } + *d ++ = b64char(w >> 18); + *d ++ = b64char((w >> 12) & 0x3F); + if (u + 1 < len) { + *d ++ = b64char((w >> 6) & 0x3F); + } else { + *d ++ = 0x3D; + } + *d ++ = 0x3D; + off ++; + } + if (off != 0) { + if ((flags & BR_PEM_CRLF) != 0) { + *d ++ = 0x0D; + } + *d ++ = 0x0A; + } + + memcpy(d, "-----END ", 9); + d += 9; + memcpy(d, banner, banner_len); + d += banner_len; + memcpy(d, "-----", 5); + d += 5; + if ((flags & BR_PEM_CRLF) != 0) { + *d ++ = 0x0D; + } + *d ++ = 0x0A; + + /* Final zero, not counted in returned length. */ + *d ++ = 0x00; + + return dlen; +} |