diff options
Diffstat (limited to 'third_party/heimdal/lib/krb5/n-fold.c')
| -rw-r--r-- | third_party/heimdal/lib/krb5/n-fold.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/n-fold.c b/third_party/heimdal/lib/krb5/n-fold.c new file mode 100644 index 0000000..ba3150d --- /dev/null +++ b/third_party/heimdal/lib/krb5/n-fold.c @@ -0,0 +1,150 @@ +/* + * Copyright (c) 1999 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of KTH nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY KTH AND ITS CONTRIBUTORS ``AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KTH OR ITS CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ + +#include "krb5_locl.h" + +static void +rr13(uint8_t *dst1, uint8_t *dst2, uint8_t *src, size_t len) +{ + int bytes = (len + 7) / 8; + int i; + const int bits = 13 % len; + + for (i = 0; i < bytes; i++) { + int bb; + int b1, s1, b2, s2; + /* calculate first bit position of this byte */ + bb = 8 * i - bits; + while(bb < 0) + bb += len; + /* byte offset and shift count */ + b1 = bb / 8; + s1 = bb % 8; + + if (bb + 8 > bytes * 8) + /* watch for wraparound */ + s2 = (len + 8 - s1) % 8; + else + s2 = 8 - s1; + b2 = (b1 + 1) % bytes; + dst1[i] = (src[b1] << s1) | (src[b2] >> s2); + dst2[i] = dst1[i]; + } + + return; +} + +/* + * Add `b' to `a', both being one's complement numbers. + * This function assumes that inputs *a, *b are aligned + * to 4 bytes. + */ +static void +add1(uint8_t *a, uint8_t *b, size_t len) +{ + int i; + int carry = 0; + uint32_t x; + uint32_t left, right; + + for (i = len - 1; (i+1) % 4; i--) { + x = a[i] + b[i] + carry; + carry = x > 0xff; + a[i] = x & 0xff; + } + + for (i = len / 4 - 1; i >= 0; i--) { + left = ntohl(((uint32_t *)a)[i]); + right = ntohl(((uint32_t *)b)[i]); + x = left + right + carry; + carry = x < left || x < right; + ((uint32_t *)a)[i] = x; + } + + for (i = len - 1; (i+1) % 4; i--) { + x = a[i] + carry; + carry = x > 0xff; + a[i] = x & 0xff; + } + + for (i = len / 4 - 1; carry && i >= 0; i--) { + left = ((uint32_t *)a)[i]; + x = left + carry; + carry = x < left; + ((uint32_t *)a)[i] = x; + } + + for (i = len / 4 - 1; i >=0; i--) + ((uint32_t *)a)[i] = htonl(((uint32_t *)a)[i]); +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +_krb5_n_fold(const void *str, size_t len, void *key, size_t size) +{ + /* if len < size we need at most N * len bytes, ie < 2 * size; + if len > size we need at most 2 * len */ + size_t maxlen = 2 * max(size, len); + size_t l = 0; + uint8_t *tmp; + uint8_t *tmpbuf; + uint8_t *buf1; + uint8_t *buf2; + + tmp = malloc(maxlen + 2 * len); + if (tmp == NULL) + return ENOMEM; + + buf1 = tmp + maxlen; + buf2 = tmp + maxlen + len; + + memset(key, 0, size); + memcpy(buf1, str, len); + memcpy(tmp, buf1, len); + do { + l += len; + while(l >= size) { + add1(key, tmp, size); + l -= size; + if(l == 0) + break; + memmove(tmp, tmp + size, l); + } + rr13(tmp + l, buf2, buf1, len * 8); + tmpbuf = buf1; + buf1 = buf2; + buf2 = tmpbuf; + } while(l != 0); + + memset(tmp, 0, maxlen + 2 * len); + free(tmp); + return 0; +} |