Index: libsrtp/crypto/math/math.c |
=================================================================== |
--- libsrtp/crypto/math/math.c (revision 0) |
+++ libsrtp/crypto/math/math.c (revision 0) |
@@ -0,0 +1,802 @@ |
+/* |
+ * math.c |
+ * |
+ * crypto math operations and data types |
+ * |
+ * David A. McGrew |
+ * Cisco Systems, Inc. |
+ */ |
+/* |
+ * |
+ * Copyright (c) 2001-2006 Cisco Systems, Inc. |
+ * All rights reserved. |
+ * |
+ * Redistribution and use in source and binary forms, with or without |
+ * modification, are permitted provided that the following conditions |
+ * are met: |
+ * |
+ * Redistributions of source code must retain the above copyright |
+ * notice, this list of conditions and the following disclaimer. |
+ * |
+ * 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. |
+ * |
+ * Neither the name of the Cisco Systems, Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE |
+ * COPYRIGHT HOLDERS OR 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 "crypto_math.h" |
+ |
+int |
+octet_weight[256] = { |
+ 0, 1, 1, 2, 1, 2, 2, 3, |
+ 1, 2, 2, 3, 2, 3, 3, 4, |
+ 1, 2, 2, 3, 2, 3, 3, 4, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 1, 2, 2, 3, 2, 3, 3, 4, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 1, 2, 2, 3, 2, 3, 3, 4, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 4, 5, 5, 6, 5, 6, 6, 7, |
+ 1, 2, 2, 3, 2, 3, 3, 4, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 4, 5, 5, 6, 5, 6, 6, 7, |
+ 2, 3, 3, 4, 3, 4, 4, 5, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 4, 5, 5, 6, 5, 6, 6, 7, |
+ 3, 4, 4, 5, 4, 5, 5, 6, |
+ 4, 5, 5, 6, 5, 6, 6, 7, |
+ 4, 5, 5, 6, 5, 6, 6, 7, |
+ 5, 6, 6, 7, 6, 7, 7, 8 |
+}; |
+ |
+int |
+low_bit[256] = { |
+ -1, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 5, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 6, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 5, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 7, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 5, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 6, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 5, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0, |
+ 4, 0, 1, 0, 2, 0, 1, 0, |
+ 3, 0, 1, 0, 2, 0, 1, 0 |
+}; |
+ |
+ |
+int |
+high_bit[256] = { |
+ -1, 0, 1, 1, 2, 2, 2, 2, |
+ 3, 3, 3, 3, 3, 3, 3, 3, |
+ 4, 4, 4, 4, 4, 4, 4, 4, |
+ 4, 4, 4, 4, 4, 4, 4, 4, |
+ 5, 5, 5, 5, 5, 5, 5, 5, |
+ 5, 5, 5, 5, 5, 5, 5, 5, |
+ 5, 5, 5, 5, 5, 5, 5, 5, |
+ 5, 5, 5, 5, 5, 5, 5, 5, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 6, 6, 6, 6, 6, 6, 6, 6, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7, |
+ 7, 7, 7, 7, 7, 7, 7, 7 |
+}; |
+ |
+int |
+octet_get_weight(uint8_t octet) { |
+ extern int octet_weight[256]; |
+ |
+ return octet_weight[octet]; |
+} |
+ |
+unsigned char |
+v32_weight(v32_t a) { |
+ unsigned int wt = 0; |
+ |
+ wt += octet_weight[a.v8[0]]; /* note: endian-ness makes no difference */ |
+ wt += octet_weight[a.v8[1]]; |
+ wt += octet_weight[a.v8[2]]; |
+ wt += octet_weight[a.v8[3]]; |
+ |
+ return wt; |
+} |
+ |
+inline unsigned char |
+v32_distance(v32_t x, v32_t y) { |
+ x.value ^= y.value; |
+ return v32_weight(x); |
+} |
+ |
+unsigned int |
+v32_dot_product(v32_t a, v32_t b) { |
+ a.value &= b.value; |
+ return v32_weight(a) & 1; |
+} |
+ |
+/* |
+ * _bit_string returns a NULL-terminated character string suitable for |
+ * printing |
+ */ |
+ |
+#define MAX_STRING_LENGTH 1024 |
+ |
+char bit_string[MAX_STRING_LENGTH]; |
+ |
+char * |
+octet_bit_string(uint8_t x) { |
+ int mask, index; |
+ |
+ for (mask = 1, index = 0; mask < 256; mask <<= 1) |
+ if ((x & mask) == 0) |
+ bit_string[index++] = '0'; |
+ else |
+ bit_string[index++] = '1'; |
+ |
+ bit_string[index++] = 0; /* NULL terminate string */ |
+ |
+ return bit_string; |
+} |
+ |
+char * |
+v16_bit_string(v16_t x) { |
+ int i, mask, index; |
+ |
+ for (i = index = 0; i < 2; i++) { |
+ for (mask = 1; mask < 256; mask <<= 1) |
+ if ((x.v8[i] & mask) == 0) |
+ bit_string[index++] = '0'; |
+ else |
+ bit_string[index++] = '1'; |
+ } |
+ bit_string[index++] = 0; /* NULL terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v32_bit_string(v32_t x) { |
+ int i, mask, index; |
+ |
+ for (i = index = 0; i < 4; i++) { |
+ for (mask = 128; mask > 0; mask >>= 1) |
+ if ((x.v8[i] & mask) == 0) |
+ bit_string[index++] = '0'; |
+ else |
+ bit_string[index++] = '1'; |
+ } |
+ bit_string[index++] = 0; /* NULL terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v64_bit_string(const v64_t *x) { |
+ int i, mask, index; |
+ |
+ for (i = index = 0; i < 8; i++) { |
+ for (mask = 1; mask < 256; mask <<= 1) |
+ if ((x->v8[i] & mask) == 0) |
+ bit_string[index++] = '0'; |
+ else |
+ bit_string[index++] = '1'; |
+ } |
+ bit_string[index++] = 0; /* NULL terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v128_bit_string(v128_t *x) { |
+ int j, index; |
+ uint32_t mask; |
+ |
+ for (j=index=0; j < 4; j++) { |
+ for (mask=0x80000000; mask > 0; mask >>= 1) { |
+ if (x->v32[j] & mask) |
+ bit_string[index] = '1'; |
+ else |
+ bit_string[index] = '0'; |
+ ++index; |
+ } |
+ } |
+ bit_string[128] = 0; /* null terminate string */ |
+ |
+ return bit_string; |
+} |
+ |
+uint8_t |
+nibble_to_hex_char(uint8_t nibble) { |
+ char buf[16] = {'0', '1', '2', '3', '4', '5', '6', '7', |
+ '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; |
+ return buf[nibble & 0xF]; |
+} |
+ |
+char * |
+octet_hex_string(uint8_t x) { |
+ |
+ bit_string[0] = nibble_to_hex_char(x >> 4); |
+ bit_string[1] = nibble_to_hex_char(x & 0xF); |
+ |
+ bit_string[2] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+octet_string_hex_string(const void *str, int length) { |
+ const uint8_t *s = str; |
+ int i; |
+ |
+ /* double length, since one octet takes two hex characters */ |
+ length *= 2; |
+ |
+ /* truncate string if it would be too long */ |
+ if (length > MAX_STRING_LENGTH) |
+ length = MAX_STRING_LENGTH-1; |
+ |
+ for (i=0; i < length; i+=2) { |
+ bit_string[i] = nibble_to_hex_char(*s >> 4); |
+ bit_string[i+1] = nibble_to_hex_char(*s++ & 0xF); |
+ } |
+ bit_string[i] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v16_hex_string(v16_t x) { |
+ int i, j; |
+ |
+ for (i=j=0; i < 2; i++) { |
+ bit_string[j++] = nibble_to_hex_char(x.v8[i] >> 4); |
+ bit_string[j++] = nibble_to_hex_char(x.v8[i] & 0xF); |
+ } |
+ |
+ bit_string[j] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v32_hex_string(v32_t x) { |
+ int i, j; |
+ |
+ for (i=j=0; i < 4; i++) { |
+ bit_string[j++] = nibble_to_hex_char(x.v8[i] >> 4); |
+ bit_string[j++] = nibble_to_hex_char(x.v8[i] & 0xF); |
+ } |
+ |
+ bit_string[j] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v64_hex_string(const v64_t *x) { |
+ int i, j; |
+ |
+ for (i=j=0; i < 8; i++) { |
+ bit_string[j++] = nibble_to_hex_char(x->v8[i] >> 4); |
+ bit_string[j++] = nibble_to_hex_char(x->v8[i] & 0xF); |
+ } |
+ |
+ bit_string[j] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+v128_hex_string(v128_t *x) { |
+ int i, j; |
+ |
+ for (i=j=0; i < 16; i++) { |
+ bit_string[j++] = nibble_to_hex_char(x->v8[i] >> 4); |
+ bit_string[j++] = nibble_to_hex_char(x->v8[i] & 0xF); |
+ } |
+ |
+ bit_string[j] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+char * |
+char_to_hex_string(char *x, int num_char) { |
+ int i, j; |
+ |
+ if (num_char >= 16) |
+ num_char = 16; |
+ for (i=j=0; i < num_char; i++) { |
+ bit_string[j++] = nibble_to_hex_char(x[i] >> 4); |
+ bit_string[j++] = nibble_to_hex_char(x[i] & 0xF); |
+ } |
+ |
+ bit_string[j] = 0; /* null terminate string */ |
+ return bit_string; |
+} |
+ |
+int |
+hex_char_to_nibble(uint8_t c) { |
+ switch(c) { |
+ case ('0'): return 0x0; |
+ case ('1'): return 0x1; |
+ case ('2'): return 0x2; |
+ case ('3'): return 0x3; |
+ case ('4'): return 0x4; |
+ case ('5'): return 0x5; |
+ case ('6'): return 0x6; |
+ case ('7'): return 0x7; |
+ case ('8'): return 0x8; |
+ case ('9'): return 0x9; |
+ case ('a'): return 0xa; |
+ case ('A'): return 0xa; |
+ case ('b'): return 0xb; |
+ case ('B'): return 0xb; |
+ case ('c'): return 0xc; |
+ case ('C'): return 0xc; |
+ case ('d'): return 0xd; |
+ case ('D'): return 0xd; |
+ case ('e'): return 0xe; |
+ case ('E'): return 0xe; |
+ case ('f'): return 0xf; |
+ case ('F'): return 0xf; |
+ default: return -1; /* this flags an error */ |
+ } |
+ /* NOTREACHED */ |
+ return -1; /* this keeps compilers from complaining */ |
+} |
+ |
+int |
+is_hex_string(char *s) { |
+ while(*s != 0) |
+ if (hex_char_to_nibble(*s++) == -1) |
+ return 0; |
+ return 1; |
+} |
+ |
+uint8_t |
+hex_string_to_octet(char *s) { |
+ uint8_t x; |
+ |
+ x = (hex_char_to_nibble(s[0]) << 4) |
+ | hex_char_to_nibble(s[1] & 0xFF); |
+ |
+ return x; |
+} |
+ |
+/* |
+ * hex_string_to_octet_string converts a hexadecimal string |
+ * of length 2 * len to a raw octet string of length len |
+ */ |
+ |
+int |
+hex_string_to_octet_string(char *raw, char *hex, int len) { |
+ uint8_t x; |
+ int tmp; |
+ int hex_len; |
+ |
+ hex_len = 0; |
+ while (hex_len < len) { |
+ tmp = hex_char_to_nibble(hex[0]); |
+ if (tmp == -1) |
+ return hex_len; |
+ x = (tmp << 4); |
+ hex_len++; |
+ tmp = hex_char_to_nibble(hex[1]); |
+ if (tmp == -1) |
+ return hex_len; |
+ x |= (tmp & 0xff); |
+ hex_len++; |
+ *raw++ = x; |
+ hex += 2; |
+ } |
+ return hex_len; |
+} |
+ |
+v16_t |
+hex_string_to_v16(char *s) { |
+ v16_t x; |
+ int i, j; |
+ |
+ for (i=j=0; i < 4; i += 2, j++) { |
+ x.v8[j] = (hex_char_to_nibble(s[i]) << 4) |
+ | hex_char_to_nibble(s[i+1] & 0xFF); |
+ } |
+ return x; |
+} |
+ |
+v32_t |
+hex_string_to_v32(char *s) { |
+ v32_t x; |
+ int i, j; |
+ |
+ for (i=j=0; i < 8; i += 2, j++) { |
+ x.v8[j] = (hex_char_to_nibble(s[i]) << 4) |
+ | hex_char_to_nibble(s[i+1] & 0xFF); |
+ } |
+ return x; |
+} |
+ |
+v64_t |
+hex_string_to_v64(char *s) { |
+ v64_t x; |
+ int i, j; |
+ |
+ for (i=j=0; i < 16; i += 2, j++) { |
+ x.v8[j] = (hex_char_to_nibble(s[i]) << 4) |
+ | hex_char_to_nibble(s[i+1] & 0xFF); |
+ } |
+ return x; |
+} |
+ |
+v128_t |
+hex_string_to_v128(char *s) { |
+ v128_t x; |
+ int i, j; |
+ |
+ for (i=j=0; i < 32; i += 2, j++) { |
+ x.v8[j] = (hex_char_to_nibble(s[i]) << 4) |
+ | hex_char_to_nibble(s[i+1] & 0xFF); |
+ } |
+ return x; |
+} |
+ |
+ |
+ |
+/* |
+ * the matrix A[] is stored in column format, i.e., A[i] is the ith |
+ * column of the matrix |
+ */ |
+ |
+uint8_t |
+A_times_x_plus_b(uint8_t A[8], uint8_t x, uint8_t b) { |
+ int index = 0; |
+ unsigned mask; |
+ |
+ for (mask=1; mask < 256; mask *= 2) { |
+ if (x & mask) |
+ b^= A[index]; |
+ ++index; |
+ } |
+ |
+ return b; |
+} |
+ |
+inline void |
+v16_copy_octet_string(v16_t *x, const uint8_t s[2]) { |
+ x->v8[0] = s[0]; |
+ x->v8[1] = s[1]; |
+} |
+ |
+inline void |
+v32_copy_octet_string(v32_t *x, const uint8_t s[4]) { |
+ x->v8[0] = s[0]; |
+ x->v8[1] = s[1]; |
+ x->v8[2] = s[2]; |
+ x->v8[3] = s[3]; |
+} |
+ |
+inline void |
+v64_copy_octet_string(v64_t *x, const uint8_t s[8]) { |
+ x->v8[0] = s[0]; |
+ x->v8[1] = s[1]; |
+ x->v8[2] = s[2]; |
+ x->v8[3] = s[3]; |
+ x->v8[4] = s[4]; |
+ x->v8[5] = s[5]; |
+ x->v8[6] = s[6]; |
+ x->v8[7] = s[7]; |
+} |
+ |
+void |
+v128_copy_octet_string(v128_t *x, const uint8_t s[16]) { |
+ x->v8[0] = s[0]; |
+ x->v8[1] = s[1]; |
+ x->v8[2] = s[2]; |
+ x->v8[3] = s[3]; |
+ x->v8[4] = s[4]; |
+ x->v8[5] = s[5]; |
+ x->v8[6] = s[6]; |
+ x->v8[7] = s[7]; |
+ x->v8[8] = s[8]; |
+ x->v8[9] = s[9]; |
+ x->v8[10] = s[10]; |
+ x->v8[11] = s[11]; |
+ x->v8[12] = s[12]; |
+ x->v8[13] = s[13]; |
+ x->v8[14] = s[14]; |
+ x->v8[15] = s[15]; |
+ |
+} |
+ |
+#ifndef DATATYPES_USE_MACROS /* little functions are not macros */ |
+ |
+void |
+v128_set_to_zero(v128_t *x) { |
+ _v128_set_to_zero(x); |
+} |
+ |
+void |
+v128_copy(v128_t *x, const v128_t *y) { |
+ _v128_copy(x, y); |
+} |
+ |
+void |
+v128_xor(v128_t *z, v128_t *x, v128_t *y) { |
+ _v128_xor(z, x, y); |
+} |
+ |
+void |
+v128_and(v128_t *z, v128_t *x, v128_t *y) { |
+ _v128_and(z, x, y); |
+} |
+ |
+void |
+v128_or(v128_t *z, v128_t *x, v128_t *y) { |
+ _v128_or(z, x, y); |
+} |
+ |
+void |
+v128_complement(v128_t *x) { |
+ _v128_complement(x); |
+} |
+ |
+int |
+v128_is_eq(const v128_t *x, const v128_t *y) { |
+ return _v128_is_eq(x, y); |
+} |
+ |
+int |
+v128_get_bit(const v128_t *x, int i) { |
+ return _v128_get_bit(x, i); |
+} |
+ |
+void |
+v128_set_bit(v128_t *x, int i) { |
+ _v128_set_bit(x, i); |
+} |
+ |
+void |
+v128_clear_bit(v128_t *x, int i){ |
+ _v128_clear_bit(x, i); |
+} |
+ |
+void |
+v128_set_bit_to(v128_t *x, int i, int y){ |
+ _v128_set_bit_to(x, i, y); |
+} |
+ |
+ |
+#endif /* DATATYPES_USE_MACROS */ |
+ |
+ |
+inline void |
+v128_left_shift2(v128_t *x, int num_bits) { |
+ int i; |
+ int word_shift = num_bits >> 5; |
+ int bit_shift = num_bits & 31; |
+ |
+ for (i=0; i < (4-word_shift); i++) { |
+ x->v32[i] = x->v32[i+word_shift] << bit_shift; |
+ } |
+ |
+ for ( ; i < word_shift; i++) { |
+ x->v32[i] = 0; |
+ } |
+ |
+} |
+ |
+void |
+v128_right_shift(v128_t *x, int index) { |
+ const int base_index = index >> 5; |
+ const int bit_index = index & 31; |
+ int i, from; |
+ uint32_t b; |
+ |
+ if (index > 127) { |
+ v128_set_to_zero(x); |
+ return; |
+ } |
+ |
+ if (bit_index == 0) { |
+ |
+ /* copy each word from left size to right side */ |
+ x->v32[4-1] = x->v32[4-1-base_index]; |
+ for (i=4-1; i > base_index; i--) |
+ x->v32[i-1] = x->v32[i-1-base_index]; |
+ |
+ } else { |
+ |
+ /* set each word to the "or" of the two bit-shifted words */ |
+ for (i = 4; i > base_index; i--) { |
+ from = i-1 - base_index; |
+ b = x->v32[from] << bit_index; |
+ if (from > 0) |
+ b |= x->v32[from-1] >> (32-bit_index); |
+ x->v32[i-1] = b; |
+ } |
+ |
+ } |
+ |
+ /* now wrap up the final portion */ |
+ for (i=0; i < base_index; i++) |
+ x->v32[i] = 0; |
+ |
+} |
+ |
+void |
+v128_left_shift(v128_t *x, int index) { |
+ int i; |
+ const int base_index = index >> 5; |
+ const int bit_index = index & 31; |
+ |
+ if (index > 127) { |
+ v128_set_to_zero(x); |
+ return; |
+ } |
+ |
+ if (bit_index == 0) { |
+ for (i=0; i < 4 - base_index; i++) |
+ x->v32[i] = x->v32[i+base_index]; |
+ } else { |
+ for (i=0; i < 4 - base_index - 1; i++) |
+ x->v32[i] = (x->v32[i+base_index] << bit_index) ^ |
+ (x->v32[i+base_index+1] >> (32 - bit_index)); |
+ x->v32[4 - base_index-1] = x->v32[4-1] << bit_index; |
+ } |
+ |
+ /* now wrap up the final portion */ |
+ for (i = 4 - base_index; i < 4; i++) |
+ x->v32[i] = 0; |
+ |
+} |
+ |
+ |
+#if 0 |
+void |
+v128_add(v128_t *z, v128_t *x, v128_t *y) { |
+ /* integer addition modulo 2^128 */ |
+ |
+#ifdef WORDS_BIGENDIAN |
+ uint64_t tmp; |
+ |
+ tmp = x->v32[3] + y->v32[3]; |
+ z->v32[3] = (uint32_t) tmp; |
+ |
+ tmp = x->v32[2] + y->v32[2] + (tmp >> 32); |
+ z->v32[2] = (uint32_t) tmp; |
+ |
+ tmp = x->v32[1] + y->v32[1] + (tmp >> 32); |
+ z->v32[1] = (uint32_t) tmp; |
+ |
+ tmp = x->v32[0] + y->v32[0] + (tmp >> 32); |
+ z->v32[0] = (uint32_t) tmp; |
+ |
+#else /* assume little endian architecture */ |
+ uint64_t tmp; |
+ |
+ tmp = htonl(x->v32[3]) + htonl(y->v32[3]); |
+ z->v32[3] = ntohl((uint32_t) tmp); |
+ |
+ tmp = htonl(x->v32[2]) + htonl(y->v32[2]) + htonl(tmp >> 32); |
+ z->v32[2] = ntohl((uint32_t) tmp); |
+ |
+ tmp = htonl(x->v32[1]) + htonl(y->v32[1]) + htonl(tmp >> 32); |
+ z->v32[1] = ntohl((uint32_t) tmp); |
+ |
+ tmp = htonl(x->v32[0]) + htonl(y->v32[0]) + htonl(tmp >> 32); |
+ z->v32[0] = ntohl((uint32_t) tmp); |
+ |
+#endif /* WORDS_BIGENDIAN */ |
+ |
+} |
+#endif |
+ |
+int |
+octet_string_is_eq(uint8_t *a, uint8_t *b, int len) { |
+ uint8_t *end = b + len; |
+ while (b < end) |
+ if (*a++ != *b++) |
+ return 1; |
+ return 0; |
+} |
+ |
+void |
+octet_string_set_to_zero(uint8_t *s, int len) { |
+ uint8_t *end = s + len; |
+ |
+ do { |
+ *s = 0; |
+ } while (++s < end); |
+ |
+} |
+ |
+ |
+/* functions below not yet tested! */ |
+ |
+int |
+v32_low_bit(v32_t *w) { |
+ int value; |
+ |
+ value = low_bit[w->v8[0]]; |
+ if (value != -1) |
+ return value; |
+ value = low_bit[w->v8[1]]; |
+ if (value != -1) |
+ return value + 8; |
+ value = low_bit[w->v8[2]]; |
+ if (value != -1) |
+ return value + 16; |
+ value = low_bit[w->v8[3]]; |
+ if (value == -1) |
+ return -1; |
+ return value + 24; |
+} |
+ |
+/* high_bit not done yet */ |
+ |
+ |
+ |
+ |
+ |
Property changes on: libsrtp/crypto/math/math.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |