Update libsrtp to version 2.0

crypto/math/datatypes.c

 /*
  * datatypes.c
  *
  * data types for finite fields and functions for input, output, and
  * manipulation
  *
  * David A. McGrew
  * Cisco Systems, Inc.
  */
 /*
@@ skipping 84 matching lines @@
 /*
  * bit_string is a buffer that is used to hold output strings, e.g.
  * for printing.
  */
 
 /* the value MAX_PRINT_STRING_LEN is defined in datatypes.h */
 
 char bit_string[MAX_PRINT_STRING_LEN];
 
 uint8_t
-nibble_to_hex_char(uint8_t nibble) {
+srtp_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_string_hex_string(const void *s, int length) {
+char * srtp_octet_string_hex_string(const void *s, int length) {
   const uint8_t *str = (const uint8_t *)s;
   int i;
   
   /* double length, since one octet takes two hex characters */
   length *= 2;
 
   /* truncate string if it would be too long */
   if (length > MAX_PRINT_STRING_LEN)
-    length = MAX_PRINT_STRING_LEN-1;
+    length = MAX_PRINT_STRING_LEN-2;
   
   for (i=0; i < length; i+=2) {
-    bit_string[i]   = nibble_to_hex_char(*str >> 4);
-    bit_string[i+1] = nibble_to_hex_char(*str++ & 0xF);
+    bit_string[i]   = srtp_nibble_to_hex_char(*str >> 4);
+    bit_string[i+1] = srtp_nibble_to_hex_char(*str++ & 0xF);
   }
   bit_string[i] = 0; /* null terminate string */
   return bit_string;
 }
 
-static inline 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;
-}
-
-/*
- * 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;
-}
-
 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++]  = srtp_nibble_to_hex_char(x->v8[i] >> 4);
+    bit_string[j++]  = srtp_nibble_to_hex_char(x->v8[i] & 0xF);
   }
   
   bit_string[j] = 0; /* null terminate string */
   return bit_string;
 }
 
 char *
 v128_bit_string(v128_t *x) {
   int j, i;
   uint32_t mask;
@@ skipping 206 matching lines @@
 
   /* Round length up to a multiple of bits_per_word */
   length = (length + bits_per_word - 1) & ~(unsigned long)((bits_per_word - 1));
 
   l = length / bits_per_word * bytes_per_word;
 
   /* allocate memory, then set parameters */
   if (l == 0)
     v->word = NULL;
   else {
-    v->word = (uint32_t*)crypto_alloc(l);
+    v->word = (uint32_t*)srtp_crypto_alloc(l);
     if (v->word == NULL) {
       v->word = NULL;
       v->length = 0;
       return -1;
     }
   }
   v->length = length;
 
   /* initialize bitvector to zero */
   bitvector_set_to_zero(v);
 
   return 0;
 }
 
 
 void
 bitvector_dealloc(bitvector_t *v) {
   if (v->word != NULL)
-    crypto_free(v->word);
+    srtp_crypto_free(v->word);
   v->word = NULL;
   v->length = 0;
 }
 
 void
 bitvector_set_to_zero(bitvector_t *x)
 {
   /* C99 guarantees that memset(0) will set the value 0 for uint32_t */
   memset(x->word, 0, x->length >> 3);
 }
@@ skipping 40 matching lines @@
         (x->word[i+base_index+1] << (32 - bit_index));
     x->word[word_length - base_index-1] = x->word[word_length-1] >> bit_index;
   }
 
   /* now wrap up the final portion */
   for (i = word_length - base_index; i < word_length; i++) 
     x->word[i] = 0;
 
 }
 
-
 int
 octet_string_is_eq(uint8_t *a, uint8_t *b, int len) {
   uint8_t *end = b + len;
+  uint8_t accumulator = 0;
+
+  /*
+   * We use this somewhat obscure implementation to try to ensure the running
+   * time only depends on len, even accounting for compiler optimizations.
+   * The accumulator ends up zero iff the strings are equal.
+   */
   while (b < end)
-    if (*a++ != *b++)
-      return 1;
-  return 0;
+    accumulator |= (*a++ ^ *b++);
+
+  /* Return 1 if *not* equal. */
+  return accumulator != 0;
 }
 
 void
 octet_string_set_to_zero(uint8_t *s, int len) {
   uint8_t *end = s + len;
 
   do {
     *s = 0;
   } while (++s < end);
   
@@ skipping 30 matching lines @@
   while (i < len && j == 0) {
     j = base64_block_to_octet_triple(out + k, in + i);
     k += 3;
     i += 4;
   }
   *pad = j;
   return i;
 }
 
 #endif