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-rw-r--r--src/common/des.c145
1 files changed, 74 insertions, 71 deletions
diff --git a/src/common/des.c b/src/common/des.c
index 706aafbdd..c680610e9 100644
--- a/src/common/des.c
+++ b/src/common/des.c
@@ -24,26 +24,23 @@
#include "common/cbasetypes.h"
+/** @file
+ * Implementation of the des interface.
+ */
+
struct des_interface des_s;
struct des_interface *des;
-/// DES (Data Encryption Standard) algorithm, modified version.
-/// @see http://www.eathena.ws/board/index.php?autocom=bugtracker&showbug=5099.
-/// @see http://en.wikipedia.org/wiki/Data_Encryption_Standard
-/// @see http://en.wikipedia.org/wiki/DES_supplementary_material
-
-
/// Bitmask for accessing individual bits of a byte.
static const uint8_t mask[8] = {
0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01
};
-
-/// Initial permutation (IP).
-static void IP(struct BIT64 *src)
+/**
+ * Initial permutation (IP).
+ */
+static void des_IP(struct des_bit64 *src)
{
- struct BIT64 tmp = {{0}};
-
static const uint8_t ip_table[64] = {
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
@@ -54,24 +51,23 @@ static void IP(struct BIT64 *src)
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7,
};
+ struct des_bit64 tmp = {{0}};
+ int i;
- size_t i;
- for( i = 0; i < ARRAYLENGTH(ip_table); ++i )
- {
+ for(i = 0; i < ARRAYLENGTH(ip_table); ++i) {
uint8_t j = ip_table[i] - 1;
- if( src->b[(j >> 3) & 7] & mask[j & 7] )
- tmp .b[(i >> 3) & 7] |= mask[i & 7];
+ if (src->b[(j >> 3) & 7] & mask[j & 7])
+ tmp.b[(i >> 3) & 7] |= mask[i & 7];
}
*src = tmp;
}
-
-/// Final permutation (IP^-1).
-static void FP(struct BIT64 *src)
+/**
+ * Final permutation (IP^-1).
+ */
+static void des_FP(struct des_bit64 *src)
{
- struct BIT64 tmp = {{0}};
-
static const uint8_t fp_table[64] = {
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
@@ -82,24 +78,26 @@ static void FP(struct BIT64 *src)
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25,
};
+ struct des_bit64 tmp = {{0}};
+ int i;
- size_t i;
- for( i = 0; i < ARRAYLENGTH(fp_table); ++i )
- {
+ for (i = 0; i < ARRAYLENGTH(fp_table); ++i) {
uint8_t j = fp_table[i] - 1;
- if( src->b[(j >> 3) & 7] & mask[j & 7] )
- tmp .b[(i >> 3) & 7] |= mask[i & 7];
+ if (src->b[(j >> 3) & 7] & mask[j & 7])
+ tmp.b[(i >> 3) & 7] |= mask[i & 7];
}
*src = tmp;
}
-
-/// Expansion (E).
-/// Expands upper four 8-bits (32b) into eight 6-bits (48b).
-static void E(struct BIT64 *src)
+/**
+ * Expansion (E).
+ *
+ * Expands upper four 8-bits (32b) into eight 6-bits (48b).
+ */
+static void des_E(struct des_bit64 *src)
{
- struct BIT64 tmp = {{0}};
+ struct des_bit64 tmp = {{0}};
#if 0
// original
@@ -113,13 +111,12 @@ static void E(struct BIT64 *src)
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1,
};
+ int i;
- size_t i;
- for( i = 0; i < ARRAYLENGTH(expand_table); ++i )
- {
+ for (i = 0; i < ARRAYLENGTH(expand_table); ++i) {
uint8_t j = expand_table[i] - 1;
- if( src->b[j / 8 + 4] & mask[j % 8] )
- tmp .b[i / 6 + 0] |= mask[i % 6];
+ if (src->b[j / 8 + 4] & mask[j % 8])
+ tmp.b[i / 6 + 0] |= mask[i % 6];
}
#endif
// optimized
@@ -135,12 +132,11 @@ static void E(struct BIT64 *src)
*src = tmp;
}
-
-/// Transposition (P-BOX).
-static void TP(struct BIT64 *src)
+/**
+ * Transposition (P-BOX).
+ */
+static void des_TP(struct des_bit64 *src)
{
- struct BIT64 tmp = {{0}};
-
static const uint8_t tp_table[32] = {
16, 7, 20, 21,
29, 12, 28, 17,
@@ -151,25 +147,27 @@ static void TP(struct BIT64 *src)
19, 13, 30, 6,
22, 11, 4, 25,
};
+ struct des_bit64 tmp = {{0}};
+ int i;
- size_t i;
- for( i = 0; i < ARRAYLENGTH(tp_table); ++i )
- {
+ for (i = 0; i < ARRAYLENGTH(tp_table); ++i) {
uint8_t j = tp_table[i] - 1;
- if( src->b[(j >> 3) + 0] & mask[j & 7] )
- tmp .b[(i >> 3) + 4] |= mask[i & 7];
+ if (src->b[(j >> 3) + 0] & mask[j & 7])
+ tmp.b[(i >> 3) + 4] |= mask[i & 7];
}
*src = tmp;
}
-/// Substitution boxes (S-boxes).
-/// NOTE: This implementation was optimized to process two nibbles in one step (twice as fast).
-static void SBOX(struct BIT64 *src)
+/**
+ * Substitution boxes (S-boxes).
+ *
+ * This implementation was optimized to process two nibbles in one step (twice
+ * as fast).
+ */
+static void des_SBOX(struct des_bit64 *src)
{
- struct BIT64 tmp = {{0}};
-
static const uint8_t s_table[4][64] = {
{
0xef, 0x03, 0x41, 0xfd, 0xd8, 0x74, 0x1e, 0x47, 0x26, 0xef, 0xfb, 0x22, 0xb3, 0xd8, 0x84, 0x1e,
@@ -193,10 +191,10 @@ static void SBOX(struct BIT64 *src)
0xa0, 0x9f, 0xf6, 0x5c, 0x6a, 0x09, 0x8d, 0xf0, 0x0f, 0xe3, 0x53, 0x25, 0x95, 0x36, 0x28, 0xcb,
}
};
+ struct des_bit64 tmp = {{0}};
+ int i;
- size_t i;
- for( i = 0; i < ARRAYLENGTH(s_table); ++i )
- {
+ for (i = 0; i < ARRAYLENGTH(s_table); ++i) {
tmp.b[i] = (s_table[i][src->b[i*2+0]] & 0xf0)
| (s_table[i][src->b[i*2+1]] & 0x0f);
}
@@ -204,15 +202,17 @@ static void SBOX(struct BIT64 *src)
*src = tmp;
}
-
-/// DES round function.
-/// XORs src[0..3] with TP(SBOX(E(src[4..7]))).
-static void RoundFunction(struct BIT64 *src)
+/**
+ * DES round function.
+ *
+ * XORs src[0..3] with TP(SBOX(E(src[4..7]))).
+ */
+static void des_RoundFunction(struct des_bit64 *src)
{
- struct BIT64 tmp = *src;
- E(&tmp);
- SBOX(&tmp);
- TP(&tmp);
+ struct des_bit64 tmp = *src;
+ des_E(&tmp);
+ des_SBOX(&tmp);
+ des_TP(&tmp);
src->b[0] ^= tmp.b[4];
src->b[1] ^= tmp.b[5];
@@ -220,24 +220,27 @@ static void RoundFunction(struct BIT64 *src)
src->b[3] ^= tmp.b[7];
}
-
-void des_decrypt_block(struct BIT64 *block)
+/// @copydoc des_interface::decrypt_block()
+void des_decrypt_block(struct des_bit64 *block)
{
- IP(block);
- RoundFunction(block);
- FP(block);
+ des_IP(block);
+ des_RoundFunction(block);
+ des_FP(block);
}
-
-void des_decrypt(unsigned char* data, size_t size)
+/// @copydoc des_interface::decrypt()
+void des_decrypt(unsigned char *data, size_t size)
{
- struct BIT64 *p = (struct BIT64 *)data;
+ struct des_bit64 *p = (struct des_bit64 *)data;
size_t i;
- for( i = 0; i*8 < size; i += 8 )
+ for (i = 0; i*8 < size; i += 8)
des->decrypt_block(p);
}
+/**
+ * Interface base initialization.
+ */
void des_defaults(void)
{
des = &des_s;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-10 21:37:19 +0000