X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbasic%2Fsiphash24.c;h=4bb41786c8b2a27b224ca9b9a0a682bde50e6fb8;hp=e7adfe48c83b4cac5bb0b8abb128c7382e2b13b5;hb=9742b1e43855b1599bd52ff95af995d9a9d35eac;hpb=f0928320e79e1cce13d6a21cfdd602cf4a12ccf4

diff --git a/src/basic/siphash24.c b/src/basic/siphash24.c
index e7adfe48c..4bb41786c 100644
--- a/src/basic/siphash24.c
+++ b/src/basic/siphash24.c
@@ -13,142 +13,188 @@
    this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
 
    (Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd)
+   (Refactored by Tom Gundersen to split up in several functions and follow systemd
+    coding style)
 */
-#include <stdint.h>
+
 #include <stdio.h>
-#include <string.h>
 
+#include "macro.h"
 #include "siphash24.h"
+#include "unaligned.h"
+
+static inline uint64_t rotate_left(uint64_t x, uint8_t b) {
+        assert(b < 64);
+
+        return (x << b) | (x >> (64 - b));
+}
 
-typedef uint64_t u64;
-typedef uint32_t u32;
-typedef uint8_t u8;
-
-#define ROTL(x,b) (u64)( ((x) << (b)) | ( (x) >> (64 - (b))) )
-
-#define U32TO8_LE(p, v)         \
-    (p)[0] = (u8)((v)      ); (p)[1] = (u8)((v) >>  8); \
-    (p)[2] = (u8)((v) >> 16); (p)[3] = (u8)((v) >> 24);
-
-#define U64TO8_LE(p, v)         \
-  U32TO8_LE((p),     (u32)((v)      ));   \
-  U32TO8_LE((p) + 4, (u32)((v) >> 32));
-
-#define U8TO64_LE(p) \
-  (((u64)((p)[0])      ) | \
-   ((u64)((p)[1]) <<  8) | \
-   ((u64)((p)[2]) << 16) | \
-   ((u64)((p)[3]) << 24) | \
-   ((u64)((p)[4]) << 32) | \
-   ((u64)((p)[5]) << 40) | \
-   ((u64)((p)[6]) << 48) | \
-   ((u64)((p)[7]) << 56))
-
-#define SIPROUND(state)         \
-  do {              \
-    (state)->v0 += (state)->v1; (state)->v1=ROTL((state)->v1,13); (state)->v1 ^= (state)->v0; (state)->v0=ROTL((state)->v0,32); \
-    (state)->v2 += (state)->v3; (state)->v3=ROTL((state)->v3,16); (state)->v3 ^= (state)->v2;     \
-    (state)->v0 += (state)->v3; (state)->v3=ROTL((state)->v3,21); (state)->v3 ^= (state)->v0;     \
-    (state)->v2 += (state)->v1; (state)->v1=ROTL((state)->v1,17); (state)->v1 ^= (state)->v2; (state)->v2=ROTL((state)->v2,32); \
-  } while(0)
-
-struct siphash {
-  u64 v0;
-  u64 v1;
-  u64 v2;
-  u64 v3;
-};
-
-static void siphash_init(struct siphash *state, const uint8_t k[16]) {
-  u64 k0, k1;
-
-  k0 = U8TO64_LE( k );
-  k1 = U8TO64_LE( k + 8 );
-
-  /* "somepseudorandomlygeneratedbytes" */
-  state->v0 = 0x736f6d6570736575ULL ^ k0;
-  state->v1 = 0x646f72616e646f6dULL ^ k1;
-  state->v2 = 0x6c7967656e657261ULL ^ k0;
-  state->v3 = 0x7465646279746573ULL ^ k1;
+static inline void sipround(struct siphash *state) {
+        assert(state);
+
+        state->v0 += state->v1;
+        state->v1 = rotate_left(state->v1, 13);
+        state->v1 ^= state->v0;
+        state->v0 = rotate_left(state->v0, 32);
+        state->v2 += state->v3;
+        state->v3 = rotate_left(state->v3, 16);
+        state->v3 ^= state->v2;
+        state->v0 += state->v3;
+        state->v3 = rotate_left(state->v3, 21);
+        state->v3 ^= state->v0;
+        state->v2 += state->v1;
+        state->v1 = rotate_left(state->v1, 17);
+        state->v1 ^= state->v2;
+        state->v2 = rotate_left(state->v2, 32);
 }
 
-static u64 siphash24_finalize(struct siphash *state) {
-  state->v2 ^= 0xff;
-  SIPROUND(state);
-  SIPROUND(state);
-  SIPROUND(state);
-  SIPROUND(state);
+void siphash24_init(struct siphash *state, const uint8_t k[16]) {
+        uint64_t k0, k1;
+
+        assert(state);
+        assert(k);
+
+        k0 = unaligned_read_le64(k);
+        k1 = unaligned_read_le64(k + 8);
 
-  return state->v0 ^ state->v1 ^ state->v2  ^ state->v3;
+        *state = (struct siphash) {
+                /* "somepseudorandomlygeneratedbytes" */
+                .v0 = 0x736f6d6570736575ULL ^ k0,
+                .v1 = 0x646f72616e646f6dULL ^ k1,
+                .v2 = 0x6c7967656e657261ULL ^ k0,
+                .v3 = 0x7465646279746573ULL ^ k1,
+                .padding = 0,
+                .inlen = 0,
+        };
 }
 
-/* SipHash-2-4 */
-void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16])
-{
-  struct siphash state;
-  u64 b;
-  u64 m;
-  const u8 *in = _in;
-  const u8 *end = in + inlen - ( inlen % sizeof( u64 ) );
-  const int left = inlen & 7;
-  b = ( ( u64 )inlen ) << 56;
-
-  siphash_init(&state, k);
-
-  for ( ; in != end; in += 8 )
-  {
-    m = U8TO64_LE( in );
+void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
+
+        const uint8_t *in = _in;
+        const uint8_t *end = in + inlen;
+        size_t left = state->inlen & 7;
+        uint64_t m;
+
+        assert(in);
+        assert(state);
+
+        /* Update total length */
+        state->inlen += inlen;
+
+        /* If padding exists, fill it out */
+        if (left > 0) {
+                for ( ; in < end && left < 8; in ++, left ++)
+                        state->padding |= ((uint64_t) *in) << (left * 8);
+
+                if (in == end && left < 8)
+                        /* We did not have enough input to fill out the padding completely */
+                        return;
+
 #ifdef DEBUG
-    printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 );
-    printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 );
-    printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 );
-    printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 );
-    printf( "(%3d) compress %08x %08x\n", ( int )inlen, ( u32 )( m >> 32 ), ( u32 )m );
+                printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+                printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+                printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+                printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+                printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding);
 #endif
-    state.v3 ^= m;
-    SIPROUND(&state);
-    SIPROUND(&state);
-    state.v0 ^= m;
-  }
 
-  switch( left )
-  {
-  case 7: b |= ( ( u64 )in[ 6] )  << 48;
+                state->v3 ^= state->padding;
+                sipround(state);
+                sipround(state);
+                state->v0 ^= state->padding;
 
-  case 6: b |= ( ( u64 )in[ 5] )  << 40;
+                state->padding = 0;
+        }
 
-  case 5: b |= ( ( u64 )in[ 4] )  << 32;
+        end -= (state->inlen % sizeof(uint64_t));
 
-  case 4: b |= ( ( u64 )in[ 3] )  << 24;
-
-  case 3: b |= ( ( u64 )in[ 2] )  << 16;
+        for ( ; in < end; in += 8) {
+                m = unaligned_read_le64(in);
+#ifdef DEBUG
+                printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+                printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+                printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+                printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+                printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m);
+#endif
+                state->v3 ^= m;
+                sipround(state);
+                sipround(state);
+                state->v0 ^= m;
+        }
+
+        left = state->inlen & 7;
+        switch (left) {
+                case 7:
+                        state->padding |= ((uint64_t) in[6]) << 48;
+                        /* fall through */
+                case 6:
+                        state->padding |= ((uint64_t) in[5]) << 40;
+                        /* fall through */
+                case 5:
+                        state->padding |= ((uint64_t) in[4]) << 32;
+                        /* fall through */
+                case 4:
+                        state->padding |= ((uint64_t) in[3]) << 24;
+                        /* fall through */
+                case 3:
+                        state->padding |= ((uint64_t) in[2]) << 16;
+                        /* fall through */
+                case 2:
+                        state->padding |= ((uint64_t) in[1]) <<  8;
+                        /* fall through */
+                case 1:
+                        state->padding |= ((uint64_t) in[0]);
+                        /* fall through */
+                case 0:
+                        break;
+        }
+}
 
-  case 2: b |= ( ( u64 )in[ 1] )  <<  8;
+uint64_t siphash24_finalize(struct siphash *state) {
+        uint64_t b;
 
-  case 1: b |= ( ( u64 )in[ 0] ); break;
+        assert(state);
 
-  case 0: break;
-  }
+        b = state->padding | (((uint64_t) state->inlen) << 56);
 
 #ifdef DEBUG
-  printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 );
-  printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 );
-  printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 );
-  printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 );
-  printf( "(%3d) padding   %08x %08x\n", ( int )inlen, ( u32 )( b >> 32 ), ( u32 )b );
+        printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+        printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+        printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+        printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
+        printf("(%3zu) padding   %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding);
 #endif
-  state.v3 ^= b;
-  SIPROUND(&state);
-  SIPROUND(&state);
-  state.v0 ^= b;
+
+        state->v3 ^= b;
+        sipround(state);
+        sipround(state);
+        state->v0 ^= b;
+
 #ifdef DEBUG
-  printf( "(%3d) v0 %08x %08x\n", ( int )inlen, ( u32 )( state.v0 >> 32 ), ( u32 )state.v0 );
-  printf( "(%3d) v1 %08x %08x\n", ( int )inlen, ( u32 )( state.v1 >> 32 ), ( u32 )state.v1 );
-  printf( "(%3d) v2 %08x %08x\n", ( int )inlen, ( u32 )( state.v2 >> 32 ), ( u32 )state.v2 );
-  printf( "(%3d) v3 %08x %08x\n", ( int )inlen, ( u32 )( state.v3 >> 32 ), ( u32 )state.v3 );
+        printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0);
+        printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1);
+        printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2);
+        printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3);
 #endif
+        state->v2 ^= 0xff;
+
+        sipround(state);
+        sipround(state);
+        sipround(state);
+        sipround(state);
+
+        return state->v0 ^ state->v1 ^ state->v2  ^ state->v3;
+}
+
+uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[16]) {
+        struct siphash state;
+
+        assert(in);
+        assert(k);
 
-  b = siphash24_finalize(&state);
+        siphash24_init(&state, k);
+        siphash24_compress(in, inlen, &state);
 
-  U64TO8_LE( out, b );
+        return siphash24_finalize(&state);
 }