libbb/md5: code shrink

[oweals/busybox.git] / libbb / pw_encrypt_sha.c

diff --git a/libbb/pw_encrypt_sha.c b/libbb/pw_encrypt_sha.c
index 08b0647501e7938484323ba3e98b5ce287cbfd8b..070e0d442cd8c66a35b4508bf18547671eaa83f2 100644 (file)
--- a/libbb/pw_encrypt_sha.c
+++ b/libbb/pw_encrypt_sha.c
@@ -20,22 +20,28 @@ sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data)
 {
        void (*sha_begin)(void *ctx) FAST_FUNC;
        void (*sha_hash)(const void *buffer, size_t len, void *ctx) FAST_FUNC;
-       void* (*sha_end)(void *resbuf, void *ctx) FAST_FUNC;
+       void (*sha_end)(void *resbuf, void *ctx) FAST_FUNC;
        int _32or64;
 
        char *result, *resptr;
 
        /* btw, sha256 needs [32] and uint32_t only */
-       unsigned char alt_result[64] __attribute__((__aligned__(__alignof__(uint64_t))));
-       unsigned char temp_result[64] __attribute__((__aligned__(__alignof__(uint64_t))));
-       union {
-               sha256_ctx_t x;
-               sha512_ctx_t y;
-       } ctx;
-       union {
-               sha256_ctx_t x;
-               sha512_ctx_t y;
-       } alt_ctx;
+       struct {
+               unsigned char alt_result[64];
+               unsigned char temp_result[64];
+               union {
+                       sha256_ctx_t x;
+                       sha512_ctx_t y;
+               } ctx;
+               union {
+                       sha256_ctx_t x;
+                       sha512_ctx_t y;
+               } alt_ctx;
+       } L __attribute__((__aligned__(__alignof__(uint64_t))));
+#define alt_result  (L.alt_result )
+#define temp_result (L.temp_result)
+#define ctx         (L.ctx        )
+#define alt_ctx     (L.alt_ctx    )
        unsigned salt_len;
        unsigned key_len;
        unsigned cnt;
@@ -186,7 +192,6 @@ sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data)
                sha_end(alt_result, &ctx);
        }
 
-
        /* Append encrypted password to result buffer */
 //TODO: replace with something like
 //     bb_uuencode(cp, src, length, bb_uuenc_tbl_XXXbase64);
@@ -197,24 +202,20 @@ do {                                                      \
 } while (0)
        if (is_sha512 == '5') {
                unsigned i = 0;
-               unsigned j = 10;
-               unsigned k = 20;
-               /* strange swap of one byte (see below why) */
-               unsigned char alt_result_31 = alt_result[31];
-               alt_result[31] = alt_result[1];
                while (1) {
+                       unsigned j = i + 10;
+                       unsigned k = i + 20;
+                       if (j >= 30) j -= 30;
+                       if (k >= 30) k -= 30;
                        b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4);
-                       if (i == 9)
+                       if (k == 29)
                                break;
-                       i += 21; i = (((i >> 4) & 2) + i) & 0x1f;
-                       j += 21; j = (((j >> 4) & 2) + j) & 0x1f;
-                       k += 21; k = (((k >> 4) & 2) + k) & 0x1f;
+                       i = k + 1;
                }
-               b64_from_24bit(0, alt_result_31, alt_result[30], 3);
+               b64_from_24bit(0, alt_result[31], alt_result[30], 3);
                /* was:
                b64_from_24bit(alt_result[0], alt_result[10], alt_result[20], 4);
                b64_from_24bit(alt_result[21], alt_result[1], alt_result[11], 4);
-               ...............................^^^^^^^^^^^^^ why [1] and not [31]?
                b64_from_24bit(alt_result[12], alt_result[22], alt_result[2], 4);
                b64_from_24bit(alt_result[3], alt_result[13], alt_result[23], 4);
                b64_from_24bit(alt_result[24], alt_result[4], alt_result[14], 4);
@@ -227,15 +228,15 @@ do {                                                      \
                */
        } else {
                unsigned i = 0;
-               unsigned j = 21;
-               unsigned k = 42;
                while (1) {
+                       unsigned j = i + 21;
+                       unsigned k = i + 42;
+                       if (j >= 63) j -= 63;
+                       if (k >= 63) k -= 63;
                        b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4);
-                       if (i == 62)
+                       if (j == 20)
                                break;
-                       i += 22; i = ((i >> 6) + i) & 0x3f;
-                       j += 22; j = ((j >> 6) + j) & 0x3f;
-                       k += 22; k = ((k >> 6) + k) & 0x3f;
+                       i = j + 1;
                }
                b64_from_24bit(0, 0, alt_result[63], 2);
                /* was:
@@ -269,10 +270,7 @@ do {                                                       \
        /* Clear the buffer for the intermediate result so that people
           attaching to processes or reading core dumps cannot get any
           information.  */
-       memset(temp_result, 0, sizeof(temp_result));
-       memset(alt_result, 0, sizeof(alt_result));
-       memset(&ctx, 0, sizeof(ctx));
-       memset(&alt_ctx, 0, sizeof(alt_ctx));
+       memset(&L, 0, sizeof(L)); /* [alt]_ctx and XXX_result buffers */
        memset(key_data, 0, key_len); /* also p_bytes */
        memset(salt_data, 0, salt_len); /* also s_bytes */
        free(key_data);
@@ -281,4 +279,8 @@ do {                                                        \
 #undef s_bytes
 
        return result;
+#undef alt_result
+#undef temp_result
+#undef ctx
+#undef alt_ctx
 }