libbb/yescrypt: remove YESCRYPT_INIT_SHARED flag and code using it

It's only used by libxcrypt-4.4.38/lib/alg-yescrypt-opt.c code
(optimized code version?) which wasn't ported to busybox

function                                             old     new   delta
yescrypt_kdf                                         449     442      -7
static.smix                                          755     739     -16
alloc_region                                          72       -     -72
yescrypt_kdf_body                                   1467    1239    -228
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/3 up/down: 0/-323)           Total: -323 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 13 insertions, 36 deletions

diff --git a/libbb/yescrypt/alg-yescrypt-kdf.c b/libbb/yescrypt/alg-yescrypt-kdf.c
index da23c1b59..6c1108514 100644
--- a/libbb/yescrypt/alg-yescrypt-kdf.c
+++ b/libbb/yescrypt/alg-yescrypt-kdf.c
@@ -731,9 +731,7 @@ static void smix(uint8_t *B, size_t r, uint32_t N, uint32_t p, uint32_t t,
         }
 
         Nloop_rw = 0;
-        if (flags & YESCRYPT_INIT_SHARED)
-                Nloop_rw = Nloop_all;
-        else if (flags & YESCRYPT_RW)
+        if (flags & YESCRYPT_RW)
                 Nloop_rw = Nloop_all / p;
 
         Nchunk &= ~(uint32_t)1; /* round down to even */
@@ -872,19 +870,6 @@ static int yescrypt_kdf_body(
         V = NULL;
         V_size = (size_t)128 * r * N;
         need = V_size;
-        if (flags & YESCRYPT_INIT_SHARED) {
-                if (local->aligned_size < need) {
-                        if (local->base || local->aligned ||
-                            local->base_size || local->aligned_size)
-                                goto out_EINVAL;
-                        if (!alloc_region(local, need))
-                                return -1;
-                }
-                if (flags & YESCRYPT_ALLOC_ONLY)
-                        return -2; /* expected "failure" */
-                V = (salsa20_blk_t *)local->aligned;
-                need = 0;
-        }
         B_size = (size_t)128 * r * p;
         need += B_size;
         if (need < B_size)
@@ -899,25 +884,18 @@ static int yescrypt_kdf_body(
                 if (need < S_size)
                         goto out_EINVAL;
         }
-        if (flags & YESCRYPT_INIT_SHARED) {
-                if (!alloc_region(&tmp, need))
+        init_region(&tmp);
+        if (local->aligned_size < need) {
+                if (free_region(local))
+                        return -1;
+                if (!alloc_region(local, need))
                         return -1;
-                B = (uint8_t *)tmp.aligned;
-                XY = (salsa20_blk_t *)((uint8_t *)B + B_size);
-        } else {
-                init_region(&tmp);
-                if (local->aligned_size < need) {
-                        if (free_region(local))
-                                return -1;
-                        if (!alloc_region(local, need))
-                                return -1;
-                }
-                if (flags & YESCRYPT_ALLOC_ONLY)
-                        return -3; /* expected "failure" */
-                B = (uint8_t *)local->aligned;
-                V = (salsa20_blk_t *)((uint8_t *)B + B_size);
-                XY = (salsa20_blk_t *)((uint8_t *)V + V_size);
         }
+        if (flags & YESCRYPT_ALLOC_ONLY)
+                return -3; /* expected "failure" */
+        B = (uint8_t *)local->aligned;
+        V = (salsa20_blk_t *)((uint8_t *)B + B_size);
+        XY = (salsa20_blk_t *)((uint8_t *)V + V_size);
         S = NULL;
         if (flags & YESCRYPT_RW)
                 S = (uint8_t *)XY + XY_size;
@@ -1021,7 +999,7 @@ int yescrypt_kdf(
                 return -1;
         }
 
-        if ((flags & (YESCRYPT_RW | YESCRYPT_INIT_SHARED)) == YESCRYPT_RW
+        if ((flags & YESCRYPT_RW)
          && p >= 1
          && N / p >= 0x100
          && N / p * r >= 0x20000
diff --git a/libbb/yescrypt/alg-yescrypt.h b/libbb/yescrypt/alg-yescrypt.h
index 09638e3e1..fb791e899 100644
--- a/libbb/yescrypt/alg-yescrypt.h
+++ b/libbb/yescrypt/alg-yescrypt.h
@@ -83,7 +83,6 @@ typedef uint32_t yescrypt_flags_t;
 /* Private */
 #define YESCRYPT_MODE_MASK              0x003
 #define YESCRYPT_RW_FLAVOR_MASK         0x3fc
-#define YESCRYPT_INIT_SHARED            0x01000000
 #define YESCRYPT_ALLOC_ONLY             0x08000000
 #define YESCRYPT_PREHASH                0x10000000
 #endif
@@ -98,7 +97,7 @@ typedef uint32_t yescrypt_flags_t;
 #ifdef YESCRYPT_INTERNAL
 #define YESCRYPT_KNOWN_FLAGS \
         (YESCRYPT_MODE_MASK | YESCRYPT_RW_FLAVOR_MASK | \
-        YESCRYPT_INIT_SHARED | YESCRYPT_ALLOC_ONLY | YESCRYPT_PREHASH)
+        YESCRYPT_ALLOC_ONLY | YESCRYPT_PREHASH)
 #endif
 
 /**