md5: code shrink

function                                             old     new   delta
md5_end                                              125     104     -21

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

2 files changed, 25 insertions, 30 deletions

diff --git a/libbb/md5.c b/libbb/md5.c
index cf3825a34..a1f0a923f 100644
--- a/libbb/md5.c
+++ b/libbb/md5.c
@@ -418,31 +418,30 @@ void FAST_FUNC md5_hash(md5_ctx_t *ctx, const void *buffer, size_t len)
  */
 void FAST_FUNC md5_end(md5_ctx_t *ctx, void *resbuf)
 {
-        uint64_t total;
-        unsigned i;
         unsigned bufpos = BUFPOS(ctx);
-
-        /* Pad data to block size.  */
+        /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */
         ctx->buffer[bufpos++] = 0x80;
-        memset(ctx->buffer + bufpos, 0, 64 - bufpos);
 
-        if (bufpos > 56) {
+        /* This loop iterates either once or twice, no more, no less */
+        while (1) {
+                unsigned remaining = 64 - bufpos;
+                memset(ctx->buffer + bufpos, 0, remaining);
+                /* Do we have enough space for the length count? */
+                if (remaining >= 8) {
+                        /* Store the 64-bit counter of bits in the buffer in BE format */
+                        uint64_t t = ctx->total << 3;
+                        unsigned i;
+                        for (i = 0; i < 8; i++) {
+                                ctx->buffer[56 + i] = t;
+                                t >>= 8;
+                        }
+                }
                 md5_hash_block(ctx);
-                memset(ctx->buffer, 0, 64);
-        }
-
-        /* Put the 64-bit file length, expressed in *bits*,
-         * at the end of the buffer.
-         */
-        total = ctx->total << 3;
-        for (i = 0; i < 8; i++) {
-                ctx->buffer[56 + i] = total;
-                total >>= 8;
+                if (remaining >= 8)
+                        break;
+                bufpos = 0;
         }
 
-        /* Process last bytes.  */
-        md5_hash_block(ctx);
-
         /* The MD5 result is in little endian byte order.
          * We (ab)use the fact that A-D are consecutive in memory.
          */
diff --git a/libbb/sha1.c b/libbb/sha1.c
index 70efd581b..3e61aff6d 100644
--- a/libbb/sha1.c
+++ b/libbb/sha1.c
@@ -462,17 +462,15 @@ void FAST_FUNC sha512_hash(sha512_ctx_t *ctx, const void *buffer, size_t len)
 /* Used also for sha256 */
 void FAST_FUNC sha1_end(sha1_ctx_t *ctx, void *resbuf)
 {
-        unsigned pad, bufpos;
+        unsigned bufpos = ctx->total64 & 63;
 
-        bufpos = ctx->total64 & 63;
         /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */
         ctx->wbuffer[bufpos++] = 0x80;
 
         /* This loop iterates either once or twice, no more, no less */
         while (1) {
-                pad = 64 - bufpos;
+                unsigned pad = 64 - bufpos;
                 memset(ctx->wbuffer + bufpos, 0, pad);
-                bufpos = 0;
                 /* Do we have enough space for the length count? */
                 if (pad >= 8) {
                         /* Store the 64-bit counter of bits in the buffer in BE format */
@@ -484,6 +482,7 @@ void FAST_FUNC sha1_end(sha1_ctx_t *ctx, void *resbuf)
                 ctx->process_block(ctx);
                 if (pad >= 8)
                         break;
+                bufpos = 0;
         }
 
         bufpos = (ctx->process_block == sha1_process_block64) ? 5 : 8;
@@ -498,18 +497,14 @@ void FAST_FUNC sha1_end(sha1_ctx_t *ctx, void *resbuf)
 
 void FAST_FUNC sha512_end(sha512_ctx_t *ctx, void *resbuf)
 {
-        unsigned pad, bufpos;
+        unsigned bufpos = ctx->total64[0] & 127;
 
-        bufpos = ctx->total64[0] & 127;
-        /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0...
-         * (FIPS 180-2:5.1.2)
-         */
+        /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0... */
         ctx->wbuffer[bufpos++] = 0x80;
 
         while (1) {
-                pad = 128 - bufpos;
+                unsigned pad = 128 - bufpos;
                 memset(ctx->wbuffer + bufpos, 0, pad);
-                bufpos = 0;
                 if (pad >= 16) {
                         /* Store the 128-bit counter of bits in the buffer in BE format */
                         uint64_t t;
@@ -523,6 +518,7 @@ void FAST_FUNC sha512_end(sha512_ctx_t *ctx, void *resbuf)
                 sha512_process_block128(ctx);
                 if (pad >= 16)
                         break;
+                bufpos = 0;
         }
 
         if (BB_LITTLE_ENDIAN) {