From 273abcbf664adc92ef3bc1d9752a2b571623ad52 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 16 Oct 2010 22:43:34 +0200 Subject: shaN: small code shrink function old new delta sha512_hash 134 128 -6 sha1_hash 114 106 -8 Signed-off-by: Denys Vlasenko --- libbb/md5.c | 61 +++++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 41 insertions(+), 20 deletions(-) (limited to 'libbb/md5.c') diff --git a/libbb/md5.c b/libbb/md5.c index f192d0e47..cf3825a34 100644 --- a/libbb/md5.c +++ b/libbb/md5.c @@ -354,8 +354,8 @@ static void md5_hash_block(md5_ctx_t *ctx) ctx->D = D; } -/* The size of filled part of ctx->buffer: */ -#define BUFLEN(ctx) (((unsigned)ctx->total) & 63) +/* The first unused position in ctx->buffer: */ +#define BUFPOS(ctx) (((unsigned)ctx->total) & 63) /* Feed data through a temporary buffer to call md5_hash_aligned_block() * with chunks of data that are 4-byte aligned and a multiple of 64 bytes. @@ -363,31 +363,52 @@ static void md5_hash_block(md5_ctx_t *ctx) * bytes worth to pass on. Call md5_end() to flush this buffer. */ void FAST_FUNC md5_hash(md5_ctx_t *ctx, const void *buffer, size_t len) { - const char *buf = buffer; - unsigned buflen = BUFLEN(ctx); +#if 1 + /* Tiny bit smaller code */ + unsigned bufpos = BUFPOS(ctx); /* RFC 1321 specifies the possible length of the file up to 2^64 bits. * Here we only track the number of bytes. */ ctx->total += len; - /* Process all input. */ while (1) { - unsigned i = 64 - buflen; - if (i > len) - i = len; + unsigned remaining = 64 - bufpos; + if (remaining > len) + remaining = len; /* Copy data into aligned buffer. */ - memcpy(ctx->buffer + buflen, buf, i); - len -= i; - buf += i; - buflen += i; - /* clever way to do "if (buflen != 64) break; ... ; buflen = 0;" */ - buflen -= 64; - if (buflen != 0) + memcpy(ctx->buffer + bufpos, buffer, remaining); + len -= remaining; + buffer = (const char *)buffer + remaining; + bufpos += remaining; + /* clever way to do "if (bufpos != 64) break; ... ; bufpos = 0;" */ + bufpos -= 64; + if (bufpos != 0) break; /* Buffer is filled up, process it. */ md5_hash_block(ctx); - /*buflen = 0; - already is */ + /*bufpos = 0; - already is */ } +#else + unsigned bufpos = BUFPOS(ctx); + unsigned add = 64 - bufpos; + + /* RFC 1321 specifies the possible length of the file up to 2^64 bits. + * Here we only track the number of bytes. */ + ctx->total += len; + + /* Hash whole blocks */ + while (len >= add) { + memcpy(ctx->buffer + bufpos, buffer, add); + buffer = (const char *)buffer + add; + len -= add; + add = 64; + bufpos = 0; + md5_hash_block(ctx); + } + + /* Save last, partial blosk */ + memcpy(ctx->buffer + bufpos, buffer, len); +#endif } /* Process the remaining bytes in the buffer and put result from CTX @@ -399,13 +420,13 @@ void FAST_FUNC md5_end(md5_ctx_t *ctx, void *resbuf) { uint64_t total; unsigned i; - unsigned buflen = BUFLEN(ctx); + unsigned bufpos = BUFPOS(ctx); /* Pad data to block size. */ - ctx->buffer[buflen++] = 0x80; - memset(ctx->buffer + buflen, 0, 64 - buflen); + ctx->buffer[bufpos++] = 0x80; + memset(ctx->buffer + bufpos, 0, 64 - bufpos); - if (buflen > 56) { + if (bufpos > 56) { md5_hash_block(ctx); memset(ctx->buffer, 0, 64); } -- cgit v1.2.3