diff options
| -rw-r--r-- | include/libbb.h | 1 | ||||
| -rw-r--r-- | libbb/md5.c | 48 |
2 files changed, 26 insertions, 23 deletions
diff --git a/include/libbb.h b/include/libbb.h index 8d7beffe7..034016f4a 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1540,7 +1540,6 @@ typedef struct md5_ctx_t { uint32_t C; uint32_t D; uint64_t total; - uint32_t buflen; char buffer[128]; } md5_ctx_t; #else diff --git a/libbb/md5.c b/libbb/md5.c index 9e5b496ce..1f9d59e6e 100644 --- a/libbb/md5.c +++ b/libbb/md5.c @@ -1,7 +1,7 @@ /* vi: set sw=4 ts=4: */ /* - * md5.c - Compute MD5 checksum of strings according to the - * definition of MD5 in RFC 1321 from April 1992. + * Compute MD5 checksum of strings according to the + * definition of MD5 in RFC 1321 from April 1992. * * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. * @@ -34,7 +34,6 @@ void FAST_FUNC md5_begin(md5_ctx_t *ctx) ctx->C = 0x98badcfe; ctx->D = 0x10325476; ctx->total = 0; - ctx->buflen = 0; } /* These are the four functions used in the four steps of the MD5 algorithm @@ -355,35 +354,39 @@ static void md5_hash_block(const void *buffer, md5_ctx_t *ctx) ctx->D = D; } +/* The size of filled part of ctx->buffer: */ +#define BUFLEN(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. * This function's internal buffer remembers previous data until it has 64 * bytes worth to pass on. Call md5_end() to flush this buffer. */ void FAST_FUNC md5_hash(const void *buffer, size_t len, md5_ctx_t *ctx) { - char *buf = (char *)buffer; + const char *buf = buffer; + unsigned buflen = BUFLEN(ctx); - /* RFC 1321 specifies the possible length of the file up to 2^64 bits, + /* 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 (len) { - unsigned i = 64 - ctx->buflen; - - /* Copy data into aligned buffer. */ + while (1) { + unsigned i = 64 - buflen; if (i > len) i = len; - memcpy(ctx->buffer + ctx->buflen, buf, i); + /* Copy data into aligned buffer. */ + memcpy(ctx->buffer + buflen, buf, i); len -= i; - ctx->buflen += i; buf += i; - - /* When buffer fills up, process it. */ - if (ctx->buflen == 64) { - md5_hash_block(ctx->buffer, ctx); - ctx->buflen = 0; - } + buflen += i; + /* clever way to do "if (buflen != 64) break; ... ; buflen = 0;" */ + buflen -= 64; + if (buflen != 0) + break; + /* Buffer is filled up, process it. */ + md5_hash_block(ctx->buffer, ctx); + /*buflen = 0; - already is */ } } @@ -396,18 +399,19 @@ void FAST_FUNC md5_end(void *resbuf, md5_ctx_t *ctx) { uint64_t total; char *buf = ctx->buffer; - int i; + unsigned i; + unsigned buflen = BUFLEN(ctx); /* Pad data to block size. */ - buf[ctx->buflen++] = 0x80; - memset(buf + ctx->buflen, 0, 128 - ctx->buflen); + buf[buflen++] = 0x80; + memset(buf + buflen, 0, 128 - buflen); /* Put the 64-bit file length, expressed in *bits*, * at the end of the buffer. */ + /* clever way to do "if (buflen > 56) buf += 64": */ + buf += ((buflen + 7) & 64); total = ctx->total << 3; - if (ctx->buflen > 56) - buf += 64; for (i = 0; i < 8; i++) { buf[56 + i] = total; total >>= 8; |