From d324e1b808daca7eec5b8700824a886a21508714 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 4 Dec 2008 15:29:35 +0000 Subject: libbb/crypt: code shrink function old new delta to64_msb_first - 63 +63 des_crypt 1509 1338 -171 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/1 up/down: 63/-171) Total: -108 bytes --- libbb/pw_encrypt_des.c | 64 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 39 insertions(+), 25 deletions(-) (limited to 'libbb/pw_encrypt_des.c') diff --git a/libbb/pw_encrypt_des.c b/libbb/pw_encrypt_des.c index cd19a63f7..4e506f498 100644 --- a/libbb/pw_encrypt_des.c +++ b/libbb/pw_encrypt_des.c @@ -696,13 +696,22 @@ do_des(struct des_ctx *ctx, /*uint32_t l_in, uint32_t r_in,*/ uint32_t *l_out, u #define DES_OUT_BUFSIZE 21 +static void +to64_msb_first(char *s, unsigned v) +{ + *s++ = ascii64[(v >> 18) & 0x3f]; /* bits 23..18 */ + *s++ = ascii64[(v >> 12) & 0x3f]; /* bits 17..12 */ + *s++ = ascii64[(v >> 6) & 0x3f]; /* bits 11..6 */ + *s = ascii64[v & 0x3f]; /* bits 5..0 */ +} + static char * NOINLINE des_crypt(struct des_ctx *ctx, char output[DES_OUT_BUFSIZE], const unsigned char *key, const unsigned char *setting) { - uint32_t salt, l, r0, r1, keybuf[2]; - uint8_t *p, *q; + uint32_t salt, r0, r1, keybuf[2]; + uint8_t *q; /* * Copy the key, shifting each character up by one bit @@ -733,34 +742,39 @@ des_crypt(struct des_ctx *ctx, char output[DES_OUT_BUFSIZE], */ output[1] = setting[1] ? setting[1] : output[0]; - p = (uint8_t *)output + 2; - setup_salt(ctx, salt); - /* - * Do it. - */ + /* Do it. */ do_des(ctx, /*0, 0,*/ &r0, &r1, 25 /* count */); - /* - * Now encode the result... - */ - l = (r0 >> 8); - *p++ = ascii64[(l >> 18) & 0x3f]; - *p++ = ascii64[(l >> 12) & 0x3f]; - *p++ = ascii64[(l >> 6) & 0x3f]; - *p++ = ascii64[l & 0x3f]; - + /* Now encode the result. */ +#if 0 +{ + uint32_t l = (r0 >> 8); + q = (uint8_t *)output + 2; + *q++ = ascii64[(l >> 18) & 0x3f]; /* bits 31..26 of r0 */ + *q++ = ascii64[(l >> 12) & 0x3f]; /* bits 25..20 of r0 */ + *q++ = ascii64[(l >> 6) & 0x3f]; /* bits 19..14 of r0 */ + *q++ = ascii64[l & 0x3f]; /* bits 13..8 of r0 */ l = ((r0 << 16) | (r1 >> 16)); - *p++ = ascii64[(l >> 18) & 0x3f]; - *p++ = ascii64[(l >> 12) & 0x3f]; - *p++ = ascii64[(l >> 6) & 0x3f]; - *p++ = ascii64[l & 0x3f]; - + *q++ = ascii64[(l >> 18) & 0x3f]; /* bits 7..2 of r0 */ + *q++ = ascii64[(l >> 12) & 0x3f]; /* bits 1..2 of r0 and 31..28 of r1 */ + *q++ = ascii64[(l >> 6) & 0x3f]; /* bits 27..22 of r1 */ + *q++ = ascii64[l & 0x3f]; /* bits 21..16 of r1 */ l = r1 << 2; - *p++ = ascii64[(l >> 12) & 0x3f]; - *p++ = ascii64[(l >> 6) & 0x3f]; - *p++ = ascii64[l & 0x3f]; - *p = 0; + *q++ = ascii64[(l >> 12) & 0x3f]; /* bits 15..10 of r1 */ + *q++ = ascii64[(l >> 6) & 0x3f]; /* bits 9..4 of r1 */ + *q++ = ascii64[l & 0x3f]; /* bits 3..0 of r1 + 00 */ + *q = 0; +} +#else + /* Each call takes low-order 24 bits and stores 4 chars */ + /* bits 31..8 of r0 */ + to64_msb_first(output + 2, (r0 >> 8)); + /* bits 7..0 of r0 and 31..16 of r1 */ + to64_msb_first(output + 6, (r0 << 16) | (r1 >> 16)); + /* (bits 15..0 of r1 + 00) and NUL byte */ + to64_msb_first(output + 10, (r1 << 8)); +#endif return output; } -- cgit v1.2.3