From 3470f9297ef179dd327031351a2ac1feccce32f6 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 13 Nov 2008 13:25:18 +0000 Subject: libbb: sha_crypt -123 bytes --- libbb/pw_encrypt_sha.c | 64 +++++++++++++++++++++++++++----------------------- 1 file changed, 34 insertions(+), 30 deletions(-) (limited to 'libbb') diff --git a/libbb/pw_encrypt_sha.c b/libbb/pw_encrypt_sha.c index 3dbaeabc9..3173506f5 100644 --- a/libbb/pw_encrypt_sha.c +++ b/libbb/pw_encrypt_sha.c @@ -26,16 +26,22 @@ sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data) char *result, *resptr; /* btw, sha256 needs [32] and uint32_t only */ - unsigned char alt_result[64] __attribute__((__aligned__(__alignof__(uint64_t)))); - unsigned char temp_result[64] __attribute__((__aligned__(__alignof__(uint64_t)))); - union { - sha256_ctx_t x; - sha512_ctx_t y; - } ctx; - union { - sha256_ctx_t x; - sha512_ctx_t y; - } alt_ctx; + struct { + unsigned char alt_result[64]; + unsigned char temp_result[64]; + union { + sha256_ctx_t x; + sha512_ctx_t y; + } ctx; + union { + sha256_ctx_t x; + sha512_ctx_t y; + } alt_ctx; + } L __attribute__((__aligned__(__alignof__(uint64_t)))); +#define alt_result (L.alt_result ) +#define temp_result (L.temp_result) +#define ctx (L.ctx ) +#define alt_ctx (L.alt_ctx ) unsigned salt_len; unsigned key_len; unsigned cnt; @@ -186,7 +192,6 @@ sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data) sha_end(alt_result, &ctx); } - /* Append encrypted password to result buffer */ //TODO: replace with something like // bb_uuencode(cp, src, length, bb_uuenc_tbl_XXXbase64); @@ -196,18 +201,16 @@ do { \ resptr = to64(resptr, w, N); \ } while (0) if (is_sha512 == '5') { - int i = 0; - int j = 10; - int k = 20; + unsigned i = 0; while (1) { + unsigned j = i + 10; + unsigned k = i + 20; + if (j >= 30) j -= 30; + if (k >= 30) k -= 30; b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4); - if (i == 9) + if (k == 29) break; - /* if x - 9 produces < 0, subtract 2 more: - * ((i >> 8) << 1) is either 0 or binary 111111...1110 */ - i -= 9; i = (i & 0x1f) + ((i >> 8) << 1); - j -= 9; j = (j & 0x1f) + ((j >> 8) << 1); - k -= 9; k = (k & 0x1f) + ((k >> 8) << 1); + i = k + 1; } b64_from_24bit(0, alt_result[31], alt_result[30], 3); /* was: @@ -225,15 +228,15 @@ do { \ */ } else { unsigned i = 0; - unsigned j = 21; - unsigned k = 42; while (1) { + unsigned j = i + 21; + unsigned k = i + 42; + if (j >= 63) j -= 63; + if (k >= 63) k -= 63; b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4); - if (i == 62) + if (j == 20) break; - i += 22; i = ((i >> 6) + i) & 0x3f; - j += 22; j = ((j >> 6) + j) & 0x3f; - k += 22; k = ((k >> 6) + k) & 0x3f; + i = j + 1; } b64_from_24bit(0, 0, alt_result[63], 2); /* was: @@ -267,10 +270,7 @@ do { \ /* Clear the buffer for the intermediate result so that people attaching to processes or reading core dumps cannot get any information. */ - memset(temp_result, 0, sizeof(temp_result)); - memset(alt_result, 0, sizeof(alt_result)); - memset(&ctx, 0, sizeof(ctx)); - memset(&alt_ctx, 0, sizeof(alt_ctx)); + memset(&L, 0, sizeof(L)); /* [alt]_ctx and XXX_result buffers */ memset(key_data, 0, key_len); /* also p_bytes */ memset(salt_data, 0, salt_len); /* also s_bytes */ free(key_data); @@ -279,4 +279,8 @@ do { \ #undef s_bytes return result; +#undef alt_result +#undef temp_result +#undef ctx +#undef alt_ctx } -- cgit v1.2.3