00b5051cd
Denys Vlasenko
2021-11-28
Subject
libbb: code shrink in des encryption, in setup_salt()
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libbb/pw_encrypt_des.c+14 -15
| @@ -363,7 +363,7 @@ des_init(struct des_ctx *ctx, const struct const_des_ctx *cctx) | |
| old_rawkey0 = old_rawkey1 = 0; | |
| old_salt = 0; | |
| #endif | |
| - | saltbits = 0; |
| + | //saltbits = 0; /* not needed: we call setup_salt() before do_des() */ |
| bits28 = bits32 + 4; | |
| bits24 = bits28 + 4; | |
| @@ -481,12 +481,11 @@ des_init(struct des_ctx *ctx, const struct const_des_ctx *cctx) | |
| return ctx; | |
| } | |
| - | |
| + | /* Accepts 24-bit salt at max */ |
| static void | |
| setup_salt(struct des_ctx *ctx, uint32_t salt) | |
| { | |
| - | uint32_t obit, saltbit; |
| - | int i; |
| + | uint32_t invbits; |
| #if USE_REPETITIVE_SPEEDUP | |
| if (salt == old_salt) | |
| @@ -494,15 +493,15 @@ setup_salt(struct des_ctx *ctx, uint32_t salt) | |
| old_salt = salt; | |
| #endif | |
| - | saltbits = 0; |
| - | saltbit = 1; |
| - | obit = 0x800000; |
| - | for (i = 0; i < 24; i++) { |
| - | if (salt & saltbit) |
| - | saltbits |= obit; |
| - | saltbit <<= 1; |
| - | obit >>= 1; |
| - | } |
| + | invbits = 0; |
| + | |
| + | salt |= (1 << 24); |
| + | do { |
| + | invbits = (invbits << 1) + (salt & 1); |
| + | salt >>= 1; |
| + | } while (salt != 1); |
| + | |
| + | saltbits = invbits; |
| } | |
| static void | |
| @@ -736,14 +735,14 @@ des_crypt(struct des_ctx *ctx, char output[DES_OUT_BUFSIZE], | |
| des_setkey(ctx, (char *)keybuf); | |
| /* | |
| - | * salt_str - 2 bytes of salt |
| + | * salt_str - 2 chars of salt (converted to 12 bits) |
| * key - up to 8 characters | |
| */ | |
| output[0] = salt_str[0]; | |
| output[1] = salt_str[1]; | |
| salt = (ascii_to_bin(salt_str[1]) << 6) | |
| | ascii_to_bin(salt_str[0]); | |
| - | setup_salt(ctx, salt); |
| + | setup_salt(ctx, salt); /* set ctx->saltbits for do_des() */ |
| /* Do it. */ | |
| do_des(ctx, /*0, 0,*/ &r0, &r1, 25 /* count */); | |
testsuite/cryptpw.tests+14 -0
| @@ -7,6 +7,20 @@ | |
| # testing "description" "command" "result" "infile" "stdin" | |
| + | #optional USE_BB_CRYPT |
| + | testing "cryptpw des 12" \ |
| + | "cryptpw -m des QWErty '123456789012345678901234567890'" \ |
| + | '12MnB3PqfVbMA\n' "" "" |
| + | |
| + | testing "cryptpw des 55" \ |
| + | "cryptpw -m des QWErty 55" \ |
| + | '55tgFLtkT1Y72\n' "" "" |
| + | |
| + | testing "cryptpw des zz" \ |
| + | "cryptpw -m des QWErty zz" \ |
| + | 'zzIZaaXWOkxVk\n' "" "" |
| + | #SKIP= |
| + | |
| optional USE_BB_CRYPT_SHA | |
| testing "cryptpw sha256" \ | |
| "cryptpw -m sha256 QWErty '123456789012345678901234567890'" \ | |