diff options
Diffstat (limited to 'release/src/router/busybox/libbb/pw_encrypt_sha.c')
| -rw-r--r-- | release/src/router/busybox/libbb/pw_encrypt_sha.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/release/src/router/busybox/libbb/pw_encrypt_sha.c b/release/src/router/busybox/libbb/pw_encrypt_sha.c new file mode 100644 index 00000000..070e0d44 --- /dev/null +++ b/release/src/router/busybox/libbb/pw_encrypt_sha.c @@ -0,0 +1,286 @@ +/* SHA256 and SHA512-based Unix crypt implementation. + * Released into the Public Domain by Ulrich Drepper <drepper@redhat.com>. + */ + +/* Prefix for optional rounds specification. */ +static const char str_rounds[] = "rounds=%u$"; + +/* Maximum salt string length. */ +#define SALT_LEN_MAX 16 +/* Default number of rounds if not explicitly specified. */ +#define ROUNDS_DEFAULT 5000 +/* Minimum number of rounds. */ +#define ROUNDS_MIN 1000 +/* Maximum number of rounds. */ +#define ROUNDS_MAX 999999999 + +static char * +NOINLINE +sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data) +{ + void (*sha_begin)(void *ctx) FAST_FUNC; + void (*sha_hash)(const void *buffer, size_t len, void *ctx) FAST_FUNC; + void (*sha_end)(void *resbuf, void *ctx) FAST_FUNC; + int _32or64; + + char *result, *resptr; + + /* btw, sha256 needs [32] and uint32_t only */ + struct { + unsigned char alt_result[64]; + unsigned char temp_result[64]; + union { + sha256_ctx_t x; + sha512_ctx_t y; + } ctx; + union { + sha256_ctx_t x; + sha512_ctx_t y; + } alt_ctx; + } L __attribute__((__aligned__(__alignof__(uint64_t)))); +#define alt_result (L.alt_result ) +#define temp_result (L.temp_result) +#define ctx (L.ctx ) +#define alt_ctx (L.alt_ctx ) + unsigned salt_len; + unsigned key_len; + unsigned cnt; + unsigned rounds; + char *cp; + char is_sha512; + + /* Analyze salt, construct already known part of result */ + cnt = strlen(salt_data) + 1 + 43 + 1; + is_sha512 = salt_data[1]; + if (is_sha512 == '6') + cnt += 43; + result = resptr = xzalloc(cnt); /* will provide NUL terminator */ + *resptr++ = '$'; + *resptr++ = is_sha512; + *resptr++ = '$'; + rounds = ROUNDS_DEFAULT; + salt_data += 3; + if (strncmp(salt_data, str_rounds, 7) == 0) { + /* 7 == strlen("rounds=") */ + char *endp; + cnt = bb_strtou(salt_data + 7, &endp, 10); + if (*endp == '$') { + salt_data = endp + 1; + rounds = cnt; + if (rounds < ROUNDS_MIN) + rounds = ROUNDS_MIN; + if (rounds > ROUNDS_MAX) + rounds = ROUNDS_MAX; + /* add "rounds=NNNNN$" to result */ + resptr += sprintf(resptr, str_rounds, rounds); + } + } + salt_len = strchrnul(salt_data, '$') - salt_data; + if (salt_len > SALT_LEN_MAX) + salt_len = SALT_LEN_MAX; + /* xstrdup assures suitable alignment; also we will use it + as a scratch space later. */ + salt_data = xstrndup(salt_data, salt_len); + /* add "salt$" to result */ + strcpy(resptr, salt_data); + resptr += salt_len; + *resptr++ = '$'; + /* key data doesn't need much processing */ + key_len = strlen(key_data); + key_data = xstrdup(key_data); + + /* Which flavor of SHAnnn ops to use? */ + sha_begin = (void*)sha256_begin; + sha_hash = (void*)sha256_hash; + sha_end = (void*)sha256_end; + _32or64 = 32; + if (is_sha512 == '6') { + sha_begin = (void*)sha512_begin; + sha_hash = (void*)sha512_hash; + sha_end = (void*)sha512_end; + _32or64 = 64; + } + + /* Add KEY, SALT. */ + sha_begin(&ctx); + sha_hash(key_data, key_len, &ctx); + sha_hash(salt_data, salt_len, &ctx); + + /* Compute alternate SHA sum with input KEY, SALT, and KEY. + The final result will be added to the first context. */ + sha_begin(&alt_ctx); + sha_hash(key_data, key_len, &alt_ctx); + sha_hash(salt_data, salt_len, &alt_ctx); + sha_hash(key_data, key_len, &alt_ctx); + sha_end(alt_result, &alt_ctx); + + /* Add result of this to the other context. */ + /* Add for any character in the key one byte of the alternate sum. */ + for (cnt = key_len; cnt > _32or64; cnt -= _32or64) + sha_hash(alt_result, _32or64, &ctx); + sha_hash(alt_result, cnt, &ctx); + + /* Take the binary representation of the length of the key and for every + 1 add the alternate sum, for every 0 the key. */ + for (cnt = key_len; cnt != 0; cnt >>= 1) + if ((cnt & 1) != 0) + sha_hash(alt_result, _32or64, &ctx); + else + sha_hash(key_data, key_len, &ctx); + + /* Create intermediate result. */ + sha_end(alt_result, &ctx); + + /* Start computation of P byte sequence. */ + /* For every character in the password add the entire password. */ + sha_begin(&alt_ctx); + for (cnt = 0; cnt < key_len; ++cnt) + sha_hash(key_data, key_len, &alt_ctx); + sha_end(temp_result, &alt_ctx); + + /* NB: past this point, raw key_data is not used anymore */ + + /* Create byte sequence P. */ +#define p_bytes key_data /* reuse the buffer as it is of the key_len size */ + cp = p_bytes; /* was: ... = alloca(key_len); */ + for (cnt = key_len; cnt >= _32or64; cnt -= _32or64) { + cp = memcpy(cp, temp_result, _32or64); + cp += _32or64; + } + memcpy(cp, temp_result, cnt); + + /* Start computation of S byte sequence. */ + /* For every character in the password add the entire password. */ + sha_begin(&alt_ctx); + for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt) + sha_hash(salt_data, salt_len, &alt_ctx); + sha_end(temp_result, &alt_ctx); + + /* NB: past this point, raw salt_data is not used anymore */ + + /* Create byte sequence S. */ +#define s_bytes salt_data /* reuse the buffer as it is of the salt_len size */ + cp = s_bytes; /* was: ... = alloca(salt_len); */ + for (cnt = salt_len; cnt >= _32or64; cnt -= _32or64) { + cp = memcpy(cp, temp_result, _32or64); + cp += _32or64; + } + memcpy(cp, temp_result, cnt); + + /* Repeatedly run the collected hash value through SHA to burn + CPU cycles. */ + for (cnt = 0; cnt < rounds; ++cnt) { + sha_begin(&ctx); + + /* Add key or last result. */ + if ((cnt & 1) != 0) + sha_hash(p_bytes, key_len, &ctx); + else + sha_hash(alt_result, _32or64, &ctx); + /* Add salt for numbers not divisible by 3. */ + if (cnt % 3 != 0) + sha_hash(s_bytes, salt_len, &ctx); + /* Add key for numbers not divisible by 7. */ + if (cnt % 7 != 0) + sha_hash(p_bytes, key_len, &ctx); + /* Add key or last result. */ + if ((cnt & 1) != 0) + sha_hash(alt_result, _32or64, &ctx); + else + sha_hash(p_bytes, key_len, &ctx); + + 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); +#define b64_from_24bit(B2, B1, B0, N) \ +do { \ + unsigned w = ((B2) << 16) | ((B1) << 8) | (B0); \ + resptr = to64(resptr, w, N); \ +} while (0) + if (is_sha512 == '5') { + 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 (k == 29) + break; + i = k + 1; + } + b64_from_24bit(0, alt_result[31], alt_result[30], 3); + /* was: + b64_from_24bit(alt_result[0], alt_result[10], alt_result[20], 4); + b64_from_24bit(alt_result[21], alt_result[1], alt_result[11], 4); + b64_from_24bit(alt_result[12], alt_result[22], alt_result[2], 4); + b64_from_24bit(alt_result[3], alt_result[13], alt_result[23], 4); + b64_from_24bit(alt_result[24], alt_result[4], alt_result[14], 4); + b64_from_24bit(alt_result[15], alt_result[25], alt_result[5], 4); + b64_from_24bit(alt_result[6], alt_result[16], alt_result[26], 4); + b64_from_24bit(alt_result[27], alt_result[7], alt_result[17], 4); + b64_from_24bit(alt_result[18], alt_result[28], alt_result[8], 4); + b64_from_24bit(alt_result[9], alt_result[19], alt_result[29], 4); + b64_from_24bit(0, alt_result[31], alt_result[30], 3); + */ + } else { + unsigned i = 0; + 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 (j == 20) + break; + i = j + 1; + } + b64_from_24bit(0, 0, alt_result[63], 2); + /* was: + b64_from_24bit(alt_result[0], alt_result[21], alt_result[42], 4); + b64_from_24bit(alt_result[22], alt_result[43], alt_result[1], 4); + b64_from_24bit(alt_result[44], alt_result[2], alt_result[23], 4); + b64_from_24bit(alt_result[3], alt_result[24], alt_result[45], 4); + b64_from_24bit(alt_result[25], alt_result[46], alt_result[4], 4); + b64_from_24bit(alt_result[47], alt_result[5], alt_result[26], 4); + b64_from_24bit(alt_result[6], alt_result[27], alt_result[48], 4); + b64_from_24bit(alt_result[28], alt_result[49], alt_result[7], 4); + b64_from_24bit(alt_result[50], alt_result[8], alt_result[29], 4); + b64_from_24bit(alt_result[9], alt_result[30], alt_result[51], 4); + b64_from_24bit(alt_result[31], alt_result[52], alt_result[10], 4); + b64_from_24bit(alt_result[53], alt_result[11], alt_result[32], 4); + b64_from_24bit(alt_result[12], alt_result[33], alt_result[54], 4); + b64_from_24bit(alt_result[34], alt_result[55], alt_result[13], 4); + b64_from_24bit(alt_result[56], alt_result[14], alt_result[35], 4); + b64_from_24bit(alt_result[15], alt_result[36], alt_result[57], 4); + b64_from_24bit(alt_result[37], alt_result[58], alt_result[16], 4); + b64_from_24bit(alt_result[59], alt_result[17], alt_result[38], 4); + b64_from_24bit(alt_result[18], alt_result[39], alt_result[60], 4); + b64_from_24bit(alt_result[40], alt_result[61], alt_result[19], 4); + b64_from_24bit(alt_result[62], alt_result[20], alt_result[41], 4); + b64_from_24bit(0, 0, alt_result[63], 2); + */ + } + /* *resptr = '\0'; - xzalloc did it */ +#undef b64_from_24bit + + /* Clear the buffer for the intermediate result so that people + attaching to processes or reading core dumps cannot get any + information. */ + 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); + free(salt_data); +#undef p_bytes +#undef s_bytes + + return result; +#undef alt_result +#undef temp_result +#undef ctx +#undef alt_ctx +} |