diff options
Diffstat (limited to 'libbb')
| -rw-r--r-- | libbb/pw_encrypt.c | 43 | ||||
| -rw-r--r-- | libbb/pw_encrypt_md5.c | 14 | ||||
| -rw-r--r-- | libbb/pw_encrypt_sha.c | 251 |
3 files changed, 281 insertions, 27 deletions
diff --git a/libbb/pw_encrypt.c b/libbb/pw_encrypt.c index 0b826f48d..572591ea9 100644 --- a/libbb/pw_encrypt.c +++ b/libbb/pw_encrypt.c @@ -15,16 +15,27 @@ * DES and MD5 crypt implementations are taken from uclibc. * They were modified to not use static buffers. */ -/* Common for them */ + +/* Used by pw_encrypt_XXX.c */ static const uint8_t ascii64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; +static char* +to64(char *s, unsigned v, int n) +{ + while (--n >= 0) { + *s++ = ascii64[v & 0x3f]; + v >>= 6; + } + return s; +} + #include "pw_encrypt_des.c" #include "pw_encrypt_md5.c" +#if ENABLE_USE_BB_CRYPT_SHA +#include "pw_encrypt_sha.c" +#endif -/* Other advanced crypt ids: */ +/* Other advanced crypt ids (TODO?): */ /* $2$ or $2a$: Blowfish */ -/* $5$: SHA-256 */ -/* $6$: SHA-512 */ -/* TODO: implement SHA - http://people.redhat.com/drepper/SHA-crypt.txt */ static struct const_des_ctx *des_cctx; static struct des_ctx *des_ctx; @@ -32,18 +43,20 @@ static struct des_ctx *des_ctx; /* my_crypt returns malloc'ed data */ static char *my_crypt(const char *key, const char *salt) { - /* First, check if we are supposed to be using the MD5 replacement - * instead of DES... */ - if (salt[0] == '$' && salt[1] == '1' && salt[2] == '$') { - return md5_crypt(xzalloc(MD5_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt); + /* MD5 or SHA? */ + if (salt[0] == '$' && salt[1] && salt[2] == '$') { + if (salt[1] == '1') + return md5_crypt(xzalloc(MD5_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt); +#if ENABLE_USE_BB_CRYPT_SHA + if (salt[1] == '5' || salt[1] == '6') + return sha_crypt((char*)key, (char*)salt); +#endif } - { - if (!des_cctx) - des_cctx = const_des_init(); - des_ctx = des_init(des_ctx, des_cctx); - return des_crypt(des_ctx, xzalloc(DES_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt); - } + if (!des_cctx) + des_cctx = const_des_init(); + des_ctx = des_init(des_ctx, des_cctx); + return des_crypt(des_ctx, xzalloc(DES_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt); } /* So far nobody wants to have it public */ diff --git a/libbb/pw_encrypt_md5.c b/libbb/pw_encrypt_md5.c index 8d0a516cf..b7478aa9d 100644 --- a/libbb/pw_encrypt_md5.c +++ b/libbb/pw_encrypt_md5.c @@ -494,16 +494,6 @@ static void __md5_Transform(uint32_t state[4], const unsigned char block[64]) } -static char* -__md5_to64(char *s, unsigned v, int n) -{ - while (--n >= 0) { - *s++ = ascii64[v & 0x3f]; - v >>= 6; - } - return s; -} - /* * UNIX password * @@ -605,9 +595,9 @@ md5_crypt(char passwd[MD5_OUT_BUFSIZE], const unsigned char *pw, const unsigned final[16] = final[5]; for (i = 0; i < 5; i++) { unsigned l = (final[i] << 16) | (final[i+6] << 8) | final[i+12]; - p = __md5_to64(p, l, 4); + p = to64(p, l, 4); } - p = __md5_to64(p, final[11], 2); + p = to64(p, final[11], 2); *p = '\0'; /* Don't leave anything around in vm they could use. */ diff --git a/libbb/pw_encrypt_sha.c b/libbb/pw_encrypt_sha.c new file mode 100644 index 000000000..9acbabb3b --- /dev/null +++ b/libbb/pw_encrypt_sha.c @@ -0,0 +1,251 @@ +/* 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$"; + +/* Maximum salt string length. */ +#define SALT_LEN_MAX 16 +/* Default number of rounds if not explicitly specified. */ +#define ROUNDS_DEFAULT 5000 +/* Minimum number of rounds. */ +#define ROUNDS_MIN 1000 +/* Maximum number of rounds. */ +#define ROUNDS_MAX 999999999 + +static char * +NOINLINE +sha_crypt(/*const*/ char *key_data, /*const*/ char *salt_data) +{ + void (*sha_begin)(void *ctx) FAST_FUNC; + void (*sha_hash)(const void *buffer, size_t len, void *ctx) FAST_FUNC; + void* (*sha_end)(void *resbuf, void *ctx) FAST_FUNC; + int _32or64; + + char *result, *resptr; + + /* btw, sha256 needs [32] and uint32_t only */ + unsigned char alt_result[64] __attribute__((__aligned__(__alignof__(uint64_t)))); + unsigned char temp_result[64] __attribute__((__aligned__(__alignof__(uint64_t)))); + union { + sha256_ctx_t x; + sha512_ctx_t y; + } ctx; + union { + sha256_ctx_t x; + sha512_ctx_t y; + } alt_ctx; + unsigned salt_len; + unsigned key_len; + unsigned cnt; + unsigned rounds; + char *cp; + char is_sha512; + + /* Analyze salt, construct already known part of result */ + cnt = strlen(salt_data) + 1 + 43 + 1; + is_sha512 = salt_data[1]; + if (is_sha512 == '6') + cnt += 43; + result = resptr = xzalloc(cnt); /* will provide NUL terminator */ + *resptr++ = '$'; + *resptr++ = is_sha512; + *resptr++ = '$'; + rounds = ROUNDS_DEFAULT; + salt_data += 3; + if (strncmp(salt_data, str_rounds, 7) == 0) { + /* 7 == strlen("rounds=") */ + char *endp; + unsigned srounds = bb_strtou(salt_data + 7, &endp, 10); + if (*endp == '$') { + salt_data = endp + 1; + rounds = srounds; + if (rounds < ROUNDS_MIN) + rounds = ROUNDS_MIN; + if (rounds > ROUNDS_MAX) + rounds = ROUNDS_MAX; + } + } + salt_len = strchrnul(salt_data, '$') - salt_data; + if (salt_len > SALT_LEN_MAX) + salt_len = SALT_LEN_MAX; + /* xstrdup assures suitable alignment; also we will use it + as a scratch space later. */ + salt_data = xstrndup(salt_data, salt_len); + if (rounds != ROUNDS_DEFAULT) /* add "rounds=NNNNN$" */ + resptr += sprintf(resptr, str_rounds, rounds); + 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') { + 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 { + 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(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(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; +} |