lobase

Linux port of OpenBSDs userland.
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commit b26cb592042f9942ca6e4c3022e5df3623739089
parent 566568d666f37c2263f12aabee692238580daf1e
Author: Duncaen <mail@duncano.de>
Date:   Wed,  8 Mar 2017 23:34:25 +0100

lib/libopenbsd: import bcrypt(3)

Diffstat:
lib/libopenbsd/crypt/Makefile.inc | 2+-
lib/libopenbsd/crypt/bcrypt.c | 397+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 398 insertions(+), 1 deletion(-)

diff --git a/lib/libopenbsd/crypt/Makefile.inc b/lib/libopenbsd/crypt/Makefile.inc @@ -2,6 +2,6 @@ VPATH+= ${LIBCSRCDIR}/arch/${MACHINE_CPU}/crypt ${LIBCSRCDIR}/crypt -SRCS+= arc4random.c arc4random_uniform.c blowfish.c +SRCS+= arc4random.c arc4random_uniform.c bcrypt.c blowfish.c MAN+= blowfish.3 arc4random.3 diff --git a/lib/libopenbsd/crypt/bcrypt.c b/lib/libopenbsd/crypt/bcrypt.c @@ -0,0 +1,397 @@ +/* $OpenBSD: bcrypt.c,v 1.57 2016/08/26 08:25:02 guenther Exp $ */ + +/* + * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org> + * Copyright (c) 1997 Niels Provos <provos@umich.edu> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +/* This password hashing algorithm was designed by David Mazieres + * <dm@lcs.mit.edu> and works as follows: + * + * 1. state := InitState () + * 2. state := ExpandKey (state, salt, password) + * 3. REPEAT rounds: + * state := ExpandKey (state, 0, password) + * state := ExpandKey (state, 0, salt) + * 4. ctext := "OrpheanBeholderScryDoubt" + * 5. REPEAT 64: + * ctext := Encrypt_ECB (state, ctext); + * 6. RETURN Concatenate (salt, ctext); + * + */ + +#include <sys/types.h> +#include <blf.h> +#include <ctype.h> +#include <errno.h> +#include <pwd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +/* This implementation is adaptable to current computing power. + * You can have up to 2^31 rounds which should be enough for some + * time to come. + */ + +#define BCRYPT_VERSION '2' +#define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ +#define BCRYPT_WORDS 6 /* Ciphertext words */ +#define BCRYPT_MINLOGROUNDS 4 /* we have log2(rounds) in salt */ + +#define BCRYPT_SALTSPACE (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1) +#define BCRYPT_HASHSPACE 61 + +char *bcrypt_gensalt(u_int8_t); + +static int encode_base64(char *, const u_int8_t *, size_t); +static int decode_base64(u_int8_t *, size_t, const char *); + +/* + * Generates a salt for this version of crypt. + */ +static int +bcrypt_initsalt(int log_rounds, uint8_t *salt, size_t saltbuflen) +{ + uint8_t csalt[BCRYPT_MAXSALT]; + + if (saltbuflen < BCRYPT_SALTSPACE) { + errno = EINVAL; + return -1; + } + + arc4random_buf(csalt, sizeof(csalt)); + + if (log_rounds < 4) + log_rounds = 4; + else if (log_rounds > 31) + log_rounds = 31; + + snprintf(salt, saltbuflen, "$2b$%2.2u$", log_rounds); + encode_base64(salt + 7, csalt, sizeof(csalt)); + + return 0; +} + +/* + * the core bcrypt function + */ +static int +bcrypt_hashpass(const char *key, const char *salt, char *encrypted, + size_t encryptedlen) +{ + blf_ctx state; + u_int32_t rounds, i, k; + u_int16_t j; + size_t key_len; + u_int8_t salt_len, logr, minor; + u_int8_t ciphertext[4 * BCRYPT_WORDS] = "OrpheanBeholderScryDoubt"; + u_int8_t csalt[BCRYPT_MAXSALT]; + u_int32_t cdata[BCRYPT_WORDS]; + + if (encryptedlen < BCRYPT_HASHSPACE) + goto inval; + + /* Check and discard "$" identifier */ + if (salt[0] != '$') + goto inval; + salt += 1; + + if (salt[0] != BCRYPT_VERSION) + goto inval; + + /* Check for minor versions */ + switch ((minor = salt[1])) { + case 'a': + key_len = (u_int8_t)(strlen(key) + 1); + break; + case 'b': + /* strlen() returns a size_t, but the function calls + * below result in implicit casts to a narrower integer + * type, so cap key_len at the actual maximum supported + * length here to avoid integer wraparound */ + key_len = strlen(key); + if (key_len > 72) + key_len = 72; + key_len++; /* include the NUL */ + break; + default: + goto inval; + } + if (salt[2] != '$') + goto inval; + /* Discard version + "$" identifier */ + salt += 3; + + /* Check and parse num rounds */ + if (!isdigit((unsigned char)salt[0]) || + !isdigit((unsigned char)salt[1]) || salt[2] != '$') + goto inval; + logr = (salt[1] - '0') + ((salt[0] - '0') * 10); + if (logr < BCRYPT_MINLOGROUNDS || logr > 31) + goto inval; + /* Computer power doesn't increase linearly, 2^x should be fine */ + rounds = 1U << logr; + + /* Discard num rounds + "$" identifier */ + salt += 3; + + if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT) + goto inval; + + /* We dont want the base64 salt but the raw data */ + if (decode_base64(csalt, BCRYPT_MAXSALT, salt)) + goto inval; + salt_len = BCRYPT_MAXSALT; + + /* Setting up S-Boxes and Subkeys */ + Blowfish_initstate(&state); + Blowfish_expandstate(&state, csalt, salt_len, + (u_int8_t *) key, key_len); + for (k = 0; k < rounds; k++) { + Blowfish_expand0state(&state, (u_int8_t *) key, key_len); + Blowfish_expand0state(&state, csalt, salt_len); + } + + /* This can be precomputed later */ + j = 0; + for (i = 0; i < BCRYPT_WORDS; i++) + cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_WORDS, &j); + + /* Now do the encryption */ + for (k = 0; k < 64; k++) + blf_enc(&state, cdata, BCRYPT_WORDS / 2); + + for (i = 0; i < BCRYPT_WORDS; i++) { + ciphertext[4 * i + 3] = cdata[i] & 0xff; + cdata[i] = cdata[i] >> 8; + ciphertext[4 * i + 2] = cdata[i] & 0xff; + cdata[i] = cdata[i] >> 8; + ciphertext[4 * i + 1] = cdata[i] & 0xff; + cdata[i] = cdata[i] >> 8; + ciphertext[4 * i + 0] = cdata[i] & 0xff; + } + + + snprintf(encrypted, 8, "$2%c$%2.2u$", minor, logr); + encode_base64(encrypted + 7, csalt, BCRYPT_MAXSALT); + encode_base64(encrypted + 7 + 22, ciphertext, 4 * BCRYPT_WORDS - 1); + explicit_bzero(&state, sizeof(state)); + explicit_bzero(ciphertext, sizeof(ciphertext)); + explicit_bzero(csalt, sizeof(csalt)); + explicit_bzero(cdata, sizeof(cdata)); + return 0; + +inval: + errno = EINVAL; + return -1; +} + +/* + * user friendly functions + */ +int +bcrypt_newhash(const char *pass, int log_rounds, char *hash, size_t hashlen) +{ + char salt[BCRYPT_SALTSPACE]; + + if (bcrypt_initsalt(log_rounds, salt, sizeof(salt)) != 0) + return -1; + + if (bcrypt_hashpass(pass, salt, hash, hashlen) != 0) + return -1; + + explicit_bzero(salt, sizeof(salt)); + return 0; +} +DEF_WEAK(bcrypt_newhash); + +int +bcrypt_checkpass(const char *pass, const char *goodhash) +{ + char hash[BCRYPT_HASHSPACE]; + + if (bcrypt_hashpass(pass, goodhash, hash, sizeof(hash)) != 0) + return -1; + if (strlen(hash) != strlen(goodhash) || + timingsafe_bcmp(hash, goodhash, strlen(goodhash)) != 0) { + errno = EACCES; + return -1; + } + + explicit_bzero(hash, sizeof(hash)); + return 0; +} +DEF_WEAK(bcrypt_checkpass); + +/* + * Measure this system's performance by measuring the time for 8 rounds. + * We are aiming for something that takes around 0.1s, but not too much over. + */ +int +_bcrypt_autorounds(void) +{ + struct timespec before, after; + int r = 8; + char buf[_PASSWORD_LEN]; + int duration; + + clock_gettime(CLOCK_THREAD_CPUTIME_ID, &before); + bcrypt_newhash("testpassword", r, buf, sizeof(buf)); + clock_gettime(CLOCK_THREAD_CPUTIME_ID, &after); + + duration = after.tv_sec - before.tv_sec; + duration *= 1000000; + duration += (after.tv_nsec - before.tv_nsec) / 1000; + + /* too quick? slow it down. */ + while (r < 16 && duration <= 60000) { + r += 1; + duration *= 2; + } + /* too slow? speed it up. */ + while (r > 6 && duration > 120000) { + r -= 1; + duration /= 2; + } + + return r; +} + +/* + * internal utilities + */ +static const u_int8_t Base64Code[] = +"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; + +static const u_int8_t index_64[128] = { + 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, + 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, + 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, + 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, + 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, + 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, + 255, 255, 255, 255, 255, 255, 28, 29, 30, + 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, + 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, + 51, 52, 53, 255, 255, 255, 255, 255 +}; +#define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) + +/* + * read buflen (after decoding) bytes of data from b64data + */ +static int +decode_base64(u_int8_t *buffer, size_t len, const char *b64data) +{ + u_int8_t *bp = buffer; + const u_int8_t *p = b64data; + u_int8_t c1, c2, c3, c4; + + while (bp < buffer + len) { + c1 = CHAR64(*p); + /* Invalid data */ + if (c1 == 255) + return -1; + + c2 = CHAR64(*(p + 1)); + if (c2 == 255) + return -1; + + *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4); + if (bp >= buffer + len) + break; + + c3 = CHAR64(*(p + 2)); + if (c3 == 255) + return -1; + + *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); + if (bp >= buffer + len) + break; + + c4 = CHAR64(*(p + 3)); + if (c4 == 255) + return -1; + *bp++ = ((c3 & 0x03) << 6) | c4; + + p += 4; + } + return 0; +} + +/* + * Turn len bytes of data into base64 encoded data. + * This works without = padding. + */ +static int +encode_base64(char *b64buffer, const u_int8_t *data, size_t len) +{ + u_int8_t *bp = b64buffer; + const u_int8_t *p = data; + u_int8_t c1, c2; + + while (p < data + len) { + c1 = *p++; + *bp++ = Base64Code[(c1 >> 2)]; + c1 = (c1 & 0x03) << 4; + if (p >= data + len) { + *bp++ = Base64Code[c1]; + break; + } + c2 = *p++; + c1 |= (c2 >> 4) & 0x0f; + *bp++ = Base64Code[c1]; + c1 = (c2 & 0x0f) << 2; + if (p >= data + len) { + *bp++ = Base64Code[c1]; + break; + } + c2 = *p++; + c1 |= (c2 >> 6) & 0x03; + *bp++ = Base64Code[c1]; + *bp++ = Base64Code[c2 & 0x3f]; + } + *bp = '\0'; + return 0; +} + +/* + * classic interface + */ +char * +bcrypt_gensalt(u_int8_t log_rounds) +{ + static char gsalt[BCRYPT_SALTSPACE]; + + bcrypt_initsalt(log_rounds, gsalt, sizeof(gsalt)); + + return gsalt; +} + +char * +bcrypt(const char *pass, const char *salt) +{ + static char gencrypted[BCRYPT_HASHSPACE]; + + if (bcrypt_hashpass(pass, salt, gencrypted, sizeof(gencrypted)) != 0) + return NULL; + + return gencrypted; +} +DEF_WEAK(bcrypt);