diff options
Diffstat (limited to 'src/libstrongswan/crypto/prfs')
| -rw-r--r-- | src/libstrongswan/crypto/prfs/fips_prf.c | 258 | ||||
| -rw-r--r-- | src/libstrongswan/crypto/prfs/fips_prf.h | 80 | ||||
| -rw-r--r-- | src/libstrongswan/crypto/prfs/prf.c | 16 | ||||
| -rw-r--r-- | src/libstrongswan/crypto/prfs/prf.h | 16 |
4 files changed, 358 insertions, 12 deletions
diff --git a/src/libstrongswan/crypto/prfs/fips_prf.c b/src/libstrongswan/crypto/prfs/fips_prf.c new file mode 100644 index 000000000..320e56dfc --- /dev/null +++ b/src/libstrongswan/crypto/prfs/fips_prf.c @@ -0,0 +1,258 @@ +/** + * @file fips_prf.c + * + * @brief Implementation for fips_prf_t. + * + */ + +/* + * Copyright (C) 2006 Martin Willi + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "fips_prf.h" + +#include <arpa/inet.h> + +#include <debug.h> + +typedef struct private_fips_prf_t private_fips_prf_t; + +/** + * Private data of a fips_prf_t object. + */ +struct private_fips_prf_t { + /** + * Public fips_prf_t interface. + */ + fips_prf_t public; + + /** + * key of prf function, "b" long + */ + u_int8_t *key; + + /** + * size of "b" in bytes + */ + size_t b; + + /** + * G function, either SHA1 or DES + */ + void (*g)(u_int8_t t[], chunk_t c, u_int8_t res[]); +}; + +/** + * t used in G(), equals to initial SHA1 value + */ +static u_int8_t t[] = { + 0x67,0x45,0x23,0x01,0xEF,0xCD,0xAB,0x89,0x98,0xBA, + 0xDC,0xFE,0x10,0x32,0x54,0x76,0xC3,0xD2,0xE1,0xF0, +}; + +/** + * sum = (a + b) mod 2 ^ (length * 8) + */ +static void add_mod(size_t length, u_int8_t a[], u_int8_t b[], u_int8_t sum[]) +{ + int i; + + for(i = length - 1; i >= 0; i--) + { + u_int32_t tmp; + int c = 0; + + tmp = a[i] + b[i] + c; + sum[i] = 0xff & tmp; + c = tmp >> 8; + } +} + +/** + * calculate "chunk mod 2^(length*8)" and save it into buffer + */ +static void chunk_mod(size_t length, chunk_t chunk, u_int8_t buffer[]) +{ + if (chunk.len < length) + { + /* apply seed as least significant bits, others are zero */ + memset(buffer, 0, length - chunk.len); + memcpy(buffer + length - chunk.len, chunk.ptr, chunk.len); + } + else + { + /* use least significant bytes from seed, as we use mod 2^b */ + memcpy(buffer, chunk.ptr + chunk.len - length, length); + } +} + +/** + * Implementation of prf_t.get_bytes. + * + * Test vector: + * + * key: + * 0xbd, 0x02, 0x9b, 0xbe, 0x7f, 0x51, 0x96, 0x0b, + * 0xcf, 0x9e, 0xdb, 0x2b, 0x61, 0xf0, 0x6f, 0x0f, + * 0xeb, 0x5a, 0x38, 0xb6 + * + * seed: + * 0x00 + * + * result: + * 0x20, 0x70, 0xb3, 0x22, 0x3d, 0xba, 0x37, 0x2f, + * 0xde, 0x1c, 0x0f, 0xfc, 0x7b, 0x2e, 0x3b, 0x49, + * 0x8b, 0x26, 0x06, 0x14, 0x3c, 0x6c, 0x18, 0xba, + * 0xcb, 0x0f, 0x6c, 0x55, 0xba, 0xbb, 0x13, 0x78, + * 0x8e, 0x20, 0xd7, 0x37, 0xa3, 0x27, 0x51, 0x16 + */ +static void get_bytes(private_fips_prf_t *this, chunk_t seed, u_int8_t w[]) +{ + int i; + u_int8_t xval[this->b]; + u_int8_t xseed[this->b]; + u_int8_t *xkey = this->key; + u_int8_t one[this->b]; + chunk_t xval_chunk = chunk_from_buf(xval); + + memset(one, 0, this->b); + one[this->b - 1] = 0x01; + + /* 3.1 */ + chunk_mod(this->b, seed, xseed); + + /* 3.2 */ + for (i = 0; i < 2; i++) /* twice */ + { + /* a. XVAL = (XKEY + XSEED j) mod 2^b */ + add_mod(this->b, xkey, xseed, xval); + DBG3("XVAL %b", xval, this->b); + /* b. wi = G(t, XVAL ) */ + this->g(t, xval_chunk, &w[i * this->b]); + DBG3("w[%d] %b", i, &w[i * this->b], this->b); + /* c. XKEY = (1 + XKEY + wi) mod 2b */ + add_mod(this->b, xkey, one, xkey); + add_mod(this->b, xkey, &w[i * this->b], xkey); + DBG3("XKEY %b", xkey, this->b); + } + + /* 3.3 done already, mod q not used */ +} + +/** + * Implementation of prf_t.get_block_size. + */ +static size_t get_block_size(private_fips_prf_t *this) +{ + return 2 * this->b; +} +/** + * Implementation of prf_t.allocate_bytes. + */ +static void allocate_bytes(private_fips_prf_t *this, chunk_t seed, chunk_t *chunk) +{ + *chunk = chunk_alloc(get_block_size(this)); + get_bytes(this, seed, chunk->ptr); +} + +/** + * Implementation of prf_t.get_key_size. + */ +static size_t get_key_size(private_fips_prf_t *this) +{ + return this->b; +} + +/** + * Implementation of prf_t.set_key. + */ +static void set_key(private_fips_prf_t *this, chunk_t key) +{ + /* save key as "key mod 2^b" */ + chunk_mod(this->b, key, this->key); +} + +/** + * Implementation of the G() function based on SHA1 + */ +void g_sha1(u_int8_t t[], chunk_t c, u_int8_t res[]) +{ + hasher_t *hasher; + u_int8_t buf[64]; + chunk_t state_chunk; + u_int32_t *state, *iv, *hash; + + if (c.len < sizeof(buf)) + { + /* pad c with zeros */ + memset(buf, 0, sizeof(buf)); + memcpy(buf, c.ptr, c.len); + c.ptr = buf; + c.len = sizeof(buf); + } + else + { + /* not more than 512 bits can be G()-ed */ + c.len = sizeof(buf); + } + + /* our SHA1 hasher's state is 32-Bit integers in host order. We must + * convert them */ + hasher = hasher_create(HASH_SHA1); + state_chunk = hasher->get_state(hasher); + state = (u_int32_t*)state_chunk.ptr; + iv = (u_int32_t*)t; + hash = (u_int32_t*)res; + state[0] = htonl(iv[0]); + state[1] = htonl(iv[1]); + state[2] = htonl(iv[2]); + state[3] = htonl(iv[3]); + hasher->get_hash(hasher, c, NULL); + hash[0] = htonl(state[0]); + hash[1] = htonl(state[1]); + hash[2] = htonl(state[2]); + hash[3] = htonl(state[3]); + hash[4] = htonl(state[4]); + hasher->destroy(hasher); +} + +/** + * Implementation of prf_t.destroy. + */ +static void destroy(private_fips_prf_t *this) +{ + free(this->key); + free(this); +} + +/* + * Described in header. + */ +fips_prf_t *fips_prf_create(size_t b, void(*g)(u_int8_t[],chunk_t,u_int8_t[])) +{ + private_fips_prf_t *this = malloc_thing(private_fips_prf_t); + + this->public.prf_interface.get_bytes = (void (*) (prf_t *,chunk_t,u_int8_t*))get_bytes; + this->public.prf_interface.allocate_bytes = (void (*) (prf_t*,chunk_t,chunk_t*))allocate_bytes; + this->public.prf_interface.get_block_size = (size_t (*) (prf_t*))get_block_size; + this->public.prf_interface.get_key_size = (size_t (*) (prf_t*))get_key_size; + this->public.prf_interface.set_key = (void (*) (prf_t *,chunk_t))set_key; + this->public.prf_interface.destroy = (void (*) (prf_t *))destroy; + + this->g = g; + this->b = b; + this->key = malloc(b); + + return &(this->public); +} diff --git a/src/libstrongswan/crypto/prfs/fips_prf.h b/src/libstrongswan/crypto/prfs/fips_prf.h new file mode 100644 index 000000000..283ee1f61 --- /dev/null +++ b/src/libstrongswan/crypto/prfs/fips_prf.h @@ -0,0 +1,80 @@ +/** + * @file fips_prf.h + * + * @brief Interface of fips_prf_t. + * + */ + +/* + * Copyright (C) 2006 Martin Willi + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#ifndef FIPS_PRF_H_ +#define FIPS_PRF_H_ + +typedef struct fips_prf_t fips_prf_t; + +#include <library.h> +#include <crypto/prfs/prf.h> +#include <crypto/hashers/hasher.h> + +/** + * @brief Implementation of prf_t using the FIPS 186-2-change1 standard. + * + * FIPS defines a "General Purpose Random Number Generator" (Revised + * Algorithm for Computing m values of x (Appendix 3.1 of FIPS 186-2)). This + * implementation is not intended for private key generation and therefore does + * not include the "mod q" operation (see FIPS 186-2-change1 p74). + * The FIPS PRF is stateful; the key changes every time when bytes are acquired. + * + * @b Constructors: + * - fips_prf_create() + * - prf_create() using one of the FIPS algorithms + * + * @ingroup prfs + */ +struct fips_prf_t { + + /** + * Generic prf_t interface for this fips_prf_t class. + */ + prf_t prf_interface; +}; + +/** + * @brief Creates a new fips_prf_t object. + * + * FIPS 186-2 defines G() functions used in the PRF function. It can + * be implemented either based on SHA1 or DES. + * + * @param b size of b (in bytes, not bits) + * @param g G() function to use (e.g. g_sha1) + * @return + * - fips_prf_t object + * - NULL if b invalid not supported + * + * @ingroup prfs + */ +fips_prf_t *fips_prf_create(size_t b, void(*g)(u_int8_t[],chunk_t,u_int8_t[])); + +/** + * @brief Implementation of the G() function based on SHA1. + * + * @param t initialization vector for SHA1 hasher, 20 bytes long + * @param c value to hash, not longer than 512 bit + * @param res result of G(), requries 20 bytes + */ +void g_sha1(u_int8_t t[], chunk_t c, u_int8_t res[]); + +#endif /* FIPS_PRF_H_ */ diff --git a/src/libstrongswan/crypto/prfs/prf.c b/src/libstrongswan/crypto/prfs/prf.c index aa5d1d2b7..f3b05ea00 100644 --- a/src/libstrongswan/crypto/prfs/prf.c +++ b/src/libstrongswan/crypto/prfs/prf.c @@ -26,10 +26,13 @@ #include <crypto/hashers/hasher.h> #include <crypto/prfs/hmac_prf.h> +#include <crypto/prfs/fips_prf.h> -ENUM_BEGIN(pseudo_random_function_names, PRF_UNDEFINED, PRF_UNDEFINED, - "PRF_UNDEFINED"); -ENUM_NEXT(pseudo_random_function_names, PRF_HMAC_MD5, PRF_AES128_CBC, PRF_UNDEFINED, +ENUM_BEGIN(pseudo_random_function_names, PRF_UNDEFINED, PRF_FIPS_DES, + "PRF_UNDEFINED", + "PRF_FIPS_SHA1_160", + "PRF_FIPS_DES"); +ENUM_NEXT(pseudo_random_function_names, PRF_HMAC_MD5, PRF_AES128_CBC, PRF_FIPS_DES, "PRF_HMAC_MD5", "PRF_HMAC_SHA1", "PRF_HMAC_TIGER", @@ -44,13 +47,12 @@ prf_t *prf_create(pseudo_random_function_t pseudo_random_function) switch (pseudo_random_function) { case PRF_HMAC_SHA1: - { return (prf_t*)hmac_prf_create(HASH_SHA1); - } case PRF_HMAC_MD5: - { return (prf_t*)hmac_prf_create(HASH_MD5); - } + case PRF_FIPS_SHA1_160: + return (prf_t*)fips_prf_create(20, g_sha1); + case PRF_FIPS_DES: case PRF_HMAC_TIGER: case PRF_AES128_CBC: default: diff --git a/src/libstrongswan/crypto/prfs/prf.h b/src/libstrongswan/crypto/prfs/prf.h index 897cf906b..7a4501866 100644 --- a/src/libstrongswan/crypto/prfs/prf.h +++ b/src/libstrongswan/crypto/prfs/prf.h @@ -31,11 +31,10 @@ typedef struct prf_t prf_t; /** * @brief Pseudo random function, as in IKEv2 RFC 3.3.2. - * - * Currently only the following algorithms are implemented: - * - PRF_HMAC_MD5 - * - PRF_HMAC_SHA1 - * + * + * PRF algorithms not defined in IKEv2 are allocated in "private use" + * space. + * * @ingroup prfs */ enum pseudo_random_function_t { @@ -46,6 +45,10 @@ enum pseudo_random_function_t { PRF_HMAC_SHA1 = 2, PRF_HMAC_TIGER = 3, PRF_AES128_CBC = 4, + /** Implemented via fips_prf_t, other output sizes would be possible */ + PRF_FIPS_SHA1_160 = 1025, + /** Could be implemented via fips_prf_t, uses fixed output size of 160bit */ + PRF_FIPS_DES = 1026, }; /** @@ -93,6 +96,9 @@ struct prf_t { /** * @brief Get the key size of this prf_t object. + * + * This is a suggestion only, all implemented PRFs accept variable key + * length. * * @param this calling object * @return key size in bytes |