../svn-commit.tmp

This commit is contained in:
Martin Willi
2006-04-05 12:10:50 +00:00
parent 3dbbbf3e16
commit 6862128151
171 changed files with 674 additions and 1355 deletions
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# Copyright (C) 2005 Jan Hutter, 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.
#
RSA_DIR= $(CRYPTO_DIR)rsa/
LIB_OBJS+= $(BUILD_DIR)rsa_private_key.o
$(BUILD_DIR)rsa_private_key.o : $(RSA_DIR)rsa_private_key.c $(RSA_DIR)rsa_private_key.h
$(CC) $(CFLAGS) -c -o $@ $<
LIB_OBJS+= $(BUILD_DIR)rsa_public_key.o
$(BUILD_DIR)rsa_public_key.o : $(RSA_DIR)rsa_public_key.c $(RSA_DIR)rsa_public_key.h
$(CC) $(CFLAGS) -c -o $@ $<
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/**
* @file rsa_private_key.c
*
* @brief Implementation of rsa_private_key_t.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, 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 <gmp.h>
#include <sys/stat.h>
#include <unistd.h>
#include "rsa_private_key.h"
#include <daemon.h>
#include <utils/allocator.h>
#include <asn1/der_decoder.h>
/*
* Oids for hash algorithms are defined in
* rsa_public_key.c.
*/
extern u_int8_t md2_oid[18];
extern u_int8_t md5_oid[18];
extern u_int8_t sha1_oid[15];
extern u_int8_t sha256_oid[19];
extern u_int8_t sha384_oid[19];
extern u_int8_t sha512_oid[19];
/**
* Public exponent to use for key generation.
*/
#define PUBLIC_EXPONENT 0x10001
typedef struct private_rsa_private_key_t private_rsa_private_key_t;
/**
* Private data of a rsa_private_key_t object.
*/
struct private_rsa_private_key_t {
/**
* Public interface for this signer.
*/
rsa_private_key_t public;
/**
* Version of key, as encoded in PKCS#1
*/
u_int version;
/**
* Public modulus.
*/
mpz_t n;
/**
* Public exponent.
*/
mpz_t e;
/**
* Private prime 1.
*/
mpz_t p;
/**
* Private Prime 2.
*/
mpz_t q;
/**
* Private exponent.
*/
mpz_t d;
/**
* Private exponent 1.
*/
mpz_t exp1;
/**
* Private exponent 2.
*/
mpz_t exp2;
/**
* Private coefficient.
*/
mpz_t coeff;
/**
* Keysize in bytes.
*/
size_t k;
/**
* @brief Implements the RSADP algorithm specified in PKCS#1.
*
* @param this calling object
* @param data data to process
* @return processed data
*/
chunk_t (*rsadp) (private_rsa_private_key_t *this, chunk_t data);
/**
* @brief Implements the RSASP1 algorithm specified in PKCS#1.
* @param this calling object
* @param data data to process
* @return processed data
*/
chunk_t (*rsasp1) (private_rsa_private_key_t *this, chunk_t data);
/**
* @brief Generate a prime value.
*
* @param this calling object
* @param prime_size size of the prime, in bytes
* @param[out] prime uninitialized mpz
*/
status_t (*compute_prime) (private_rsa_private_key_t *this, size_t prime_size, mpz_t *prime);
};
/**
* Rules for de-/encoding of a private key from/in ASN1
*/
static asn1_rule_t rsa_private_key_rules[] = {
{ASN1_SEQUENCE, 0, 0, 0},
{ ASN1_INTEGER, 0, offsetof(private_rsa_private_key_t, version), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, n), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, e), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, d), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, p), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, q), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, exp1), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, exp2), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_private_key_t, coeff), 0},
{ASN1_END, 0, 0, 0},
};
static private_rsa_private_key_t *rsa_private_key_create_empty();
/**
* Implementation of private_rsa_private_key_t.compute_prime.
*/
static status_t compute_prime(private_rsa_private_key_t *this, size_t prime_size, mpz_t *prime)
{
randomizer_t *randomizer;
chunk_t random_bytes;
status_t status;
randomizer = randomizer_create();
mpz_init(*prime);
do
{
status = randomizer->allocate_random_bytes(randomizer, prime_size, &random_bytes);
if (status != SUCCESS)
{
randomizer->destroy(randomizer);
mpz_clear(*prime);
return FAILED;
}
/* make sure most significant bit is set */
random_bytes.ptr[0] = random_bytes.ptr[0] | 0x80;
/* convert chunk to mpz value */
mpz_import(*prime, random_bytes.len, 1, 1, 1, 0, random_bytes.ptr);
/* get next prime */
mpz_nextprime (*prime, *prime);
allocator_free(random_bytes.ptr);
}
/* check if it isnt too large */
while (((mpz_sizeinbase(*prime, 2) + 7) / 8) > prime_size);
randomizer->destroy(randomizer);
return SUCCESS;
}
/**
* Implementation of private_rsa_private_key_t.rsadp and private_rsa_private_key_t.rsasp1.
*/
static chunk_t rsadp(private_rsa_private_key_t *this, chunk_t data)
{
mpz_t t1, t2;
chunk_t decrypted;
mpz_init(t1);
mpz_init(t2);
mpz_import(t1, data.len, 1, 1, 1, 0, data.ptr);
mpz_powm(t2, t1, this->exp1, this->p); /* m1 = c^dP mod p */
mpz_powm(t1, t1, this->exp2, this->q); /* m2 = c^dQ mod Q */
mpz_sub(t2, t2, t1); /* h = qInv (m1 - m2) mod p */
mpz_mod(t2, t2, this->p);
mpz_mul(t2, t2, this->coeff);
mpz_mod(t2, t2, this->p);
mpz_mul(t2, t2, this->q); /* m = m2 + h q */
mpz_add(t1, t1, t2);
decrypted.len = this->k;
decrypted.ptr = mpz_export(NULL, NULL, 1, decrypted.len, 1, 0, t1);
mpz_clear(t1);
mpz_clear(t2);
return decrypted;
}
/**
* Implementation of rsa_private_key.build_emsa_signature.
*/
static status_t build_emsa_pkcs1_signature(private_rsa_private_key_t *this, hash_algorithm_t hash_algorithm, chunk_t data, chunk_t *signature)
{
hasher_t *hasher;
chunk_t hash;
chunk_t oid;
chunk_t em;
/* get oid string prepended to hash */
switch (hash_algorithm)
{
case HASH_MD2:
{
oid.ptr = md2_oid;
oid.len = sizeof(md2_oid);
break;
}
case HASH_MD5:
{
oid.ptr = md5_oid;
oid.len = sizeof(md5_oid);
break;
}
case HASH_SHA1:
{
oid.ptr = sha1_oid;
oid.len = sizeof(sha1_oid);
break;
}
case HASH_SHA256:
{
oid.ptr = sha256_oid;
oid.len = sizeof(sha256_oid);
break;
}
case HASH_SHA384:
{
oid.ptr = sha384_oid;
oid.len = sizeof(sha384_oid);
break;
}
case HASH_SHA512:
{
oid.ptr = sha512_oid;
oid.len = sizeof(sha512_oid);
break;
}
default:
{
return NOT_SUPPORTED;
}
}
/* get hasher */
hasher = hasher_create(hash_algorithm);
if (hasher == NULL)
{
return NOT_SUPPORTED;
}
/* build hash */
hasher->allocate_hash(hasher, data, &hash);
hasher->destroy(hasher);
/* build chunk to rsa-decrypt:
* EM = 0x00 || 0x01 || PS || 0x00 || T.
* PS = 0xFF padding, with length to fill em
* T = oid || hash
*/
em.len = this->k;
em.ptr = allocator_alloc(em.len);
/* fill em with padding */
memset(em.ptr, 0xFF, em.len);
/* set magic bytes */
*(em.ptr) = 0x00;
*(em.ptr+1) = 0x01;
*(em.ptr + em.len - hash.len - oid.len - 1) = 0x00;
/* set hash */
memcpy(em.ptr + em.len - hash.len, hash.ptr, hash.len);
/* set oid */
memcpy(em.ptr + em.len - hash.len - oid.len, oid.ptr, oid.len);
/* build signature */
*signature = this->rsasp1(this, em);
allocator_free(hash.ptr);
allocator_free(em.ptr);
return SUCCESS;
}
/**
* Implementation of rsa_private_key.get_key.
*/
static status_t get_key(private_rsa_private_key_t *this, chunk_t *key)
{
chunk_t n, e, p, q, d, exp1, exp2, coeff;
n.len = this->k;
n.ptr = mpz_export(NULL, NULL, 1, n.len, 1, 0, this->n);
e.len = this->k;
e.ptr = mpz_export(NULL, NULL, 1, e.len, 1, 0, this->e);
p.len = this->k;
p.ptr = mpz_export(NULL, NULL, 1, p.len, 1, 0, this->p);
q.len = this->k;
q.ptr = mpz_export(NULL, NULL, 1, q.len, 1, 0, this->q);
d.len = this->k;
d.ptr = mpz_export(NULL, NULL, 1, d.len, 1, 0, this->d);
exp1.len = this->k;
exp1.ptr = mpz_export(NULL, NULL, 1, exp1.len, 1, 0, this->exp1);
exp2.len = this->k;
exp2.ptr = mpz_export(NULL, NULL, 1, exp2.len, 1, 0, this->exp2);
coeff.len = this->k;
coeff.ptr = mpz_export(NULL, NULL, 1, coeff.len, 1, 0, this->coeff);
key->len = this->k * 8;
key->ptr = allocator_alloc(key->len);
memcpy(key->ptr + this->k * 0, n.ptr , n.len);
memcpy(key->ptr + this->k * 1, e.ptr, e.len);
memcpy(key->ptr + this->k * 2, p.ptr, p.len);
memcpy(key->ptr + this->k * 3, q.ptr, q.len);
memcpy(key->ptr + this->k * 4, d.ptr, d.len);
memcpy(key->ptr + this->k * 5, exp1.ptr, exp1.len);
memcpy(key->ptr + this->k * 6, exp2.ptr, exp2.len);
memcpy(key->ptr + this->k * 7, coeff.ptr, coeff.len);
allocator_free(n.ptr);
allocator_free(e.ptr);
allocator_free(p.ptr);
allocator_free(q.ptr);
allocator_free(d.ptr);
allocator_free(exp1.ptr);
allocator_free(exp2.ptr);
allocator_free(coeff.ptr);
return SUCCESS;
}
/**
* Implementation of rsa_private_key.save_key.
*/
static status_t save_key(private_rsa_private_key_t *this, char *file)
{
return NOT_SUPPORTED;
}
/**
* Implementation of rsa_private_key.get_public_key.
*/
rsa_public_key_t *get_public_key(private_rsa_private_key_t *this)
{
return NULL;
}
/**
* Implementation of rsa_private_key.belongs_to.
*/
static bool belongs_to(private_rsa_private_key_t *this, rsa_public_key_t *public)
{
if (mpz_cmp(this->n, *public->get_modulus(public)) == 0)
{
return TRUE;
}
return FALSE;
}
/**
* Implementation of rsa_private_key.clone.
*/
static rsa_private_key_t* _clone(private_rsa_private_key_t *this)
{
private_rsa_private_key_t *clone = rsa_private_key_create_empty();
mpz_init_set(clone->n, this->n);
mpz_init_set(clone->e, this->e);
mpz_init_set(clone->p, this->p);
mpz_init_set(clone->q, this->q);
mpz_init_set(clone->d, this->d);
mpz_init_set(clone->exp1, this->exp1);
mpz_init_set(clone->exp2, this->exp2);
mpz_init_set(clone->coeff, this->coeff);
clone->k = this->k;
return &clone->public;
}
/**
* Implementation of rsa_private_key.destroy.
*/
static void destroy(private_rsa_private_key_t *this)
{
mpz_clear(this->n);
mpz_clear(this->e);
mpz_clear(this->p);
mpz_clear(this->q);
mpz_clear(this->d);
mpz_clear(this->exp1);
mpz_clear(this->exp2);
mpz_clear(this->coeff);
allocator_free(this);
}
/**
* Internal generic constructor
*/
static private_rsa_private_key_t *rsa_private_key_create_empty()
{
private_rsa_private_key_t *this = allocator_alloc_thing(private_rsa_private_key_t);
/* public functions */
this->public.build_emsa_pkcs1_signature = (status_t (*) (rsa_private_key_t*,hash_algorithm_t,chunk_t,chunk_t*))build_emsa_pkcs1_signature;
this->public.get_key = (status_t (*) (rsa_private_key_t*,chunk_t*))get_key;
this->public.save_key = (status_t (*) (rsa_private_key_t*,char*))save_key;
this->public.get_public_key = (rsa_public_key_t *(*) (rsa_private_key_t*))get_public_key;
this->public.belongs_to = (bool (*) (rsa_private_key_t*,rsa_public_key_t*))belongs_to;
this->public.clone = (rsa_private_key_t*(*)(rsa_private_key_t*))_clone;
this->public.destroy = (void (*) (rsa_private_key_t*))destroy;
/* private functions */
this->rsadp = rsadp;
this->rsasp1 = rsadp; /* same algorithm */
this->compute_prime = compute_prime;
return this;
}
/*
* See header
*/
rsa_private_key_t *rsa_private_key_create(size_t key_size)
{
mpz_t p, q, n, e, d, exp1, exp2, coeff;
mpz_t m, q1, t;
private_rsa_private_key_t *this;
this = rsa_private_key_create_empty();
key_size = key_size / 8;
/* Get values of primes p and q */
if (this->compute_prime(this, key_size/2, &p) != SUCCESS)
{
allocator_free(this);
return NULL;
}
if (this->compute_prime(this, key_size/2, &q) != SUCCESS)
{
mpz_clear(p);
allocator_free(this);
return NULL;
}
mpz_init(t);
mpz_init(n);
mpz_init(d);
mpz_init(exp1);
mpz_init(exp2);
mpz_init(coeff);
/* Swapping Primes so p is larger then q */
if (mpz_cmp(p, q) < 0)
{
mpz_set(t, p);
mpz_set(p, q);
mpz_set(q, t);
}
mpz_mul(n, p, q); /* n = p*q */
mpz_init_set_ui(e, PUBLIC_EXPONENT); /* assign public exponent */
mpz_init_set(m, p); /* m = p */
mpz_sub_ui(m, m, 1); /* m = m -1 */
mpz_init_set(q1, q); /* q1 = q */
mpz_sub_ui(q1, q1, 1); /* q1 = q1 -1 */
mpz_gcd(t, m, q1); /* t = gcd(p-1, q-1) */
mpz_mul(m, m, q1); /* m = (p-1)*(q-1) */
mpz_divexact(m, m, t); /* m = m / t */
mpz_gcd(t, m, e); /* t = gcd(m, e) (greatest common divisor) */
mpz_invert(d, e, m); /* e has an inverse mod m */
if (mpz_cmp_ui(d, 0) < 0) /* make sure d is positive */
{
mpz_add(d, d, m);
}
mpz_sub_ui(t, p, 1); /* t = p-1 */
mpz_mod(exp1, d, t); /* exp1 = d mod p-1 */
mpz_sub_ui(t, q, 1); /* t = q-1 */
mpz_mod(exp2, d, t); /* exp2 = d mod q-1 */
mpz_invert(coeff, q, p); /* coeff = q^-1 mod p */
if (mpz_cmp_ui(coeff, 0) < 0) /* make coeff d is positive */
{
mpz_add(coeff, coeff, p);
}
mpz_clear(q1);
mpz_clear(m);
mpz_clear(t);
/* apply values */
*(this->p) = *p;
*(this->q) = *q;
*(this->n) = *n;
*(this->e) = *e;
*(this->d) = *d;
*(this->exp1) = *exp1;
*(this->exp2) = *exp2;
*(this->coeff) = *coeff;
/* set key size in bytes */
this->k = key_size;
return &this->public;
}
/*
* see header
*/
rsa_private_key_t *rsa_private_key_create_from_chunk(chunk_t chunk)
{
private_rsa_private_key_t *this;
der_decoder_t *dd;
status_t status;
this = rsa_private_key_create_empty();
mpz_init(this->n);
mpz_init(this->e);
mpz_init(this->p);
mpz_init(this->q);
mpz_init(this->d);
mpz_init(this->exp1);
mpz_init(this->exp2);
mpz_init(this->coeff);
dd = der_decoder_create(rsa_private_key_rules);
status = dd->decode(dd, chunk, this);
dd->destroy(dd);
if (status != SUCCESS)
{
destroy(this);
return NULL;
}
this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8;
return &this->public;
}
/*
* see header
*/
rsa_private_key_t *rsa_private_key_create_from_file(char *filename, char *passphrase)
{
chunk_t chunk;
struct stat stb;
FILE *file;
char *buffer;
if (stat(filename, &stb) == -1)
{
return NULL;
}
buffer = alloca(stb.st_size);
file = fopen(filename, "r");
if (file == NULL)
{
return NULL;
}
if (fread(buffer, stb.st_size, 1, file) != 1)
{
return NULL;
}
chunk.ptr = buffer;
chunk.len = stb.st_size;
return rsa_private_key_create_from_chunk(chunk);
}
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/**
* @file rsa_private_key.h
*
* @brief Interface of rsa_private_key_t.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, 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 RSA_PRIVATE_KEY_H_
#define RSA_PRIVATE_KEY_H_
#include <types.h>
#include <definitions.h>
#include <crypto/rsa/rsa_public_key.h>
#include <crypto/hashers/hasher.h>
typedef struct rsa_private_key_t rsa_private_key_t;
/**
* @brief RSA private key with associated functions.
*
* Currently only supports signing using EMSA encoding.
*
* @b Constructors:
* - rsa_private_key_create()
* - rsa_private_key_create_from_chunk()
* - rsa_private_key_create_from_file()
*
* @see rsa_public_key_t
*
* @todo Implement get_key(), save_key(), get_public_key()
*
* @ingroup rsa
*/
struct rsa_private_key_t {
/**
* @brief Build a signature over a chunk using EMSA-PKCS1 encoding.
*
* This signature creates a hash using the specified hash algorithm, concatenates
* it with an ASN1-OID of the hash algorithm and runs the RSASP1 function
* on it.
*
* @param this calling object
* @param hash_algorithm hash algorithm to use for hashing
* @param data data to sign
* @param[out] signature allocated signature
* @return
* - SUCCESS
* - INVALID_STATE, if key not set
* - NOT_SUPPORTED, if hash algorithm not supported
*/
status_t (*build_emsa_pkcs1_signature) (rsa_private_key_t *this, hash_algorithm_t hash_algorithm, chunk_t data, chunk_t *signature);
/**
* @brief Gets the key.
*
* UNIMPLEMENTED!
*
* @param this calling object
* @param key key (in a propriarity format)
* @return
* - SUCCESS
* - INVALID_STATE, if key not set
*/
status_t (*get_key) (rsa_private_key_t *this, chunk_t *key);
/**
* @brief Saves a key to a file.
*
* Not implemented!
*
* @param this calling object
* @param file file to which the key should be written.
* @return NOT_SUPPORTED
*/
status_t (*save_key) (rsa_private_key_t *this, char *file);
/**
* @brief Generate a new key.
*
* Generates a new private_key with specified key size
*
* @param this calling object
* @param key_size size of the key in bits
* @return
* - SUCCESS
* - INVALID_ARG if key_size invalid
*/
status_t (*generate_key) (rsa_private_key_t *this, size_t key_size);
/**
* @brief Create a rsa_public_key_t with the public
* parts of the key.
*
* @param this calling object
* @return public_key
*/
rsa_public_key_t *(*get_public_key) (rsa_private_key_t *this);
/**
* @brief Check if a private key belongs to a public key.
*
* Compares the public part of the private key with the
* public key, return TRUE if it equals.
*
* @param this private key
* @param public public key
* @return TRUE, if keys belong together
*/
bool (*belongs_to) (rsa_private_key_t *this, rsa_public_key_t *public);
/**
* @brief Clone the private key.
*
* @param this private key to clone
* @return clone of this
*/
rsa_private_key_t *(*clone) (rsa_private_key_t *this);
/**
* @brief Destroys the private key.
*
* @param this private key to destroy
*/
void (*destroy) (rsa_private_key_t *this);
};
/**
* @brief Generate a new RSA key with specified key lenght.
*
* @param key_size size of the key in bits
* @return generated rsa_private_key_t.
*
* @ingroup rsa
*/
rsa_private_key_t *rsa_private_key_create(size_t key_size);
/**
* @brief Load an RSA private key from a chunk.
*
* Load a key from a chunk, encoded as described in PKCS#1
* (ASN1 DER encoded).
*
* @param chunk chunk containing the DER encoded key
* @return loaded rsa_private_key_t, or NULL
*
* @ingroup rsa
*/
rsa_private_key_t *rsa_private_key_create_from_chunk(chunk_t chunk);
/**
* @brief Load an RSA private key from a file.
*
* Load a key from a file, which is either in a unencrypted binary
* format (DER), or in a (encrypted) PEM format. The supplied
* passphrase is used to decrypt an ecrypted key.
*
* @param filename filename which holds the key
* @param passphrase optional passphase for decryption
* @return loaded rsa_private_key_t, or NULL
*
* @todo Implement PEM file loading
* @todo Implement key decryption
*
* @ingroup rsa
*/
rsa_private_key_t *rsa_private_key_create_from_file(char *filename, char *passphrase);
#endif /*RSA_PRIVATE_KEY_H_*/
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/**
* @file rsa_public_key.c
*
* @brief Implementation of rsa_public_key_t.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, 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 <gmp.h>
#include <sys/stat.h>
#include <unistd.h>
#include "rsa_public_key.h"
#include <daemon.h>
#include <utils/allocator.h>
#include <crypto/hashers/hasher.h>
#include <asn1/der_decoder.h>
/*
* For simplicity,
* we use these predefined values for
* hash algorithm OIDs. These also contain
* the length of the following hash.
* These values are also used in rsa_private_key.c.
*/
u_int8_t md2_oid[] = {
0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,
0x04,0x10
};
u_int8_t md5_oid[] = {
0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,
0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,
0x04,0x10
};
u_int8_t sha1_oid[] = {
0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,
0x03,0x02,0x1a,0x05,0x00,0x04,0x14
};
u_int8_t sha256_oid[] = {
0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,
0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,
0x00,0x04,0x20
};
u_int8_t sha384_oid[] = {
0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,
0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,
0x00,0x04,0x30
};
u_int8_t sha512_oid[] = {
0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,
0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,
0x00,0x04,0x40
};
typedef struct private_rsa_public_key_t private_rsa_public_key_t;
/**
* Private data structure with signing context.
*/
struct private_rsa_public_key_t {
/**
* Public interface for this signer.
*/
rsa_public_key_t public;
/**
* Public modulus.
*/
mpz_t n;
/**
* Public exponent.
*/
mpz_t e;
/**
* Keysize in bytes.
*/
size_t k;
/**
* @brief Implements the RSAEP algorithm specified in PKCS#1.
*
* @param this calling object
* @param data data to process
* @return processed data
*/
chunk_t (*rsaep) (private_rsa_public_key_t *this, chunk_t data);
/**
* @brief Implements the RSASVP1 algorithm specified in PKCS#1.
*
* @param this calling object
* @param data data to process
* @return processed data
*/
chunk_t (*rsavp1) (private_rsa_public_key_t *this, chunk_t data);
};
typedef struct rsa_public_key_info_t rsa_public_key_info_t;
/**
* KeyInfo, as it appears in a public key file
*/
struct rsa_public_key_info_t {
/**
* Algorithm for this key
*/
chunk_t algorithm_oid;
/**
* Public key, parseable with rsa_public_key_rules
*/
chunk_t public_key;
};
/**
* Rules for de-/encoding of a public key from/in ASN1
*/
static asn1_rule_t rsa_public_key_rules[] = {
{ASN1_SEQUENCE, 0, 0, 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_public_key_t, n), 0},
{ ASN1_INTEGER, ASN1_MPZ, offsetof(private_rsa_public_key_t, e), 0},
{ASN1_END, 0, 0, 0},
};
/**
* Rules for de-/encoding of a PublicKeyInfo from/in ASN1
*/
static asn1_rule_t rsa_public_key_info_rules[] = {
{ASN1_SEQUENCE, 0, 0, 0},
{ ASN1_SEQUENCE, 0, 0, 0},
{ ASN1_OID, 0, offsetof(rsa_public_key_info_t, algorithm_oid), 0},
{ ASN1_NULL, 0, 0, 0},
{ ASN1_END, 0, 0, 0},
{ ASN1_BITSTRING, 0, offsetof(rsa_public_key_info_t, public_key), 0},
{ASN1_END, 0, 0, 0},
};
private_rsa_public_key_t *rsa_public_key_create_empty();
/**
* Implementation of private_rsa_public_key_t.rsaep and private_rsa_public_key_t.rsavp1
*/
static chunk_t rsaep(private_rsa_public_key_t *this, chunk_t data)
{
mpz_t m, c;
chunk_t encrypted;
mpz_init(c);
mpz_init(m);
mpz_import(m, data.len, 1, 1, 1, 0, data.ptr);
mpz_powm(c, m, this->e, this->n);
encrypted.len = this->k;
encrypted.ptr = mpz_export(NULL, NULL, 1, encrypted.len, 1, 0, c);
mpz_clear(c);
mpz_clear(m);
return encrypted;
}
/**
* Implementation of rsa_public_key.verify_emsa_pkcs1_signature.
*/
static status_t verify_emsa_pkcs1_signature(private_rsa_public_key_t *this, chunk_t data, chunk_t signature)
{
hasher_t *hasher = NULL;
chunk_t hash;
chunk_t em;
u_int8_t *pos;
if (signature.len > this->k)
{
return INVALID_ARG;
}
/* unpack signature */
em = this->rsavp1(this, signature);
/* result should look like this:
* EM = 0x00 || 0x01 || PS || 0x00 || T.
* PS = 0xFF padding, with length to fill em
* T = oid || hash
*/
/* check magic bytes */
if ((*(em.ptr) != 0x00) ||
(*(em.ptr+1) != 0x01))
{
allocator_free(em.ptr);
return FAILED;
}
/* find magic 0x00 */
pos = em.ptr + 2;
while (pos <= em.ptr + em.len)
{
if (*pos == 0x00)
{
/* found magic byte, stop */
pos++;
break;
}
else if (*pos != 0xFF)
{
/* bad padding, decryption failed ?!*/
allocator_free(em.ptr);
return FAILED;
}
pos++;
}
if (pos + 20 > em.ptr + em.len)
{
/* not enought room for oid compare */
allocator_free(em.ptr);
return FAILED;
}
if (memcmp(md2_oid, pos, sizeof(md2_oid)) == 0)
{
hasher = hasher_create(HASH_MD2);
pos += sizeof(md2_oid);
}
else if (memcmp(md5_oid, pos, sizeof(md5_oid)) == 0)
{
hasher = hasher_create(HASH_MD5);
pos += sizeof(md5_oid);
}
else if (memcmp(sha1_oid, pos, sizeof(sha1_oid)) == 0)
{
hasher = hasher_create(HASH_SHA1);
pos += sizeof(sha1_oid);
}
else if (memcmp(sha256_oid, pos, sizeof(sha256_oid)) == 0)
{
hasher = hasher_create(HASH_SHA256);
pos += sizeof(sha256_oid);
}
else if (memcmp(sha384_oid, pos, sizeof(sha384_oid)) == 0)
{
hasher = hasher_create(HASH_SHA384);
pos += sizeof(sha384_oid);
}
else if (memcmp(sha512_oid, pos, sizeof(sha512_oid)) == 0)
{
hasher = hasher_create(HASH_SHA512);
pos += sizeof(sha512_oid);
}
if (hasher == NULL)
{
/* not supported hash algorithm */
allocator_free(em.ptr);
return NOT_SUPPORTED;
}
if (pos + hasher->get_block_size(hasher) != em.ptr + em.len)
{
/* bad length */
allocator_free(em.ptr);
hasher->destroy(hasher);
return FAILED;
}
/* build own hash for a compare */
hasher->allocate_hash(hasher, data, &hash);
hasher->destroy(hasher);
if (memcmp(hash.ptr, pos, hash.len) != 0)
{
/* hash does not equal */
allocator_free(hash.ptr);
allocator_free(em.ptr);
return FAILED;
}
/* seems good */
allocator_free(hash.ptr);
allocator_free(em.ptr);
return SUCCESS;
}
/**
* Implementation of rsa_public_key.get_key.
*/
static status_t get_key(private_rsa_public_key_t *this, chunk_t *key)
{
chunk_t n, e;
n.len = this->k;
n.ptr = mpz_export(NULL, NULL, 1, n.len, 1, 0, this->n);
e.len = this->k;
e.ptr = mpz_export(NULL, NULL, 1, e.len, 1, 0, this->e);
key->len = this->k * 2;
key->ptr = allocator_alloc(key->len);
memcpy(key->ptr, n.ptr, n.len);
memcpy(key->ptr + n.len, e.ptr, e.len);
allocator_free(n.ptr);
allocator_free(e.ptr);
return SUCCESS;
}
/**
* Implementation of rsa_public_key.save_key.
*/
static status_t save_key(private_rsa_public_key_t *this, char *file)
{
return NOT_SUPPORTED;
}
/**
* Implementation of rsa_public_key.get_modulus.
*/
static mpz_t *get_modulus(private_rsa_public_key_t *this)
{
return &this->n;
}
/**
* Implementation of rsa_public_key.clone.
*/
static rsa_public_key_t* _clone(private_rsa_public_key_t *this)
{
private_rsa_public_key_t *clone = rsa_public_key_create_empty();
mpz_init_set(clone->n, this->n);
mpz_init_set(clone->e, this->e);
clone->k = this->k;
return &clone->public;
}
/**
* Implementation of rsa_public_key.destroy.
*/
static void destroy(private_rsa_public_key_t *this)
{
mpz_clear(this->n);
mpz_clear(this->e);
allocator_free(this);
}
/**
* Generic private constructor
*/
private_rsa_public_key_t *rsa_public_key_create_empty()
{
private_rsa_public_key_t *this = allocator_alloc_thing(private_rsa_public_key_t);
/* public functions */
this->public.verify_emsa_pkcs1_signature = (status_t (*) (rsa_public_key_t*,chunk_t,chunk_t))verify_emsa_pkcs1_signature;
this->public.get_key = (status_t (*) (rsa_public_key_t*,chunk_t*))get_key;
this->public.save_key = (status_t (*) (rsa_public_key_t*,char*))save_key;
this->public.get_modulus = (mpz_t *(*) (rsa_public_key_t*))get_modulus;
this->public.clone = (rsa_public_key_t* (*) (rsa_public_key_t*))_clone;
this->public.destroy = (void (*) (rsa_public_key_t*))destroy;
/* private functions */
this->rsaep = rsaep;
this->rsavp1 = rsaep; /* same algorithm */
return this;
}
/*
* See header
*/
rsa_public_key_t *rsa_public_key_create_from_chunk(chunk_t chunk)
{
der_decoder_t *dd;
status_t status;
private_rsa_public_key_t *this;
this = rsa_public_key_create_empty();
mpz_init(this->n);
mpz_init(this->e);
dd = der_decoder_create(rsa_public_key_rules);
status = dd->decode(dd, chunk, this);
dd->destroy(dd);
if (status != SUCCESS)
{
destroy(this);
return NULL;
}
this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8;
return &this->public;
}
/*
* See header
*/
rsa_public_key_t *rsa_public_key_create_from_file(char *filename)
{
struct stat stb;
FILE *file;
char *buffer;
chunk_t chunk;
rsa_public_key_info_t key_info = {CHUNK_INITIALIZER, CHUNK_INITIALIZER};
der_decoder_t *dd;
status_t status;
rsa_public_key_t *public_key = NULL;
if (stat(filename, &stb) == -1)
{
return NULL;
}
buffer = alloca(stb.st_size);
file = fopen(filename, "r");
if (file == NULL)
{
return NULL;
}
if (fread(buffer, stb.st_size, 1, file) != 1)
{
return NULL;
}
chunk.ptr = buffer;
chunk.len = stb.st_size;
/* parse public key info first */
dd = der_decoder_create(rsa_public_key_info_rules);
status = dd->decode(dd, chunk, &key_info);
dd->destroy(dd);
allocator_free_chunk(&key_info.algorithm_oid);
if (status == SUCCESS)
{
public_key = rsa_public_key_create_from_chunk(chunk);
}
allocator_free_chunk(&key_info.public_key);
return public_key;
}
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/**
* @file rsa_public_key.h
*
* @brief Interface of rsa_public_key_t.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, 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 RSA_PUBLIC_KEY_H_
#define RSA_PUBLIC_KEY_H_
#include <gmp.h>
#include <types.h>
#include <definitions.h>
typedef struct rsa_public_key_t rsa_public_key_t;
/**
* @brief RSA public key with associated functions.
*
* Currently only supports signature verification using
* the EMSA encoding (see PKCS1)
*
* @b Constructors:
* - rsa_public_key_create_from_chunk()
* - rsa_public_key_create_from_file()
* - rsa_private_key_t.get_public_key()
*
* @see rsa_private_key_t
*
* @todo Implement getkey() and savekey()
*
* @ingroup rsa
*/
struct rsa_public_key_t {
/**
* @brief Verify a EMSA-PKCS1 encodined signature.
*
* Processes the supplied signature with the RSAVP1 function,
* selects the hash algorithm form the resultign ASN1-OID and
* verifies the hash against the supplied data.
*
* @param this rsa_public_key to use
* @param data data to sign
* @param signature signature to verify
* @return
* - SUCCESS, if signature ok
* - INVALID_STATE, if key not set
* - NOT_SUPPORTED, if hash algorithm not supported
* - INVALID_ARG, if signature is not a signature
* - FAILED if signature invalid or unable to verify
*/
status_t (*verify_emsa_pkcs1_signature) (rsa_public_key_t *this, chunk_t data, chunk_t signature);
/**
* @brief Gets the key.
*
* Currently uses a proprietary format which is only inteded
* for testing. This should be replaced with a proper
* ASN1 encoded key format, when charon gets the ASN1
* capabilities.
*
* @param this calling object
* @param key key (in a propriarity format)
* @return
* - SUCCESS
* - INVALID_STATE, if key not set
*/
status_t (*get_key) (rsa_public_key_t *this, chunk_t *key);
/**
* @brief Saves a key to a file.
*
* Not implemented!
*
* @param this calling object
* @param file file to which the key should be written.
* @return NOT_SUPPORTED
*/
status_t (*save_key) (rsa_public_key_t *this, char *file);
/**
* @brief Get the modulus of the key.
*
* @param this calling object
* @return modulus (n) of the key
*/
mpz_t *(*get_modulus) (rsa_public_key_t *this);
/**
* @brief Clone the public key.
*
* @param this public key to clone
* @return clone of this
*/
rsa_public_key_t *(*clone) (rsa_public_key_t *this);
/**
* @brief Destroys the public key.
*
* @param this public key to destroy
*/
void (*destroy) (rsa_public_key_t *this);
};
/**
* @brief Load an RSA public key from a chunk.
*
* Load a key from a chunk, encoded in the more frequently
* used PublicKeyInfo struct (ASN1 DER encoded).
*
* @param chunk chunk containing the DER encoded key
* @return loaded rsa_public_key_t, or NULL
*
* @todo Check OID in PublicKeyInfo
*
* @ingroup rsa
*/
rsa_public_key_t *rsa_public_key_create_from_chunk(chunk_t chunk);
/**
* @brief Load an RSA public key from a file.
*
* Load a key from a file, which is either in binary
* format (DER), or in PEM format.
*
* @param filename filename which holds the key
* @return loaded rsa_public_key_t, or NULL
*
* @todo Implement PEM file loading
*
* @ingroup rsa
*/
rsa_public_key_t *rsa_public_key_create_from_file(char *filename);
#endif /*RSA_PUBLIC_KEY_H_*/