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author | Rene Mayrhofer <rene@mayrhofer.eu.org> | 2007-04-12 20:41:31 +0000 |
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committer | Rene Mayrhofer <rene@mayrhofer.eu.org> | 2007-04-12 20:41:31 +0000 |
commit | 774a362e87feab25f1be16fbca08269ddc7121a4 (patch) | |
tree | cf71f4e7466468ac3edc2127125f333224a9acfb /src/libstrongswan/crypto/rsa/rsa_private_key.c | |
parent | c54a140a445bfe7aa66721f68bb0781f26add91c (diff) | |
download | vyos-strongswan-774a362e87feab25f1be16fbca08269ddc7121a4.tar.gz vyos-strongswan-774a362e87feab25f1be16fbca08269ddc7121a4.zip |
Major new upstream release, just ran svn-upgrade for now (and wrote some
debian/changelong entries).
Diffstat (limited to 'src/libstrongswan/crypto/rsa/rsa_private_key.c')
-rw-r--r-- | src/libstrongswan/crypto/rsa/rsa_private_key.c | 774 |
1 files changed, 774 insertions, 0 deletions
diff --git a/src/libstrongswan/crypto/rsa/rsa_private_key.c b/src/libstrongswan/crypto/rsa/rsa_private_key.c new file mode 100644 index 000000000..5b1647965 --- /dev/null +++ b/src/libstrongswan/crypto/rsa/rsa_private_key.c @@ -0,0 +1,774 @@ +/** + * @file rsa_private_key.c + * + * @brief Implementation of rsa_private_key_t. + * + */ + +/* + * Copyright (C) 2005-2006 Martin Willi + * Copyright (C) 2005 Jan Hutter + * 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 <string.h> + +#include "rsa_public_key.h" +#include "rsa_private_key.h" + +#include <asn1/asn1.h> +#include <asn1/pem.h> +#include <utils/randomizer.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]; + + +/** + * defined in rsa_public_key.c + */ +extern chunk_t rsa_public_key_info_to_asn1(const mpz_t n, const mpz_t e); + + +/** + * 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; + + /** + * Keyid formed as a SHA-1 hash of a publicKeyInfo object + */ + chunk_t keyid; + + + /** + * @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); + +}; + +/* ASN.1 definition of a PKCS#1 RSA private key */ +static const asn1Object_t privkey_objects[] = { + { 0, "RSAPrivateKey", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ + { 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */ + { 1, "modulus", ASN1_INTEGER, ASN1_BODY }, /* 2 */ + { 1, "publicExponent", ASN1_INTEGER, ASN1_BODY }, /* 3 */ + { 1, "privateExponent", ASN1_INTEGER, ASN1_BODY }, /* 4 */ + { 1, "prime1", ASN1_INTEGER, ASN1_BODY }, /* 5 */ + { 1, "prime2", ASN1_INTEGER, ASN1_BODY }, /* 6 */ + { 1, "exponent1", ASN1_INTEGER, ASN1_BODY }, /* 7 */ + { 1, "exponent2", ASN1_INTEGER, ASN1_BODY }, /* 8 */ + { 1, "coefficient", ASN1_INTEGER, ASN1_BODY }, /* 9 */ + { 1, "otherPrimeInfos", ASN1_SEQUENCE, ASN1_OPT | + ASN1_LOOP }, /* 10 */ + { 2, "otherPrimeInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 11 */ + { 3, "prime", ASN1_INTEGER, ASN1_BODY }, /* 12 */ + { 3, "exponent", ASN1_INTEGER, ASN1_BODY }, /* 13 */ + { 3, "coefficient", ASN1_INTEGER, ASN1_BODY }, /* 14 */ + { 1, "end opt or loop", ASN1_EOC, ASN1_END } /* 15 */ +}; + +#define PRIV_KEY_VERSION 1 +#define PRIV_KEY_MODULUS 2 +#define PRIV_KEY_PUB_EXP 3 +#define PRIV_KEY_PRIV_EXP 4 +#define PRIV_KEY_PRIME1 5 +#define PRIV_KEY_PRIME2 6 +#define PRIV_KEY_EXP1 7 +#define PRIV_KEY_EXP2 8 +#define PRIV_KEY_COEFF 9 +#define PRIV_KEY_ROOF 16 + +static private_rsa_private_key_t *rsa_private_key_create_empty(void); + +/** + * 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); + + 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 em; + chunk_t oid; + + /* 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 = malloc(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); + + free(hash.ptr); + 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 = malloc(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); + + free(n.ptr); + free(e.ptr); + free(p.ptr); + free(q.ptr); + free(d.ptr); + free(exp1.ptr); + free(exp2.ptr); + 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) +{ + return chunk_equals(this->keyid, public->get_keyid(public)); +} + +/** + * Check the loaded key if it is valid and usable + * TODO: Log errors + */ +static status_t check(private_rsa_private_key_t *this) +{ + mpz_t t, u, q1; + status_t status = SUCCESS; + + /* PKCS#1 1.5 section 6 requires modulus to have at least 12 octets. + * We actually require more (for security). + */ + if (this->k < 512/8) + { + return FAILED; + } + + /* we picked a max modulus size to simplify buffer allocation */ + if (this->k > 8192/8) + { + return FAILED; + } + + mpz_init(t); + mpz_init(u); + mpz_init(q1); + + /* check that n == p * q */ + mpz_mul(u, this->p, this->q); + if (mpz_cmp(u, this->n) != 0) + { + status = FAILED; + } + + /* check that e divides neither p-1 nor q-1 */ + mpz_sub_ui(t, this->p, 1); + mpz_mod(t, t, this->e); + if (mpz_cmp_ui(t, 0) == 0) + { + status = FAILED; + } + + mpz_sub_ui(t, this->q, 1); + mpz_mod(t, t, this->e); + if (mpz_cmp_ui(t, 0) == 0) + { + status = FAILED; + } + + /* check that d is e^-1 (mod lcm(p-1, q-1)) */ + /* see PKCS#1v2, aka RFC 2437, for the "lcm" */ + mpz_sub_ui(q1, this->q, 1); + mpz_sub_ui(u, this->p, 1); + mpz_gcd(t, u, q1); /* t := gcd(p-1, q-1) */ + mpz_mul(u, u, q1); /* u := (p-1) * (q-1) */ + mpz_divexact(u, u, t); /* u := lcm(p-1, q-1) */ + + mpz_mul(t, this->d, this->e); + mpz_mod(t, t, u); + if (mpz_cmp_ui(t, 1) != 0) + { + status = FAILED; + } + + /* check that exp1 is d mod (p-1) */ + mpz_sub_ui(u, this->p, 1); + mpz_mod(t, this->d, u); + if (mpz_cmp(t, this->exp1) != 0) + { + status = FAILED; + } + + /* check that exp2 is d mod (q-1) */ + mpz_sub_ui(u, this->q, 1); + mpz_mod(t, this->d, u); + if (mpz_cmp(t, this->exp2) != 0) + { + status = FAILED; + } + + /* check that coeff is (q^-1) mod p */ + mpz_mul(t, this->coeff, this->q); + mpz_mod(t, t, this->p); + if (mpz_cmp_ui(t, 1) != 0) + { + status = FAILED; + } + + mpz_clear(t); + mpz_clear(u); + mpz_clear(q1); + return status; +} + +/** + * 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->keyid = chunk_clone(this->keyid); + 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); + free(this->keyid.ptr); + free(this); +} + +/** + * Internal generic constructor + */ +static private_rsa_private_key_t *rsa_private_key_create_empty(void) +{ + private_rsa_private_key_t *this = malloc_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) + { + free(this); + return NULL; + } + if (this->compute_prime(this, key_size/2, &q) != SUCCESS) + { + mpz_clear(p); + 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 blob) +{ + asn1_ctx_t ctx; + chunk_t object; + u_int level; + int objectID = 0; + private_rsa_private_key_t *this; + + 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); + + asn1_init(&ctx, blob, 0, FALSE, TRUE); + + while (objectID < PRIV_KEY_ROOF) + { + if (!extract_object(privkey_objects, &objectID, &object, &level, &ctx)) + { + destroy(this); + return FALSE; + } + switch (objectID) + { + case PRIV_KEY_VERSION: + if (object.len > 0 && *object.ptr != 0) + { + destroy(this); + return NULL; + } + break; + case PRIV_KEY_MODULUS: + mpz_import(this->n, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_PUB_EXP: + mpz_import(this->e, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_PRIV_EXP: + mpz_import(this->d, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_PRIME1: + mpz_import(this->p, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_PRIME2: + mpz_import(this->q, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_EXP1: + mpz_import(this->exp1, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_EXP2: + mpz_import(this->exp2, object.len, 1, 1, 1, 0, object.ptr); + break; + case PRIV_KEY_COEFF: + mpz_import(this->coeff, object.len, 1, 1, 1, 0, object.ptr); + break; + } + objectID++; + } + + this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8; + + /* form the keyid as a SHA-1 hash of a publicKeyInfo object */ + { + chunk_t publicKeyInfo = rsa_public_key_info_to_asn1(this->n, this->e); + hasher_t *hasher = hasher_create(HASH_SHA1); + + hasher->allocate_hash(hasher, publicKeyInfo, &this->keyid); + hasher->destroy(hasher); + free(publicKeyInfo.ptr); + } + + if (check(this) != SUCCESS) + { + destroy(this); + return NULL; + } + else + { + return &this->public; + } +} + +/* + * see header + */ +rsa_private_key_t *rsa_private_key_create_from_file(char *filename, chunk_t *passphrase) +{ + bool pgp = FALSE; + chunk_t chunk = chunk_empty; + rsa_private_key_t *key = NULL; + + if (!pem_asn1_load_file(filename, passphrase, "private key", &chunk, &pgp)) + return NULL; + + key = rsa_private_key_create_from_chunk(chunk); + free(chunk.ptr); + return key; +} |