diff options
Diffstat (limited to 'rsa.c')
| -rw-r--r-- | rsa.c | 353 |
1 files changed, 111 insertions, 242 deletions
@@ -9,7 +9,7 @@ * (but no simpler). * * Much of the code in this module is based, at least loosely, on Tom - * St Denis's libtomcrypt code. + * St Denis's libtomcrypt code. * * Authors: Rob Austein * Copyright (c) 2015, SUNET @@ -40,6 +40,25 @@ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +/* + * We use "Tom's Fast Math" library for our bignum implementation. + * This particular implementation has a couple of nice features: + * + * - The code is relatively readable, thus reviewable. + * + * - The bignum representation doesn't use dynamic memory, which + * simplifies things for us. + * + * The price tag for not using dynamic memory is that libtfm has to be + * configured to know about the largest bignum one wants it to be able + * to support at compile time. This should not be a serious problem. + * + * Unfortunately, libtfm is bad about const-ification, but we want to + * hide that from our users, so our public API uses const as + * appropriate and we use inline functions to remove const constraints + * in a relatively type-safe manner before calling libtom. + */ + #include <stdio.h> #include <stdint.h> #include <stdlib.h> @@ -48,6 +67,8 @@ #include <assert.h> #include "hal.h" +#include <tfm.h> +#include "asn1_internal.h" /* * Whether to use ModExp core. It works, but at the moment it's so @@ -59,22 +80,6 @@ #endif /* - * Use "Tom's Fast Math" library for our bignum implementation. This - * particular implementation has a couple of nice features: - * - * - The code is relatively readable, thus reviewable. - * - * - The bignum representation doesn't use dynamic memory, which - * simplifies things for us. - * - * The price tag for not using dynamic memory is that libtfm has to be - * configured to know about the largest bignum one wants it to be able - * to support at compile time. This should not be a serious problem. - */ - -#include <tfm.h> - -/* * Whether we want debug output. */ @@ -103,7 +108,7 @@ void hal_rsa_set_blinding(const int onoff) * can make memory allocation the caller's problem. */ -struct rsa_key { +struct hal_rsa_key { hal_rsa_key_type_t type; /* What kind of key this is */ fp_int n; /* The modulus */ fp_int e; /* Public exponent */ @@ -115,7 +120,7 @@ struct rsa_key { fp_int dQ; /* d mod (q - 1) */ }; -const size_t hal_rsa_key_t_size = sizeof(struct rsa_key); +const size_t hal_rsa_key_t_size = sizeof(hal_rsa_key_t); /* * Error handling. @@ -139,19 +144,19 @@ const size_t hal_rsa_key_t_size = sizeof(struct rsa_key); * Unpack a bignum into a byte array, with length check. */ -static hal_error_t unpack_fp(fp_int *bn, uint8_t *buffer, const size_t length) +static hal_error_t unpack_fp(const fp_int * const bn, uint8_t *buffer, const size_t length) { hal_error_t err = HAL_OK; assert(bn != NULL && buffer != NULL); - const size_t bytes = fp_unsigned_bin_size(bn); + const size_t bytes = fp_unsigned_bin_size(unconst_fp_int(bn)); if (bytes > length) lose(HAL_ERROR_RESULT_TOO_LONG); memset(buffer, 0, length); - fp_to_unsigned_bin(bn, buffer + length - bytes); + fp_to_unsigned_bin(unconst_fp_int(bn), buffer + length - bytes); fail: return err; @@ -164,7 +169,10 @@ static hal_error_t unpack_fp(fp_int *bn, uint8_t *buffer, const size_t length) * wrap result back up as a bignum. */ -static hal_error_t modexp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) +static hal_error_t modexp(const fp_int * msg, + const fp_int * const exp, + const fp_int * const mod, + fp_int *res) { hal_error_t err = HAL_OK; @@ -172,14 +180,14 @@ static hal_error_t modexp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) fp_int reduced_msg; - if (fp_cmp_mag(msg, mod) != FP_LT) { + if (fp_cmp_mag(unconst_fp_int(msg), unconst_fp_int(mod)) != FP_LT) { fp_init(&reduced_msg); - fp_mod(msg, mod, &reduced_msg); + fp_mod(unconst_fp_int(msg), unconst_fp_int(mod), &reduced_msg); msg = &reduced_msg; } - const size_t exp_len = (fp_unsigned_bin_size(exp) + 3) & ~3; - const size_t mod_len = (fp_unsigned_bin_size(mod) + 3) & ~3; + const size_t exp_len = (fp_unsigned_bin_size(unconst_fp_int(exp)) + 3) & ~3; + const size_t mod_len = (fp_unsigned_bin_size(unconst_fp_int(mod)) + 3) & ~3; uint8_t msgbuf[mod_len]; uint8_t expbuf[exp_len]; @@ -227,10 +235,13 @@ int fp_exptmod(fp_int *a, fp_int *b, fp_int *c, fp_int *d) * wait for the slow FPGA implementation. */ -static hal_error_t modexp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) +static hal_error_t modexp(const fp_int * const msg, + const fp_int * const exp, + const fp_int * const mod, + fp_int *res) { hal_error_t err = HAL_OK; - FP_CHECK(fp_exptmod(msg, exp, mod, res)); + FP_CHECK(fp_exptmod(unconst_fp_int(msg), unconst_fp_int(exp), unconst_fp_int(mod), res)); fail: return err; } @@ -243,11 +254,11 @@ static hal_error_t modexp(fp_int *msg, fp_int *exp, fp_int *mod, fp_int *res) * try. Come back to this if it looks like a bottleneck. */ -static hal_error_t create_blinding_factors(struct rsa_key *key, fp_int *bf, fp_int *ubf) +static hal_error_t create_blinding_factors(const hal_rsa_key_t * const key, fp_int *bf, fp_int *ubf) { assert(key != NULL && bf != NULL && ubf != NULL); - uint8_t rnd[fp_unsigned_bin_size(&key->n)]; + uint8_t rnd[fp_unsigned_bin_size(unconst_fp_int(&key->n))]; hal_error_t err = HAL_OK; if ((err = hal_get_random(rnd, sizeof(rnd))) != HAL_OK) @@ -260,7 +271,7 @@ static hal_error_t create_blinding_factors(struct rsa_key *key, fp_int *bf, fp_i if ((err = modexp(bf, &key->e, &key->n, bf)) != HAL_OK) goto fail; - FP_CHECK(fp_invmod(ubf, &key->n, ubf)); + FP_CHECK(fp_invmod(ubf, unconst_fp_int(&key->n), ubf)); fail: memset(rnd, 0, sizeof(rnd)); @@ -271,7 +282,7 @@ static hal_error_t create_blinding_factors(struct rsa_key *key, fp_int *bf, fp_i * RSA decryption via Chinese Remainder Theorem (Garner's formula). */ -static hal_error_t rsa_crt(struct rsa_key *key, fp_int *msg, fp_int *sig) +static hal_error_t rsa_crt(const hal_rsa_key_t * const key, fp_int *msg, fp_int *sig) { assert(key != NULL && msg != NULL && sig != NULL); @@ -288,7 +299,7 @@ static hal_error_t rsa_crt(struct rsa_key *key, fp_int *msg, fp_int *sig) if (blinding) { if ((err = create_blinding_factors(key, &bf, &ubf)) != HAL_OK) goto fail; - FP_CHECK(fp_mulmod(msg, &bf, &key->n, msg)); + FP_CHECK(fp_mulmod(msg, &bf, unconst_fp_int(&key->n), msg)); } /* @@ -309,24 +320,24 @@ static hal_error_t rsa_crt(struct rsa_key *key, fp_int *msg, fp_int *sig) * once or twice doesn't help, something is very wrong. */ if (fp_cmp_d(&t, 0) == FP_LT) - fp_add(&t, &key->p, &t); + fp_add(&t, unconst_fp_int(&key->p), &t); if (fp_cmp_d(&t, 0) == FP_LT) - fp_add(&t, &key->p, &t); + fp_add(&t, unconst_fp_int(&key->p), &t); if (fp_cmp_d(&t, 0) == FP_LT) lose(HAL_ERROR_IMPOSSIBLE); /* * sig = (t * u mod p) * q + m2 */ - FP_CHECK(fp_mulmod(&t, &key->u, &key->p, &t)); - fp_mul(&t, &key->q, &t); + FP_CHECK(fp_mulmod(&t, unconst_fp_int(&key->u), unconst_fp_int(&key->p), &t)); + fp_mul(&t, unconst_fp_int(&key->q), &t); fp_add(&t, &m2, sig); /* * Unblind if necessary. */ if (blinding) - FP_CHECK(fp_mulmod(sig, &ubf, &key->n, sig)); + FP_CHECK(fp_mulmod(sig, &ubf, unconst_fp_int(&key->n), sig)); fail: fp_zero(&t); @@ -342,11 +353,10 @@ static hal_error_t rsa_crt(struct rsa_key *key, fp_int *msg, fp_int *sig) * to the caller. */ -hal_error_t hal_rsa_encrypt(hal_rsa_key_t key_, +hal_error_t hal_rsa_encrypt(const hal_rsa_key_t * const key, const uint8_t * const input, const size_t input_len, uint8_t * output, const size_t output_len) { - struct rsa_key *key = key_.key; hal_error_t err = HAL_OK; if (key == NULL || input == NULL || output == NULL || input_len > output_len) @@ -356,7 +366,7 @@ hal_error_t hal_rsa_encrypt(hal_rsa_key_t key_, fp_init(&i); fp_init(&o); - fp_read_unsigned_bin(&i, (uint8_t *) input, input_len); + fp_read_unsigned_bin(&i, unconst_uint8_t(input), input_len); if ((err = modexp(&i, &key->e, &key->n, &o)) != HAL_OK || (err = unpack_fp(&o, output, output_len)) != HAL_OK) @@ -368,11 +378,10 @@ hal_error_t hal_rsa_encrypt(hal_rsa_key_t key_, return err; } -hal_error_t hal_rsa_decrypt(hal_rsa_key_t key_, +hal_error_t hal_rsa_decrypt(const hal_rsa_key_t * const key, const uint8_t * const input, const size_t input_len, uint8_t * output, const size_t output_len) { - struct rsa_key *key = key_.key; hal_error_t err = HAL_OK; if (key == NULL || input == NULL || output == NULL || input_len > output_len) @@ -382,7 +391,7 @@ hal_error_t hal_rsa_decrypt(hal_rsa_key_t key_, fp_init(&i); fp_init(&o); - fp_read_unsigned_bin(&i, (uint8_t *) input, input_len); + fp_read_unsigned_bin(&i, unconst_uint8_t(input), input_len); /* * Do CRT if we have all the necessary key components, otherwise @@ -393,7 +402,7 @@ hal_error_t hal_rsa_decrypt(hal_rsa_key_t key_, err = modexp(&i, &key->d, &key->n, &o); else err = rsa_crt(key, &i, &o); - + if (err != HAL_OK || (err = unpack_fp(&o, output, output_len)) != HAL_OK) goto fail; @@ -408,10 +417,10 @@ hal_error_t hal_rsa_decrypt(hal_rsa_key_t key_, * than plain old memset() eventually. */ -void hal_rsa_key_clear(hal_rsa_key_t key) +void hal_rsa_key_clear(hal_rsa_key_t *key) { - if (key.key != NULL) - memset(key.key, 0, sizeof(struct rsa_key)); + if (key != NULL) + memset(key, 0, sizeof(*key)); } /* @@ -425,7 +434,7 @@ void hal_rsa_key_clear(hal_rsa_key_t key) */ static hal_error_t load_key(const hal_rsa_key_type_t type, - hal_rsa_key_t *key_, + hal_rsa_key_t **key_, void *keybuf, const size_t keybuf_len, const uint8_t * const n, const size_t n_len, const uint8_t * const e, const size_t e_len, @@ -436,22 +445,22 @@ static hal_error_t load_key(const hal_rsa_key_type_t type, const uint8_t * const dP, const size_t dP_len, const uint8_t * const dQ, const size_t dQ_len) { - if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(struct rsa_key)) + if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(hal_rsa_key_t)) return HAL_ERROR_BAD_ARGUMENTS; memset(keybuf, 0, keybuf_len); - struct rsa_key *key = keybuf; + hal_rsa_key_t *key = keybuf; key->type = type; -#define _(x) do { fp_init(&key->x); if (x == NULL) goto fail; fp_read_unsigned_bin(&key->x, (uint8_t *) x, x##_len); } while (0) +#define _(x) do { fp_init(&key->x); if (x == NULL) goto fail; fp_read_unsigned_bin(&key->x, unconst_uint8_t(x), x##_len); } while (0) switch (type) { case HAL_RSA_PRIVATE: _(d); _(p); _(q); _(u); _(dP); _(dQ); case HAL_RSA_PUBLIC: _(n); _(e); - key_->key = key; + *key_ = key; return HAL_OK; } #undef _ @@ -465,7 +474,7 @@ static hal_error_t load_key(const hal_rsa_key_type_t type, * Public API to load_key(). */ -hal_error_t hal_rsa_key_load_private(hal_rsa_key_t *key_, +hal_error_t hal_rsa_key_load_private(hal_rsa_key_t **key_, void *keybuf, const size_t keybuf_len, const uint8_t * const n, const size_t n_len, const uint8_t * const e, const size_t e_len, @@ -481,7 +490,7 @@ hal_error_t hal_rsa_key_load_private(hal_rsa_key_t *key_, d, d_len, p, p_len, q, q_len, u, u_len, dP, dP_len, dQ, dQ_len); } -hal_error_t hal_rsa_key_load_public(hal_rsa_key_t *key_, +hal_error_t hal_rsa_key_load_public(hal_rsa_key_t **key_, void *keybuf, const size_t keybuf_len, const uint8_t * const n, const size_t n_len, const uint8_t * const e, const size_t e_len) @@ -495,11 +504,9 @@ hal_error_t hal_rsa_key_load_public(hal_rsa_key_t *key_, * Extract the key type. */ -hal_error_t hal_rsa_key_get_type(hal_rsa_key_t key_, +hal_error_t hal_rsa_key_get_type(const hal_rsa_key_t * const key, hal_rsa_key_type_t *key_type) { - struct rsa_key *key = key_.key; - if (key == NULL || key_type == NULL) return HAL_ERROR_BAD_ARGUMENTS; @@ -511,15 +518,16 @@ hal_error_t hal_rsa_key_get_type(hal_rsa_key_t key_, * Extract public key components. */ -static hal_error_t extract_component(hal_rsa_key_t key_, const size_t offset, +static hal_error_t extract_component(const hal_rsa_key_t * const key, + const size_t offset, uint8_t *res, size_t *res_len, const size_t res_max) { - if (key_.key == NULL) + if (key == NULL) return HAL_ERROR_BAD_ARGUMENTS; - fp_int *bn = (fp_int *) (((uint8_t *) key_.key) + offset); + const fp_int * const bn = (const fp_int *) (((const uint8_t *) key) + offset); - const size_t len = fp_unsigned_bin_size(bn); + const size_t len = fp_unsigned_bin_size(unconst_fp_int(bn)); if (res_len != NULL) *res_len = len; @@ -531,31 +539,33 @@ static hal_error_t extract_component(hal_rsa_key_t key_, const size_t offset, return HAL_ERROR_RESULT_TOO_LONG; memset(res, 0, res_max); - fp_to_unsigned_bin(bn, res); + fp_to_unsigned_bin(unconst_fp_int(bn), res); return HAL_OK; } -hal_error_t hal_rsa_key_get_modulus(hal_rsa_key_t key_, +hal_error_t hal_rsa_key_get_modulus(const hal_rsa_key_t * const key, uint8_t *res, size_t *res_len, const size_t res_max) { - return extract_component(key_, offsetof(struct rsa_key, n), res, res_len, res_max); + return extract_component(key, offsetof(hal_rsa_key_t, n), res, res_len, res_max); } -hal_error_t hal_rsa_key_get_public_exponent(hal_rsa_key_t key_, +hal_error_t hal_rsa_key_get_public_exponent(const hal_rsa_key_t * const key, uint8_t *res, size_t *res_len, const size_t res_max) { - return extract_component(key_, offsetof(struct rsa_key, e), res, res_len, res_max); + return extract_component(key, offsetof(hal_rsa_key_t, e), res, res_len, res_max); } /* * Generate a prime factor for an RSA keypair. - * + * * Get random bytes, munge a few bits, and stuff into a bignum. Keep * doing this until we find a result that's (probably) prime and for * which result - 1 is relatively prime with respect to e. */ -static hal_error_t find_prime(unsigned prime_length, fp_int *e, fp_int *result) +static hal_error_t find_prime(const unsigned prime_length, + const fp_int * const e, + fp_int *result) { uint8_t buffer[prime_length]; hal_error_t err; @@ -571,7 +581,7 @@ static hal_error_t find_prime(unsigned prime_length, fp_int *e, fp_int *result) fp_read_unsigned_bin(result, buffer, sizeof(buffer)); } while (!fp_isprime(result) || - (fp_sub_d(result, 1, &t), fp_gcd(&t, e, &t), fp_cmp_d(&t, 1) != FP_EQ)); + (fp_sub_d(result, 1, &t), fp_gcd(&t, unconst_fp_int(e), &t), fp_cmp_d(&t, 1) != FP_EQ)); fp_zero(&t); return HAL_OK; @@ -581,16 +591,16 @@ static hal_error_t find_prime(unsigned prime_length, fp_int *e, fp_int *result) * Generate a new RSA keypair. */ -hal_error_t hal_rsa_key_gen(hal_rsa_key_t *key_, +hal_error_t hal_rsa_key_gen(hal_rsa_key_t **key_, void *keybuf, const size_t keybuf_len, const unsigned key_length, const uint8_t * const public_exponent, const size_t public_exponent_len) { - struct rsa_key *key = keybuf; + hal_rsa_key_t *key = keybuf; hal_error_t err = HAL_OK; fp_int p_1, q_1; - if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(struct rsa_key)) + if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(hal_rsa_key_t)) return HAL_ERROR_BAD_ARGUMENTS; memset(keybuf, 0, keybuf_len); @@ -624,7 +634,7 @@ hal_error_t hal_rsa_key_gen(hal_rsa_key_t *key_, FP_CHECK(fp_mod(&key->d, &q_1, &key->dQ)); /* dQ = d % (q-1) */ FP_CHECK(fp_invmod(&key->q, &key->p, &key->u)); /* u = (1/q) % p */ - key_->key = key; + *key_ = key; /* Fall through to cleanup */ @@ -637,19 +647,9 @@ hal_error_t hal_rsa_key_gen(hal_rsa_key_t *key_, } /* - * Minimal ASN.1 encoding and decoding for private keys. This is NOT - * a general-purpose ASN.1 implementation, just enough to read and - * write PKCS #1.5 RSAPrivateKey syntax (RFC 2313 section 7.2). + * Just enough ASN.1 to read and write PKCS #1.5 RSAPrivateKey syntax + * (RFC 2313 section 7.2). * - * If at some later date we need a full ASN.1 implementation we'll add - * it as (a) separate library module(s), but for now the goal is just - * to let us serialize private keys for internal use and debugging. - */ - -#define ASN1_INTEGER 0x02 -#define ASN1_SEQUENCE 0x30 - -/* * RSAPrivateKey fields in the required order. */ @@ -664,139 +664,9 @@ hal_error_t hal_rsa_key_gen(hal_rsa_key_t *key_, _(&key->dQ); \ _(&key->u); -static size_t count_length(size_t length) -{ - size_t result = 1; - - if (length >= 128) - for (; length > 0; length >>= 8) - result++; - - return result; -} - -static void encode_length(size_t length, size_t length_len, uint8_t *der) -{ - assert(der != NULL && length_len > 0 && length_len < 128); - - if (length < 128) { - assert(length_len == 1); - *der = (uint8_t) length; - } - - else { - *der = 0x80 | (uint8_t) --length_len; - while (length > 0 && length_len > 0) { - der[length_len--] = (uint8_t) (length & 0xFF); - length >>= 8; - } - assert(length == 0 && length_len == 0); - } -} - -static hal_error_t decode_header(const uint8_t tag, - const uint8_t * const der, size_t der_max, - size_t *hlen, size_t *vlen) -{ - assert(der != NULL && hlen != NULL && vlen != NULL); - - if (der_max < 2 || der[0] != tag) - return HAL_ERROR_ASN1_PARSE_FAILED; - - if ((der[1] & 0x80) == 0) { - *hlen = 2; - *vlen = der[1]; - } - - else { - *hlen = 2 + (der[1] & 0x7F); - *vlen = 0; - - if (*hlen > der_max) - return HAL_ERROR_ASN1_PARSE_FAILED; - - for (size_t i = 2; i < *hlen; i++) - *vlen = (*vlen << 8) + der[i]; - } - - if (*hlen + *vlen > der_max) - return HAL_ERROR_ASN1_PARSE_FAILED; - - return HAL_OK; -} - -static hal_error_t encode_integer(fp_int *bn, - uint8_t *der, size_t *der_len, const size_t der_max) -{ - if (bn == NULL || der_len == NULL) - return HAL_ERROR_BAD_ARGUMENTS; - - /* - * Calculate length. Need to pad data with a leading zero if most - * significant bit is set, to avoid flipping ASN.1 sign bit. If - * caller didn't supply a buffer, just return the total length. - */ - - const int cmp = fp_cmp_d(bn, 0); - - if (cmp != FP_EQ && cmp != FP_GT) - return HAL_ERROR_BAD_ARGUMENTS; - - const int leading_zero = (cmp == FP_EQ || (fp_count_bits(bn) & 7) == 0); - const size_t data_len = fp_unsigned_bin_size(bn) + leading_zero; - const size_t tag_len = 1; - const size_t length_len = count_length(data_len); - const size_t total_len = tag_len + length_len + data_len; - - *der_len = total_len; - - if (der == NULL) - return HAL_OK; - - if (total_len > der_max) - return HAL_ERROR_RESULT_TOO_LONG; - - /* - * Now encode. - */ - - *der++ = ASN1_INTEGER; - encode_length(data_len, length_len, der); - der += length_len; - if (leading_zero) - *der++ = 0x00; - fp_to_unsigned_bin(bn, der); - - return HAL_OK; -} - -static hal_error_t decode_integer(fp_int *bn, - const uint8_t * const der, size_t *der_len, const size_t der_max) -{ - if (bn == NULL || der == NULL) - return HAL_ERROR_BAD_ARGUMENTS; - - hal_error_t err; - size_t hlen, vlen; - - if ((err = decode_header(ASN1_INTEGER, der, der_max, &hlen, &vlen)) != HAL_OK) - return err; - - if (der_len != NULL) - *der_len = hlen + vlen; - - if (vlen < 1 || (der[hlen] & 0x80) != 0x00) - return HAL_ERROR_ASN1_PARSE_FAILED; - - fp_init(bn); - fp_read_unsigned_bin(bn, (uint8_t *) der + hlen, vlen); - return HAL_OK; -} - -hal_error_t hal_rsa_key_to_der(hal_rsa_key_t key_, +hal_error_t hal_rsa_key_to_der(const hal_rsa_key_t * const key, uint8_t *der, size_t *der_len, const size_t der_max) { - struct rsa_key *key = key_.key; hal_error_t err = HAL_OK; if (key == NULL || der_len == NULL || key->type != HAL_RSA_PRIVATE) @@ -806,65 +676,64 @@ hal_error_t hal_rsa_key_to_der(hal_rsa_key_t key_, fp_zero(&version); /* - * Calculate length. + * Calculate data length. */ - size_t data_len = 0; + size_t vlen = 0; -#define _(x) { size_t i; if ((err = encode_integer(x, NULL, &i, der_max - data_len)) != HAL_OK) return err; data_len += i; } +#define _(x) { size_t i; if ((err = hal_asn1_encode_integer(x, NULL, &i, der_max - vlen)) != HAL_OK) return err; vlen += i; } RSAPrivateKey_fields; #undef _ - const size_t tag_len = 1; - const size_t length_len = count_length(data_len); - const size_t total_len = tag_len + length_len + data_len; + /* + * Encode header. + */ - *der_len = total_len; + if ((err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, der_len, der_max)) != HAL_OK) + return err; + + const size_t hlen = *der_len; + *der_len += vlen; if (der == NULL) return HAL_OK; - if (total_len > der_max) - return HAL_ERROR_RESULT_TOO_LONG; - /* - * Now encode. + * Encode data. */ - *der++ = ASN1_SEQUENCE; - encode_length(data_len, length_len, der); - der += length_len; - -#define _(x) { size_t i; if ((err = encode_integer(x, der, &i, data_len)) != HAL_OK) return err; der += i; data_len -= i; } + der += hlen; + +#define _(x) { size_t i; if ((err = hal_asn1_encode_integer(x, der, &i, vlen)) != HAL_OK) return err; der += i; vlen -= i; } RSAPrivateKey_fields; #undef _ return HAL_OK; } -size_t hal_rsa_key_to_der_len(hal_rsa_key_t key_) +size_t hal_rsa_key_to_der_len(const hal_rsa_key_t * const key) { size_t len = 0; - return hal_rsa_key_to_der(key_, NULL, &len, 0) == HAL_OK ? len : 0; + return hal_rsa_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0; } -hal_error_t hal_rsa_key_from_der(hal_rsa_key_t *key_, +hal_error_t hal_rsa_key_from_der(hal_rsa_key_t **key_, void *keybuf, const size_t keybuf_len, const uint8_t *der, const size_t der_len) { - if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(struct rsa_key) || der == NULL) + if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(hal_rsa_key_t) || der == NULL) return HAL_ERROR_BAD_ARGUMENTS; memset(keybuf, 0, keybuf_len); - struct rsa_key *key = keybuf; + hal_rsa_key_t *key = keybuf; key->type = HAL_RSA_PRIVATE; hal_error_t err = HAL_OK; size_t hlen, vlen; - if ((err = decode_header(ASN1_SEQUENCE, der, der_len, &hlen, &vlen)) != HAL_OK) + if ((err = hal_asn1_decode_header(ASN1_SEQUENCE, der, der_len, &hlen, &vlen)) != HAL_OK) return err; der += hlen; @@ -872,14 +741,14 @@ hal_error_t hal_rsa_key_from_der(hal_rsa_key_t *key_, fp_int version; fp_init(&version); -#define _(x) { size_t i; if ((err = decode_integer(x, der, &i, vlen)) != HAL_OK) return err; der += i; vlen -= i; } +#define _(x) { size_t i; if ((err = hal_asn1_decode_integer(x, der, &i, vlen)) != HAL_OK) return err; der += i; vlen -= i; } RSAPrivateKey_fields; #undef _ if (fp_cmp_d(&version, 0) != FP_EQ) return HAL_ERROR_ASN1_PARSE_FAILED; - key_->key = key; + *key_ = key; return HAL_OK; } |