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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
commit | 69c6a41ffb878ef98c9378ed4b1634a404cfaa7f (patch) | |
tree | b2a4f704565d62fbb129ab9dc3b35977c50e6e7f /src/libdnssec/sign | |
parent | Initial commit. (diff) | |
download | knot-upstream.tar.xz knot-upstream.zip |
Adding upstream version 2.7.6.upstream/2.7.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libdnssec/sign')
-rw-r--r-- | src/libdnssec/sign/der.c | 229 | ||||
-rw-r--r-- | src/libdnssec/sign/der.h | 56 | ||||
-rw-r--r-- | src/libdnssec/sign/sign.c | 408 |
3 files changed, 693 insertions, 0 deletions
diff --git a/src/libdnssec/sign/der.c b/src/libdnssec/sign/der.c new file mode 100644 index 0000000..4d79876 --- /dev/null +++ b/src/libdnssec/sign/der.c @@ -0,0 +1,229 @@ +/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + 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 3 of the License, or + (at your option) any later version. + + 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdbool.h> + +#include "libdnssec/shared/bignum.h" +#include "libdnssec/binary.h" +#include "libdnssec/error.h" +#include "libdnssec/sign/der.h" +#include "libdnssec/shared/binary_wire.h" + +/* + * In fact, this is a very tiny subset of ASN.1 encoding format implementation, + * which is necessary for the purpose of DNSSEC. + * + * References: RFC 3279 (X.509 PKI), X.690, RFC 6605 (ECDSA), RFC8080 (EDDSA) + * + * Dss-Sig-Value ::= SEQUENCE { r INTEGER, s INTEGER } + */ + +#define ASN1_TYPE_SEQUENCE 0x30 +#define ASN1_TYPE_INTEGER 0x02 + +#define ASN1_MAX_SIZE 127 + +/*! + * Check if the next object has a given type. + */ +static bool asn1_expect_type(wire_ctx_t *wire, uint8_t type) +{ + assert(wire); + return (wire_ctx_available(wire) >= 1 && wire_ctx_read_u8(wire) == type); +} + +/*! + * Decode the size of the object (only short format is supported). + */ +static int asn1_decode_size(wire_ctx_t *wire, size_t *size) +{ + assert(wire); + assert(size); + + if (wire_ctx_available(wire) < 1) { + return DNSSEC_MALFORMED_DATA; + } + + uint8_t byte = wire_ctx_read_u8(wire); + if (byte & 0x80) { + // long form, we do not need it for DNSSEC + return DNSSEC_NOT_IMPLEMENTED_ERROR; + } + + *size = byte; + + return DNSSEC_EOK; +} + +/*! + * Decode an unsigned integer object. + */ +static int asn1_decode_integer(wire_ctx_t *wire, dnssec_binary_t *_value) +{ + assert(wire); + assert(_value); + + if (!asn1_expect_type(wire, ASN1_TYPE_INTEGER)) { + return DNSSEC_MALFORMED_DATA; + } + + size_t size; + int result = asn1_decode_size(wire, &size); + if (result != DNSSEC_EOK) { + return result; + } + + if (size == 0 || size > wire_ctx_available(wire)) { + return DNSSEC_MALFORMED_DATA; + } + + dnssec_binary_t value = { .data = wire->position, .size = size }; + wire->position += size; + + // skip leading zeroes (unless equal to zero) + while (value.size > 1 && value.data[0] == 0) { + value.data += 1; + value.size -= 1; + } + + *_value = value; + + return DNSSEC_EOK; +} + +/*! + * Encode object header (type and length). + */ +static void asn1_write_header(wire_ctx_t *wire, uint8_t type, size_t length) +{ + assert(wire); + assert(length < ASN1_MAX_SIZE); + + wire_ctx_write_u8(wire, type); + wire_ctx_write_u8(wire, length); +} + +/*! + * Encode unsigned integer object. + */ +static void asn1_write_integer(wire_ctx_t *wire, size_t integer_size, + const dnssec_binary_t *integer) +{ + assert(wire); + assert(integer); + assert(integer->data); + + asn1_write_header(wire, ASN1_TYPE_INTEGER, integer_size); + bignum_write(wire, integer_size, integer); +} + +/*! + * Decode signature parameters from X.509 ECDSA signature. + */ +int dss_sig_value_decode(const dnssec_binary_t *der, + dnssec_binary_t *r, dnssec_binary_t *s) +{ + if (!der || !der->data || !r || !s) { + return DNSSEC_EINVAL; + } + + wire_ctx_t wire = binary_init(der); + + size_t size; + int result; + + // decode the sequence + + if (!asn1_expect_type(&wire, ASN1_TYPE_SEQUENCE)) { + return DNSSEC_MALFORMED_DATA; + } + + result = asn1_decode_size(&wire, &size); + if (result != DNSSEC_EOK) { + return result; + } + + if (size != wire_ctx_available(&wire)) { + return DNSSEC_MALFORMED_DATA; + } + + // decode the 'r' and 's' values + + dnssec_binary_t der_r; + result = asn1_decode_integer(&wire, &der_r); + if (result != DNSSEC_EOK) { + return result; + } + + dnssec_binary_t der_s; + result = asn1_decode_integer(&wire, &der_s); + if (result != DNSSEC_EOK) { + return result; + } + + if (wire_ctx_available(&wire) != 0) { + return DNSSEC_MALFORMED_DATA; + } + + *r = der_r; + *s = der_s; + + return DNSSEC_EOK; +} + +/*! + * Encode signature parameters from X.509 ECDSA signature. + */ +int dss_sig_value_encode(const dnssec_binary_t *r, const dnssec_binary_t *s, + dnssec_binary_t *der) +{ + if (!r || !r->data || !s || !s->data || !der) { + return DNSSEC_EINVAL; + } + + size_t r_size = bignum_size_s(r); + size_t s_size = bignum_size_s(s); + + // check supported inputs range + + if (r_size > ASN1_MAX_SIZE || s_size > ASN1_MAX_SIZE) { + return DNSSEC_NOT_IMPLEMENTED_ERROR; + } + + size_t seq_size = 2 + r_size + 2 + s_size; + if (seq_size > ASN1_MAX_SIZE) { + return DNSSEC_NOT_IMPLEMENTED_ERROR; + } + + // encode result + + size_t total_size = 2 + seq_size; + + dnssec_binary_t _der = { 0 }; + if (dnssec_binary_alloc(&_der, total_size)) { + return DNSSEC_ENOMEM; + } + + wire_ctx_t wire = binary_init(&_der); + asn1_write_header(&wire, ASN1_TYPE_SEQUENCE, seq_size); + asn1_write_integer(&wire, r_size, r); + asn1_write_integer(&wire, s_size, s); + assert(wire_ctx_available(&wire) == 0); + + *der = _der; + + return DNSSEC_EOK; +} diff --git a/src/libdnssec/sign/der.h b/src/libdnssec/sign/der.h new file mode 100644 index 0000000..db8e910 --- /dev/null +++ b/src/libdnssec/sign/der.h @@ -0,0 +1,56 @@ +/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + 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 3 of the License, or + (at your option) any later version. + + 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#pragma once + +#include "libdnssec/binary.h" + +/* + * The ECDSA signatures in DNSSEC are encoded differently than in X.509 + * (PKCS #1). The cryptographic libraries usually produce the signatures in + * X.509 format, which uses Dss-Sig-Value to encapsulate 'r' and 's' values + * of the signature. + * + * This module provides decoding and encoding of this format. + * + * The 'r' and 's' values are treated as unsigned values: The leading zeroes + * are stripped on decoding; an extra leading zero is added on encoding in case + * the value starts with a set bit. + */ + +/*! + * Decode signature parameters from X.509 ECDSA signature. + * + * \param[in] der X.509 encoded signature. + * \param[out] s Value 's' of the signature, will point to the data in DER. + * \param[out] r Value 'r' of the signature, will point to the data in DER. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dss_sig_value_decode(const dnssec_binary_t *der, + dnssec_binary_t *r, dnssec_binary_t *s); + +/*! + * Encode signature parameters from X.509 ECDSA signature. + * + * \param[in] s Value 's' of the signature. + * \param[in] r Value 'r' of the signature. + * \param[out] der X.509 signature, the content will be allocated. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dss_sig_value_encode(const dnssec_binary_t *r, const dnssec_binary_t *s, + dnssec_binary_t *der); diff --git a/src/libdnssec/sign/sign.c b/src/libdnssec/sign/sign.c new file mode 100644 index 0000000..16b4e64 --- /dev/null +++ b/src/libdnssec/sign/sign.c @@ -0,0 +1,408 @@ +/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + 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 3 of the License, or + (at your option) any later version. + + 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. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <gnutls/gnutls.h> +#include <gnutls/crypto.h> + +#include "contrib/macros.h" +#include "libdnssec/shared/bignum.h" +#include "libdnssec/error.h" +#include "libdnssec/key.h" +#include "libdnssec/key/internal.h" +#include "libdnssec/shared/shared.h" +#include "libdnssec/sign.h" +#include "libdnssec/sign/der.h" +#include "libdnssec/shared/binary_wire.h" +#include "libdnssec/contrib/vpool.h" + +/*! + * Signature format conversion callback. + * + * \param ctx DNSSEC signing context. + * \param from Data in source format. + * \param to Allocated data in target format. + * + * \return Error code, DNSSEC_EOK if successful. + */ +typedef int (*signature_convert_cb)(dnssec_sign_ctx_t *ctx, + const dnssec_binary_t *from, + dnssec_binary_t *to); + +/*! + * Algorithm specific callbacks. + */ +typedef struct algorithm_functions { + //! Convert X.509 signature to DNSSEC format. + signature_convert_cb x509_to_dnssec; + //! Convert DNSSEC signature to X.509 format. + signature_convert_cb dnssec_to_x509; +} algorithm_functions_t; + +typedef struct dnssec_buffer { + uint8_t *allocd; //!< Pointer to allocated data. + uint8_t *data; //!< API: pointer to data to copy from. + size_t max_length; + size_t length; //!< API: current length. +} dnssec_buffer_t; + +/*! + * DNSSEC signing context. + */ +struct dnssec_sign_ctx { + const dnssec_key_t *key; //!< Signing key. + const algorithm_functions_t *functions; //!< Implementation specific. + + gnutls_sign_algorithm_t sign_algorithm; //!< Used algorithm for signing. + struct vpool buffer; //!< Buffer for the data to be signed. +}; + +/* -- signature format conversions ----------------------------------------- */ + +/*! + * Conversion of RSA signature between X.509 and DNSSEC format is a NOOP. + * + * \note Described in RFC 3110. + */ +static int rsa_copy_signature(dnssec_sign_ctx_t *ctx, + const dnssec_binary_t *from, + dnssec_binary_t *to) +{ + assert(ctx); + assert(from); + assert(to); + + return dnssec_binary_dup(from, to); +} + +static const algorithm_functions_t rsa_functions = { + .x509_to_dnssec = rsa_copy_signature, + .dnssec_to_x509 = rsa_copy_signature, +}; + +static size_t ecdsa_sign_integer_size(dnssec_sign_ctx_t *ctx) +{ + assert(ctx); + + switch (ctx->sign_algorithm) { + case GNUTLS_SIGN_ECDSA_SHA256: return 32; + case GNUTLS_SIGN_ECDSA_SHA384: return 48; + default: return 0; + }; +} + +/*! + * Convert ECDSA signature to DNSSEC format. + * + * \note Described in RFC 6605. + */ +static int ecdsa_x509_to_dnssec(dnssec_sign_ctx_t *ctx, + const dnssec_binary_t *x509, + dnssec_binary_t *dnssec) +{ + assert(ctx); + assert(x509); + assert(dnssec); + + dnssec_binary_t value_r = { 0 }; + dnssec_binary_t value_s = { 0 }; + + int result = dss_sig_value_decode(x509, &value_r, &value_s); + if (result != DNSSEC_EOK) { + return result; + } + + size_t int_size = ecdsa_sign_integer_size(ctx); + size_t r_size = bignum_size_u(&value_r); + size_t s_size = bignum_size_u(&value_s); + + if (r_size > int_size || s_size > int_size) { + return DNSSEC_MALFORMED_DATA; + } + + result = dnssec_binary_alloc(dnssec, 2 * int_size); + if (result != DNSSEC_EOK) { + return result; + } + + wire_ctx_t wire = binary_init(dnssec); + bignum_write(&wire, int_size, &value_r); + bignum_write(&wire, int_size, &value_s); + assert(wire_ctx_offset(&wire) == dnssec->size); + + return DNSSEC_EOK; +} + +static int ecdsa_dnssec_to_x509(dnssec_sign_ctx_t *ctx, + const dnssec_binary_t *dnssec, + dnssec_binary_t *x509) +{ + assert(ctx); + assert(x509); + assert(dnssec); + + size_t int_size = ecdsa_sign_integer_size(ctx); + + if (dnssec->size != 2 * int_size) { + return DNSSEC_INVALID_SIGNATURE; + } + + const dnssec_binary_t value_r = { .size = int_size, .data = dnssec->data }; + const dnssec_binary_t value_s = { .size = int_size, .data = dnssec->data + int_size }; + + return dss_sig_value_encode(&value_r, &value_s, x509); +} + +static const algorithm_functions_t ecdsa_functions = { + .x509_to_dnssec = ecdsa_x509_to_dnssec, + .dnssec_to_x509 = ecdsa_dnssec_to_x509, +}; + +#define eddsa_copy_signature rsa_copy_signature +static const algorithm_functions_t eddsa_functions = { + .x509_to_dnssec = eddsa_copy_signature, + .dnssec_to_x509 = eddsa_copy_signature, +}; + +/* -- crypto helper functions --------------------------------------------- */ + +static const algorithm_functions_t *get_functions(const dnssec_key_t *key) +{ + uint8_t algorithm = dnssec_key_get_algorithm(key); + + switch ((dnssec_key_algorithm_t)algorithm) { + case DNSSEC_KEY_ALGORITHM_RSA_SHA1: + case DNSSEC_KEY_ALGORITHM_RSA_SHA1_NSEC3: + case DNSSEC_KEY_ALGORITHM_RSA_SHA256: + case DNSSEC_KEY_ALGORITHM_RSA_SHA512: + return &rsa_functions; + case DNSSEC_KEY_ALGORITHM_ECDSA_P256_SHA256: + case DNSSEC_KEY_ALGORITHM_ECDSA_P384_SHA384: + return &ecdsa_functions; + case DNSSEC_KEY_ALGORITHM_ED25519: + case DNSSEC_KEY_ALGORITHM_ED448: + return &eddsa_functions; + default: + return NULL; + } +} + +#ifndef HAVE_SIGN_DATA2 +/** + * Get digest algorithm used with a given key. + */ +static gnutls_digest_algorithm_t get_digest_algorithm(const dnssec_key_t *key) +{ + uint8_t algorithm = dnssec_key_get_algorithm(key); + + switch ((dnssec_key_algorithm_t)algorithm) { + case DNSSEC_KEY_ALGORITHM_RSA_SHA1: + case DNSSEC_KEY_ALGORITHM_RSA_SHA1_NSEC3: + return GNUTLS_DIG_SHA1; + case DNSSEC_KEY_ALGORITHM_RSA_SHA256: + case DNSSEC_KEY_ALGORITHM_ECDSA_P256_SHA256: + return GNUTLS_DIG_SHA256; + case DNSSEC_KEY_ALGORITHM_RSA_SHA512: + return GNUTLS_DIG_SHA512; + case DNSSEC_KEY_ALGORITHM_ECDSA_P384_SHA384: + return GNUTLS_DIG_SHA384; + case DNSSEC_KEY_ALGORITHM_ED25519: + return GNUTLS_DIG_SHA512; + case DNSSEC_KEY_ALGORITHM_ED448: + default: + return GNUTLS_DIG_UNKNOWN; + } +} +#endif + +static gnutls_sign_algorithm_t get_sign_algorithm(const dnssec_key_t *key) +{ + uint8_t algorithm = dnssec_key_get_algorithm(key); + + switch ((dnssec_key_algorithm_t)algorithm) { + case DNSSEC_KEY_ALGORITHM_RSA_SHA1: + case DNSSEC_KEY_ALGORITHM_RSA_SHA1_NSEC3: + return GNUTLS_SIGN_RSA_SHA1; + case DNSSEC_KEY_ALGORITHM_RSA_SHA256: + return GNUTLS_SIGN_RSA_SHA256; + case DNSSEC_KEY_ALGORITHM_ECDSA_P256_SHA256: + return GNUTLS_SIGN_ECDSA_SHA256; + case DNSSEC_KEY_ALGORITHM_RSA_SHA512: + return GNUTLS_SIGN_RSA_SHA512; + case DNSSEC_KEY_ALGORITHM_ECDSA_P384_SHA384: + return GNUTLS_SIGN_ECDSA_SHA384; + case DNSSEC_KEY_ALGORITHM_ED25519: +#ifdef HAVE_ED25519 + return GNUTLS_SIGN_EDDSA_ED25519; +#endif + case DNSSEC_KEY_ALGORITHM_ED448: +#ifdef HAVE_ED448 + return GNUTLS_SIGN_EDDSA_ED448; +#endif + default: + return GNUTLS_SIGN_UNKNOWN; + } +} + +/* -- public API ---------------------------------------------------------- */ + +_public_ +int dnssec_sign_new(dnssec_sign_ctx_t **ctx_ptr, const dnssec_key_t *key) +{ + if (!ctx_ptr) { + return DNSSEC_EINVAL; + } + + dnssec_sign_ctx_t *ctx = calloc(1, sizeof(*ctx)); + + ctx->key = key; + + ctx->functions = get_functions(key); + if (ctx->functions == NULL) { + free(ctx); + return DNSSEC_INVALID_KEY_ALGORITHM; + } + + ctx->sign_algorithm = get_sign_algorithm(key); + int result = dnssec_sign_init(ctx); + if (result != DNSSEC_EOK) { + free(ctx); + return result; + } + + *ctx_ptr = ctx; + + return DNSSEC_EOK; +} + +_public_ +void dnssec_sign_free(dnssec_sign_ctx_t *ctx) +{ + if (!ctx) { + return; + } + + vpool_reset(&ctx->buffer); + + free(ctx); +} + +_public_ +int dnssec_sign_init(dnssec_sign_ctx_t *ctx) +{ + if (!ctx) { + return DNSSEC_EINVAL; + } + + if (vpool_get_buf(&ctx->buffer) != NULL) { + vpool_wipe(&ctx->buffer); + } else { + vpool_init(&ctx->buffer, 1024, 0); + } + + return DNSSEC_EOK; +} + +_public_ +int dnssec_sign_add(dnssec_sign_ctx_t *ctx, const dnssec_binary_t *data) +{ + if (!ctx || !data || !data->data) { + return DNSSEC_EINVAL; + } + + void *result = vpool_insert(&ctx->buffer, vpool_get_length(&ctx->buffer), data->data, data->size); + if (result == NULL) { + return DNSSEC_SIGN_ERROR; + } + + return DNSSEC_EOK; +} + +_public_ +int dnssec_sign_write(dnssec_sign_ctx_t *ctx, dnssec_binary_t *signature) +{ + if (!ctx || !signature) { + return DNSSEC_EINVAL; + } + + if (!dnssec_key_can_sign(ctx->key)) { + return DNSSEC_NO_PRIVATE_KEY; + } + + gnutls_datum_t data = { + .data = vpool_get_buf(&ctx->buffer), + .size = vpool_get_length(&ctx->buffer) + }; + + assert(ctx->key->private_key); + _cleanup_datum_ gnutls_datum_t raw = { 0 }; +#ifdef HAVE_SIGN_DATA2 + int result = gnutls_privkey_sign_data2(ctx->key->private_key, + ctx->sign_algorithm, + 0, &data, &raw); +#else + gnutls_digest_algorithm_t digest_algorithm = get_digest_algorithm(ctx->key); + int result = gnutls_privkey_sign_data(ctx->key->private_key, + digest_algorithm, + 0, &data, &raw); +#endif + if (result < 0) { + return DNSSEC_SIGN_ERROR; + } + + dnssec_binary_t bin_raw = binary_from_datum(&raw); + + return ctx->functions->x509_to_dnssec(ctx, &bin_raw, signature); +} + +_public_ +int dnssec_sign_verify(dnssec_sign_ctx_t *ctx, const dnssec_binary_t *signature) +{ + if (!ctx || !signature) { + return DNSSEC_EINVAL; + } + + if (!dnssec_key_can_verify(ctx->key)) { + return DNSSEC_NO_PUBLIC_KEY; + } + + gnutls_datum_t data = { + .data = vpool_get_buf(&ctx->buffer), + .size = vpool_get_length(&ctx->buffer) + }; + + _cleanup_binary_ dnssec_binary_t bin_raw = { 0 }; + int result = ctx->functions->dnssec_to_x509(ctx, signature, &bin_raw); + if (result != DNSSEC_EOK) { + return result; + } + + gnutls_datum_t raw = binary_to_datum(&bin_raw); + + assert(ctx->key->public_key); + result = gnutls_pubkey_verify_data2(ctx->key->public_key, + ctx->sign_algorithm, + 0, &data, &raw); + if (result == GNUTLS_E_PK_SIG_VERIFY_FAILED) { + return DNSSEC_INVALID_SIGNATURE; + } else if (result < 0) { + return DNSSEC_ERROR; + } + + return DNSSEC_EOK; +} |