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Diffstat (limited to 'hashsig.c')
| -rw-r--r-- | hashsig.c | 2122 |
1 files changed, 2122 insertions, 0 deletions
diff --git a/hashsig.c b/hashsig.c new file mode 100644 index 0000000..4060818 --- /dev/null +++ b/hashsig.c @@ -0,0 +1,2122 @@ +/* + * hashsig.c + * --------- + * Implementation of draft-mcgrew-hash-sigs-10.txt + * + * Copyright (c) 2018, NORDUnet A/S All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * - Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * - Neither the name of the NORDUnet nor the names of its contributors may + * be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "hal.h" +#include "hashsig.h" +#include "ks.h" +#include "asn1_internal.h" +#include "xdr_internal.h" + +typedef struct { uint8_t bytes[32]; } bytestring32; +typedef struct { uint8_t bytes[16]; } bytestring16; + +#define D_PBLC 0x8080 +#define D_MESG 0x8181 +#define D_LEAF 0x8282 +#define D_INTR 0x8383 + +#define u32str(X) htonl(X) +#define u16str(X) htons(X) +#define u8str(X) (X & 0xff) + +#define check(op) do { hal_error_t _err = (op); if (_err != HAL_OK) return _err; } while (0) + +/* ---------------------------------------------------------------- */ + +/* + * XDR extensions + */ + +static inline hal_error_t hal_xdr_encode_bytestring32(uint8_t ** const outbuf, const uint8_t * const limit, const bytestring32 * const value) +{ + return hal_xdr_encode_fixed_opaque(outbuf, limit, (const uint8_t *)value, sizeof(bytestring32)); +} + +static inline hal_error_t hal_xdr_decode_bytestring32_ptr(const uint8_t ** const inbuf, const uint8_t * const limit, bytestring32 **value) +{ + return hal_xdr_decode_fixed_opaque_ptr(inbuf, limit, (const uint8_t ** const)value, sizeof(bytestring32)); +} + +static inline hal_error_t hal_xdr_decode_bytestring32(const uint8_t ** const inbuf, const uint8_t * const limit, bytestring32 * const value) +{ + return hal_xdr_decode_fixed_opaque(inbuf, limit, (uint8_t * const)value, sizeof(bytestring32)); +} + +static inline hal_error_t hal_xdr_encode_bytestring16(uint8_t ** const outbuf, const uint8_t * const limit, const bytestring16 *value) +{ + return hal_xdr_encode_fixed_opaque(outbuf, limit, (const uint8_t *)value, sizeof(bytestring16)); +} + +static inline hal_error_t hal_xdr_decode_bytestring16_ptr(const uint8_t ** const inbuf, const uint8_t * const limit, bytestring16 **value) +{ + return hal_xdr_decode_fixed_opaque_ptr(inbuf, limit, (const uint8_t ** const)value, sizeof(bytestring16)); +} + +static inline hal_error_t hal_xdr_decode_bytestring16(const uint8_t ** const inbuf, const uint8_t * const limit, bytestring16 * const value) +{ + return hal_xdr_decode_fixed_opaque(inbuf, limit, (uint8_t * const)value, sizeof(bytestring16)); +} + +/* ---------------------------------------------------------------- */ + +/* + * ASN.1 extensions + */ + +static inline hal_error_t hal_asn1_encode_size_t(const size_t n, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_uint32((const uint32_t)n, der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_size_t(size_t *np, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + /* trust the compiler to optimize out the unused code path */ + if (sizeof(size_t) == sizeof(uint32_t)) { + return hal_asn1_decode_uint32((uint32_t *)np, der, der_len, der_max); + } + else { + uint32_t n; + hal_error_t err; + + if ((err = hal_asn1_decode_uint32(&n, der, der_len, der_max)) == HAL_OK) + *np = (size_t)n; + + return err; + } +} + +static inline hal_error_t hal_asn1_encode_lms_algorithm(const lms_algorithm_t type, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_uint32((const uint32_t)type, der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_lms_algorithm(lms_algorithm_t *type, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + uint32_t n; + hal_error_t err; + + if ((err = hal_asn1_decode_uint32(&n, der, der_len, der_max)) == HAL_OK) + *type = (lms_algorithm_t)n; + + return err; +} + +static inline hal_error_t hal_asn1_encode_lmots_algorithm(const lmots_algorithm_t type, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_uint32((const uint32_t)type, der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_lmots_algorithm(lmots_algorithm_t *type, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + uint32_t n; + hal_error_t err; + + if ((err = hal_asn1_decode_uint32(&n, der, der_len, der_max)) == HAL_OK) + *type = (lmots_algorithm_t)n; + + return err; +} + +static inline hal_error_t hal_asn1_encode_uuid(const hal_uuid_t * const data, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_octet_string((const uint8_t * const)data, sizeof(hal_uuid_t), der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_uuid(hal_uuid_t *data, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_decode_octet_string((uint8_t *)data, sizeof(hal_uuid_t), der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_encode_bytestring16(const bytestring16 * const data, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_octet_string((const uint8_t * const)data, sizeof(bytestring16), der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_bytestring16(bytestring16 *data, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_decode_octet_string((uint8_t *)data, sizeof(bytestring16), der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_encode_bytestring32(const bytestring32 * const data, uint8_t *der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_encode_octet_string((const uint8_t * const)data, sizeof(bytestring32), der, der_len, der_max); +} + +static inline hal_error_t hal_asn1_decode_bytestring32(bytestring32 *data, const uint8_t * const der, size_t *der_len, const size_t der_max) +{ + return hal_asn1_decode_octet_string((uint8_t *)data, sizeof(bytestring32), der, der_len, der_max); +} + +/* ---------------------------------------------------------------- */ + +/* + * LM-OTS + */ + +typedef const struct lmots_parameter_set { + lmots_algorithm_t type; + size_t n, w, p, ls; +} lmots_parameter_t; +static lmots_parameter_t lmots_parameters[] = { + { lmots_sha256_n32_w1, 32, 1, 265, 7 }, + { lmots_sha256_n32_w2, 32, 2, 133, 6 }, + { lmots_sha256_n32_w4, 32, 4, 67, 4 }, + { lmots_sha256_n32_w8, 32, 8, 34, 0 }, +}; + +typedef struct lmots_key { + hal_key_type_t type; + lmots_parameter_t *lmots; + bytestring16 I; + size_t q; + bytestring32 * x; + bytestring32 K; +} lmots_key_t; + +static inline lmots_parameter_t *lmots_select_parameter_set(const lmots_algorithm_t lmots_type) +{ + if (lmots_type < lmots_sha256_n32_w1 || lmots_type > lmots_sha256_n32_w8) + return NULL; + else + return &lmots_parameters[lmots_type - lmots_sha256_n32_w1]; +} + +static inline size_t lmots_private_key_len(lmots_parameter_t * const lmots) +{ + /* u32str(type) || I || u32str(q) || x[0] || x[1] || ... || x[p-1] */ + return 2 * sizeof(uint32_t) + sizeof(bytestring16) + (lmots->p * lmots->n); +} + +static inline size_t lmots_public_key_len(lmots_parameter_t * const lmots) +{ + /* u32str(type) || I || u32str(q) || K */ + return 2 * sizeof(uint32_t) + sizeof(bytestring16) + lmots->n; +} + +static inline size_t lmots_signature_len(lmots_parameter_t * const lmots) +{ + /* u32str(type) || C || y[0] || ... || y[p-1] */ + return sizeof(uint32_t) + (lmots->p + 1) * lmots->n; +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +/* Given a key with most fields filled in, generate the lmots private and + * public key components (x and K). + * Let the caller worry about storage. + */ +static hal_error_t lmots_generate(lmots_key_t * const key) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMOTS || key->lmots == NULL || key->x == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + +// Algorithm 0: Generating a Private Key + +// 3. set n and p according to the typecode and Table 1 + + size_t n = key->lmots->n; + size_t p = key->lmots->p; + size_t w = key->lmots->w; + +// 4. compute the array x as follows: +// for ( i = 0; i < p; i = i + 1 ) { +// set x[i] to a uniformly random n-byte string +// } + + for (size_t i = 0; i < p; ++i) + check(hal_rpc_get_random(&key->x[i], n)); + +// Algorithm 1: Generating a One Time Signature Public Key From a +// Private Key + +// 4. compute the string K as follows: + + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + bytestring32 y[p]; + uint32_t l; + uint16_t s; + uint8_t b; + +// for ( i = 0; i < p; i = i + 1 ) { + for (size_t i = 0; i < p; ++i) { + +// tmp = x[i] + bytestring32 tmp; + memcpy(&tmp, &key->x[i], sizeof(tmp)); + +// for ( j = 0; j < 2^w - 1; j = j + 1 ) { + for (size_t j = 0; j < (1U << w) - 1; ++j) { + +// tmp = H(I || u32str(q) || u16str(i) || u8str(j) || tmp) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(i); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + b = u8str(j); check(hal_hash_update(state, (const uint8_t *)&b, sizeof(b))); + check(hal_hash_update(state, (const uint8_t *)&tmp, sizeof(tmp))); + check(hal_hash_finalize(state, (uint8_t *)&tmp, sizeof(tmp))); + } + +// y[i] = tmp + memcpy(&y[i], &tmp, sizeof(tmp)); +// } + } + +// K = H(I || u32str(q) || u16str(D_PBLC) || y[0] || ... || y[p-1]) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_PBLC); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + for (size_t i = 0; i < p; ++i) + check(hal_hash_update(state, (const uint8_t *)&y[i], sizeof(y[i]))); + check(hal_hash_finalize(state, (uint8_t *)&key->K, sizeof(key->K))); + + return HAL_OK; +} +#endif + +/* strings of w-bit elements */ +static uint8_t coef(const uint8_t * const S, const size_t i, size_t w) +{ + switch (w) { + case 1: + return (S[i/8] >> (7 - (i % 8))) & 0x01; + case 2: + return (S[i/4] >> (6 - (2 * (i % 4)))) & 0x03; + case 4: + return (S[i/2] >> (4 - (4 * (i % 2)))) & 0x0f; + case 8: + return S[i]; + default: + return 0; + } +} + +/* checksum */ +static uint16_t Cksm(const uint8_t * const S, lmots_parameter_t *lmots) +{ + uint16_t sum = 0; + + for (size_t i = 0; i < (lmots->n * 8 / lmots->w); ++i) + sum += ((1 << lmots->w) - 1) - coef(S, i, lmots->w); + + return (sum << lmots->ls); +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +static hal_error_t lmots_sign(lmots_key_t *key, + const uint8_t * const msg, const size_t msg_len, + uint8_t * sig, size_t *sig_len, const size_t sig_max) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMOTS || msg == NULL || sig == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + +// Algorithm 3: Generating a One Time Signature From a Private Key and a +// Message + +// 1. set type to the typecode of the algorithm +// +// 2. set n, p, and w according to the typecode and Table 1 + + size_t n = key->lmots->n; + size_t p = key->lmots->p; + size_t w = key->lmots->w; + + if (sig_max < lmots_signature_len(key->lmots)) + return HAL_ERROR_BAD_ARGUMENTS; + +// 3. determine x, I and q from the private key +// +// 4. set C to a uniformly random n-byte string + + bytestring32 C; + check(hal_rpc_get_random(&C, n)); + +// 5. compute the array y as follows: + + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + uint8_t Q[n + 2]; /* hash || 16-bit checksum */ + uint32_t l; + uint16_t s; + uint8_t b; + +// Q = H(I || u32str(q) || u16str(D_MESG) || C || message) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_MESG); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + check(hal_hash_update(state, (const uint8_t *)&C, sizeof(C))); + check(hal_hash_update(state, msg, msg_len)); + check(hal_hash_finalize(state, Q, n)); + + /* append checksum */ + *(uint16_t *)&Q[n] = u16str(Cksm((uint8_t *)Q, key->lmots)); + + bytestring32 y[p]; + +// for ( i = 0; i < p; i = i + 1 ) { + for (size_t i = 0; i < p; ++i) { + +// a = coef(Q || Cksm(Q), i, w) + uint8_t a = coef(Q, i, w); + +// tmp = x[i] + bytestring32 tmp; + memcpy(&tmp, &key->x[i], sizeof(tmp)); + +// for ( j = 0; j < a; j = j + 1 ) { + for (size_t j = 0; j < (size_t)a; ++j) { + +// tmp = H(I || u32str(q) || u16str(i) || u8str(j) || tmp) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(i); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + b = u8str(j); check(hal_hash_update(state, (const uint8_t *)&b, sizeof(b))); + check(hal_hash_update(state, (const uint8_t *)&tmp, sizeof(tmp))); + check(hal_hash_finalize(state, (uint8_t *)&tmp, sizeof(tmp))); +// } + } + +// y[i] = tmp + memcpy(&y[i], &tmp, sizeof(tmp)); + } + +// 6. return u32str(type) || C || y[0] || ... || y[p-1] + uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_max; + check(hal_xdr_encode_int(&sigptr, siglim, key->lmots->type)); + check(hal_xdr_encode_bytestring32(&sigptr, siglim, &C)); + for (size_t i = 0; i < p; ++i) + check(hal_xdr_encode_bytestring32(&sigptr, siglim, &y[i])); + + if (sig_len != NULL) + *sig_len = sigptr - sig; + + return HAL_OK; +} +#endif + +static hal_error_t lmots_public_key_candidate(const lmots_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + const uint8_t * const sig, const size_t sig_len) +{ + if (key == NULL || msg == NULL || sig == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + /* Skip the length checks here, because we did a unitary length check + * at the start of lms_verify. + */ + +// 1. if the signature is not at least four bytes long, return INVALID +// +// 2. parse sigtype, C, and y from the signature as follows: +// a. sigtype = strTou32(first 4 bytes of signature) + + const uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_len; + + uint32_t sigtype; + check(hal_xdr_decode_int(&sigptr, siglim, &sigtype)); + +// b. if sigtype is not equal to pubtype, return INVALID + + if ((lmots_algorithm_t)sigtype != key->lmots->type) + return HAL_ERROR_INVALID_SIGNATURE; + +// c. set n and p according to the pubtype and Table 1; if the +// signature is not exactly 4 + n * (p+1) bytes long, return INVALID + + size_t n = key->lmots->n; + size_t p = key->lmots->p; + size_t w = key->lmots->w; + +// d. C = next n bytes of signature + + bytestring32 C; + check(hal_xdr_decode_bytestring32(&sigptr, siglim, &C)); + +// e. y[0] = next n bytes of signature +// y[1] = next n bytes of signature +// ... +// y[p-1] = next n bytes of signature + + bytestring32 y[p]; + for (size_t i = 0; i < p; ++i) + check(hal_xdr_decode_bytestring32(&sigptr, siglim, &y[i])); + +// 3. compute the string Kc as follows + + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + uint8_t Q[n + 2]; /* hash || 16-bit checksum */ + uint32_t l; + uint16_t s; + uint8_t b; + +// Q = H(I || u32str(q) || u16str(D_MESG) || C || message) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_MESG); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + check(hal_hash_update(state, (const uint8_t *)&C, sizeof(C))); + check(hal_hash_update(state, msg, msg_len)); + check(hal_hash_finalize(state, Q, n)); + + /* append checksum */ + *(uint16_t *)&Q[n] = u16str(Cksm((uint8_t *)Q, key->lmots)); + + bytestring32 z[p]; + +// for ( i = 0; i < p; i = i + 1 ) { + for (size_t i = 0; i < p; ++i) { + +// a = coef(Q || Cksm(Q), i, w) + uint8_t a = coef(Q, i, w); + +// tmp = y[i] + bytestring32 tmp; + memcpy(&tmp, &y[i], sizeof(tmp)); + +// for ( j = a; j < 2^w - 1; j = j + 1 ) { + for (size_t j = (size_t)a; j < (1U << w) - 1; ++j) { + +// tmp = H(I || u32str(q) || u16str(i) || u8str(j) || tmp) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(i); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + b = u8str(j); check(hal_hash_update(state, (const uint8_t *)&b, sizeof(b))); + check(hal_hash_update(state, (const uint8_t *)&tmp, sizeof(tmp))); + check(hal_hash_finalize(state, (uint8_t *)&tmp, sizeof(tmp))); +// } + } + +// z[i] = tmp + memcpy(&z[i], &tmp, sizeof(tmp)); +// } + } + +// Kc = H(I || u32str(q) || u16str(D_PBLC) || z[0] || z[1] || ... || z[p-1]) + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(key->q); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_PBLC); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + for (size_t i = 0; i < p; ++i) + check(hal_hash_update(state, (const uint8_t *)&z[i], sizeof(z[i]))); + check(hal_hash_finalize(state, (uint8_t *)&key->K, sizeof(key->K))); + +// 4. return Kc + return HAL_OK; +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +static hal_error_t lmots_private_key_to_der(const lmots_key_t * const key, + uint8_t *der, size_t *der_len, const size_t der_max) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMOTS) + return HAL_ERROR_BAD_ARGUMENTS; + + // u32str(lmots_type) || I || u32str(q) || K || x[0] || x[1] || ... || x[p-1] + /* K is not an integral part of the private key, but we store it to speed up restart */ + + /* + * Calculate data length. + */ + + size_t len, vlen = 0, hlen; + + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring16(&key->I, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_size_t(key->q, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring32(&key->K, NULL, &len, 0)); vlen += len; + for (size_t i = 0; i < key->lmots->p; ++i) { + check(hal_asn1_encode_bytestring32(&key->x[i], NULL, &len, 0)); vlen += len; + } + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, NULL, &hlen, 0)); + + check(hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, NULL, hlen + vlen, NULL, der_len, der_max)); + + if (der == NULL) + return HAL_OK; + + /* + * Encode data. + */ + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)); + + uint8_t *d = der + hlen; + memset(d, 0, vlen); + + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_bytestring16(&key->I, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_size_t(key->q, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_bytestring32(&key->K, d, &len, vlen)); d += len; vlen -= len; + for (size_t i = 0; i < key->lmots->p; ++i) { + check(hal_asn1_encode_bytestring32(&key->x[i], d, &len, vlen)); d += len; vlen -= len; + } + + return hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, der, d - der, der, der_len, der_max); +} + +static size_t lmots_private_key_to_der_len(const lmots_key_t * const key) +{ + size_t len = 0; + return (lmots_private_key_to_der(key, NULL, &len, 0) == HAL_OK) ? len : 0; +} + +static hal_error_t lmots_private_key_from_der(lmots_key_t *key, + const uint8_t *der, const size_t der_len) +{ + if (key == NULL || der == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + key->type = HAL_KEY_TYPE_HASHSIG_LMOTS; + + size_t hlen, vlen, alg_oid_len, curve_oid_len, privkey_len; + const uint8_t *alg_oid, *curve_oid, *privkey; + + check(hal_asn1_decode_pkcs8_privatekeyinfo(&alg_oid, &alg_oid_len, + &curve_oid, &curve_oid_len, + &privkey, &privkey_len, + der, der_len)); + + if (alg_oid_len != hal_asn1_oid_mts_hashsig_len || + memcmp(alg_oid, hal_asn1_oid_mts_hashsig, alg_oid_len) != 0 || + curve_oid_len != 0) + return HAL_ERROR_ASN1_PARSE_FAILED; + + check(hal_asn1_decode_header(ASN1_SEQUENCE, privkey, privkey_len, &hlen, &vlen)); + + const uint8_t *d = privkey + hlen; + size_t len; + + // u32str(lmots_type) || I || u32str(q) || K || x[0] || x[1] || ... || x[p-1] + + lmots_algorithm_t lmots_type; + check(hal_asn1_decode_lmots_algorithm(&lmots_type, d, &len, vlen)); d += len; vlen -= len; + key->lmots = lmots_select_parameter_set(lmots_type); + check(hal_asn1_decode_bytestring16(&key->I, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_decode_size_t(&key->q, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_decode_bytestring32(&key->K, d, &len, vlen)); d += len; vlen -= len; + if (key->x != NULL) { + for (size_t i = 0; i < key->lmots->p; ++i) { + check(hal_asn1_decode_bytestring32(&key->x[i], d, &len, vlen)); d += len; vlen -= len; + } + + if (d != privkey + privkey_len) + return HAL_ERROR_ASN1_PARSE_FAILED; + } + + return HAL_OK; +} +#endif + +/* ---------------------------------------------------------------- */ + +/* + * LMS + */ + +typedef const struct lms_parameter_set { + lms_algorithm_t type; + size_t m, h; +} lms_parameter_t; +static lms_parameter_t lms_parameters[] = { + { lms_sha256_n32_h5, 32, 5 }, + { lms_sha256_n32_h10, 32, 10 }, + { lms_sha256_n32_h15, 32, 15 }, + { lms_sha256_n32_h20, 32, 20 }, + { lms_sha256_n32_h25, 32, 25 }, +}; + +typedef struct lms_key { + hal_key_type_t type; + size_t level; + lms_parameter_t *lms; + lmots_parameter_t *lmots; + bytestring16 I; + size_t q; /* index of next lmots signing key */ + hal_uuid_t *lmots_keys; /* private key components */ + bytestring32 *T; /* public key components */ + bytestring32 T1; /* copy of T[1] */ + uint8_t *pubkey; /* in XDR format */ + size_t pubkey_len; + uint8_t *signature; /* of public key by parent lms key */ + size_t signature_len; +} lms_key_t; + +static inline lms_parameter_t *lms_select_parameter_set(const lms_algorithm_t lms_type) +{ + if (lms_type < lms_sha256_n32_h5 || lms_type > lms_sha256_n32_h25) + return NULL; + else + return &lms_parameters[lms_type - lms_sha256_n32_h5]; +} + +static inline size_t lms_public_key_len(lms_parameter_t * const lms) +{ + /* u32str(type) || u32str(otstype) || I || T[1] */ + return 2 * sizeof(uint32_t) + 16 + lms->m; +} + +static inline size_t lms_signature_len(lms_parameter_t * const lms, lmots_parameter_t * const lmots) +{ + /* u32str(q) || ots_signature || u32str(type) || path[0] || path[1] || ... || path[h-1] */ + return 2 * sizeof(uint32_t) + lmots_signature_len(lmots) + lms->h * lms->m; +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +/* Given a key with most fields filled in, generate the lms private and + * public key components. + * Let the caller worry about storage. + */ +static hal_error_t lms_generate(lms_key_t *key) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMS || key->lms == NULL || key->lmots == NULL || key->lmots_keys == NULL || key->T == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + check(hal_uuid_gen((hal_uuid_t *)&key->I)); + key->q = 0; + + bytestring32 x[key->lmots->p]; + lmots_key_t lmots_key = { + .type = HAL_KEY_TYPE_HASHSIG_LMOTS, + .lmots = key->lmots, + .x = x + }; + memcpy(&lmots_key.I, &key->I, sizeof(key->I)); + + hal_pkey_slot_t slot = { + .type = HAL_KEY_TYPE_HASHSIG_LMOTS, + .curve = HAL_CURVE_NONE, + .flags = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE | ((key->level == 0) ? HAL_KEY_FLAG_TOKEN: 0) + }; + hal_ks_t *ks = (key->level == 0) ? hal_ks_token : hal_ks_volatile; + + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + uint32_t l; + uint16_t s; + size_t h2 = (1 << key->lms->h); + + /* private key - array of lmots key names */ + for (size_t q = 0; q < h2; ++q) { + /* generate the lmots private and public key components */ + lmots_key.q = q; + check(lmots_generate(&lmots_key)); + + /* store the lmots key */ + uint8_t der[lmots_private_key_to_der_len(&lmots_key)]; + size_t der_len; + check(lmots_private_key_to_der(&lmots_key, der, &der_len, sizeof(der))); + check(hal_uuid_gen(&slot.name)); + hal_error_t err = hal_ks_store(ks, &slot, der, der_len); + memset(&x, 0, sizeof(x)); + memset(der, 0, sizeof(der)); + if (err != HAL_OK) return err; + + /* record the lmots keystore name */ + memcpy(&key->lmots_keys[q], &slot.name, sizeof(slot.name)); + + /* compute T[r] = H(I || u32str(r) || u16str(D_LEAF) || OTS_PUB_HASH[r-2^h]) */ + size_t r = h2 + q; + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(r); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_LEAF); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + check(hal_hash_update(state, (const uint8_t *)&lmots_key.K, sizeof(lmots_key.K))); + check(hal_hash_finalize(state, (uint8_t *)&key->T[r], sizeof(key->T[r]))); + hal_task_yield_maybe(); + } + + /* generate the rest of T[r] = H(I || u32str(r) || u16str(D_INTR) || T[2*r] || T[2*r+1]) */ + for (size_t r = h2 - 1; r > 0; --r) { + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(r); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_INTR); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + check(hal_hash_update(state, (const uint8_t *)&key->T[2*r], sizeof(key->T[r]))); + check(hal_hash_update(state, (const uint8_t *)&key->T[2*r+1], sizeof(key->T[r]))); + check(hal_hash_finalize(state, (uint8_t *)&key->T[r], sizeof(key->T[r]))); + hal_task_yield_maybe(); + } + + memcpy(&key->T1, &key->T[1], sizeof(key->T1)); + + /* generate the XDR encoding of the public key, which will be signed + * by the previous lms key + */ + uint8_t *pubkey = key->pubkey; + const uint8_t * const publim = key->pubkey + key->pubkey_len; + // u32str(lms_type) || u32str(lmots_type) || I || T[1] + check(hal_xdr_encode_int(&pubkey, publim, key->lms->type)); + check(hal_xdr_encode_int(&pubkey, publim, key->lmots->type)); + check(hal_xdr_encode_bytestring16(&pubkey, publim, &key->I)); + check(hal_xdr_encode_bytestring32(&pubkey, publim, &key->T1)); + + return HAL_OK; +} + +static hal_error_t lms_delete(const lms_key_t * const key) +{ + hal_pkey_slot_t slot = {0}; + hal_ks_t *ks = (key->level == 0) ? hal_ks_token : hal_ks_volatile; + + /* delete the lmots keys */ + for (size_t i = 0; i < (1U << key->lms->h); ++i) { + memcpy(&slot.name, &key->lmots_keys[i], sizeof(slot.name)); + check(hal_ks_delete(ks, &slot)); + hal_task_yield_maybe(); + } + + /* delete the lms key */ + memcpy(&slot.name, &key->I, sizeof(slot.name)); + return hal_ks_delete(ks, &slot); +} + +static hal_error_t lms_private_key_to_der(const lms_key_t * const key, + uint8_t *der, size_t *der_len, const size_t der_max); + +static hal_error_t lms_sign(lms_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + uint8_t *sig, size_t *sig_len, const size_t sig_max) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMS || msg == NULL || sig == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + if (key->q >= (1U << key->lms->h)) + return HAL_ERROR_HASHSIG_KEY_EXHAUSTED; + + if (sig_max < lms_signature_len(key->lms, key->lmots)) + return HAL_ERROR_RESULT_TOO_LONG; + + /* u32str(q) || ots_signature || u32str(lms_type) || path[0] || path[1] || ... || path[h-1] */ + + uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_max; + check(hal_xdr_encode_int(&sigptr, siglim, key->q)); + + /* fetch and decode the lmots signing key from the keystore */ + hal_pkey_slot_t slot; + memset(&slot, 0, sizeof(slot)); + memcpy(&slot.name, &key->lmots_keys[key->q], sizeof(slot.name)); + + lmots_key_t lmots_key; + memset(&lmots_key, 0, sizeof(lmots_key)); + bytestring32 x[key->lmots->p]; + memset(&x, 0, sizeof(x)); + lmots_key.x = x; + + uint8_t der[HAL_KS_WRAPPED_KEYSIZE]; + size_t der_len; + hal_ks_t *ks = (key->level == 0) ? hal_ks_token : hal_ks_volatile; + check(hal_ks_fetch(ks, &slot, der, &der_len, sizeof(der))); + check(lmots_private_key_from_der(&lmots_key, der, der_len)); + memset(&der, 0, sizeof(der)); + + //? check lmots_type and I vs. lms key? + + /* generate the lmots signature */ + size_t lmots_sig_len; + check(lmots_sign(&lmots_key, msg, msg_len, sigptr, &lmots_sig_len, sig_max - (sigptr - sig))); + memset(&x, 0, sizeof(x)); + sigptr += lmots_sig_len; + + check(hal_xdr_encode_int(&sigptr, siglim, key->lms->type)); + + /* generate the path array */ + for (size_t r = (1 << key->lms->h) + key->q; r > 1; r /= 2) + check(hal_xdr_encode_bytestring32(&sigptr, siglim, ((r & 1) ? &key->T[r-1] : &key->T[r+1]))); + + if (sig_len != NULL) + *sig_len = sigptr - sig; + + /* update and store q before returning the signature */ + ++key->q; + check(lms_private_key_to_der(key, der, &der_len, sizeof(der))); + slot.type = HAL_KEY_TYPE_HASHSIG_LMS; + slot.flags = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE | ((key->level == 0) ? HAL_KEY_FLAG_TOKEN : 0); + memcpy(&slot.name, &key->I, sizeof(slot.name)); + check(hal_ks_rewrite_der(ks, &slot, der, der_len)); + + return HAL_OK; +} +#endif + +static hal_error_t lms_public_key_candidate(const lms_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + const uint8_t * const sig, const size_t sig_len, + bytestring32 * Tc); + +static hal_error_t lms_verify(const lms_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + const uint8_t * const sig, const size_t sig_len) +{ + if (key == NULL || msg == NULL || sig == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + /* We can do one length check right now, rather than the 3 in + * Algorithm 6b and 2 in Algorithm 4b, because the lms and lmots types + * in the signature have to match the key. + */ + if (sig_len != lms_signature_len(key->lms, key->lmots)) + return HAL_ERROR_INVALID_SIGNATURE; + +// Algorithm 6: LMS Signature Verification +// +// 1. if the public key is not at least eight bytes long, return +// INVALID +// +// 2. parse pubtype, I, and T[1] from the public key as follows: +// +// a. pubtype = strTou32(first 4 bytes of public key) +// +// b. ots_typecode = strTou32(next 4 bytes of public key) +// +// c. set m according to pubtype, based on Table 2 +// +// d. if the public key is not exactly 24 + m bytes +// long, return INVALID +// +// e. I = next 16 bytes of the public key +// +// f. T[1] = next m bytes of the public key +// +// 3. compute the candidate LMS root value Tc from the signature, +// message, identifier and pubtype using Algorithm 6b. + + bytestring32 Tc; + check(lms_public_key_candidate(key, msg, msg_len, sig, sig_len, &Tc)); + +// 4. if Tc is equal to T[1], return VALID; otherwise, return INVALID + + return (memcmp(&Tc, &key->T1, sizeof(Tc)) ? HAL_ERROR_INVALID_SIGNATURE : HAL_OK); +} + +static hal_error_t lms_public_key_candidate(const lms_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + const uint8_t * const sig, const size_t sig_len, + bytestring32 * Tc) +{ +// Algorithm 6b: Computing an LMS Public Key Candidate from a Signature, +// Message, Identifier, and algorithm typecode + /* XXX and pubotstype */ + +// 1. if the signature is not at least eight bytes long, return INVALID +// +// 2. parse sigtype, q, ots_signature, and path from the signature as +// follows: +// +// a. q = strTou32(first 4 bytes of signature) + + const uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_len; + + uint32_t q; + check(hal_xdr_decode_int(&sigptr, siglim, &q)); + +// b. otssigtype = strTou32(next 4 bytes of signature) + + uint32_t otssigtype; + check(hal_xdr_decode_int_peek(&sigptr, siglim, &otssigtype)); + +// c. if otssigtype is not the OTS typecode from the public key, return INVALID + + if ((lmots_algorithm_t)otssigtype != key->lmots->type) + return HAL_ERROR_INVALID_SIGNATURE; + +// d. set n, p according to otssigtype and Table 1; if the +// signature is not at least 12 + n * (p + 1) bytes long, return INVALID +// +// e. ots_signature = bytes 8 through 8 + n * (p + 1) - 1 of signature + + /* XXX Technically, this is also wrong - this is the remainder of + * ots_signature after otssigtype. The full ots_signature would be + * bytes 4 through 8 + n * (p + 1) - 1. + */ + + const uint8_t * const ots_signature = sigptr; + sigptr += lmots_signature_len(key->lmots); + +// f. sigtype = strTou32(4 bytes of signature at location 8 + n * (p + 1)) + + uint32_t sigtype; + check(hal_xdr_decode_int(&sigptr, siglim, &sigtype)); + +// f. if sigtype is not the LM typecode from the public key, return INVALID + + if ((lms_algorithm_t)sigtype != key->lms->type) + return HAL_ERROR_INVALID_SIGNATURE; + +// g. set m, h according to sigtype and Table 2 + + size_t m = key->lms->m; + size_t h = key->lms->h; + size_t h2 = (1 << key->lms->h); + +// h. if q >= 2^h or the signature is not exactly 12 + n * (p + 1) + m * h bytes long, return INVALID + + if (q >= h2) + return HAL_ERROR_INVALID_SIGNATURE; + +// i. set path as follows: +// path[0] = next m bytes of signature +// path[1] = next m bytes of signature +// ... +// path[h-1] = next m bytes of signature + + bytestring32 path[h]; + for (size_t i = 0; i < h; ++i) + check(hal_xdr_decode_bytestring32(&sigptr, siglim, &path[i])); + +// 3. Kc = candidate public key computed by applying Algorithm 4b +// to the signature ots_signature, the message, and the +// identifiers I, q + + lmots_key_t lmots_key = { + .type = HAL_KEY_TYPE_HASHSIG_LMOTS, + .lmots = key->lmots, + .q = q + }; + memcpy(&lmots_key.I, &key->I, sizeof(lmots_key.I)); + check(lmots_public_key_candidate(&lmots_key, msg, msg_len, ots_signature, lmots_signature_len(key->lmots))); + +// 4. compute the candidate LMS root value Tc as follows: + + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + uint32_t l; + uint16_t s; + +// node_num = 2^h + q + size_t r = h2 + q; + +// tmp = H(I || u32str(node_num) || u16str(D_LEAF) || Kc) + bytestring32 tmp; + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&lmots_key.I, sizeof(lmots_key.I))); + l = u32str(r); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_LEAF); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + check(hal_hash_update(state, (const uint8_t *)&lmots_key.K, sizeof(lmots_key.K))); + check(hal_hash_finalize(state, (uint8_t *)&tmp, sizeof(tmp))); + +// i = 0 +// while (node_num > 1) { +// if (node_num is odd): +// tmp = H(I || u32str(node_num/2) || u16str(D_INTR) || path[i] || tmp) +// else: +// tmp = H(I || u32str(node_num/2) || u16str(D_INTR) || tmp || path[i]) +// node_num = node_num/2 +// i = i + 1 +// } + for (size_t i = 0; r > 1; r /= 2, ++i) { + check(hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf))); + check(hal_hash_update(state, (const uint8_t *)&key->I, sizeof(key->I))); + l = u32str(r/2); check(hal_hash_update(state, (const uint8_t *)&l, sizeof(l))); + s = u16str(D_INTR); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + if (r & 1) { + check(hal_hash_update(state, (const uint8_t *)&path[i], m)); + check(hal_hash_update(state, (const uint8_t *)&tmp, sizeof(tmp))); + } + else { + check(hal_hash_update(state, (const uint8_t *)&tmp, sizeof(tmp))); + check(hal_hash_update(state, (const uint8_t *)&path[i], m)); + } + check(hal_hash_finalize(state, (uint8_t *)&tmp, sizeof(tmp))); + } + +// Tc = tmp + memcpy(Tc, &tmp, sizeof(*Tc)); + + return HAL_OK; +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +static hal_error_t lms_private_key_to_der(const lms_key_t * const key, + uint8_t *der, size_t *der_len, const size_t der_max) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_LMS) + return HAL_ERROR_BAD_ARGUMENTS; + + /* + * Calculate data length. + */ + + // u32str(lms_type) || u32str(lmots_type) || I || q + + size_t len, vlen = 0, hlen; + + check(hal_asn1_encode_lms_algorithm(key->lms->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring16(&key->I, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_size_t(key->q, NULL, &len, 0)); vlen += len; + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, NULL, &hlen, 0)); + + check(hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, NULL, hlen + vlen, NULL, der_len, der_max)); + + if (der == NULL) + return HAL_OK; + + /* + * Encode data. + */ + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)); + + uint8_t *d = der + hlen; + memset(d, 0, vlen); + + check(hal_asn1_encode_lms_algorithm(key->lms->type, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_bytestring16(&key->I, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_size_t(key->q, d, &len, vlen)); d += len; vlen -= len; + + return hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, der, d - der, der, der_len, der_max); +} + +static size_t lms_private_key_to_der_len(const lms_key_t * const key) +{ + size_t len = 0; + return lms_private_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0; +} + +static hal_error_t lms_private_key_from_der(lms_key_t *key, + const uint8_t *der, const size_t der_len) +{ + if (key == NULL || der == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + key->type = HAL_KEY_TYPE_HASHSIG_LMS; + + size_t hlen, vlen, alg_oid_len, curve_oid_len, privkey_len; + const uint8_t *alg_oid, *curve_oid, *privkey; + + check(hal_asn1_decode_pkcs8_privatekeyinfo(&alg_oid, &alg_oid_len, + &curve_oid, &curve_oid_len, + &privkey, &privkey_len, + der, der_len)); + + if (alg_oid_len != hal_asn1_oid_mts_hashsig_len || + memcmp(alg_oid, hal_asn1_oid_mts_hashsig, alg_oid_len) != 0 || + curve_oid_len != 0) + return HAL_ERROR_ASN1_PARSE_FAILED; + + check(hal_asn1_decode_header(ASN1_SEQUENCE, privkey, privkey_len, &hlen, &vlen)); + + const uint8_t *d = privkey + hlen; + size_t n; + + // u32str(lms_type) || u32str(lmots_type) || I || q + + lms_algorithm_t lms_type; + check(hal_asn1_decode_lms_algorithm(&lms_type, d, &n, vlen)); d += n; vlen -= n; + key->lms = lms_select_parameter_set(lms_type); + lmots_algorithm_t lmots_type; + check(hal_asn1_decode_lmots_algorithm(&lmots_type, d, &n, vlen)); d += n; vlen -= n; + key->lmots = lmots_select_parameter_set(lmots_type); + check(hal_asn1_decode_bytestring16(&key->I, d, &n, vlen)); d += n; vlen -= n; + check(hal_asn1_decode_size_t(&key->q, d, &n, vlen)); d += n; vlen -= n; + + if (d != privkey + privkey_len) + return HAL_ERROR_ASN1_PARSE_FAILED; + + return HAL_OK; +} +#endif + +/* ---------------------------------------------------------------- */ + +/* + * HSS + */ + +/* For purposes of the external API, the key type is "hal_hashsig_key_t". + * Internally, we refer to it as "hss_key_t". + */ + +typedef struct hal_hashsig_key hss_key_t; + +struct hal_hashsig_key { + hal_key_type_t type; + hss_key_t *next; + hal_uuid_t name; + size_t L; + lms_parameter_t *lms; + lmots_parameter_t *lmots; + bytestring16 I; + bytestring32 T1; + lms_key_t *lms_keys; +}; + +const size_t hal_hashsig_key_t_size = sizeof(hss_key_t); + +static hss_key_t *hss_keys = NULL; + +static inline size_t hss_public_key_len(lms_parameter_t * const lms) +{ + /* L || pub[0] */ + return sizeof(uint32_t) + lms_public_key_len(lms); +} + +static inline size_t hss_signature_len(const size_t L, lms_parameter_t * const lms, lmots_parameter_t * const lmots) +{ + /* u32str(Nspk) || sig[0] || pub[1] || ... || sig[Nspk-1] || pub[Nspk] || sig[Nspk] */ + return sizeof(uint32_t) + L * lms_signature_len(lms, lmots) + (L - 1) * lms_public_key_len(lms); +} + +size_t hal_hashsig_signature_len(const size_t L, + const lms_algorithm_t lms_type, + const lmots_algorithm_t lmots_type) +{ + lms_parameter_t * const lms = lms_select_parameter_set(lms_type); + if (lms == NULL) + return 0; + + lmots_parameter_t * const lmots = lmots_select_parameter_set(lmots_type); + if (lmots == NULL) + return 0; + + return hss_signature_len(L, lms, lmots); +} + +size_t hal_hashsig_lmots_private_key_len(const lmots_algorithm_t lmots_type) +{ + lmots_parameter_t * const lmots = lmots_select_parameter_set(lmots_type); + if (lmots == NULL) + return 0; + + return lmots_private_key_len(lmots); +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +static int restart_in_progress = 0; + +static inline void *gnaw(uint8_t **mem, size_t *len, const size_t size) +{ + if (mem == NULL || *mem == NULL || len == NULL || size > *len) + return NULL; + void *ret = *mem; + *mem += size; + *len -= size; + return ret; +} + +static hal_error_t hss_alloc(hal_hashsig_key_t **key_, + const size_t L, + const lms_algorithm_t lms_type, + const lmots_algorithm_t lmots_type) +{ + if (key_ == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + if (L == 0 || L > 8) + return HAL_ERROR_BAD_ARGUMENTS; + + lms_parameter_t *lms = lms_select_parameter_set(lms_type); + if (lms == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + size_t h2 = (1 << lms->h); + + lmots_parameter_t *lmots = lmots_select_parameter_set(lmots_type); + if (lmots == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + /* w=1 fails on the Alpha, because the key exceeds the keystore block + * size. The XDR encoding of the key is going to differ from the DER + * encoding, but it's at least in the ballpark to tell us whether the key + * will fit. + */ + if (lmots_private_key_len(lmots) > HAL_KS_BLOCK_SIZE) + return HAL_ERROR_UNSUPPORTED_KEY; + + if (hss_signature_len(L, lms, lmots) > HAL_RPC_MAX_PKT_SIZE) + return HAL_ERROR_UNSUPPORTED_KEY; + + /* check volatile keystore for space to store the lower-level trees */ + size_t available; + check(hal_ks_available(hal_ks_volatile, &available)); + if (available < (L - 1) * (h2 + 1)) + return HAL_ERROR_NO_KEY_INDEX_SLOTS; + + size_t lms_sig_len = lms_signature_len(lms, lmots); + size_t lms_pub_len = lms_public_key_len(lms); + + /* allocate lms tree nodes and lmots key names, atomically */ + size_t len = (sizeof(hss_key_t) + + L * sizeof(lms_key_t) + + L * lms_sig_len + + L * lms_pub_len + + L * h2 * sizeof(hal_uuid_t) + + L * (2 * h2) * sizeof(bytestring32)); + uint8_t *mem = hal_allocate_static_memory(len); + if (mem == NULL) + return HAL_ERROR_ALLOCATION_FAILURE; + memset(mem, 0, len); + + /* allocate the key that will stay in working memory */ + hss_key_t *key = gnaw(&mem, &len, sizeof(hss_key_t)); + *key_ = key; + key->type = HAL_KEY_TYPE_HASHSIG_PRIVATE; + key->L = L; + key->lms = lms; + key->lmots = lmots; + + /* add to the list of active keys */ + key->next = hss_keys; + hss_keys = key; + + /* allocate the list of lms trees */ + key->lms_keys = gnaw(&mem, &len, L * sizeof(lms_key_t)); + for (size_t i = 0; i < L; ++i) { + /* XXX some of this is redundant to lms_private_key_from_der */ + lms_key_t * lms_key = &key->lms_keys[i]; + lms_key->type = HAL_KEY_TYPE_HASHSIG_LMS; + lms_key->lms = lms; + lms_key->lmots = lmots; + lms_key->level = i; + lms_key->lmots_keys = (hal_uuid_t *)gnaw(&mem, &len, h2 * sizeof(hal_uuid_t)); + lms_key->T = gnaw(&mem, &len, (2 * h2) * sizeof(bytestring32)); + lms_key->signature = gnaw(&mem, &len, lms_sig_len); + lms_key->signature_len = lms_sig_len; + lms_key->pubkey = gnaw(&mem, &len, lms_pub_len); + lms_key->pubkey_len = lms_pub_len; + } + + return HAL_OK; +} + +/* called from pkey_local_generate_hashsig */ +hal_error_t hal_hashsig_key_gen(hal_core_t *core, + hal_hashsig_key_t **key_, + const size_t L, + const lms_algorithm_t lms_type, + const lmots_algorithm_t lmots_type) +{ + /* hss_alloc does most of the checks */ + + if (restart_in_progress) + return HAL_ERROR_NOT_READY; + + /* check flash keystore for space to store the root tree */ + lms_parameter_t *lms = lms_select_parameter_set(lms_type); + if (lms == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + size_t available; + check(hal_ks_available(hal_ks_token, &available)); + if (available < (1U << lms->h) + 2) + return HAL_ERROR_NO_KEY_INDEX_SLOTS; + + check(hss_alloc(key_, L, lms_type, lmots_type)); + hss_key_t *key = *key_; + + /* generate the lms trees */ + for (size_t i = 0; i < L; ++i) { + lms_key_t * lms_key = &key->lms_keys[i]; + + check(lms_generate(lms_key)); + + if (i > 0) + /* sign this tree with the previous */ + check(lms_sign(&key->lms_keys[i-1], + (const uint8_t * const)lms_key->pubkey, lms_public_key_len(key->lms), + lms_key->signature, NULL, lms_signature_len(key->lms, key->lmots))); + + /* store the lms key */ + hal_pkey_slot_t slot = { + .type = HAL_KEY_TYPE_HASHSIG_LMS, + .curve = HAL_CURVE_NONE, + .flags = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE | ((i == 0) ? HAL_KEY_FLAG_TOKEN: 0) + }; + hal_ks_t *ks = (i == 0) ? hal_ks_token : hal_ks_volatile; + uint8_t der[lms_private_key_to_der_len(lms_key)]; + size_t der_len; + + memcpy(&slot.name, &lms_key->I, sizeof(slot.name)); + check(lms_private_key_to_der(lms_key, der, &der_len, sizeof(der))); + check(hal_ks_store(ks, &slot, der, der_len)); + } + + memcpy(&key->I, &key->lms_keys[0].I, sizeof(key->I)); + memcpy(&key->T1, &key->lms_keys[0].T1, sizeof(key->T1)); + + /* pkey_local_generate_hashsig stores the key */ + + return HAL_OK; +} + +/* caller will delete the hss key from the keystore */ +hal_error_t hal_hashsig_key_delete(const hal_hashsig_key_t * const key) +{ + if (restart_in_progress) + return HAL_ERROR_NOT_READY; + + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_PRIVATE) + return HAL_ERROR_BAD_ARGUMENTS; + + /* delete the lms trees and their lmots keys */ + for (size_t level = 0; level < key->L; ++level) + check(lms_delete(&key->lms_keys[level])); + + /* XXX free memory, if supported */ + (void)hal_free_static_memory(key); + + /* remove from global hss_keys linked list */ + /* XXX or mark it unused, for possible re-use */ + if (hss_keys == key) { + hss_keys = key->next; + } + else { + for (hss_key_t *prev = hss_keys; prev != NULL; prev = prev->next) { + if (prev->next == key) { + prev->next = key->next; + break; + } + } + } + + return HAL_OK; +} + +hal_error_t hal_hashsig_sign(hal_core_t *core, + const hal_hashsig_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + uint8_t *sig, size_t *sig_len, const size_t sig_max) +{ + if (restart_in_progress) + return HAL_ERROR_NOT_READY; + + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_PRIVATE || msg == NULL || sig == NULL || sig_len == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + if (sig_max < hss_signature_len(key->L, key->lms, key->lmots)) + return HAL_ERROR_RESULT_TOO_LONG; + +// To sign a message using the private key prv, the following steps are +// performed: +// +// If prv[L-1] is exhausted, then determine the smallest integer d +// such that all of the private keys prv[d], prv[d+1], ... , prv[L-1] +// are exhausted. If d is equal to zero, then the HSS key pair is +// exhausted, and it MUST NOT generate any more signatures. +// Otherwise, the key pairs for levels d through L-1 must be +// regenerated during the signature generation process, as follows. +// For i from d to L-1, a new LMS public and private key pair with a +// new identifier is generated, pub[i] and prv[i] are set to those +// values, then the public key pub[i] is signed with prv[i-1], and +// sig[i-1] is set to the resulting value. + + size_t h2 = (1 << key->lms->h); + if (key->lms_keys[key->L-1].q >= h2) { + size_t d; + for (d = key->L-1; d > 0 && key->lms_keys[d-1].q >= h2; --d) { + } + if (d == 0) + return HAL_ERROR_HASHSIG_KEY_EXHAUSTED; + for ( ; d < key->L; ++d) { + lms_key_t *lms_key = &key->lms_keys[d]; + /* Delete then regenerate the LMS key. We don't worry about + * power-cycling in the middle, because the lower-level trees are + * all stored in the volatile keystore, so we'd have to regenerate + * them anyway on restart; and this way we don't have to allocate + * any additional memory. + */ + check(lms_delete(lms_key)); + check(lms_generate(lms_key)); + check(lms_sign(&key->lms_keys[d-1], + (const uint8_t * const)lms_key->pubkey, lms_key->pubkey_len, + lms_key->signature, NULL, lms_key->signature_len)); + + hal_pkey_slot_t slot = { + .type = HAL_KEY_TYPE_HASHSIG_LMS, + .curve = HAL_CURVE_NONE, + .flags = (lms_key->level == 0) ? HAL_KEY_FLAG_TOKEN: 0 + }; + hal_ks_t *ks = (lms_key->level == 0) ? hal_ks_token : hal_ks_volatile; + uint8_t der[lms_private_key_to_der_len(lms_key)]; + size_t der_len; + + memcpy(&slot.name, &lms_key->I, sizeof(slot.name)); + check(lms_private_key_to_der(lms_key, der, &der_len, sizeof(der))); + check(hal_ks_store(ks, &slot, der, der_len)); + } + } + +// The message is signed with prv[L-1], and the value sig[L-1] is set +// to that result. +// +// The value of the HSS signature is set as follows. We let +// signed_pub_key denote an array of octet strings, where +// signed_pub_key[i] = sig[i] || pub[i+1], for i between 0 and Nspk- +// 1, inclusive, where Nspk = L-1 denotes the number of signed public +// keys. Then the HSS signature is u32str(Nspk) || +// signed_pub_key[0] || ... || signed_pub_key[Nspk-1] || sig[Nspk]. + + uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_max; + check(hal_xdr_encode_int(&sigptr, siglim, key->L - 1)); + + /* copy the lms signed public keys into the signature */ + for (size_t i = 1; i < key->L; ++i) { + lms_key_t *lms_key = &key->lms_keys[i]; + check(hal_xdr_encode_fixed_opaque(&sigptr, siglim, lms_key->signature, lms_key->signature_len)); + check(hal_xdr_encode_fixed_opaque(&sigptr, siglim, lms_key->pubkey, lms_key->pubkey_len)); + } + + /* sign the message with the last lms private key */ + size_t len; + check(lms_sign(&key->lms_keys[key->L-1], msg, msg_len, sigptr, &len, sig_max - (sigptr - sig))); + sigptr += len; + *sig_len = sigptr - sig; + + return HAL_OK; +} +#endif + +hal_error_t hal_hashsig_verify(hal_core_t *core, + const hal_hashsig_key_t * const key, + const uint8_t * const msg, const size_t msg_len, + const uint8_t * const sig, const size_t sig_len) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_PUBLIC || msg == NULL || sig == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + core = core; + +// To verify a signature sig and message using the public key pub, the +// following steps are performed: +// +// The signature S is parsed into its components as follows: +// +// Nspk = strTou32(first four bytes of S) +// if Nspk+1 is not equal to the number of levels L in pub: +// return INVALID + + const uint8_t *sigptr = sig; + const uint8_t * const siglim = sig + sig_len; + + uint32_t Nspk; + check(hal_xdr_decode_int(&sigptr, siglim, &Nspk)); + if (Nspk + 1 != key->L) + return HAL_ERROR_INVALID_SIGNATURE; + +// key = pub +// for (i = 0; i < Nspk; i = i + 1) { +// sig = next LMS signature parsed from S +// msg = next LMS public key parsed from S +// if (lms_verify(msg, key, sig) != VALID): +// return INVALID +// key = msg +// } + + lms_key_t pub = { + .type = HAL_KEY_TYPE_HASHSIG_LMS, + .lms = key->lms, + .lmots = key->lmots + }; + memcpy(&pub.I, &key->I, sizeof(pub.I)); + memcpy(&pub.T1, &key->T1, sizeof(pub.T1)); + + for (size_t i = 0; i < Nspk; ++i) { + const uint8_t * const lms_sig = sigptr; + /* peek into the signature for the lmots and lms types */ + /* XXX The structure of the LMS signature makes this a bigger pain + * in the ass than necessary. + */ + /* skip over q */ + sigptr += 4; + /* read lmots_type out of the ots_signature */ + uint32_t lmots_type; + check(hal_xdr_decode_int_peek(&sigptr, siglim, &lmots_type)); + lmots_parameter_t *lmots = lmots_select_parameter_set((lmots_algorithm_t)lmots_type); + if (lmots == NULL) + return HAL_ERROR_INVALID_SIGNATURE; + /* skip over ots_signature */ + sigptr += lmots_signature_len(lmots); + /* read lms_type after ots_signature */ + uint32_t lms_type; + check(hal_xdr_decode_int(&sigptr, siglim, &lms_type)); + lms_parameter_t *lms = lms_select_parameter_set((lms_algorithm_t)lms_type); + if (lms == NULL) + return HAL_ERROR_INVALID_SIGNATURE; + /* skip over the path elements of the lms signature */ + sigptr += lms->h * lms->m; + /*XXX sigptr = lms_sig + lms_signature_len(lms, lmots); */ + + /* verify the signature over the bytestring version of the signed public key */ + check(lms_verify(&pub, sigptr, lms_public_key_len(lms), lms_sig, sigptr - lms_sig)); + + /* parse the signed public key */ + check(hal_xdr_decode_int(&sigptr, siglim, &lms_type)); + pub.lms = lms_select_parameter_set((lmots_algorithm_t)lms_type); + if (pub.lms == NULL) + return HAL_ERROR_INVALID_SIGNATURE; + check(hal_xdr_decode_int(&sigptr, siglim, &lmots_type)); + pub.lmots = lmots_select_parameter_set((lmots_algorithm_t)lmots_type); + if (pub.lmots == NULL) + return HAL_ERROR_INVALID_SIGNATURE; + check(hal_xdr_decode_bytestring16(&sigptr, siglim, &pub.I)); + check(hal_xdr_decode_bytestring32(&sigptr, siglim, &pub.T1)); + } + + /* verify the final signature over the message */ + return lms_verify(&pub, msg, msg_len, sigptr, sig_len - (sigptr - sig)); +} + +hal_error_t hal_hashsig_private_key_to_der(const hal_hashsig_key_t * const key, + uint8_t *der, size_t *der_len, const size_t der_max) +{ + if (key == NULL || key->type != HAL_KEY_TYPE_HASHSIG_PRIVATE) + return HAL_ERROR_BAD_ARGUMENTS; + + /* + * Calculate data length. + */ + + size_t len, vlen = 0, hlen; + + check(hal_asn1_encode_size_t(key->L, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_lms_algorithm(key->lms->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring16(&key->I, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring32(&key->T1, NULL, &len, 0)); vlen += len; + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, NULL, &hlen, 0)); + + check(hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, NULL, hlen + vlen, NULL, der_len, der_max)); + + if (der == NULL) + return HAL_OK; + + /* + * Encode data. + */ + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)); + + uint8_t *d = der + hlen; + memset(d, 0, vlen); + + check(hal_asn1_encode_size_t(key->L, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_lms_algorithm(key->lms->type, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_bytestring16(&key->I, d, &len, vlen)); d += len; vlen -= len; + check(hal_asn1_encode_bytestring32(&key->T1, d, &len, vlen)); d += len; vlen -= len; + + return hal_asn1_encode_pkcs8_privatekeyinfo(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, der, d - der, der, der_len, der_max); +} + +size_t hal_hashsig_private_key_to_der_len(const hal_hashsig_key_t * const key) +{ + size_t len = 0; + return hal_hashsig_private_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0; +} + +hal_error_t hal_hashsig_private_key_from_der(hal_hashsig_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(hal_hashsig_key_t) || der == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + memset(keybuf, 0, keybuf_len); + + hss_key_t *key = *key_ = keybuf; + + key->type = HAL_KEY_TYPE_HASHSIG_PRIVATE; + + size_t hlen, vlen, alg_oid_len, curve_oid_len, privkey_len; + const uint8_t *alg_oid, *curve_oid, *privkey; + hal_error_t err; + + if ((err = hal_asn1_decode_pkcs8_privatekeyinfo(&alg_oid, &alg_oid_len, + &curve_oid, &curve_oid_len, + &privkey, &privkey_len, + der, der_len)) != HAL_OK) + return err; + + if (alg_oid_len != hal_asn1_oid_mts_hashsig_len || + memcmp(alg_oid, hal_asn1_oid_mts_hashsig, alg_oid_len) != 0 || + curve_oid_len != 0) + return HAL_ERROR_ASN1_PARSE_FAILED; + + if ((err = hal_asn1_decode_header(ASN1_SEQUENCE, privkey, privkey_len, &hlen, &vlen)) != HAL_OK) + return err; + + const uint8_t *d = privkey + hlen; + size_t n; + + check(hal_asn1_decode_size_t(&key->L, d, &n, vlen)); d += n; vlen -= n; + lms_algorithm_t lms_type; + check(hal_asn1_decode_lms_algorithm(&lms_type, d, &n, vlen)); d += n; vlen -= n; + key->lms = lms_select_parameter_set(lms_type); + lmots_algorithm_t lmots_type; + check(hal_asn1_decode_lmots_algorithm(&lmots_type, d, &n, vlen)); d += n; vlen -= n; + key->lmots = lmots_select_parameter_set(lmots_type); + check(hal_asn1_decode_bytestring16(&key->I, d, &n, vlen)); d += n; vlen -= n; + check(hal_asn1_decode_bytestring32(&key->T1, d, &n, vlen)); d += n; vlen -= n; + + if (d != privkey + privkey_len) + return HAL_ERROR_ASN1_PARSE_FAILED; + + /* Find this key in the list of active hashsig keys, and return a + * pointer to that key structure, rather than the caller-provided key + * structure. (The caller will wipe his own key structure when done, + * and not molest ours.) + */ + for (hss_key_t *hss_key = hss_keys; hss_key != NULL; hss_key = hss_key->next) { + if (memcmp(&key->I, &hss_key->lms_keys[0].I, sizeof(key->I)) == 0) { + *key_ = hss_key; + } + } + + return HAL_OK; +} + +hal_error_t hal_hashsig_public_key_to_der(const hal_hashsig_key_t * const key, + uint8_t *der, size_t *der_len, const size_t der_max) +{ + if (key == NULL || (key->type != HAL_KEY_TYPE_HASHSIG_PRIVATE && + key->type != HAL_KEY_TYPE_HASHSIG_PUBLIC)) + return HAL_ERROR_BAD_ARGUMENTS; + + // L || u32str(lms_type) || u32str(lmots_type) || I || T[1] + + size_t len, vlen = 0, hlen; + + check(hal_asn1_encode_size_t(key->L, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_lms_algorithm(key->lms->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring16(&key->I, NULL, &len, 0)); vlen += len; + check(hal_asn1_encode_bytestring32(&key->T1, NULL, &len, 0)); vlen += len; + + check(hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)); + + if (der != NULL) { + uint8_t *d = der + hlen; + size_t dlen = vlen; + memset(d, 0, vlen); + + check(hal_asn1_encode_size_t(key->L, d, &len, dlen)); d += len; dlen -= len; + check(hal_asn1_encode_lms_algorithm(key->lms->type, d, &len, dlen)); d += len; dlen -= len; + check(hal_asn1_encode_lmots_algorithm(key->lmots->type, d, &len, dlen)); d += len; dlen -= len; + check(hal_asn1_encode_bytestring16(&key->I, d, &len, dlen)); d += len; dlen -= len; + check(hal_asn1_encode_bytestring32(&key->T1, d, &len, dlen)); d += len; dlen -= len; + } + + return hal_asn1_encode_spki(hal_asn1_oid_mts_hashsig, hal_asn1_oid_mts_hashsig_len, + NULL, 0, der, hlen + vlen, + der, der_len, der_max); + +} + +size_t hal_hashsig_public_key_to_der_len(const hal_hashsig_key_t * const key) +{ + size_t len = 0; + return hal_hashsig_public_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0; +} + +hal_error_t hal_hashsig_public_key_from_der(hal_hashsig_key_t **key_, + void *keybuf, const size_t keybuf_len, + const uint8_t * const der, const size_t der_len) +{ + if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(hss_key_t) || der == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + hss_key_t *key = keybuf; + + memset(keybuf, 0, keybuf_len); + *key_ = key; + + key->type = HAL_KEY_TYPE_HASHSIG_PUBLIC; + + const uint8_t *alg_oid = NULL, *null = NULL, *pubkey = NULL; + size_t alg_oid_len, null_len, pubkey_len; + + check(hal_asn1_decode_spki(&alg_oid, &alg_oid_len, &null, &null_len, &pubkey, &pubkey_len, der, der_len)); + + if (null != NULL || null_len != 0 || alg_oid == NULL || + alg_oid_len != hal_asn1_oid_mts_hashsig_len || memcmp(alg_oid, hal_asn1_oid_mts_hashsig, alg_oid_len) != 0) + return HAL_ERROR_ASN1_PARSE_FAILED; + + size_t len, hlen, vlen; + + check(hal_asn1_decode_header(ASN1_SEQUENCE, pubkey, pubkey_len, &hlen, &vlen)); + + const uint8_t * const pubkey_end = pubkey + hlen + vlen; + const uint8_t *d = pubkey + hlen; + + // L || u32str(lms_type) || u32str(lmots_type) || I || T[1] + + lms_algorithm_t lms_type; + lmots_algorithm_t lmots_type; + + check(hal_asn1_decode_size_t(&key->L, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_lms_algorithm(&lms_type, d, &len, pubkey_end - d)); d += len; + key->lms = lms_select_parameter_set(lms_type); + check(hal_asn1_decode_lmots_algorithm(&lmots_type, d, &len, pubkey_end - d)); d += len; + key->lmots = lmots_select_parameter_set(lmots_type); + check(hal_asn1_decode_bytestring16(&key->I, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_bytestring32(&key->T1, d, &len, pubkey_end - d)); d += len; + + if (d != pubkey_end) + return HAL_ERROR_ASN1_PARSE_FAILED; + + + return HAL_OK; +} + +hal_error_t hal_hashsig_key_load_public(hal_hashsig_key_t **key_, + void *keybuf, const size_t keybuf_len, + const size_t L, + const lms_algorithm_t lms_type, + const lmots_algorithm_t lmots_type, + const uint8_t * const I, const size_t I_len, + const uint8_t * const T1, const size_t T1_len) +{ + if (key_ == NULL || keybuf == NULL || keybuf_len < sizeof(hal_hashsig_key_t) || + I == NULL || I_len != sizeof(bytestring16) || + T1 == NULL || T1_len != sizeof(bytestring32)) + return HAL_ERROR_BAD_ARGUMENTS; + + memset(keybuf, 0, keybuf_len); + + hal_hashsig_key_t *key = keybuf; + + key->type = HAL_KEY_TYPE_HASHSIG_PUBLIC; + + key->L = L; + key->lms = lms_select_parameter_set(lms_type); + key->lmots = lmots_select_parameter_set(lmots_type); + if (key->lms == NULL || key->lmots == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + memcpy(&key->I, I, I_len); + memcpy(&key->T1, T1, T1_len); + + *key_ = key; + + return HAL_OK; +} + + +hal_error_t hal_hashsig_key_load_public_xdr(hal_hashsig_key_t **key_, + void *keybuf, const size_t keybuf_len, + const uint8_t * const xdr, const size_t xdr_len) +{ + const uint8_t *xdrptr = xdr; + const uint8_t * const xdrlim = xdr + xdr_len; + + /* L || u32str(lms_type) || u32str(lmots_type) || I || T[1] */ + + uint32_t L, lms_type, lmots_type; + bytestring16 *I; + bytestring32 *T1; + + check(hal_xdr_decode_int(&xdrptr, xdrlim, &L)); + check(hal_xdr_decode_int(&xdrptr, xdrlim, &lms_type)); + check(hal_xdr_decode_int(&xdrptr, xdrlim, &lmots_type)); + check(hal_xdr_decode_bytestring16_ptr(&xdrptr, xdrlim, &I)); + check(hal_xdr_decode_bytestring32_ptr(&xdrptr, xdrlim, &T1)); + + return hal_hashsig_key_load_public(key_, keybuf, keybuf_len, L, lms_type, lmots_type, + (const uint8_t * const)I, sizeof(bytestring16), + (const uint8_t * const)T1, sizeof(bytestring32)); +} + +hal_error_t hal_hashsig_public_key_der_to_xdr(const uint8_t * const der, const size_t der_len, + uint8_t * const xdr, size_t * const xdr_len , const size_t xdr_max) +{ + if (der == NULL || xdr == NULL) + return HAL_ERROR_BAD_ARGUMENTS; + + const uint8_t *alg_oid = NULL, *null = NULL, *pubkey = NULL; + size_t alg_oid_len, null_len, pubkey_len; + + check(hal_asn1_decode_spki(&alg_oid, &alg_oid_len, &null, &null_len, &pubkey, &pubkey_len, der, der_len)); + + if (null != NULL || null_len != 0 || alg_oid == NULL || + alg_oid_len != hal_asn1_oid_mts_hashsig_len || memcmp(alg_oid, hal_asn1_oid_mts_hashsig, alg_oid_len) != 0) + return HAL_ERROR_ASN1_PARSE_FAILED; + + size_t len, hlen, vlen; + + check(hal_asn1_decode_header(ASN1_SEQUENCE, pubkey, pubkey_len, &hlen, &vlen)); + + const uint8_t * const pubkey_end = pubkey + hlen + vlen; + const uint8_t *d = pubkey + hlen; + + // L || u32str(lms_type) || u32str(lmots_type) || I || T[1] + + size_t L; + lms_algorithm_t lms_type; + lmots_algorithm_t lmots_type; + bytestring16 I; + bytestring32 T1; + + check(hal_asn1_decode_size_t(&L, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_lms_algorithm(&lms_type, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_lmots_algorithm(&lmots_type, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_bytestring16(&I, d, &len, pubkey_end - d)); d += len; + check(hal_asn1_decode_bytestring32(&T1, d, &len, pubkey_end - d)); d += len; + + if (d != pubkey_end) + return HAL_ERROR_ASN1_PARSE_FAILED; + + uint8_t * xdrptr = xdr; + const uint8_t * const xdrlim = xdr + xdr_max; + + check(hal_xdr_encode_int(&xdrptr, xdrlim, L)); + check(hal_xdr_encode_int(&xdrptr, xdrlim, lms_type)); + check(hal_xdr_encode_int(&xdrptr, xdrlim, lmots_type)); + check(hal_xdr_encode_bytestring16(&xdrptr, xdrlim, &I)); + check(hal_xdr_encode_bytestring32(&xdrptr, xdrlim, &T1)); + + if (xdr_len != NULL) + *xdr_len = xdrptr - xdr; + + return HAL_OK; +} + +#if RPC_CLIENT == RPC_CLIENT_LOCAL +/* Reinitialize the hashsig key structures after a device restart */ +hal_error_t hal_hashsig_ks_init(void) +{ + const hal_client_handle_t client = { -1 }; + const hal_session_handle_t session = { HAL_HANDLE_NONE }; + hal_uuid_t prev_name = {{0}}; + unsigned len; + hal_pkey_slot_t slot = {0}; + uint8_t der[HAL_KS_WRAPPED_KEYSIZE]; + size_t der_len; + + restart_in_progress = 1; + + /* Find all hss private keys */ + while ((hal_ks_match(hal_ks_token, client, session, + HAL_KEY_TYPE_HASHSIG_PRIVATE, HAL_CURVE_NONE, 0, 0, NULL, 0, + &slot.name, &len, 1, &prev_name) == HAL_OK) && (len > 0)) { + hal_hashsig_key_t keybuf, *key; + if (hal_ks_fetch(hal_ks_token, &slot, der, &der_len, sizeof(der)) != HAL_OK || + hal_hashsig_private_key_from_der(&key, (void *)&keybuf, sizeof(keybuf), der, der_len) != HAL_OK) { + (void)hal_ks_delete(hal_ks_token, &slot); + continue; + } + + /* Make sure we have the lms key */ + hal_pkey_slot_t lms_slot = {0}; + lms_key_t lms_key; + memcpy(&lms_slot.name, &key->I, sizeof(lms_slot.name)); + if (hal_ks_fetch(hal_ks_token, &lms_slot, der, &der_len, sizeof(der)) != HAL_OK || + lms_private_key_from_der(&lms_key, der, der_len) != HAL_OK || + /* check keys for consistency */ + lms_key.lms != key->lms || + lms_key.lmots != key->lmots || + memcmp(&lms_key.I, &key->I, sizeof(lms_key.I)) != 0 || + /* optimistically allocate the full hss key structure */ + hss_alloc(&key, key->L, key->lms->type, key->lmots->type) != HAL_OK) { + (void)hal_ks_delete(hal_ks_token, &slot); + (void)hal_ks_delete(hal_ks_token, &lms_slot); + continue; + } + + /* hss_alloc redefines key, so copy fields from the old version of the key */ + memcpy(&key->I, &keybuf.I, sizeof(key->I)); + memcpy(&key->T1, &keybuf.T1, sizeof(key->T1)); + key->name = slot.name; + + /* initialize top-level lms key (beyond what hss_alloc did) */ + memcpy(&key->lms_keys[0].I, &lms_key.I, sizeof(lms_key.I)); + key->lms_keys[0].q = lms_key.q; + + prev_name = slot.name; + } + + /* Delete orphaned lms keys */ + memset(&prev_name, 0, sizeof(prev_name)); + while ((hal_ks_match(hal_ks_token, client, session, + HAL_KEY_TYPE_HASHSIG_LMS, HAL_CURVE_NONE, 0, 0, NULL, 0, + &slot.name, &len, 1, &prev_name) == HAL_OK) && (len > 0)) { + hss_key_t *hss_key; + for (hss_key = hss_keys; hss_key != NULL; hss_key = hss_key->next) { + if (memcmp(&slot.name, &hss_key->I, sizeof(slot.name)) == 0) + break; + } + if (hss_key == NULL) { + (void)hal_ks_delete(hal_ks_token, &slot); + continue; + } + + prev_name = slot.name; + } + + /* Find all lmots keys */ + memset(&prev_name, 0, sizeof(prev_name)); + while ((hal_ks_match(hal_ks_token, client, session, + HAL_KEY_TYPE_HASHSIG_LMOTS, HAL_CURVE_NONE, 0, 0, NULL, 0, + &slot.name, &len, 1, &prev_name) == HAL_OK) && (len > 0)) { + if (hss_keys == NULL) { + /* if no hss keys were recovered, all lmots keys are orphaned */ + (void)hal_ks_delete(hal_ks_token, &slot); + continue; + } + + lmots_key_t lmots_key = {0}; + if (hal_ks_fetch(hal_ks_token, &slot, der, &der_len, sizeof(der)) != HAL_OK || + lmots_private_key_from_der(&lmots_key, der, der_len) != HAL_OK) { + (void)hal_ks_delete(hal_ks_token, &slot); + continue; + } + + hss_key_t *hss_key; + for (hss_key = hss_keys; hss_key != NULL; hss_key = hss_key->next) { + if (memcmp(&hss_key->I, &lmots_key.I, sizeof(lmots_key.I)) == 0) + break; + } + if (hss_key == NULL) { + /* delete orphaned key */ + (void)hal_ks_delete(hal_ks_token, &slot); + continue; + } + + /* record this lmots key in the top-level lms key */ + memcpy(&hss_key->lms_keys[0].lmots_keys[lmots_key.q], &slot.name, sizeof(slot.name)); + + /* compute T[r] = H(I || u32str(r) || u16str(D_LEAF) || K) */ + size_t r = (1U << hss_key->lms->h) + lmots_key.q; + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf)); + hal_hash_update(state, (const uint8_t *)&hss_key->I, sizeof(hss_key->I)); + uint32_t l = u32str(r); hal_hash_update(state, (const uint8_t *)&l, sizeof(l)); + uint16_t s = u16str(D_LEAF); hal_hash_update(state, (const uint8_t *)&s, sizeof(s)); + hal_hash_update(state, (const uint8_t *)&lmots_key.K, sizeof(lmots_key.K)); + hal_hash_finalize(state, (uint8_t *)&hss_key->lms_keys[0].T[r], sizeof(hss_key->lms_keys[0].T[r])); + + prev_name = slot.name; + } + + /* After all keys have been read, scan for completeness. */ + hal_uuid_t uuid_0 = {{0}}; + hss_key_t *hss_key, *hss_next = NULL; + for (hss_key = hss_keys; hss_key != NULL; hss_key = hss_next) { + hss_next = hss_key->next; + int fail = 0; + for (size_t i = 0; i < (1U << hss_key->lms->h); ++i) { + if (hal_uuid_cmp(&hss_key->lms_keys[0].lmots_keys[i], &uuid_0) == 0) { + fail = 1; + break; + } + } + if (fail) { + fail: + /* lms key is incomplete, give up on it */ + /* delete lmots keys */ + for (size_t i = 0; i < (1U << hss_key->lms->h); ++i) { + if (hal_uuid_cmp(&hss_key->lms_keys[0].lmots_keys[i], &uuid_0) != 0) { + memcpy(&slot.name, &hss_key->lms_keys[0].lmots_keys[i], sizeof(slot.name)); + (void)hal_ks_delete(hal_ks_token, &slot); + } + } + /* delete lms key */ + memcpy(&slot.name, &hss_key->I, sizeof(slot.name)); + (void)hal_ks_delete(hal_ks_token, &slot); + /* delete hss key */ + slot.name = hss_key->name; + (void)hal_ks_delete(hal_ks_token, &slot); + /* remove the hss key from the key list */ + if (hss_keys == hss_key) { + hss_keys = hss_key->next; + } + else { + for (hss_key_t *prev = hss_keys; prev != NULL; prev = prev->next) { + if (prev->next == hss_key) { + prev->next = hss_key->next; + break; + } + } + } + (void)hal_free_static_memory(hss_key); + continue; + } + + /* generate the rest of T[] */ + for (size_t r = (1U << hss_key->lms->h) - 1; r > 0; --r) { + uint8_t statebuf[512]; + hal_hash_state_t *state = NULL; + hal_hash_initialize(NULL, hal_hash_sha256, &state, statebuf, sizeof(statebuf)); + hal_hash_update(state, (const uint8_t *)&hss_key->I, sizeof(hss_key->I)); + uint32_t l = u32str(r); hal_hash_update(state, (const uint8_t *)&l, sizeof(l)); + uint16_t s = u16str(D_INTR); check(hal_hash_update(state, (const uint8_t *)&s, sizeof(s))); + hal_hash_update(state, (const uint8_t *)&hss_key->lms_keys[0].T[2*r], sizeof(hss_key->lms_keys[0].T[r])); + hal_hash_update(state, (const uint8_t *)&hss_key->lms_keys[0].T[2*r+1], sizeof(hss_key->lms_keys[0].T[r])); + hal_hash_finalize(state, (uint8_t *)&hss_key->lms_keys[0].T[r], sizeof(hss_key->lms_keys[0].T[r])); + } + if (memcmp(&hss_key->lms_keys[0].T[1], &hss_key->T1, sizeof(hss_key->lms_keys[0].T[1])) != 0) + goto fail; + + /* generate the lower-level lms keys */ + for (size_t i = 1; i < hss_key->L; ++i) { + lms_key_t * lms_key = &hss_key->lms_keys[i]; + if (lms_generate(lms_key) != HAL_OK) + goto fail; + + /* store the lms key */ + slot.type = HAL_KEY_TYPE_HASHSIG_LMS; + slot.flags = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE; + memcpy(&slot.name, &lms_key->I, sizeof(slot.name)); + if (lms_private_key_to_der(lms_key, der, &der_len, sizeof(der)) != HAL_OK || + hal_ks_store(hal_ks_volatile, &slot, der, der_len) != HAL_OK || + /* sign this lms key with the previous */ + lms_sign(&hss_key->lms_keys[i-1], + (const uint8_t * const)lms_key->pubkey, lms_key->pubkey_len, + lms_key->signature, NULL, lms_key->signature_len) != HAL_OK) + goto fail; + } + } + + restart_in_progress = 0; + return HAL_OK; +} +#endif |