/* * Copyright (c) 2019-2022 Yubico AB. All rights reserved. * Use of this source code is governed by a BSD-style * license that can be found in the LICENSE file. * SPDX-License-Identifier: BSD-2-Clause */ #include #include "fido.h" #include "fido/credman.h" #include "fido/es256.h" #define CMD_CRED_METADATA 0x01 #define CMD_RP_BEGIN 0x02 #define CMD_RP_NEXT 0x03 #define CMD_RK_BEGIN 0x04 #define CMD_RK_NEXT 0x05 #define CMD_DELETE_CRED 0x06 #define CMD_UPDATE_CRED 0x07 static int credman_grow_array(void **ptr, size_t *n_alloc, const size_t *n_rx, size_t n, size_t size) { void *new_ptr; #ifdef FIDO_FUZZ if (n > UINT8_MAX) { fido_log_debug("%s: n > UINT8_MAX", __func__); return (-1); } #endif if (n < *n_alloc) return (0); /* sanity check */ if (*n_rx > 0 || *n_rx > *n_alloc || n < *n_alloc) { fido_log_debug("%s: n=%zu, n_rx=%zu, n_alloc=%zu", __func__, n, *n_rx, *n_alloc); return (-1); } if ((new_ptr = recallocarray(*ptr, *n_alloc, n, size)) == NULL) return (-1); *ptr = new_ptr; *n_alloc = n; return (0); } static int credman_prepare_hmac(uint8_t cmd, const void *body, cbor_item_t **param, fido_blob_t *hmac_data) { cbor_item_t *param_cbor[3]; const fido_cred_t *cred; size_t n; int ok = -1; memset(¶m_cbor, 0, sizeof(param_cbor)); if (body == NULL) return (fido_blob_set(hmac_data, &cmd, sizeof(cmd))); switch (cmd) { case CMD_RK_BEGIN: n = 1; if ((param_cbor[0] = fido_blob_encode(body)) == NULL) { fido_log_debug("%s: cbor encode", __func__); goto fail; } break; case CMD_DELETE_CRED: n = 2; if ((param_cbor[1] = cbor_encode_pubkey(body)) == NULL) { fido_log_debug("%s: cbor encode", __func__); goto fail; } break; case CMD_UPDATE_CRED: n = 3; cred = body; param_cbor[1] = cbor_encode_pubkey(&cred->attcred.id); param_cbor[2] = cbor_encode_user_entity(&cred->user); if (param_cbor[1] == NULL || param_cbor[2] == NULL) { fido_log_debug("%s: cbor encode", __func__); goto fail; } break; default: fido_log_debug("%s: unknown cmd=0x%02x", __func__, cmd); return (-1); } if ((*param = cbor_flatten_vector(param_cbor, n)) == NULL) { fido_log_debug("%s: cbor_flatten_vector", __func__); goto fail; } if (cbor_build_frame(cmd, param_cbor, n, hmac_data) < 0) { fido_log_debug("%s: cbor_build_frame", __func__); goto fail; } ok = 0; fail: cbor_vector_free(param_cbor, nitems(param_cbor)); return (ok); } static uint8_t credman_get_cmd(const fido_dev_t *dev) { if (dev->flags & FIDO_DEV_CREDMAN) return (CTAP_CBOR_CRED_MGMT); return (CTAP_CBOR_CRED_MGMT_PRE); } static int credman_tx(fido_dev_t *dev, uint8_t subcmd, const void *param, const char *pin, const char *rp_id, fido_opt_t uv, int *ms) { fido_blob_t f; fido_blob_t *ecdh = NULL; fido_blob_t hmac; es256_pk_t *pk = NULL; cbor_item_t *argv[4]; const uint8_t cmd = credman_get_cmd(dev); int r = FIDO_ERR_INTERNAL; memset(&f, 0, sizeof(f)); memset(&hmac, 0, sizeof(hmac)); memset(&argv, 0, sizeof(argv)); if (fido_dev_is_fido2(dev) == false) { fido_log_debug("%s: fido_dev_is_fido2", __func__); r = FIDO_ERR_INVALID_COMMAND; goto fail; } /* subCommand */ if ((argv[0] = cbor_build_uint8(subcmd)) == NULL) { fido_log_debug("%s: cbor encode", __func__); goto fail; } /* pinProtocol, pinAuth */ if (pin != NULL || uv == FIDO_OPT_TRUE) { if (credman_prepare_hmac(subcmd, param, &argv[1], &hmac) < 0) { fido_log_debug("%s: credman_prepare_hmac", __func__); goto fail; } if ((r = fido_do_ecdh(dev, &pk, &ecdh, ms)) != FIDO_OK) { fido_log_debug("%s: fido_do_ecdh", __func__); goto fail; } if ((r = cbor_add_uv_params(dev, cmd, &hmac, pk, ecdh, pin, rp_id, &argv[3], &argv[2], ms)) != FIDO_OK) { fido_log_debug("%s: cbor_add_uv_params", __func__); goto fail; } } /* framing and transmission */ if (cbor_build_frame(cmd, argv, nitems(argv), &f) < 0 || fido_tx(dev, CTAP_CMD_CBOR, f.ptr, f.len, ms) < 0) { fido_log_debug("%s: fido_tx", __func__); r = FIDO_ERR_TX; goto fail; } r = FIDO_OK; fail: es256_pk_free(&pk); fido_blob_free(&ecdh); cbor_vector_free(argv, nitems(argv)); free(f.ptr); free(hmac.ptr); return (r); } static int credman_parse_metadata(const cbor_item_t *key, const cbor_item_t *val, void *arg) { fido_credman_metadata_t *metadata = arg; if (cbor_isa_uint(key) == false || cbor_int_get_width(key) != CBOR_INT_8) { fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } switch (cbor_get_uint8(key)) { case 1: return (cbor_decode_uint64(val, &metadata->rk_existing)); case 2: return (cbor_decode_uint64(val, &metadata->rk_remaining)); default: fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } } static int credman_rx_metadata(fido_dev_t *dev, fido_credman_metadata_t *metadata, int *ms) { unsigned char *msg; int msglen; int r; memset(metadata, 0, sizeof(*metadata)); if ((msg = malloc(FIDO_MAXMSG)) == NULL) { r = FIDO_ERR_INTERNAL; goto out; } if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) { fido_log_debug("%s: fido_rx", __func__); r = FIDO_ERR_RX; goto out; } if ((r = cbor_parse_reply(msg, (size_t)msglen, metadata, credman_parse_metadata)) != FIDO_OK) { fido_log_debug("%s: credman_parse_metadata", __func__); goto out; } r = FIDO_OK; out: freezero(msg, FIDO_MAXMSG); return (r); } static int credman_get_metadata_wait(fido_dev_t *dev, fido_credman_metadata_t *metadata, const char *pin, int *ms) { int r; if ((r = credman_tx(dev, CMD_CRED_METADATA, NULL, pin, NULL, FIDO_OPT_TRUE, ms)) != FIDO_OK || (r = credman_rx_metadata(dev, metadata, ms)) != FIDO_OK) return (r); return (FIDO_OK); } int fido_credman_get_dev_metadata(fido_dev_t *dev, fido_credman_metadata_t *metadata, const char *pin) { int ms = dev->timeout_ms; return (credman_get_metadata_wait(dev, metadata, pin, &ms)); } static int credman_parse_rk(const cbor_item_t *key, const cbor_item_t *val, void *arg) { fido_cred_t *cred = arg; uint64_t prot; if (cbor_isa_uint(key) == false || cbor_int_get_width(key) != CBOR_INT_8) { fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } switch (cbor_get_uint8(key)) { case 6: return (cbor_decode_user(val, &cred->user)); case 7: return (cbor_decode_cred_id(val, &cred->attcred.id)); case 8: if (cbor_decode_pubkey(val, &cred->attcred.type, &cred->attcred.pubkey) < 0) return (-1); cred->type = cred->attcred.type; /* XXX */ return (0); case 10: if (cbor_decode_uint64(val, &prot) < 0 || prot > INT_MAX || fido_cred_set_prot(cred, (int)prot) != FIDO_OK) return (-1); return (0); case 11: return (fido_blob_decode(val, &cred->largeblob_key)); default: fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } } static void credman_reset_rk(fido_credman_rk_t *rk) { for (size_t i = 0; i < rk->n_alloc; i++) { fido_cred_reset_tx(&rk->ptr[i]); fido_cred_reset_rx(&rk->ptr[i]); } free(rk->ptr); rk->ptr = NULL; memset(rk, 0, sizeof(*rk)); } static int credman_parse_rk_count(const cbor_item_t *key, const cbor_item_t *val, void *arg) { fido_credman_rk_t *rk = arg; uint64_t n; /* totalCredentials */ if (cbor_isa_uint(key) == false || cbor_int_get_width(key) != CBOR_INT_8 || cbor_get_uint8(key) != 9) { fido_log_debug("%s: cbor_type", __func__); return (0); /* ignore */ } if (cbor_decode_uint64(val, &n) < 0 || n > SIZE_MAX) { fido_log_debug("%s: cbor_decode_uint64", __func__); return (-1); } if (credman_grow_array((void **)&rk->ptr, &rk->n_alloc, &rk->n_rx, (size_t)n, sizeof(*rk->ptr)) < 0) { fido_log_debug("%s: credman_grow_array", __func__); return (-1); } return (0); } static int credman_rx_rk(fido_dev_t *dev, fido_credman_rk_t *rk, int *ms) { unsigned char *msg; int msglen; int r; credman_reset_rk(rk); if ((msg = malloc(FIDO_MAXMSG)) == NULL) { r = FIDO_ERR_INTERNAL; goto out; } if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) { fido_log_debug("%s: fido_rx", __func__); r = FIDO_ERR_RX; goto out; } /* adjust as needed */ if ((r = cbor_parse_reply(msg, (size_t)msglen, rk, credman_parse_rk_count)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rk_count", __func__); goto out; } if (rk->n_alloc == 0) { fido_log_debug("%s: n_alloc=0", __func__); r = FIDO_OK; goto out; } /* parse the first rk */ if ((r = cbor_parse_reply(msg, (size_t)msglen, &rk->ptr[0], credman_parse_rk)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rk", __func__); goto out; } rk->n_rx = 1; r = FIDO_OK; out: freezero(msg, FIDO_MAXMSG); return (r); } static int credman_rx_next_rk(fido_dev_t *dev, fido_credman_rk_t *rk, int *ms) { unsigned char *msg; int msglen; int r; if ((msg = malloc(FIDO_MAXMSG)) == NULL) { r = FIDO_ERR_INTERNAL; goto out; } if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) { fido_log_debug("%s: fido_rx", __func__); r = FIDO_ERR_RX; goto out; } /* sanity check */ if (rk->n_rx >= rk->n_alloc) { fido_log_debug("%s: n_rx=%zu, n_alloc=%zu", __func__, rk->n_rx, rk->n_alloc); r = FIDO_ERR_INTERNAL; goto out; } if ((r = cbor_parse_reply(msg, (size_t)msglen, &rk->ptr[rk->n_rx], credman_parse_rk)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rk", __func__); goto out; } r = FIDO_OK; out: freezero(msg, FIDO_MAXMSG); return (r); } static int credman_get_rk_wait(fido_dev_t *dev, const char *rp_id, fido_credman_rk_t *rk, const char *pin, int *ms) { fido_blob_t rp_dgst; uint8_t dgst[SHA256_DIGEST_LENGTH]; int r; if (SHA256((const unsigned char *)rp_id, strlen(rp_id), dgst) != dgst) { fido_log_debug("%s: sha256", __func__); return (FIDO_ERR_INTERNAL); } rp_dgst.ptr = dgst; rp_dgst.len = sizeof(dgst); if ((r = credman_tx(dev, CMD_RK_BEGIN, &rp_dgst, pin, rp_id, FIDO_OPT_TRUE, ms)) != FIDO_OK || (r = credman_rx_rk(dev, rk, ms)) != FIDO_OK) return (r); while (rk->n_rx < rk->n_alloc) { if ((r = credman_tx(dev, CMD_RK_NEXT, NULL, NULL, NULL, FIDO_OPT_FALSE, ms)) != FIDO_OK || (r = credman_rx_next_rk(dev, rk, ms)) != FIDO_OK) return (r); rk->n_rx++; } return (FIDO_OK); } int fido_credman_get_dev_rk(fido_dev_t *dev, const char *rp_id, fido_credman_rk_t *rk, const char *pin) { int ms = dev->timeout_ms; return (credman_get_rk_wait(dev, rp_id, rk, pin, &ms)); } static int credman_del_rk_wait(fido_dev_t *dev, const unsigned char *cred_id, size_t cred_id_len, const char *pin, int *ms) { fido_blob_t cred; int r; memset(&cred, 0, sizeof(cred)); if (fido_blob_set(&cred, cred_id, cred_id_len) < 0) return (FIDO_ERR_INVALID_ARGUMENT); if ((r = credman_tx(dev, CMD_DELETE_CRED, &cred, pin, NULL, FIDO_OPT_TRUE, ms)) != FIDO_OK || (r = fido_rx_cbor_status(dev, ms)) != FIDO_OK) goto fail; r = FIDO_OK; fail: free(cred.ptr); return (r); } int fido_credman_del_dev_rk(fido_dev_t *dev, const unsigned char *cred_id, size_t cred_id_len, const char *pin) { int ms = dev->timeout_ms; return (credman_del_rk_wait(dev, cred_id, cred_id_len, pin, &ms)); } static int credman_parse_rp(const cbor_item_t *key, const cbor_item_t *val, void *arg) { struct fido_credman_single_rp *rp = arg; if (cbor_isa_uint(key) == false || cbor_int_get_width(key) != CBOR_INT_8) { fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } switch (cbor_get_uint8(key)) { case 3: return (cbor_decode_rp_entity(val, &rp->rp_entity)); case 4: return (fido_blob_decode(val, &rp->rp_id_hash)); default: fido_log_debug("%s: cbor type", __func__); return (0); /* ignore */ } } static void credman_reset_rp(fido_credman_rp_t *rp) { for (size_t i = 0; i < rp->n_alloc; i++) { free(rp->ptr[i].rp_entity.id); free(rp->ptr[i].rp_entity.name); rp->ptr[i].rp_entity.id = NULL; rp->ptr[i].rp_entity.name = NULL; fido_blob_reset(&rp->ptr[i].rp_id_hash); } free(rp->ptr); rp->ptr = NULL; memset(rp, 0, sizeof(*rp)); } static int credman_parse_rp_count(const cbor_item_t *key, const cbor_item_t *val, void *arg) { fido_credman_rp_t *rp = arg; uint64_t n; /* totalRPs */ if (cbor_isa_uint(key) == false || cbor_int_get_width(key) != CBOR_INT_8 || cbor_get_uint8(key) != 5) { fido_log_debug("%s: cbor_type", __func__); return (0); /* ignore */ } if (cbor_decode_uint64(val, &n) < 0 || n > SIZE_MAX) { fido_log_debug("%s: cbor_decode_uint64", __func__); return (-1); } if (credman_grow_array((void **)&rp->ptr, &rp->n_alloc, &rp->n_rx, (size_t)n, sizeof(*rp->ptr)) < 0) { fido_log_debug("%s: credman_grow_array", __func__); return (-1); } return (0); } static int credman_rx_rp(fido_dev_t *dev, fido_credman_rp_t *rp, int *ms) { unsigned char *msg; int msglen; int r; credman_reset_rp(rp); if ((msg = malloc(FIDO_MAXMSG)) == NULL) { r = FIDO_ERR_INTERNAL; goto out; } if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) { fido_log_debug("%s: fido_rx", __func__); r = FIDO_ERR_RX; goto out; } /* adjust as needed */ if ((r = cbor_parse_reply(msg, (size_t)msglen, rp, credman_parse_rp_count)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rp_count", __func__); goto out; } if (rp->n_alloc == 0) { fido_log_debug("%s: n_alloc=0", __func__); r = FIDO_OK; goto out; } /* parse the first rp */ if ((r = cbor_parse_reply(msg, (size_t)msglen, &rp->ptr[0], credman_parse_rp)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rp", __func__); goto out; } rp->n_rx = 1; r = FIDO_OK; out: freezero(msg, FIDO_MAXMSG); return (r); } static int credman_rx_next_rp(fido_dev_t *dev, fido_credman_rp_t *rp, int *ms) { unsigned char *msg; int msglen; int r; if ((msg = malloc(FIDO_MAXMSG)) == NULL) { r = FIDO_ERR_INTERNAL; goto out; } if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) { fido_log_debug("%s: fido_rx", __func__); r = FIDO_ERR_RX; goto out; } /* sanity check */ if (rp->n_rx >= rp->n_alloc) { fido_log_debug("%s: n_rx=%zu, n_alloc=%zu", __func__, rp->n_rx, rp->n_alloc); r = FIDO_ERR_INTERNAL; goto out; } if ((r = cbor_parse_reply(msg, (size_t)msglen, &rp->ptr[rp->n_rx], credman_parse_rp)) != FIDO_OK) { fido_log_debug("%s: credman_parse_rp", __func__); goto out; } r = FIDO_OK; out: freezero(msg, FIDO_MAXMSG); return (r); } static int credman_get_rp_wait(fido_dev_t *dev, fido_credman_rp_t *rp, const char *pin, int *ms) { int r; if ((r = credman_tx(dev, CMD_RP_BEGIN, NULL, pin, NULL, FIDO_OPT_TRUE, ms)) != FIDO_OK || (r = credman_rx_rp(dev, rp, ms)) != FIDO_OK) return (r); while (rp->n_rx < rp->n_alloc) { if ((r = credman_tx(dev, CMD_RP_NEXT, NULL, NULL, NULL, FIDO_OPT_FALSE, ms)) != FIDO_OK || (r = credman_rx_next_rp(dev, rp, ms)) != FIDO_OK) return (r); rp->n_rx++; } return (FIDO_OK); } int fido_credman_get_dev_rp(fido_dev_t *dev, fido_credman_rp_t *rp, const char *pin) { int ms = dev->timeout_ms; return (credman_get_rp_wait(dev, rp, pin, &ms)); } static int credman_set_dev_rk_wait(fido_dev_t *dev, fido_cred_t *cred, const char *pin, int *ms) { int r; if ((r = credman_tx(dev, CMD_UPDATE_CRED, cred, pin, NULL, FIDO_OPT_TRUE, ms)) != FIDO_OK || (r = fido_rx_cbor_status(dev, ms)) != FIDO_OK) return (r); return (FIDO_OK); } int fido_credman_set_dev_rk(fido_dev_t *dev, fido_cred_t *cred, const char *pin) { int ms = dev->timeout_ms; return (credman_set_dev_rk_wait(dev, cred, pin, &ms)); } fido_credman_rk_t * fido_credman_rk_new(void) { return (calloc(1, sizeof(fido_credman_rk_t))); } void fido_credman_rk_free(fido_credman_rk_t **rk_p) { fido_credman_rk_t *rk; if (rk_p == NULL || (rk = *rk_p) == NULL) return; credman_reset_rk(rk); free(rk); *rk_p = NULL; } size_t fido_credman_rk_count(const fido_credman_rk_t *rk) { return (rk->n_rx); } const fido_cred_t * fido_credman_rk(const fido_credman_rk_t *rk, size_t idx) { if (idx >= rk->n_alloc) return (NULL); return (&rk->ptr[idx]); } fido_credman_metadata_t * fido_credman_metadata_new(void) { return (calloc(1, sizeof(fido_credman_metadata_t))); } void fido_credman_metadata_free(fido_credman_metadata_t **metadata_p) { fido_credman_metadata_t *metadata; if (metadata_p == NULL || (metadata = *metadata_p) == NULL) return; free(metadata); *metadata_p = NULL; } uint64_t fido_credman_rk_existing(const fido_credman_metadata_t *metadata) { return (metadata->rk_existing); } uint64_t fido_credman_rk_remaining(const fido_credman_metadata_t *metadata) { return (metadata->rk_remaining); } fido_credman_rp_t * fido_credman_rp_new(void) { return (calloc(1, sizeof(fido_credman_rp_t))); } void fido_credman_rp_free(fido_credman_rp_t **rp_p) { fido_credman_rp_t *rp; if (rp_p == NULL || (rp = *rp_p) == NULL) return; credman_reset_rp(rp); free(rp); *rp_p = NULL; } size_t fido_credman_rp_count(const fido_credman_rp_t *rp) { return (rp->n_rx); } const char * fido_credman_rp_id(const fido_credman_rp_t *rp, size_t idx) { if (idx >= rp->n_alloc) return (NULL); return (rp->ptr[idx].rp_entity.id); } const char * fido_credman_rp_name(const fido_credman_rp_t *rp, size_t idx) { if (idx >= rp->n_alloc) return (NULL); return (rp->ptr[idx].rp_entity.name); } size_t fido_credman_rp_id_hash_len(const fido_credman_rp_t *rp, size_t idx) { if (idx >= rp->n_alloc) return (0); return (rp->ptr[idx].rp_id_hash.len); } const unsigned char * fido_credman_rp_id_hash_ptr(const fido_credman_rp_t *rp, size_t idx) { if (idx >= rp->n_alloc) return (NULL); return (rp->ptr[idx].rp_id_hash.ptr); }