diff options
Diffstat (limited to 'src/pin.c')
| -rw-r--r-- | src/pin.c | 723 |
1 files changed, 723 insertions, 0 deletions
diff --git a/src/pin.c b/src/pin.c new file mode 100644 index 0000000..c3dd927 --- /dev/null +++ b/src/pin.c @@ -0,0 +1,723 @@ +/* + * Copyright (c) 2018-2022 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 <openssl/sha.h> +#include "fido.h" +#include "fido/es256.h" + +#define CTAP21_UV_TOKEN_PERM_MAKECRED 0x01 +#define CTAP21_UV_TOKEN_PERM_ASSERT 0x02 +#define CTAP21_UV_TOKEN_PERM_CRED_MGMT 0x04 +#define CTAP21_UV_TOKEN_PERM_BIO 0x08 +#define CTAP21_UV_TOKEN_PERM_LARGEBLOB 0x10 +#define CTAP21_UV_TOKEN_PERM_CONFIG 0x20 + +int +fido_sha256(fido_blob_t *digest, const u_char *data, size_t data_len) +{ + if ((digest->ptr = calloc(1, SHA256_DIGEST_LENGTH)) == NULL) + return (-1); + + digest->len = SHA256_DIGEST_LENGTH; + + if (SHA256(data, data_len, digest->ptr) != digest->ptr) { + fido_blob_reset(digest); + return (-1); + } + + return (0); +} + +static int +pin_sha256_enc(const fido_dev_t *dev, const fido_blob_t *shared, + const fido_blob_t *pin, fido_blob_t **out) +{ + fido_blob_t *ph = NULL; + int r; + + if ((*out = fido_blob_new()) == NULL || + (ph = fido_blob_new()) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (fido_sha256(ph, pin->ptr, pin->len) < 0 || ph->len < 16) { + fido_log_debug("%s: SHA256", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + ph->len = 16; /* first 16 bytes */ + + if (aes256_cbc_enc(dev, shared, ph, *out) < 0) { + fido_log_debug("%s: aes256_cbc_enc", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + r = FIDO_OK; +fail: + fido_blob_free(&ph); + + return (r); +} + +static int +pad64(const char *pin, fido_blob_t **ppin) +{ + size_t pin_len; + size_t ppin_len; + + pin_len = strlen(pin); + if (pin_len < 4 || pin_len > 63) { + fido_log_debug("%s: invalid pin length", __func__); + return (FIDO_ERR_PIN_POLICY_VIOLATION); + } + + if ((*ppin = fido_blob_new()) == NULL) + return (FIDO_ERR_INTERNAL); + + ppin_len = (pin_len + 63U) & ~63U; + if (ppin_len < pin_len || + ((*ppin)->ptr = calloc(1, ppin_len)) == NULL) { + fido_blob_free(ppin); + return (FIDO_ERR_INTERNAL); + } + + memcpy((*ppin)->ptr, pin, pin_len); + (*ppin)->len = ppin_len; + + return (FIDO_OK); +} + +static int +pin_pad64_enc(const fido_dev_t *dev, const fido_blob_t *shared, + const char *pin, fido_blob_t **out) +{ + fido_blob_t *ppin = NULL; + int r; + + if ((r = pad64(pin, &ppin)) != FIDO_OK) { + fido_log_debug("%s: pad64", __func__); + goto fail; + } + + if ((*out = fido_blob_new()) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (aes256_cbc_enc(dev, shared, ppin, *out) < 0) { + fido_log_debug("%s: aes256_cbc_enc", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + r = FIDO_OK; +fail: + fido_blob_free(&ppin); + + return (r); +} + +static cbor_item_t * +encode_uv_permission(uint8_t cmd) +{ + switch (cmd) { + case CTAP_CBOR_ASSERT: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_ASSERT)); + case CTAP_CBOR_BIO_ENROLL_PRE: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_BIO)); + case CTAP_CBOR_CONFIG: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_CONFIG)); + case CTAP_CBOR_MAKECRED: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_MAKECRED)); + case CTAP_CBOR_CRED_MGMT_PRE: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_CRED_MGMT)); + case CTAP_CBOR_LARGEBLOB: + return (cbor_build_uint8(CTAP21_UV_TOKEN_PERM_LARGEBLOB)); + default: + fido_log_debug("%s: cmd 0x%02x", __func__, cmd); + return (NULL); + } +} + +static int +ctap20_uv_token_tx(fido_dev_t *dev, const char *pin, const fido_blob_t *ecdh, + const es256_pk_t *pk, int *ms) +{ + fido_blob_t f; + fido_blob_t *p = NULL; + fido_blob_t *phe = NULL; + cbor_item_t *argv[6]; + int r; + + memset(&f, 0, sizeof(f)); + memset(argv, 0, sizeof(argv)); + + if (pin == NULL) { + fido_log_debug("%s: NULL pin", __func__); + r = FIDO_ERR_PIN_REQUIRED; + goto fail; + } + + if ((p = fido_blob_new()) == NULL || fido_blob_set(p, + (const unsigned char *)pin, strlen(pin)) < 0) { + fido_log_debug("%s: fido_blob_set", __func__); + r = FIDO_ERR_INVALID_ARGUMENT; + goto fail; + } + + if ((r = pin_sha256_enc(dev, ecdh, p, &phe)) != FIDO_OK) { + fido_log_debug("%s: pin_sha256_enc", __func__); + goto fail; + } + + if ((argv[0] = cbor_encode_pin_opt(dev)) == NULL || + (argv[1] = cbor_build_uint8(5)) == NULL || + (argv[2] = es256_pk_encode(pk, 1)) == NULL || + (argv[5] = fido_blob_encode(phe)) == NULL) { + fido_log_debug("%s: cbor encode", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, 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: + cbor_vector_free(argv, nitems(argv)); + fido_blob_free(&p); + fido_blob_free(&phe); + free(f.ptr); + + return (r); +} + +static int +ctap21_uv_token_tx(fido_dev_t *dev, const char *pin, const fido_blob_t *ecdh, + const es256_pk_t *pk, uint8_t cmd, const char *rpid, int *ms) +{ + fido_blob_t f; + fido_blob_t *p = NULL; + fido_blob_t *phe = NULL; + cbor_item_t *argv[10]; + uint8_t subcmd; + int r; + + memset(&f, 0, sizeof(f)); + memset(argv, 0, sizeof(argv)); + + if (pin != NULL) { + if ((p = fido_blob_new()) == NULL || fido_blob_set(p, + (const unsigned char *)pin, strlen(pin)) < 0) { + fido_log_debug("%s: fido_blob_set", __func__); + r = FIDO_ERR_INVALID_ARGUMENT; + goto fail; + } + if ((r = pin_sha256_enc(dev, ecdh, p, &phe)) != FIDO_OK) { + fido_log_debug("%s: pin_sha256_enc", __func__); + goto fail; + } + subcmd = 9; /* getPinUvAuthTokenUsingPinWithPermissions */ + } else { + if (fido_dev_has_uv(dev) == false) { + fido_log_debug("%s: fido_dev_has_uv", __func__); + r = FIDO_ERR_PIN_REQUIRED; + goto fail; + } + subcmd = 6; /* getPinUvAuthTokenUsingUvWithPermissions */ + } + + if ((argv[0] = cbor_encode_pin_opt(dev)) == NULL || + (argv[1] = cbor_build_uint8(subcmd)) == NULL || + (argv[2] = es256_pk_encode(pk, 1)) == NULL || + (phe != NULL && (argv[5] = fido_blob_encode(phe)) == NULL) || + (argv[8] = encode_uv_permission(cmd)) == NULL || + (rpid != NULL && (argv[9] = cbor_build_string(rpid)) == NULL)) { + fido_log_debug("%s: cbor encode", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, 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: + cbor_vector_free(argv, nitems(argv)); + fido_blob_free(&p); + fido_blob_free(&phe); + free(f.ptr); + + return (r); +} + +static int +parse_uv_token(const cbor_item_t *key, const cbor_item_t *val, void *arg) +{ + fido_blob_t *token = arg; + + if (cbor_isa_uint(key) == false || + cbor_int_get_width(key) != CBOR_INT_8 || + cbor_get_uint8(key) != 2) { + fido_log_debug("%s: cbor type", __func__); + return (0); /* ignore */ + } + + return (fido_blob_decode(val, token)); +} + +static int +uv_token_rx(fido_dev_t *dev, const fido_blob_t *ecdh, fido_blob_t *token, + int *ms) +{ + fido_blob_t *aes_token = NULL; + unsigned char *msg = NULL; + int msglen; + int r; + + if ((aes_token = fido_blob_new()) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if ((msg = malloc(FIDO_MAXMSG)) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + 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 fail; + } + + if ((r = cbor_parse_reply(msg, (size_t)msglen, aes_token, + parse_uv_token)) != FIDO_OK) { + fido_log_debug("%s: parse_uv_token", __func__); + goto fail; + } + + if (aes256_cbc_dec(dev, ecdh, aes_token, token) < 0) { + fido_log_debug("%s: aes256_cbc_dec", __func__); + r = FIDO_ERR_RX; + goto fail; + } + + r = FIDO_OK; +fail: + fido_blob_free(&aes_token); + freezero(msg, FIDO_MAXMSG); + + return (r); +} + +static int +uv_token_wait(fido_dev_t *dev, uint8_t cmd, const char *pin, + const fido_blob_t *ecdh, const es256_pk_t *pk, const char *rpid, + fido_blob_t *token, int *ms) +{ + int r; + + if (ecdh == NULL || pk == NULL) + return (FIDO_ERR_INVALID_ARGUMENT); + if (fido_dev_supports_permissions(dev)) + r = ctap21_uv_token_tx(dev, pin, ecdh, pk, cmd, rpid, ms); + else + r = ctap20_uv_token_tx(dev, pin, ecdh, pk, ms); + if (r != FIDO_OK) + return (r); + + return (uv_token_rx(dev, ecdh, token, ms)); +} + +int +fido_dev_get_uv_token(fido_dev_t *dev, uint8_t cmd, const char *pin, + const fido_blob_t *ecdh, const es256_pk_t *pk, const char *rpid, + fido_blob_t *token, int *ms) +{ + return (uv_token_wait(dev, cmd, pin, ecdh, pk, rpid, token, ms)); +} + +static int +fido_dev_change_pin_tx(fido_dev_t *dev, const char *pin, const char *oldpin, + int *ms) +{ + fido_blob_t f; + fido_blob_t *ppine = NULL; + fido_blob_t *ecdh = NULL; + fido_blob_t *opin = NULL; + fido_blob_t *opinhe = NULL; + cbor_item_t *argv[6]; + es256_pk_t *pk = NULL; + int r; + + memset(&f, 0, sizeof(f)); + memset(argv, 0, sizeof(argv)); + + if ((opin = fido_blob_new()) == NULL || fido_blob_set(opin, + (const unsigned char *)oldpin, strlen(oldpin)) < 0) { + fido_log_debug("%s: fido_blob_set", __func__); + r = FIDO_ERR_INVALID_ARGUMENT; + goto fail; + } + + if ((r = fido_do_ecdh(dev, &pk, &ecdh, ms)) != FIDO_OK) { + fido_log_debug("%s: fido_do_ecdh", __func__); + goto fail; + } + + /* pad and encrypt new pin */ + if ((r = pin_pad64_enc(dev, ecdh, pin, &ppine)) != FIDO_OK) { + fido_log_debug("%s: pin_pad64_enc", __func__); + goto fail; + } + + /* hash and encrypt old pin */ + if ((r = pin_sha256_enc(dev, ecdh, opin, &opinhe)) != FIDO_OK) { + fido_log_debug("%s: pin_sha256_enc", __func__); + goto fail; + } + + if ((argv[0] = cbor_encode_pin_opt(dev)) == NULL || + (argv[1] = cbor_build_uint8(4)) == NULL || + (argv[2] = es256_pk_encode(pk, 1)) == NULL || + (argv[3] = cbor_encode_change_pin_auth(dev, ecdh, ppine, opinhe)) == NULL || + (argv[4] = fido_blob_encode(ppine)) == NULL || + (argv[5] = fido_blob_encode(opinhe)) == NULL) { + fido_log_debug("%s: cbor encode", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, 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: + cbor_vector_free(argv, nitems(argv)); + es256_pk_free(&pk); + fido_blob_free(&ppine); + fido_blob_free(&ecdh); + fido_blob_free(&opin); + fido_blob_free(&opinhe); + free(f.ptr); + + return (r); + +} + +static int +fido_dev_set_pin_tx(fido_dev_t *dev, const char *pin, int *ms) +{ + fido_blob_t f; + fido_blob_t *ppine = NULL; + fido_blob_t *ecdh = NULL; + cbor_item_t *argv[5]; + es256_pk_t *pk = NULL; + int r; + + memset(&f, 0, sizeof(f)); + memset(argv, 0, sizeof(argv)); + + if ((r = fido_do_ecdh(dev, &pk, &ecdh, ms)) != FIDO_OK) { + fido_log_debug("%s: fido_do_ecdh", __func__); + goto fail; + } + + if ((r = pin_pad64_enc(dev, ecdh, pin, &ppine)) != FIDO_OK) { + fido_log_debug("%s: pin_pad64_enc", __func__); + goto fail; + } + + if ((argv[0] = cbor_encode_pin_opt(dev)) == NULL || + (argv[1] = cbor_build_uint8(3)) == NULL || + (argv[2] = es256_pk_encode(pk, 1)) == NULL || + (argv[3] = cbor_encode_pin_auth(dev, ecdh, ppine)) == NULL || + (argv[4] = fido_blob_encode(ppine)) == NULL) { + fido_log_debug("%s: cbor encode", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, 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: + cbor_vector_free(argv, nitems(argv)); + es256_pk_free(&pk); + fido_blob_free(&ppine); + fido_blob_free(&ecdh); + free(f.ptr); + + return (r); +} + +static int +fido_dev_set_pin_wait(fido_dev_t *dev, const char *pin, const char *oldpin, + int *ms) +{ + int r; + + if (oldpin != NULL) { + if ((r = fido_dev_change_pin_tx(dev, pin, oldpin, + ms)) != FIDO_OK) { + fido_log_debug("%s: fido_dev_change_pin_tx", __func__); + return (r); + } + } else { + if ((r = fido_dev_set_pin_tx(dev, pin, ms)) != FIDO_OK) { + fido_log_debug("%s: fido_dev_set_pin_tx", __func__); + return (r); + } + } + + if ((r = fido_rx_cbor_status(dev, ms)) != FIDO_OK) { + fido_log_debug("%s: fido_rx_cbor_status", __func__); + return (r); + } + + if (dev->flags & FIDO_DEV_PIN_UNSET) { + dev->flags &= ~FIDO_DEV_PIN_UNSET; + dev->flags |= FIDO_DEV_PIN_SET; + } + + return (FIDO_OK); +} + +int +fido_dev_set_pin(fido_dev_t *dev, const char *pin, const char *oldpin) +{ + int ms = dev->timeout_ms; + + return (fido_dev_set_pin_wait(dev, pin, oldpin, &ms)); +} + +static int +parse_retry_count(const uint8_t keyval, const cbor_item_t *key, + const cbor_item_t *val, void *arg) +{ + int *retries = arg; + uint64_t n; + + if (cbor_isa_uint(key) == false || + cbor_int_get_width(key) != CBOR_INT_8 || + cbor_get_uint8(key) != keyval) { + fido_log_debug("%s: cbor type", __func__); + return (0); /* ignore */ + } + + if (cbor_decode_uint64(val, &n) < 0 || n > INT_MAX) { + fido_log_debug("%s: cbor_decode_uint64", __func__); + return (-1); + } + + *retries = (int)n; + + return (0); +} + +static int +parse_pin_retry_count(const cbor_item_t *key, const cbor_item_t *val, void *arg) +{ + return (parse_retry_count(3, key, val, arg)); +} + +static int +parse_uv_retry_count(const cbor_item_t *key, const cbor_item_t *val, void *arg) +{ + return (parse_retry_count(5, key, val, arg)); +} + +static int +fido_dev_get_retry_count_tx(fido_dev_t *dev, uint8_t subcmd, int *ms) +{ + fido_blob_t f; + cbor_item_t *argv[2]; + int r; + + memset(&f, 0, sizeof(f)); + memset(argv, 0, sizeof(argv)); + + if ((argv[0] = cbor_build_uint8(1)) == NULL || + (argv[1] = cbor_build_uint8(subcmd)) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, 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: + cbor_vector_free(argv, nitems(argv)); + free(f.ptr); + + return (r); +} + +static int +fido_dev_get_pin_retry_count_rx(fido_dev_t *dev, int *retries, int *ms) +{ + unsigned char *msg; + int msglen; + int r; + + *retries = 0; + + if ((msg = malloc(FIDO_MAXMSG)) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + 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 fail; + } + + if ((r = cbor_parse_reply(msg, (size_t)msglen, retries, + parse_pin_retry_count)) != FIDO_OK) { + fido_log_debug("%s: parse_pin_retry_count", __func__); + goto fail; + } + + r = FIDO_OK; +fail: + freezero(msg, FIDO_MAXMSG); + + return (r); +} + +static int +fido_dev_get_pin_retry_count_wait(fido_dev_t *dev, int *retries, int *ms) +{ + int r; + + if ((r = fido_dev_get_retry_count_tx(dev, 1, ms)) != FIDO_OK || + (r = fido_dev_get_pin_retry_count_rx(dev, retries, ms)) != FIDO_OK) + return (r); + + return (FIDO_OK); +} + +int +fido_dev_get_retry_count(fido_dev_t *dev, int *retries) +{ + int ms = dev->timeout_ms; + + return (fido_dev_get_pin_retry_count_wait(dev, retries, &ms)); +} + +static int +fido_dev_get_uv_retry_count_rx(fido_dev_t *dev, int *retries, int *ms) +{ + unsigned char *msg; + int msglen; + int r; + + *retries = 0; + + if ((msg = malloc(FIDO_MAXMSG)) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + 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 fail; + } + + if ((r = cbor_parse_reply(msg, (size_t)msglen, retries, + parse_uv_retry_count)) != FIDO_OK) { + fido_log_debug("%s: parse_uv_retry_count", __func__); + goto fail; + } + + r = FIDO_OK; +fail: + freezero(msg, FIDO_MAXMSG); + + return (r); +} + +static int +fido_dev_get_uv_retry_count_wait(fido_dev_t *dev, int *retries, int *ms) +{ + int r; + + if ((r = fido_dev_get_retry_count_tx(dev, 7, ms)) != FIDO_OK || + (r = fido_dev_get_uv_retry_count_rx(dev, retries, ms)) != FIDO_OK) + return (r); + + return (FIDO_OK); +} + +int +fido_dev_get_uv_retry_count(fido_dev_t *dev, int *retries) +{ + int ms = dev->timeout_ms; + + return (fido_dev_get_uv_retry_count_wait(dev, retries, &ms)); +} + +int +cbor_add_uv_params(fido_dev_t *dev, uint8_t cmd, const fido_blob_t *hmac_data, + const es256_pk_t *pk, const fido_blob_t *ecdh, const char *pin, + const char *rpid, cbor_item_t **auth, cbor_item_t **opt, int *ms) +{ + fido_blob_t *token = NULL; + int r; + + if ((token = fido_blob_new()) == NULL) { + r = FIDO_ERR_INTERNAL; + goto fail; + } + + if ((r = fido_dev_get_uv_token(dev, cmd, pin, ecdh, pk, rpid, + token, ms)) != FIDO_OK) { + fido_log_debug("%s: fido_dev_get_uv_token", __func__); + goto fail; + } + + if ((*auth = cbor_encode_pin_auth(dev, token, hmac_data)) == NULL || + (*opt = cbor_encode_pin_opt(dev)) == NULL) { + fido_log_debug("%s: cbor encode", __func__); + r = FIDO_ERR_INTERNAL; + goto fail; + } + + r = FIDO_OK; +fail: + fido_blob_free(&token); + + return (r); +} |