diff options
Diffstat (limited to 'common/u2f.c')
| -rw-r--r-- | common/u2f.c | 77 |
1 files changed, 52 insertions, 25 deletions
diff --git a/common/u2f.c b/common/u2f.c index eaeb38b08c..91cb4ab121 100644 --- a/common/u2f.c +++ b/common/u2f.c @@ -10,6 +10,7 @@ #include "cryptoc/sha256.h" #include "dcrypto.h" #include "extension.h" +#include "fips_rand.h" #include "system.h" #include "u2f_impl.h" #include "u2f.h" @@ -127,8 +128,10 @@ static enum vendor_cmd_rc u2f_generate(enum vendor_cmd_cc code, void *buf, struct u2f_key_handle kh; struct u2f_versioned_key_handle vkh; } kh_buf; - size_t kh_size = (kh_version == 0) ? sizeof(kh_buf.kh) : - sizeof(kh_buf.vkh); + size_t keypair_input_size = + (kh_version == 0) ? + sizeof(kh_buf.kh) : + sizeof(struct u2f_versioned_key_handle_header); /* Whether key handle generation succeeded */ int generate_kh_rc; @@ -168,13 +171,14 @@ static enum vendor_cmd_rc u2f_generate(enum vendor_cmd_cc code, void *buf, else generate_kh_rc = u2f_origin_user_versioned_keyhandle( req->appId, req->userSecret, od_seed, - kh_version, &kh_buf.vkh); + kh_version, &kh_buf.vkh.header); if (generate_kh_rc != EC_SUCCESS) return VENDOR_RC_INTERNAL_ERROR; generate_keypair_rc = u2f_origin_user_keypair( - (uint8_t *)&kh_buf, kh_size, &od, &opk_x, &opk_y); + (uint8_t *)&kh_buf, keypair_input_size, &od, &opk_x, + &opk_y); } while (generate_keypair_rc == EC_ERROR_TRY_AGAIN); if (generate_keypair_rc != EC_SUCCESS) @@ -188,6 +192,17 @@ static enum vendor_cmd_rc u2f_generate(enum vendor_cmd_cc code, void *buf, copy_kh_pubkey_out(&opk_x, &opk_y, &kh_buf.kh, buf); *response_size = sizeof(struct u2f_generate_resp); } else { + if (!fips_rand_bytes(kh_buf.vkh.authorization_salt, + U2F_AUTHORIZATION_SALT_SIZE)) + return VENDOR_RC_INTERNAL_ERROR; + + if (u2f_authorization_hmac(kh_buf.vkh.authorization_salt, + &kh_buf.vkh.header, + req->authTimeSecretHash, + kh_buf.vkh.authorization_hmac) != + EC_SUCCESS) + return VENDOR_RC_INTERNAL_ERROR; + copy_versioned_kh_pubkey_out(&opk_x, &opk_y, &kh_buf.vkh, buf); *response_size = sizeof(struct u2f_generate_versioned_resp); } @@ -242,14 +257,14 @@ static int verify_kh_owned(const uint8_t *user_secret, const uint8_t *app_id, return rc; } -static int -verify_versioned_kh_owned(const uint8_t *user_secret, const uint8_t *app_id, - const struct u2f_versioned_key_handle *key_handle, - int *owned) +static int verify_versioned_kh_owned( + const uint8_t *user_secret, const uint8_t *app_id, + const struct u2f_versioned_key_handle_header *key_handle_header, + int *owned) { int rc; /* Re-created key handle. */ - struct u2f_versioned_key_handle recreated_kh; + struct u2f_versioned_key_handle_header recreated_kh_header; /* * Re-create the key handle and compare against that which @@ -258,13 +273,13 @@ verify_versioned_kh_owned(const uint8_t *user_secret, const uint8_t *app_id, */ rc = u2f_origin_user_versioned_keyhandle(app_id, user_secret, - key_handle->origin_seed, - key_handle->version, - &recreated_kh); + key_handle_header->origin_seed, + key_handle_header->version, + &recreated_kh_header); if (rc == EC_SUCCESS) - *owned = safe_memcmp(&recreated_kh, key_handle, - sizeof(recreated_kh)) == 0; + *owned = safe_memcmp(&recreated_kh_header, key_handle_header, + sizeof(recreated_kh_header)) == 0; return rc; } @@ -321,8 +336,8 @@ static enum vendor_cmd_rc u2f_sign(enum vendor_cmd_cc code, void *buf, /* Version of KH; 0 if KH is not versioned. */ uint8_t version; - /* Size of KH in bytes. */ - size_t kh_size; + /* Size of the part of KH used to derive keypair, in bytes. */ + size_t keypair_input_size; int verify_owned_rc; @@ -334,18 +349,19 @@ static enum vendor_cmd_rc u2f_sign(enum vendor_cmd_cc code, void *buf, key_handle = (uint8_t *)&req->keyHandle; hash = req->hash; flags = req->flags; - kh_size = sizeof(struct u2f_key_handle); + keypair_input_size = sizeof(struct u2f_key_handle); verify_owned_rc = verify_kh_owned(req->userSecret, req->appId, &req->keyHandle, &kh_owned); } else if (input_size == sizeof(struct u2f_sign_versioned_req)) { - version = req_versioned->keyHandle.version; + version = req_versioned->keyHandle.header.version; key_handle = (uint8_t *)&req_versioned->keyHandle; hash = req_versioned->hash; flags = req_versioned->flags; - kh_size = sizeof(struct u2f_versioned_key_handle); + keypair_input_size = + sizeof(struct u2f_versioned_key_handle_header); verify_owned_rc = verify_versioned_kh_owned( req_versioned->userSecret, req_versioned->appId, - &req_versioned->keyHandle, &kh_owned); + &req_versioned->keyHandle.header, &kh_owned); } else { return VENDOR_RC_BOGUS_ARGS; } @@ -378,17 +394,28 @@ static enum vendor_cmd_rc u2f_sign(enum vendor_cmd_cc code, void *buf, if ((flags & U2F_AUTH_CHECK_ONLY) == U2F_AUTH_CHECK_ONLY) return VENDOR_RC_SUCCESS; - /* Always enforce user presence, with optional consume. */ - if (pop_check_presence(flags & G2F_CONSUME) != POP_TOUCH_YES) - return VENDOR_RC_NOT_ALLOWED; + /* + * Enforce user presence for version 0 KHs, with optional consume. + */ + if (pop_check_presence(flags & G2F_CONSUME) != POP_TOUCH_YES) { + if (version != U2F_KH_VERSION_1) + return VENDOR_RC_NOT_ALLOWED; + if ((flags & U2F_AUTH_FLAG_TUP) != 0) + return VENDOR_RC_NOT_ALLOWED; + /* + * TODO(yichengli): When auth-time secrets is ready, enforce + * authorization hmac when no power button press. + */ + } /* Re-create origin-specific key. */ if (legacy_kh) { if (u2f_origin_key(legacy_origin_seed, &origin_d) != EC_SUCCESS) return VENDOR_RC_INTERNAL_ERROR; } else { - if (u2f_origin_user_keypair(key_handle, kh_size, &origin_d, - NULL, NULL) != EC_SUCCESS) + if (u2f_origin_user_keypair(key_handle, keypair_input_size, + &origin_d, NULL, + NULL) != EC_SUCCESS) return VENDOR_RC_INTERNAL_ERROR; } |