diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/sgx/sigstruct.c | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c new file mode 100644 index 000000000..d73b29bec --- /dev/null +++ b/tools/testing/selftests/sgx/sigstruct.c @@ -0,0 +1,391 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016-20 Intel Corporation. */ + +#define _GNU_SOURCE +#include <assert.h> +#include <getopt.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <openssl/err.h> +#include <openssl/pem.h> +#include "defines.h" +#include "main.h" + +/* + * FIXME: OpenSSL 3.0 has deprecated some functions. For now just ignore + * the warnings. + */ +#pragma GCC diagnostic ignored "-Wdeprecated-declarations" + +struct q1q2_ctx { + BN_CTX *bn_ctx; + BIGNUM *m; + BIGNUM *s; + BIGNUM *q1; + BIGNUM *qr; + BIGNUM *q2; +}; + +static void free_q1q2_ctx(struct q1q2_ctx *ctx) +{ + BN_CTX_free(ctx->bn_ctx); + BN_free(ctx->m); + BN_free(ctx->s); + BN_free(ctx->q1); + BN_free(ctx->qr); + BN_free(ctx->q2); +} + +static bool alloc_q1q2_ctx(const uint8_t *s, const uint8_t *m, + struct q1q2_ctx *ctx) +{ + ctx->bn_ctx = BN_CTX_new(); + ctx->s = BN_bin2bn(s, SGX_MODULUS_SIZE, NULL); + ctx->m = BN_bin2bn(m, SGX_MODULUS_SIZE, NULL); + ctx->q1 = BN_new(); + ctx->qr = BN_new(); + ctx->q2 = BN_new(); + + if (!ctx->bn_ctx || !ctx->s || !ctx->m || !ctx->q1 || !ctx->qr || + !ctx->q2) { + free_q1q2_ctx(ctx); + return false; + } + + return true; +} + +static void reverse_bytes(void *data, int length) +{ + int i = 0; + int j = length - 1; + uint8_t temp; + uint8_t *ptr = data; + + while (i < j) { + temp = ptr[i]; + ptr[i] = ptr[j]; + ptr[j] = temp; + i++; + j--; + } +} + +static bool calc_q1q2(const uint8_t *s, const uint8_t *m, uint8_t *q1, + uint8_t *q2) +{ + struct q1q2_ctx ctx; + int len; + + if (!alloc_q1q2_ctx(s, m, &ctx)) { + fprintf(stderr, "Not enough memory for Q1Q2 calculation\n"); + return false; + } + + if (!BN_mul(ctx.q1, ctx.s, ctx.s, ctx.bn_ctx)) + goto out; + + if (!BN_div(ctx.q1, ctx.qr, ctx.q1, ctx.m, ctx.bn_ctx)) + goto out; + + if (BN_num_bytes(ctx.q1) > SGX_MODULUS_SIZE) { + fprintf(stderr, "Too large Q1 %d bytes\n", + BN_num_bytes(ctx.q1)); + goto out; + } + + if (!BN_mul(ctx.q2, ctx.s, ctx.qr, ctx.bn_ctx)) + goto out; + + if (!BN_div(ctx.q2, NULL, ctx.q2, ctx.m, ctx.bn_ctx)) + goto out; + + if (BN_num_bytes(ctx.q2) > SGX_MODULUS_SIZE) { + fprintf(stderr, "Too large Q2 %d bytes\n", + BN_num_bytes(ctx.q2)); + goto out; + } + + len = BN_bn2bin(ctx.q1, q1); + reverse_bytes(q1, len); + len = BN_bn2bin(ctx.q2, q2); + reverse_bytes(q2, len); + + free_q1q2_ctx(&ctx); + return true; +out: + free_q1q2_ctx(&ctx); + return false; +} + +struct sgx_sigstruct_payload { + struct sgx_sigstruct_header header; + struct sgx_sigstruct_body body; +}; + +static bool check_crypto_errors(void) +{ + int err; + bool had_errors = false; + const char *filename; + int line; + char str[256]; + + for ( ; ; ) { + if (ERR_peek_error() == 0) + break; + + had_errors = true; + err = ERR_get_error_line(&filename, &line); + ERR_error_string_n(err, str, sizeof(str)); + fprintf(stderr, "crypto: %s: %s:%d\n", str, filename, line); + } + + return had_errors; +} + +static inline const BIGNUM *get_modulus(RSA *key) +{ + const BIGNUM *n; + + RSA_get0_key(key, &n, NULL, NULL); + return n; +} + +static RSA *gen_sign_key(void) +{ + unsigned long sign_key_length; + BIO *bio; + RSA *key; + + sign_key_length = (unsigned long)&sign_key_end - + (unsigned long)&sign_key; + + bio = BIO_new_mem_buf(&sign_key, sign_key_length); + if (!bio) + return NULL; + + key = PEM_read_bio_RSAPrivateKey(bio, NULL, NULL, NULL); + BIO_free(bio); + + return key; +} + +enum mrtags { + MRECREATE = 0x0045544145524345, + MREADD = 0x0000000044444145, + MREEXTEND = 0x00444E4554584545, +}; + +static bool mrenclave_update(EVP_MD_CTX *ctx, const void *data) +{ + if (!EVP_DigestUpdate(ctx, data, 64)) { + fprintf(stderr, "digest update failed\n"); + return false; + } + + return true; +} + +static bool mrenclave_commit(EVP_MD_CTX *ctx, uint8_t *mrenclave) +{ + unsigned int size; + + if (!EVP_DigestFinal_ex(ctx, (unsigned char *)mrenclave, &size)) { + fprintf(stderr, "digest commit failed\n"); + return false; + } + + if (size != 32) { + fprintf(stderr, "invalid digest size = %u\n", size); + return false; + } + + return true; +} + +struct mrecreate { + uint64_t tag; + uint32_t ssaframesize; + uint64_t size; + uint8_t reserved[44]; +} __attribute__((__packed__)); + + +static bool mrenclave_ecreate(EVP_MD_CTX *ctx, uint64_t blob_size) +{ + struct mrecreate mrecreate; + uint64_t encl_size; + + for (encl_size = 0x1000; encl_size < blob_size; ) + encl_size <<= 1; + + memset(&mrecreate, 0, sizeof(mrecreate)); + mrecreate.tag = MRECREATE; + mrecreate.ssaframesize = 1; + mrecreate.size = encl_size; + + if (!EVP_DigestInit_ex(ctx, EVP_sha256(), NULL)) + return false; + + return mrenclave_update(ctx, &mrecreate); +} + +struct mreadd { + uint64_t tag; + uint64_t offset; + uint64_t flags; /* SECINFO flags */ + uint8_t reserved[40]; +} __attribute__((__packed__)); + +static bool mrenclave_eadd(EVP_MD_CTX *ctx, uint64_t offset, uint64_t flags) +{ + struct mreadd mreadd; + + memset(&mreadd, 0, sizeof(mreadd)); + mreadd.tag = MREADD; + mreadd.offset = offset; + mreadd.flags = flags; + + return mrenclave_update(ctx, &mreadd); +} + +struct mreextend { + uint64_t tag; + uint64_t offset; + uint8_t reserved[48]; +} __attribute__((__packed__)); + +static bool mrenclave_eextend(EVP_MD_CTX *ctx, uint64_t offset, + const uint8_t *data) +{ + struct mreextend mreextend; + int i; + + for (i = 0; i < 0x1000; i += 0x100) { + memset(&mreextend, 0, sizeof(mreextend)); + mreextend.tag = MREEXTEND; + mreextend.offset = offset + i; + + if (!mrenclave_update(ctx, &mreextend)) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x00])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x40])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0x80])) + return false; + + if (!mrenclave_update(ctx, &data[i + 0xC0])) + return false; + } + + return true; +} + +static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl, + struct encl_segment *seg) +{ + uint64_t end = seg->size; + uint64_t offset; + + for (offset = 0; offset < end; offset += PAGE_SIZE) { + if (!mrenclave_eadd(ctx, seg->offset + offset, seg->flags)) + return false; + + if (seg->measure) { + if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset)) + return false; + } + } + + return true; +} + +bool encl_measure(struct encl *encl) +{ + uint64_t header1[2] = {0x000000E100000006, 0x0000000000010000}; + uint64_t header2[2] = {0x0000006000000101, 0x0000000100000060}; + struct sgx_sigstruct *sigstruct = &encl->sigstruct; + struct sgx_sigstruct_payload payload; + uint8_t digest[SHA256_DIGEST_LENGTH]; + EVP_MD_CTX *ctx = NULL; + unsigned int siglen; + RSA *key = NULL; + int i; + + memset(sigstruct, 0, sizeof(*sigstruct)); + + sigstruct->header.header1[0] = header1[0]; + sigstruct->header.header1[1] = header1[1]; + sigstruct->header.header2[0] = header2[0]; + sigstruct->header.header2[1] = header2[1]; + sigstruct->exponent = 3; + sigstruct->body.attributes = SGX_ATTR_MODE64BIT; + sigstruct->body.xfrm = 3; + + /* sanity check */ + if (check_crypto_errors()) + goto err; + + key = gen_sign_key(); + if (!key) { + ERR_print_errors_fp(stdout); + goto err; + } + + BN_bn2bin(get_modulus(key), sigstruct->modulus); + + ctx = EVP_MD_CTX_create(); + if (!ctx) + goto err; + + if (!mrenclave_ecreate(ctx, encl->src_size)) + goto err; + + for (i = 0; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (!mrenclave_segment(ctx, encl, seg)) + goto err; + } + + if (!mrenclave_commit(ctx, sigstruct->body.mrenclave)) + goto err; + + memcpy(&payload.header, &sigstruct->header, sizeof(sigstruct->header)); + memcpy(&payload.body, &sigstruct->body, sizeof(sigstruct->body)); + + SHA256((unsigned char *)&payload, sizeof(payload), digest); + + if (!RSA_sign(NID_sha256, digest, SHA256_DIGEST_LENGTH, + sigstruct->signature, &siglen, key)) + goto err; + + if (!calc_q1q2(sigstruct->signature, sigstruct->modulus, sigstruct->q1, + sigstruct->q2)) + goto err; + + /* BE -> LE */ + reverse_bytes(sigstruct->signature, SGX_MODULUS_SIZE); + reverse_bytes(sigstruct->modulus, SGX_MODULUS_SIZE); + + EVP_MD_CTX_destroy(ctx); + RSA_free(key); + return true; + +err: + if (ctx) + EVP_MD_CTX_destroy(ctx); + RSA_free(key); + return false; +} |