| Message ID | 20231119165043.46960-10-zohar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Address non concurrency-safe libimaevm global variables | expand |
On 11/19/23 11:50, Mimi Zohar wrote: > Instead of relying on the "imaevm_params.algo" global variable, which > is not concurrency-safe, define and use a local variable. > > Update static verify_hash_v2(), verify_hash_v3(), and verify_hash_common() > function definitions to include a hash algorithm argument. > > Similarly update ima_verify_signature2() and ima_calc_hash2() to define > and use a local hash algorithm variable. > > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> > --- > src/libimaevm.c | 40 ++++++++++++++++++++++++---------------- > 1 file changed, 24 insertions(+), 16 deletions(-) > > diff --git a/src/libimaevm.c b/src/libimaevm.c > index 4c9da7a2f06b..18b6a6f27237 100644 > --- a/src/libimaevm.c > +++ b/src/libimaevm.c > @@ -488,6 +488,7 @@ void init_public_keys(const char *keyfiles) > * (Note: signature_v2_hdr struct does not contain the 'type'.) > */ > static int verify_hash_common(void *public_keys, const char *file, > + const char *hash_algo, > const unsigned char *hash, > int size, unsigned char *sig, int siglen) > { > @@ -499,7 +500,7 @@ static int verify_hash_common(void *public_keys, const char *file, > const char *st; > > if (imaevm_params.verbose > LOG_INFO) { > - log_info("hash(%s): ", imaevm_params.hash_algo); > + log_info("hash(%s): ", hash_algo); > log_dump(hash, size); > } > > @@ -530,7 +531,7 @@ static int verify_hash_common(void *public_keys, const char *file, > if (!EVP_PKEY_verify_init(ctx)) > goto err; > st = "EVP_get_digestbyname"; > - if (!(md = EVP_get_digestbyname(imaevm_params.hash_algo))) > + if (!(md = EVP_get_digestbyname(hash_algo))) > goto err; > st = "EVP_PKEY_CTX_set_signature_md"; > if (!EVP_PKEY_CTX_set_signature_md(ctx, md)) > @@ -566,11 +567,12 @@ err: > * Return: 0 verification good, 1 verification bad, -1 error. > */ > static int verify_hash_v2(void *public_keys, const char *file, > + const char *hash_algo, > const unsigned char *hash, > int size, unsigned char *sig, int siglen) > { > /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ > - return verify_hash_common(public_keys, file, hash, size, > + return verify_hash_common(public_keys, file, hash_algo, hash, size, > sig + 1, siglen - 1); > } > > @@ -581,19 +583,20 @@ static int verify_hash_v2(void *public_keys, const char *file, > * Return: 0 verification good, 1 verification bad, -1 error. > */ > static int verify_hash_v3(void *public_keys, const char *file, > + const char *hash_algo, > const unsigned char *hash, > int size, unsigned char *sig, int siglen) > { > unsigned char sigv3_hash[MAX_DIGEST_SIZE]; > int ret; > > - ret = calc_hash_sigv3(sig[0], NULL, hash, sigv3_hash); > + ret = calc_hash_sigv3(sig[0], hash_algo, hash, sigv3_hash); > if (ret < 0) > return ret; > > /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ > - return verify_hash_common(public_keys, file, sigv3_hash, size, > - sig + 1, siglen - 1); > + return verify_hash_common(public_keys, file, hash_algo, sigv3_hash, > + size, sig + 1, siglen - 1); > } > > #define HASH_MAX_DIGESTSIZE 64 /* kernel HASH_MAX_DIGESTSIZE is 64 bytes */ > @@ -636,8 +639,10 @@ int calc_hash_sigv3(enum evm_ima_xattr_type type, const char *algo, > return -EINVAL; > } > > - if (!algo) > - algo = imaevm_params.hash_algo; > + if (!algo) { > + log_err("Hash algorithm unspecified\n"); > + return -EINVAL; > + } > > if ((hash_algo = imaevm_get_hash_algo(algo)) < 0) { > log_err("Hash algorithm %s not supported\n", algo); > @@ -757,10 +762,10 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, > return -1; > #endif > } else if (sig[1] == DIGSIG_VERSION_2) { > - return verify_hash_v2(public_keys, file, hash, size, > + return verify_hash_v2(public_keys, file, hash_algo, hash, size, > sig, siglen); > } else if (sig[1] == DIGSIG_VERSION_3) { > - return verify_hash_v3(public_keys, file, hash, size, > + return verify_hash_v3(public_keys, file, hash_algo, hash, size, > sig, siglen); > } else > return -1; > @@ -774,7 +779,8 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, > int verify_hash(const char *file, const unsigned char *hash, int size, > unsigned char *sig, int siglen) > { > - return verify_hash2(g_public_keys, file, NULL, hash, size, sig, siglen); > + return verify_hash2(g_public_keys, file, imaevm_params.hash_algo, > + hash, size, sig, siglen); Now you are passing valid parameters into verify_hash2(). Would it not be possible to drop 4/12?
On Wed, 2023-11-22 at 08:37 -0500, Stefan Berger wrote: > > On 11/19/23 11:50, Mimi Zohar wrote: > > Instead of relying on the "imaevm_params.algo" global variable, which > > is not concurrency-safe, define and use a local variable. > > > > Update static verify_hash_v2(), verify_hash_v3(), and verify_hash_common() > > function definitions to include a hash algorithm argument. > > > > Similarly update ima_verify_signature2() and ima_calc_hash2() to define > > and use a local hash algorithm variable. > > > > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> > > --- > > src/libimaevm.c | 40 ++++++++++++++++++++++++---------------- > > 1 file changed, 24 insertions(+), 16 deletions(-) > > > > diff --git a/src/libimaevm.c b/src/libimaevm.c > > index 4c9da7a2f06b..18b6a6f27237 100644 > > --- a/src/libimaevm.c > > +++ b/src/libimaevm.c > > @@ -488,6 +488,7 @@ void init_public_keys(const char *keyfiles) > > * (Note: signature_v2_hdr struct does not contain the 'type'.) > > */ > > static int verify_hash_common(void *public_keys, const char *file, > > + const char *hash_algo, > > const unsigned char *hash, > > int size, unsigned char *sig, int siglen) > > { > > @@ -499,7 +500,7 @@ static int verify_hash_common(void *public_keys, const char *file, > > const char *st; > > > > if (imaevm_params.verbose > LOG_INFO) { > > - log_info("hash(%s): ", imaevm_params.hash_algo); > > + log_info("hash(%s): ", hash_algo); > > log_dump(hash, size); > > } > > > > @@ -530,7 +531,7 @@ static int verify_hash_common(void *public_keys, const char *file, > > if (!EVP_PKEY_verify_init(ctx)) > > goto err; > > st = "EVP_get_digestbyname"; > > - if (!(md = EVP_get_digestbyname(imaevm_params.hash_algo))) > > + if (!(md = EVP_get_digestbyname(hash_algo))) > > goto err; > > st = "EVP_PKEY_CTX_set_signature_md"; > > if (!EVP_PKEY_CTX_set_signature_md(ctx, md)) > > @@ -566,11 +567,12 @@ err: > > * Return: 0 verification good, 1 verification bad, -1 error. > > */ > > static int verify_hash_v2(void *public_keys, const char *file, > > + const char *hash_algo, > > const unsigned char *hash, > > int size, unsigned char *sig, int siglen) > > { > > /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ > > - return verify_hash_common(public_keys, file, hash, size, > > + return verify_hash_common(public_keys, file, hash_algo, hash, size, > > sig + 1, siglen - 1); > > } > > > > @@ -581,19 +583,20 @@ static int verify_hash_v2(void *public_keys, const char *file, > > * Return: 0 verification good, 1 verification bad, -1 error. > > */ > > static int verify_hash_v3(void *public_keys, const char *file, > > + const char *hash_algo, > > const unsigned char *hash, > > int size, unsigned char *sig, int siglen) > > { > > unsigned char sigv3_hash[MAX_DIGEST_SIZE]; > > int ret; > > > > - ret = calc_hash_sigv3(sig[0], NULL, hash, sigv3_hash); > > + ret = calc_hash_sigv3(sig[0], hash_algo, hash, sigv3_hash); > > if (ret < 0) > > return ret; > > > > /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ > > - return verify_hash_common(public_keys, file, sigv3_hash, size, > > - sig + 1, siglen - 1); > > + return verify_hash_common(public_keys, file, hash_algo, sigv3_hash, > > + size, sig + 1, siglen - 1); > > } > > > > #define HASH_MAX_DIGESTSIZE 64 /* kernel HASH_MAX_DIGESTSIZE is 64 bytes */ > > @@ -636,8 +639,10 @@ int calc_hash_sigv3(enum evm_ima_xattr_type type, const char *algo, > > return -EINVAL; > > } > > > > - if (!algo) > > - algo = imaevm_params.hash_algo; > > + if (!algo) { > > + log_err("Hash algorithm unspecified\n"); > > + return -EINVAL; > > + } > > > > if ((hash_algo = imaevm_get_hash_algo(algo)) < 0) { > > log_err("Hash algorithm %s not supported\n", algo); > > @@ -757,10 +762,10 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, > > return -1; > > #endif > > } else if (sig[1] == DIGSIG_VERSION_2) { > > - return verify_hash_v2(public_keys, file, hash, size, > > + return verify_hash_v2(public_keys, file, hash_algo, hash, size, > > sig, siglen); > > } else if (sig[1] == DIGSIG_VERSION_3) { > > - return verify_hash_v3(public_keys, file, hash, size, > > + return verify_hash_v3(public_keys, file, hash_algo, hash, size, > > sig, siglen); > > } else > > return -1; > > @@ -774,7 +779,8 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, > > int verify_hash(const char *file, const unsigned char *hash, int size, > > unsigned char *sig, int siglen) > > { > > - return verify_hash2(g_public_keys, file, NULL, hash, size, sig, siglen); > > + return verify_hash2(g_public_keys, file, imaevm_params.hash_algo, > > + hash, size, sig, siglen); > > Now you are passing valid parameters into verify_hash2(). Would it not > be possible to drop 4/12? Just as we can't modify the library verify_hash() definition, I don't think we should be modifying the verify_hash2() defintion either. 04/12 defines and exports the final verify_hash2() definition.
On 11/22/23 09:14, Mimi Zohar wrote: > On Wed, 2023-11-22 at 08:37 -0500, Stefan Berger wrote: >> >> Now you are passing valid parameters into verify_hash2(). Would it not >> be possible to drop 4/12? > > Just as we can't modify the library verify_hash() definition, I don't > think we should be modifying the verify_hash2() defintion either. > 04/12 defines and exports the final verify_hash2() definition. > The question is whether verify_hash2() can be only introduced here in versus made available in 4/12 with a parameter that it doesn't use at all at that point.
On Wed, 2023-11-22 at 09:33 -0500, Stefan Berger wrote: > > On 11/22/23 09:14, Mimi Zohar wrote: > > On Wed, 2023-11-22 at 08:37 -0500, Stefan Berger wrote: > >> > > >> Now you are passing valid parameters into verify_hash2(). Would it not > >> be possible to drop 4/12? > > > > Just as we can't modify the library verify_hash() definition, I don't > > think we should be modifying the verify_hash2() defintion either. > > 04/12 defines and exports the final verify_hash2() definition. > > > > The question is whether verify_hash2() can be only introduced here in > versus made available in 4/12 with a parameter that it doesn't use at > all at that point. Correct, however 6/12 "Update cmd_verify_evm to define and use a local list of public keys" calls verify_hash2().
diff --git a/src/libimaevm.c b/src/libimaevm.c index 4c9da7a2f06b..18b6a6f27237 100644 --- a/src/libimaevm.c +++ b/src/libimaevm.c @@ -488,6 +488,7 @@ void init_public_keys(const char *keyfiles) * (Note: signature_v2_hdr struct does not contain the 'type'.) */ static int verify_hash_common(void *public_keys, const char *file, + const char *hash_algo, const unsigned char *hash, int size, unsigned char *sig, int siglen) { @@ -499,7 +500,7 @@ static int verify_hash_common(void *public_keys, const char *file, const char *st; if (imaevm_params.verbose > LOG_INFO) { - log_info("hash(%s): ", imaevm_params.hash_algo); + log_info("hash(%s): ", hash_algo); log_dump(hash, size); } @@ -530,7 +531,7 @@ static int verify_hash_common(void *public_keys, const char *file, if (!EVP_PKEY_verify_init(ctx)) goto err; st = "EVP_get_digestbyname"; - if (!(md = EVP_get_digestbyname(imaevm_params.hash_algo))) + if (!(md = EVP_get_digestbyname(hash_algo))) goto err; st = "EVP_PKEY_CTX_set_signature_md"; if (!EVP_PKEY_CTX_set_signature_md(ctx, md)) @@ -566,11 +567,12 @@ err: * Return: 0 verification good, 1 verification bad, -1 error. */ static int verify_hash_v2(void *public_keys, const char *file, + const char *hash_algo, const unsigned char *hash, int size, unsigned char *sig, int siglen) { /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ - return verify_hash_common(public_keys, file, hash, size, + return verify_hash_common(public_keys, file, hash_algo, hash, size, sig + 1, siglen - 1); } @@ -581,19 +583,20 @@ static int verify_hash_v2(void *public_keys, const char *file, * Return: 0 verification good, 1 verification bad, -1 error. */ static int verify_hash_v3(void *public_keys, const char *file, + const char *hash_algo, const unsigned char *hash, int size, unsigned char *sig, int siglen) { unsigned char sigv3_hash[MAX_DIGEST_SIZE]; int ret; - ret = calc_hash_sigv3(sig[0], NULL, hash, sigv3_hash); + ret = calc_hash_sigv3(sig[0], hash_algo, hash, sigv3_hash); if (ret < 0) return ret; /* note: signature_v2_hdr does not contain 'type', use sig + 1 */ - return verify_hash_common(public_keys, file, sigv3_hash, size, - sig + 1, siglen - 1); + return verify_hash_common(public_keys, file, hash_algo, sigv3_hash, + size, sig + 1, siglen - 1); } #define HASH_MAX_DIGESTSIZE 64 /* kernel HASH_MAX_DIGESTSIZE is 64 bytes */ @@ -636,8 +639,10 @@ int calc_hash_sigv3(enum evm_ima_xattr_type type, const char *algo, return -EINVAL; } - if (!algo) - algo = imaevm_params.hash_algo; + if (!algo) { + log_err("Hash algorithm unspecified\n"); + return -EINVAL; + } if ((hash_algo = imaevm_get_hash_algo(algo)) < 0) { log_err("Hash algorithm %s not supported\n", algo); @@ -757,10 +762,10 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, return -1; #endif } else if (sig[1] == DIGSIG_VERSION_2) { - return verify_hash_v2(public_keys, file, hash, size, + return verify_hash_v2(public_keys, file, hash_algo, hash, size, sig, siglen); } else if (sig[1] == DIGSIG_VERSION_3) { - return verify_hash_v3(public_keys, file, hash, size, + return verify_hash_v3(public_keys, file, hash_algo, hash, size, sig, siglen); } else return -1; @@ -774,7 +779,8 @@ int verify_hash2(void *public_keys, const char *file, const char *hash_algo, int verify_hash(const char *file, const unsigned char *hash, int size, unsigned char *sig, int siglen) { - return verify_hash2(g_public_keys, file, NULL, hash, size, sig, siglen); + return verify_hash2(g_public_keys, file, imaevm_params.hash_algo, + hash, size, sig, siglen); } int ima_verify_signature2(void *public_keys, const char *file, @@ -783,6 +789,7 @@ int ima_verify_signature2(void *public_keys, const char *file, { unsigned char hash[MAX_DIGEST_SIZE]; int hashlen, sig_hash_algo; + const char *hash_algo; if (sig[0] != EVM_IMA_XATTR_DIGSIG && sig[0] != IMA_VERITY_DIGSIG) { log_err("%s: xattr ima has no signature\n", file); @@ -800,22 +807,23 @@ int ima_verify_signature2(void *public_keys, const char *file, return -1; } /* Use hash algorithm as retrieved from signature */ - imaevm_params.hash_algo = imaevm_hash_algo_by_id(sig_hash_algo); + hash_algo = imaevm_hash_algo_by_id(sig_hash_algo); /* * Validate the signature based on the digest included in the * measurement list, not by calculating the local file digest. */ if (digest && digestlen > 0) - return verify_hash2(public_keys, file, NULL, digest, digestlen, - sig, siglen); + return verify_hash2(public_keys, file, + hash_algo, digest, digestlen, + sig, siglen); - hashlen = ima_calc_hash(file, hash); + hashlen = ima_calc_hash2(file, hash_algo, hash); if (hashlen <= 1) return hashlen; assert(hashlen <= sizeof(hash)); - return verify_hash2(public_keys, file, NULL, hash, hashlen, + return verify_hash2(public_keys, file, hash_algo, hash, hashlen, sig, siglen); }
Instead of relying on the "imaevm_params.algo" global variable, which is not concurrency-safe, define and use a local variable. Update static verify_hash_v2(), verify_hash_v3(), and verify_hash_common() function definitions to include a hash algorithm argument. Similarly update ima_verify_signature2() and ima_calc_hash2() to define and use a local hash algorithm variable. Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> --- src/libimaevm.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-)