crypto playnice fixes #1
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…bstb-secvar-openssl.a Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
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There are several things wrong with get_hash_data:
1. it doesn't work, all returned hashes are all 0x00
2. memory leak of hash allocated by crypto_md_generate_hash
3. memory leak of der data buffer from is_x509certificate
4. useless casting of hash_ids to x509_hash_ids
Issues 1-3 can be seen below
$ bin/secvarctl-dbg -m guest generate f:e -i ./test/testdata/guest/x509certs/dbx.crt -o dbx.esl -n dbx
error: invalid crypto alg key 8
error: invalid crypto alg key 11
error: invalid crypto alg key 8
RESULT: SUCCESS
=================================================================
==88342==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 813 byte(s) in 1 object(s) allocated from:
#0 0x7fa153bdebb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
#1 0x7fa1537a42da in PEM_read_bio_ex (/lib64/libcrypto.so.1.1+0x19f2da)
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fa153bdebb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
#1 0x463e27 in crypto_md_generate_hash src/crypto_openssl.c:768
open-power#2 0x445b4a in get_hash_data backends/guest/common/generate.c:477
open-power#3 0x43234a in generate_esl backends/guest/guest_svc_generate.c:73
open-power#4 0x43505e in generate_data backends/guest/guest_svc_generate.c:365
open-power#5 0x439382 in guest_generate_command backends/guest/guest_svc_generate.c:690
open-power#6 0x4069b4 in main /home/nchild/IBM/secvarctl-stuff/erichte-guest-devel/secvarctl/secvarctl.c:249
open-power#7 0x7fa152558d84 in __libc_start_main (/lib64/libc.so.6+0x3ad84)
SUMMARY: AddressSanitizer: 845 byte(s) leaked in 2 allocation(s).
$ hexdump dbx.esl
0000000 1626 c1c4 504c 4092 a9ac f941 9336 2843
0000010 004c 0000 0000 0000 0030 0000 0000 0000
0000020 0000 0000 0000 0000 0000 0000 0000 0000
*
0000040 0000 0000 0000 0000 0000 0000
000004c
Fixing issue 1 and 2:
get_hash_data() acts as a middle function during hash generation.
First generate_esl() allocates an empty hash buffer and hands it to
get_hash_data(). get_hash_data() then hands the address to that buffer
to crypto_md_generate_hash(). crypto_md_generate_hash() allocates its
own buffer and overwrites our pointer to our buffer. get_hash_data()
has no way of updating generate_esl() of the new address. This results
in a successful hash generation but a memoryleaks and an empty hash
in the esl:
To avoid this, simply copy the returned buffer into the existing buffer.
Fixing issue 3:
is_x509certificate will allocate and return data if it finds the given
buffer contains an x509.
To fix this, simply free the der data after generating the hash.
Fixing issue 4:
This is only a semi-issue, but previously, if the buffer was a
certificate then we would cast our hash_function parameter into an
x509 hash function ID. Later on this value get passed to
get_crypto_alg_id() to get the crypto library specific MD identifier.
get_crypto_alg_id() does not keep track of x509 hash function ID (and
tbh the difference between them is not clear) and defaults to sha256.
The point of converting the given hash id to x509 hash id only to then
convert that value into crypto library specific ID is unnecessary.
To fix just stick with the hash function passed to the function.
Lastly, add a test case for all this.
Signed-off-by: Nick Child <nick.child@ibm.com>
nick-child-ibm
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Oct 6, 2023
There are several things wrong with get_hash_data:
1. it doesn't work, all returned hashes are all 0x00
2. memory leak of hash allocated by crypto_md_generate_hash
3. memory leak of der data buffer from is_x509certificate
4. useless casting of hash_ids to x509_hash_ids
Issues 1-3 can be seen below
$ bin/secvarctl-dbg -m guest generate f:e -i ./test/testdata/guest/x509certs/dbx.crt -o dbx.esl -n dbx
error: invalid crypto alg key 8
error: invalid crypto alg key 11
error: invalid crypto alg key 8
RESULT: SUCCESS
=================================================================
==88342==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 813 byte(s) in 1 object(s) allocated from:
#0 0x7fa153bdebb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
#1 0x7fa1537a42da in PEM_read_bio_ex (/lib64/libcrypto.so.1.1+0x19f2da)
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fa153bdebb8 in __interceptor_malloc (/lib64/libasan.so.5+0xefbb8)
#1 0x463e27 in crypto_md_generate_hash src/crypto_openssl.c:768
open-power#2 0x445b4a in get_hash_data backends/guest/common/generate.c:477
open-power#3 0x43234a in generate_esl backends/guest/guest_svc_generate.c:73
open-power#4 0x43505e in generate_data backends/guest/guest_svc_generate.c:365
open-power#5 0x439382 in guest_generate_command backends/guest/guest_svc_generate.c:690
open-power#6 0x4069b4 in main /home/nchild/IBM/secvarctl-stuff/erichte-guest-devel/secvarctl/secvarctl.c:249
open-power#7 0x7fa152558d84 in __libc_start_main (/lib64/libc.so.6+0x3ad84)
SUMMARY: AddressSanitizer: 845 byte(s) leaked in 2 allocation(s).
$ hexdump dbx.esl
0000000 1626 c1c4 504c 4092 a9ac f941 9336 2843
0000010 004c 0000 0000 0000 0030 0000 0000 0000
0000020 0000 0000 0000 0000 0000 0000 0000 0000
*
0000040 0000 0000 0000 0000 0000 0000
000004c
Fixing issue 1 and 2:
get_hash_data() acts as a middle function during hash generation.
First generate_esl() allocates an empty hash buffer and hands it to
get_hash_data(). get_hash_data() then hands the address to that buffer
to crypto_md_generate_hash(). crypto_md_generate_hash() allocates its
own buffer and overwrites our pointer to our buffer. get_hash_data()
has no way of updating generate_esl() of the new address. This results
in a successful hash generation but a memoryleaks and an empty hash
in the esl:
To avoid this, simply copy the returned buffer into the existing buffer.
Fixing issue 3:
is_x509certificate will allocate and return data if it finds the given
buffer contains an x509.
To fix this, simply free the der data after generating the hash.
Fixing issue 4:
This is only a semi-issue, but previously, if the buffer was a
certificate then we would cast our hash_function parameter into an
x509 hash function ID. Later on this value get passed to
get_crypto_alg_id() to get the crypto library specific MD identifier.
get_crypto_alg_id() does not keep track of x509 hash function ID (and
tbh the difference between them is not clear) and defaults to sha256.
The point of converting the given hash id to x509 hash id only to then
convert that value into crypto library specific ID is unnecessary.
To fix just stick with the hash function passed to the function.
Lastly, add a test case for all this.
Signed-off-by: Nick Child <nick.child@ibm.com>
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Set of fixes for open-power#51 , feel free to either merge this, re-implement, squash, whatever.
Changes:
crypto-openssl.c(built into library)There is one additional issue I noted in a comment on the original PR here: https://github.com/open-power/secvarctl/pull/51/files/3f33595e6eb183a70dea1027a405fcb36c1474e3#r1309015588 , I have an additional diff I can apply to this branch to fix that issue as well.