Wrong certificate obtained with atca_mbedtls_cert_add() after upgrading to ~v3.7.7 #410
Description
Describe the bug
I am not exactly sure when this error was introduced, but now the certificate added through atca_mbedtls_cert_add() does not work correctly.
When the certificate is added through this API, The following certificate gets added
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
5f:72:87:ca:61:15:ae:16:b8:d0:cd:9c:fa:f4:61:dc
Signature Algorithm: ecdsa-with-SHA256
Issuer: O=Microchip Technology Inc, CN=Crypto Authentication Signer 2D20
Validity
Not Before: Mar 1 02:00:00 2019 GMT
Not After : Mar 1 02:00:00 2047 GMT
Subject: O=Microchip Technology Inc, CN=012386E1761428FF01 ATECC
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:4f:cc:2d:ee:db:a2:eb:05:15:c0:01:70:1f:94:
7d:9d:db:1c:04:03:ca:a9:36:22:ea:43:81:03:68:
a4:e6:c5:57:32:f4:cb:71:04:e7:54:ff:b1:23:ae:
e3:3c:17:4c:71:a2:d9:87:c7:1d:6b:dd:cf:b0:18:
fe:b6:bc:36:db
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Key Usage: critical
Digital Signature, Key Agreement
X509v3 Subject Key Identifier:
F4:4F:2B:86:5D:9D:99:A3:A1:41:09:90:DC:19:06:76:DC:84:13:77
X509v3 Authority Key Identifier:
00:B5:E1:B7:3F:4B:60:66:DD:1F:C3:3C:D2:AA:CA:9D:09:52:48:BA
Signature Algorithm: ecdsa-with-SHA256
Signature Value:
30:45:02:21:00:97:88:b3:5d:a0:e2:63:1e:2c:ed:08:04:44:
58:2e:89:a6:a5:09:1e:c8:c3:f5:1e:80:d5:d6:7b:d5:0f:27:
59:02:20:01:f8:02:4e:62:18:48:35:89:57:ad:64:b7:01:da:
60:4d:ff:d5:ed:f9:45:c3:a8:39:4e:be:44:7d:5e:a1:40
whereas the actual certificate is (obtained through tng_atcacert_read_device_cert() API)
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
5f:72:87:ca:61:15:ae:16:b8:d0:cd:9c:fa:f4:61:dc
Signature Algorithm: ecdsa-with-SHA256
Issuer: O=Microchip Technology Inc, CN=Crypto Authentication Signer 2D20
Validity
Not Before: Mar 1 02:00:00 2019 GMT
Not After : Mar 1 02:00:00 2047 GMT
Subject: O=Microchip Technology Inc, CN=012386E1761428FF01 ATECC
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:4f:cc:2d:ee:db:a2:eb:05:15:c0:01:70:1f:94:
7d:9d:db:1c:04:03:ca:a9:36:22:ea:43:81:03:68:
a4:e6:c5:57:32:f4:cb:71:04:e7:54:ff:b1:23:ae:
e3:3c:17:4c:71:a2:d9:87:c7:1d:6b:dd:cf:b0:18:
fe:b6:bc:36:db
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Key Usage: critical
Digital Signature, Key Agreement
X509v3 Subject Key Identifier:
F4:4F:2B:86:5D:9D:99:A3:A1:41:09:90:DC:19:06:76:DC:84:13:77
X509v3 Authority Key Identifier:
14:BE:A9:F9:FE:D6:2F:91:42:51:87:4E:FC:0A:1C:F0:EF:44:F1:94
Signature Algorithm: ecdsa-with-SHA256
Signature Value:
30:45:02:21:00:97:88:b3:5d:a0:e2:63:1e:2c:ed:08:04:44:
58:2e:89:a6:a5:09:1e:c8:c3:f5:1e:80:d5:d6:7b:d5:0f:27:
59:02:20:01:f8:02:4e:62:18:48:35:89:57:ad:64:b7:01:da:
60:4d:ff:d5:ed:f9:45:c3:a8:39:4e:be:44:7d:5e:a1:40
The only difference here is in the X509v3 Authority Key Identifier.
Here is the signer obtained through the tng_atcacert_read_signer_cert(cert_buf, cert_len) for reference
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
71:0a:49:b4:f9:df:04:25:69:06:c7:53:df:98:2c:d0
Signature Algorithm: ecdsa-with-SHA256
Issuer: O=Microchip Technology Inc, CN=Crypto Authentication Root CA 002
Validity
Not Before: Dec 14 20:00:00 2018 GMT
Not After : Dec 14 20:00:00 2049 GMT
Subject: O=Microchip Technology Inc, CN=Crypto Authentication Signer 2D20
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:e6:0f:d3:86:83:2a:a1:52:20:b4:ba:4c:63:6f:
b4:0c:52:08:c4:10:2a:8e:5f:1b:4a:85:aa:f1:ee:
c5:aa:7a:c7:e6:36:ca:c6:78:1a:8e:9d:74:e4:77:
04:8f:ee:5b:35:9e:a1:39:13:26:8b:ad:21:3d:39:
ed:fe:ae:41:1d
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Key Usage: critical
Digital Signature, Certificate Sign, CRL Sign
X509v3 Basic Constraints: critical
CA:TRUE, pathlen:0
X509v3 Subject Key Identifier:
14:BE:A9:F9:FE:D6:2F:91:42:51:87:4E:FC:0A:1C:F0:EF:44:F1:94
X509v3 Authority Key Identifier:
7A:ED:7D:6D:C6:B7:78:9D:B2:38:01:A5:E8:4A:8C:B0:A4:0E:2A:8C
Signature Algorithm: ecdsa-with-SHA256
Signature Value:
30:45:02:20:00:f5:11:7a:3f:d2:87:c9:3a:07:f8:9a:83:15:
00:e2:ac:0a:2d:1c:e4:4a:54:0a:7e:02:44:d3:e5:20:be:dd:
02:21:00:e6:27:5e:61:7c:59:7b:30:12:7b:25:c5:75:b7:5a:
8e:e6:90:16:38:93:63:79:7c:7d:93:c4:3a:7c:92:cc:21
To Reproduce
- Use a TNG type of ATECC608 device,
Use atca_mbedtls_cert_add() to import the tng certificate to the mbedtls certificate structure and print it on console as follows:
mbedtls_x509_crt_init(&tls->clientcert);
ret = tng_get_device_cert_def(&cert_def);
if (ret != 0) {
ESP_LOGE(TAG, "Failed to get device cert def");
return ESP_ERR_ESP_TLS_SE_FAILED;
}
ret = atca_mbedtls_cert_add(&tls->clientcert, cert_def);
if (ret != 0) {
ESP_LOGE(TAG, "Failed to parse cert from device, return 0x%04X", ret);
mbedtls_print_error_msg(ret);
return ESP_ERR_ESP_TLS_SE_FAILED;
}
/* Print the certificate: DER format (mbedTLS v3.x only stores DER, not PEM) */
if (tls->clientcert.raw.p != NULL && tls->clientcert.raw.len > 0) {
/* Print DER certificate in hex format */
const unsigned char *cert_data = tls->clientcert.raw.p;
size_t cert_len = tls->clientcert.raw.len;
for (size_t i = 0; i < cert_len; i++) {
printf("%02X", cert_data[i]);
}
printf("\n");
} else {
printf("No client certificate available to print.\n");
}
Expected behavior
The certificate here must match with the certificate provided by tng_atcacert_read_device_cert API
Additional context
The problem seems to be in the loc (location) value of the auth key identifier for the device cert.
Somehow that is being messed up.
Note, I am using ATECC608A device with serial no - 012386e1761428ff01