Hello,
I am from the iTP WebServer development team. The webserver runs
on the HP NonStop Kernel. We are enhancing the webserver to comply with the TLS
1.1 standards and are using GnuTLS to extend this support.
We are facing problems with regards to validation of the CSR
generated using the GnuTLS APIs.
Though the CSR seems valid (as verified in OpenSSL and
other online CSR decoders), CAs like Verisign, Thawte etc give an error while
parsing the CSR.
We generated CSRs with same DN attributes with GnuTLS and
OpenSSL. After ASN1 parsing both the CSRs in OpenSSL, we found that the CSR
generated by GnuTLS misses NULL paddings separating the
CertificationRequestInfo, signatureAlgorithm and Signature.
The output from OpenSSL asn1parse for CSR generated by OpenSSL (with similar DN attributes):
$ openssl asn1parse -in openssl.req
0:d=0 hl=4 l= 452 cons: SEQUENCE
4:d=1 hl=4 l= 301 cons: SEQUENCE
8:d=2 hl=2 l= 1 prim: INTEGER :00
11:d=2 hl=3 l= 131 cons: SEQUENCE
14:d=3 hl=2 l= 11 cons: SET
16:d=4 hl=2 l= 9 cons: SEQUENCE
18:d=5 hl=2 l= 3 prim: OBJECT :countryName
23:d=5 hl=2 l= 2 prim: PRINTABLESTRING :IN
27:d=3 hl=2 l= 20 cons: SET
29:d=4 hl=2 l= 18 cons: SEQUENCE
31:d=5 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
36:d=5 hl=2 l= 11 prim: PRINTABLESTRING :Maharashtra
49:d=3 hl=2 l= 15 cons: SET
51:d=4 hl=2 l= 13 cons: SEQUENCE
53:d=5 hl=2 l= 3 prim: OBJECT :localityName
58:d=5 hl=2 l= 6 prim: PRINTABLESTRING :Mumbai
66:d=3 hl=2 l= 34 cons: SET
68:d=4 hl=2 l= 32 cons: SEQUENCE
70:d=5 hl=2 l= 3 prim: OBJECT :organizationName
75:d=5 hl=2 l= 25 prim: PRINTABLESTRING :Tata Consultancy Services
102:d=3 hl=2 l= 15 cons: SET
104:d=4 hl=2 l= 13 cons: SEQUENCE
106:d=5 hl=2 l= 3 prim: OBJECT :organizationalUnitName
111:d=5 hl=2 l= 6 prim: PRINTABLESTRING :HP NED
119:d=3 hl=2 l= 24 cons: SET
121:d=4 hl=2 l= 22 cons: SEQUENCE
123:d=5 hl=2 l= 3 prim: OBJECT :commonName
128:d=5 hl=2 l= 15 prim: PRINTABLESTRING :www.scarlet.com
145:d=2 hl=3 l= 159 cons: SEQUENCE
148:d=3 hl=2 l= 13 cons: SEQUENCE
150:d=4 hl=2 l= 9 prim: OBJECT :rsaEncryption
161:d=4 hl=2 l= 0 prim: NULL <==========
163:d=3 hl=3 l= 141 prim: BIT STRING
307:d=2 hl=2 l= 0 cons: cont [ 0 ]
309:d=1 hl=2 l= 13 cons: SEQUENCE
311:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption
322:d=2 hl=2 l= 0 prim: NULL <==========
324:d=1 hl=3 l= 129 prim: BIT STRING
The output from OpenSSL asn1parse for CSR generated by GnuTLS:
$ openssl asn1parse -in gnu.req
0:d=0 hl=4 l= 447 cons: SEQUENCE
4:d=1 hl=4 l= 298 cons: SEQUENCE
8:d=2 hl=2 l= 1 prim: INTEGER :00
11:d=2 hl=3 l= 131 cons: SEQUENCE
14:d=3 hl=2 l= 11 cons: SET
16:d=4 hl=2 l= 9 cons: SEQUENCE
18:d=5 hl=2 l= 3 prim: OBJECT :countryName
23:d=5 hl=2 l= 2 prim: PRINTABLESTRING :IN
27:d=3 hl=2 l= 15 cons: SET
29:d=4 hl=2 l= 13 cons: SEQUENCE
31:d=5 hl=2 l= 3 prim: OBJECT :localityName
36:d=5 hl=2 l= 6 prim: PRINTABLESTRING :Mumbai
44:d=3 hl=2 l= 20 cons: SET
46:d=4 hl=2 l= 18 cons: SEQUENCE
48:d=5 hl=2 l= 3 prim: OBJECT :stateOrProvinceName
53:d=5 hl=2 l= 11 prim: PRINTABLESTRING :Maharashtra
66:d=3 hl=2 l= 24 cons: SET
68:d=4 hl=2 l= 22 cons: SEQUENCE
70:d=5 hl=2 l= 3 prim: OBJECT :commonName
75:d=5 hl=2 l= 15 prim: PRINTABLESTRING :www.scarlet.com
92:d=3 hl=2 l= 15 cons: SET
94:d=4 hl=2 l= 13 cons: SEQUENCE
96:d=5 hl=2 l= 3 prim: OBJECT :organizationalUnitName
101:d=5 hl=2 l= 6 prim: PRINTABLESTRING :HP NED
109:d=3 hl=2 l= 34 cons: SET
111:d=4 hl=2 l= 32 cons: SEQUENCE
113:d=5 hl=2 l= 3 prim: OBJECT :organizationName
118:d=5 hl=2 l= 25 prim: PRINTABLESTRING :Tata Consultancy Services
145:d=2 hl=3 l= 156 cons: SEQUENCE
148:d=3 hl=2 l= 11 cons: SEQUENCE
150:d=4 hl=2 l= 9 prim: OBJECT :rsaEncryption
--> NULL field missing
161:d=3 hl=3 l= 140 prim: BIT STRING
304:d=2 hl=2 l= 0 cons: cont [ 0 ]
306:d=1 hl=2 l= 11 cons: SEQUENCE
308:d=2 hl=2 l= 9 prim: OBJECT :sha1WithRSAEncryption
--> NULL field missing
319:d=1 hl=3 l= 129 prim: BIT STRING
The CSR generated using GnuTLS APIs:
-----BEGIN
NEW CERTIFICATE REQUEST-----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-----END
NEW CERTIFICATE REQUEST-----
Is it possible that the CAs are unable to generate a valid certificate due to these NULL paddings or is there another reason why these CAs fail to parse the CSR.
Thanks,
Trupti