From: Chun-Yi Lee <[email protected]>
Per X.509 spec in 4.2.1.1 section, the structure of Authority Key
Identifier Extension is:
AuthorityKeyIdentifier ::= SEQUENCE {
keyIdentifier [0] KeyIdentifier OPTIONAL,
authorityCertIssuer [1] GeneralNames OPTIONAL,
authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
KeyIdentifier ::= OCTET STRING
When a certificate also provides
authorityCertIssuer and authorityCertSerialNumber then the length of
AuthorityKeyIdentifier SEQUENCE is likely to long form format.
e.g.
The example certificate demos/tunala/A-server.pem in openssl source:
X509v3 Authority Key Identifier:
keyid:49:FB:45:72:12:C4:CC:E1:45:A1:D3:08:9E:95:C4:2C:6D:55:3F:17
DirName:/C=NZ/L=Wellington/O=Really Irresponsible Authorisation Authority (RIAA)/OU=Cert-stamping/CN=Jackov al-Trades/[email protected]
serial:00
Current parsing rule of OID_authorityKeyIdentifier only take care the
short form format, it causes load certificate to modsign_keyring fail:
[ 12.061147] X.509: Extension: 47
[ 12.075121] MODSIGN: Problem loading in-kernel X.509 certificate (-74)
So, this patch add the parsing rule for support long form format against
Authority Key Identifier.
v3:
Changed the size check in "Short Form length" case, we allow v[3] smaller
then (vlen - 4) because authorityCertIssuer and authorityCertSerialNumber
are also possible attach in AuthorityKeyIdentifier sequence.
v2:
- Removed comma from author's name.
- Moved 'Short Form length' comment inside the if-body.
- Changed the type of sub to size_t.
- Use ASN1_INDEFINITE_LENGTH rather than writing 0x80 and 127.
- Moved the key_len's value assignment before alter v.
- Fixed the typo of octets.
- Add 2 to v before entering the loop for calculate the length.
- Removed the comment of check vlen.
Cc: Rusty Russell <[email protected]>
Cc: Josh Boyer <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: "David S. Miller" <[email protected]>
Acked-by: David Howells <[email protected]>
Signed-off-by: Chun-Yi Lee <[email protected]>
---
crypto/asymmetric_keys/x509_cert_parser.c | 55 ++++++++++++++++++++++++----
1 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 7fabc4c..59ab6d2 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -373,6 +373,9 @@ int rsa_extract_mpi(void *context, size_t hdrlen,
return 0;
}
+/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
+#define SEQ_TAG_KEYID (ASN1_CONT << 6)
+
/*
* Process certificate extensions that are used to qualify the certificate.
*/
@@ -407,21 +410,57 @@ int x509_process_extension(void *context, size_t hdrlen,
}
if (ctx->last_oid == OID_authorityKeyIdentifier) {
+ size_t key_len;
+
/* Get hold of the CA key fingerprint */
if (vlen < 5)
return -EBADMSG;
- if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)) ||
- v[1] != vlen - 2 ||
- v[2] != (ASN1_CONT << 6) ||
- v[3] != vlen - 4)
+
+ /* Authority Key Identifier must be a Constructed SEQUENCE */
+ if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
return -EBADMSG;
- v += 4;
- vlen -= 4;
- f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
+ /* Authority Key Identifier is not indefinite length */
+ if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
+ return -EBADMSG;
+
+ if (vlen < ASN1_INDEFINITE_LENGTH) {
+ /* Short Form length */
+ if (v[1] != vlen - 2 ||
+ v[2] != SEQ_TAG_KEYID ||
+ v[3] > vlen - 4)
+ return -EBADMSG;
+
+ key_len = v[3];
+ v += 4;
+ } else {
+ /* Long Form length */
+ size_t seq_len = 0;
+ size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
+
+ if (sub > 2)
+ return -EBADMSG;
+
+ /* calculate the length from subsequent octets */
+ v += 2;
+ for (i = 0; i < sub; i++) {
+ seq_len <<= 8;
+ seq_len |= v[i];
+ }
+
+ if (seq_len != vlen - 2 - sub ||
+ v[sub] != SEQ_TAG_KEYID ||
+ v[sub + 1] > vlen - 4 - sub)
+ return -EBADMSG;
+
+ key_len = v[sub + 1];
+ v += (sub + 2);
+ }
+
+ f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
if (!f)
return -ENOMEM;
- for (i = 0; i < vlen; i++)
+ for (i = 0; i < key_len; i++)
sprintf(f + i * 2, "%02x", v[i]);
pr_debug("authority %s\n", f);
ctx->cert->authority = f;
--
1.6.4.2
Hi David,
Sorry for bother you!
Will you take this patch for merge to v3.10 kernel?
Thanks a lot!
Joey Lee
於 五，2013-03-29 於 16:52 +0800，Lee, Chun-Yi 提到：
> From: Chun-Yi Lee <[email protected]>
>
> Per X.509 spec in 4.2.1.1 section, the structure of Authority Key
> Identifier Extension is:
>
> AuthorityKeyIdentifier ::= SEQUENCE {
> keyIdentifier [0] KeyIdentifier OPTIONAL,
> authorityCertIssuer [1] GeneralNames OPTIONAL,
> authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
>
> KeyIdentifier ::= OCTET STRING
>
> When a certificate also provides
> authorityCertIssuer and authorityCertSerialNumber then the length of
> AuthorityKeyIdentifier SEQUENCE is likely to long form format.
> e.g.
> The example certificate demos/tunala/A-server.pem in openssl source:
>
> X509v3 Authority Key Identifier:
> keyid:49:FB:45:72:12:C4:CC:E1:45:A1:D3:08:9E:95:C4:2C:6D:55:3F:17
> DirName:/C=NZ/L=Wellington/O=Really Irresponsible Authorisation Authority (RIAA)/OU=Cert-stamping/CN=Jackov al-Trades/[email protected]
> serial:00
>
> Current parsing rule of OID_authorityKeyIdentifier only take care the
> short form format, it causes load certificate to modsign_keyring fail:
>
> [ 12.061147] X.509: Extension: 47
> [ 12.075121] MODSIGN: Problem loading in-kernel X.509 certificate (-74)
>
> So, this patch add the parsing rule for support long form format against
> Authority Key Identifier.
>
> v3:
> Changed the size check in "Short Form length" case, we allow v[3] smaller
> then (vlen - 4) because authorityCertIssuer and authorityCertSerialNumber
> are also possible attach in AuthorityKeyIdentifier sequence.
>
> v2:
> - Removed comma from author's name.
> - Moved 'Short Form length' comment inside the if-body.
> - Changed the type of sub to size_t.
> - Use ASN1_INDEFINITE_LENGTH rather than writing 0x80 and 127.
> - Moved the key_len's value assignment before alter v.
> - Fixed the typo of octets.
> - Add 2 to v before entering the loop for calculate the length.
> - Removed the comment of check vlen.
>
> Cc: Rusty Russell <[email protected]>
> Cc: Josh Boyer <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Herbert Xu <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Acked-by: David Howells <[email protected]>
> Signed-off-by: Chun-Yi Lee <[email protected]>
> ---
> crypto/asymmetric_keys/x509_cert_parser.c | 55 ++++++++++++++++++++++++----
> 1 files changed, 47 insertions(+), 8 deletions(-)
>
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 7fabc4c..59ab6d2 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -373,6 +373,9 @@ int rsa_extract_mpi(void *context, size_t hdrlen,
> return 0;
> }
>
> +/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
> +#define SEQ_TAG_KEYID (ASN1_CONT << 6)
> +
> /*
> * Process certificate extensions that are used to qualify the certificate.
> */
> @@ -407,21 +410,57 @@ int x509_process_extension(void *context, size_t hdrlen,
> }
>
> if (ctx->last_oid == OID_authorityKeyIdentifier) {
> + size_t key_len;
> +
> /* Get hold of the CA key fingerprint */
> if (vlen < 5)
> return -EBADMSG;
> - if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)) ||
> - v[1] != vlen - 2 ||
> - v[2] != (ASN1_CONT << 6) ||
> - v[3] != vlen - 4)
> +
> + /* Authority Key Identifier must be a Constructed SEQUENCE */
> + if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
> return -EBADMSG;
> - v += 4;
> - vlen -= 4;
>
> - f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
> + /* Authority Key Identifier is not indefinite length */
> + if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
> + return -EBADMSG;
> +
> + if (vlen < ASN1_INDEFINITE_LENGTH) {
> + /* Short Form length */
> + if (v[1] != vlen - 2 ||
> + v[2] != SEQ_TAG_KEYID ||
> + v[3] > vlen - 4)
> + return -EBADMSG;
> +
> + key_len = v[3];
> + v += 4;
> + } else {
> + /* Long Form length */
> + size_t seq_len = 0;
> + size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
> +
> + if (sub > 2)
> + return -EBADMSG;
> +
> + /* calculate the length from subsequent octets */
> + v += 2;
> + for (i = 0; i < sub; i++) {
> + seq_len <<= 8;
> + seq_len |= v[i];
> + }
> +
> + if (seq_len != vlen - 2 - sub ||
> + v[sub] != SEQ_TAG_KEYID ||
> + v[sub + 1] > vlen - 4 - sub)
> + return -EBADMSG;
> +
> + key_len = v[sub + 1];
> + v += (sub + 2);
> + }
> +
> + f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
> if (!f)
> return -ENOMEM;
> - for (i = 0; i < vlen; i++)
> + for (i = 0; i < key_len; i++)
> sprintf(f + i * 2, "%02x", v[i]);
> pr_debug("authority %s\n", f);
> ctx->cert->authority = f;
"Lee, Chun-Yi" <[email protected]> writes:
> From: Chun-Yi Lee <[email protected]>
>
> Per X.509 spec in 4.2.1.1 section, the structure of Authority Key
> Identifier Extension is:
>
> AuthorityKeyIdentifier ::= SEQUENCE {
> keyIdentifier [0] KeyIdentifier OPTIONAL,
> authorityCertIssuer [1] GeneralNames OPTIONAL,
> authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
>
> KeyIdentifier ::= OCTET STRING
>
> When a certificate also provides
> authorityCertIssuer and authorityCertSerialNumber then the length of
> AuthorityKeyIdentifier SEQUENCE is likely to long form format.
> e.g.
> The example certificate demos/tunala/A-server.pem in openssl source:
>
> X509v3 Authority Key Identifier:
> keyid:49:FB:45:72:12:C4:CC:E1:45:A1:D3:08:9E:95:C4:2C:6D:55:3F:17
> DirName:/C=NZ/L=Wellington/O=Really Irresponsible Authorisation Authority (RIAA)/OU=Cert-stamping/CN=Jackov al-Trades/[email protected]
> serial:00
>
> Current parsing rule of OID_authorityKeyIdentifier only take care the
> short form format, it causes load certificate to modsign_keyring fail:
>
> [ 12.061147] X.509: Extension: 47
> [ 12.075121] MODSIGN: Problem loading in-kernel X.509 certificate (-74)
>
> So, this patch add the parsing rule for support long form format against
> Authority Key Identifier.
>
> v3:
> Changed the size check in "Short Form length" case, we allow v[3] smaller
> then (vlen - 4) because authorityCertIssuer and authorityCertSerialNumber
> are also possible attach in AuthorityKeyIdentifier sequence.
>
> v2:
> - Removed comma from author's name.
> - Moved 'Short Form length' comment inside the if-body.
> - Changed the type of sub to size_t.
> - Use ASN1_INDEFINITE_LENGTH rather than writing 0x80 and 127.
> - Moved the key_len's value assignment before alter v.
> - Fixed the typo of octets.
> - Add 2 to v before entering the loop for calculate the length.
> - Removed the comment of check vlen.
>
> Cc: Rusty Russell <[email protected]>
> Cc: Josh Boyer <[email protected]>
> Cc: Randy Dunlap <[email protected]>
> Cc: Herbert Xu <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Acked-by: David Howells <[email protected]>
> Signed-off-by: Chun-Yi Lee <[email protected]>
Applied to modules-next.
Thanks,
Rusty.
於 一，2013-04-22 於 11:37 +0930，Rusty Russell 提到：
> "Lee, Chun-Yi" <[email protected]> writes:
> > From: Chun-Yi Lee <[email protected]>
> >
> > Per X.509 spec in 4.2.1.1 section, the structure of Authority Key
> > Identifier Extension is:
> >
> > AuthorityKeyIdentifier ::= SEQUENCE {
> > keyIdentifier [0] KeyIdentifier OPTIONAL,
> > authorityCertIssuer [1] GeneralNames OPTIONAL,
> > authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
> >
> > KeyIdentifier ::= OCTET STRING
> >
> > When a certificate also provides
> > authorityCertIssuer and authorityCertSerialNumber then the length of
> > AuthorityKeyIdentifier SEQUENCE is likely to long form format.
> > e.g.
> > The example certificate demos/tunala/A-server.pem in openssl source:
> >
> > X509v3 Authority Key Identifier:
> > keyid:49:FB:45:72:12:C4:CC:E1:45:A1:D3:08:9E:95:C4:2C:6D:55:3F:17
> > DirName:/C=NZ/L=Wellington/O=Really Irresponsible Authorisation Authority (RIAA)/OU=Cert-stamping/CN=Jackov al-Trades/[email protected]
> > serial:00
> >
> > Current parsing rule of OID_authorityKeyIdentifier only take care the
> > short form format, it causes load certificate to modsign_keyring fail:
> >
> > [ 12.061147] X.509: Extension: 47
> > [ 12.075121] MODSIGN: Problem loading in-kernel X.509 certificate (-74)
> >
> > So, this patch add the parsing rule for support long form format against
> > Authority Key Identifier.
> >
> > v3:
> > Changed the size check in "Short Form length" case, we allow v[3] smaller
> > then (vlen - 4) because authorityCertIssuer and authorityCertSerialNumber
> > are also possible attach in AuthorityKeyIdentifier sequence.
> >
> > v2:
> > - Removed comma from author's name.
> > - Moved 'Short Form length' comment inside the if-body.
> > - Changed the type of sub to size_t.
> > - Use ASN1_INDEFINITE_LENGTH rather than writing 0x80 and 127.
> > - Moved the key_len's value assignment before alter v.
> > - Fixed the typo of octets.
> > - Add 2 to v before entering the loop for calculate the length.
> > - Removed the comment of check vlen.
> >
> > Cc: Rusty Russell <[email protected]>
> > Cc: Josh Boyer <[email protected]>
> > Cc: Randy Dunlap <[email protected]>
> > Cc: Herbert Xu <[email protected]>
> > Cc: "David S. Miller" <[email protected]>
> > Acked-by: David Howells <[email protected]>
> > Signed-off-by: Chun-Yi Lee <[email protected]>
>
> Applied to modules-next.
>
> Thanks,
> Rusty.
>
Thanks for help!
Joey Lee