pkcs7: Drop support for signature in contentInfo of signed data

The contentInfo field of PKCS7 Signed Data structures can
optionally contain the content of the signature. Per RFC 2315
it can also contain any of the PKCS7 data types. Add test and
comments making it clear that the current implementation
only supports the DATA content type and the data must be empty.

Return codes should be clear whether content was invalid or
unsupported.
Identification and fix provided by:
 - Demi Marie Obenour <demiobenour@gmail.com>
 - Dave Rodgman <dave.rodgman@arm.com>

Signed-off-by: Nick Child <nick.child@ibm.com>
This commit is contained in:
Nick Child 2023-02-07 19:59:58 +00:00
parent 50886c25f3
commit 3dafc6c3b3
5 changed files with 25 additions and 4 deletions

View file

@ -46,6 +46,8 @@
* - The RFC allows for SignerInfo structure to optionally contain
* unauthenticatedAttributes and authenticatedAttributes. In Mbed TLS it is
* assumed these fields are empty.
* - The RFC allows for the signed Data type to contain contentInfo. This
* implementation assumes the type is DATA and the content is empty.
*/
#ifndef MBEDTLS_PKCS7_H

View file

@ -495,8 +495,18 @@ static int pkcs7_get_signed_data(unsigned char *buf, size_t buflen,
return ret;
}
if (end_content_info != p) {
return MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO;
if (p != end_content_info) {
/* Determine if valid content is present */
ret = mbedtls_asn1_get_tag(&p, end_content_info, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC);
if (ret != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO, ret);
}
p += len;
if (p != end_content_info) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO, ret);
}
/* Valid content is present - this is not supported */
return MBEDTLS_ERR_PKCS7_FEATURE_UNAVAILABLE;
}
if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS7_DATA, &signed_data->content.oid)) {

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@ -1202,6 +1202,11 @@ pkcs7_data_without_cert_signed.der: $(pkcs7_test_file) $(pkcs7_test_cert_1)
$(OPENSSL) smime -sign -binary -in pkcs7_data.bin -out $@ -md sha256 -signer pkcs7-rsa-sha256-1.pem -nocerts -noattr -outform DER -out $@
all_final += pkcs7_data_without_cert_signed.der
# pkcs7 signature file with signature
pkcs7_data_with_signature.der: $(pkcs7_test_file) $(pkcs7_test_cert_1)
$(OPENSSL) smime -sign -binary -in pkcs7_data.bin -out $@ -md sha256 -signer pkcs7-rsa-sha256-1.pem -nocerts -noattr -nodetach -outform DER -out $@
all_final += pkcs7_data_with_signature.der
# pkcs7 signature file with two signers
pkcs7_data_multiple_signed.der: $(pkcs7_test_file) $(pkcs7_test_cert_1) $(pkcs7_test_cert_2)
$(OPENSSL) smime -sign -binary -in pkcs7_data.bin -out $@ -md sha256 -signer pkcs7-rsa-sha256-1.pem -signer pkcs7-rsa-sha256-2.pem -nocerts -noattr -outform DER -out $@

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@ -22,6 +22,10 @@ PKCS7 Signed Data Parse Fail with disabled alg #5.1
depends_on:MBEDTLS_RSA_C:!MBEDTLS_SHA512_C
pkcs7_parse:"data_files/pkcs7_data_cert_signed_sha512.der":MBEDTLS_ERR_PKCS7_INVALID_ALG
PKCS7 Parse Fail with Inlined Content Info #5.2
depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C
pkcs7_parse:"data_files/pkcs7_data_with_signature.der":MBEDTLS_ERR_PKCS7_FEATURE_UNAVAILABLE
PKCS7 Signed Data Parse Fail with corrupted signer info #6
depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C
pkcs7_parse:"data_files/pkcs7_data_signed_badsigner.der":MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO,MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)
@ -68,11 +72,11 @@ pkcs7_parse:"data_files/pkcs7_signerInfo_serial_invalid_size.der":MBEDTLS_ERR_PK
pkcs7_get_signers_info_set error handling (6213931373035520)
depends_on:MBEDTLS_RIPEMD160_C
pkcs7_parse:"data_files/pkcs7_get_signers_info_set-missing_free-fuzz_pkcs7-6213931373035520.der":MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO
pkcs7_parse:"data_files/pkcs7_get_signers_info_set-missing_free-fuzz_pkcs7-6213931373035520.der":MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)
pkcs7_get_signers_info_set error handling (4541044530479104)
depends_on:MBEDTLS_RIPEMD160_C
pkcs7_parse:"data_files/pkcs7_get_signers_info_set-leak-fuzz_pkcs7-4541044530479104.der":MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO
pkcs7_parse:"data_files/pkcs7_get_signers_info_set-leak-fuzz_pkcs7-4541044530479104.der": MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)
PKCS7 Only Signed Data Parse Pass #15
depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C