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| author | Demi Marie Obenour <demiobenour@gmail.com> | 2022-12-08 15:24:18 -0500 |
|---|---|---|
| committer | Demi Marie Obenour <demiobenour@gmail.com> | 2022-12-29 18:41:10 -0500 |
| commit | 94c0cfbb82980439003713b8fcb7ae78859be069 (patch) | |
| tree | aa365a24cbb8a2ab91bc3294e660a1489f1b5dfd | |
| parent | a8c8c5ef2a8f5a27772eb708f2201429dd8d32b2 (diff) | |
| download | arm-trusted-firmware-94c0cfbb82980439003713b8fcb7ae78859be069.tar.gz | |
refactor(auth): partially validate SubjectPublicKeyInfo early
This reduces the likelihood of future problems later.
Change-Id: Ia748b6ae31a7a48f17ec7f0fc08310a50cd1b135
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
| -rw-r--r-- | drivers/auth/mbedtls/mbedtls_x509_parser.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/auth/mbedtls/mbedtls_x509_parser.c b/drivers/auth/mbedtls/mbedtls_x509_parser.c index 9cccd964d..244f1c95e 100644 --- a/drivers/auth/mbedtls/mbedtls_x509_parser.c +++ b/drivers/auth/mbedtls/mbedtls_x509_parser.c @@ -144,7 +144,7 @@ static int cert_parse(void *img, unsigned int img_len) { int ret, is_critical; size_t len; - unsigned char *p, *end, *crt_end; + unsigned char *p, *end, *crt_end, *pk_end; mbedtls_asn1_buf sig_alg1, sig_alg2; /* * The unique ASN.1 DER encoding of [0] EXPLICIT INTEGER { v3(2} }. @@ -271,9 +271,22 @@ static int cert_parse(void *img, unsigned int img_len) if (ret != 0) { return IMG_PARSER_ERR_FORMAT; } - pk.len = (p + len) - pk.p; + pk_end = p + len; + pk.len = pk_end - pk.p; + + ret = mbedtls_asn1_get_tag(&p, pk_end, &len, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE); + if (ret != 0) { + return IMG_PARSER_ERR_FORMAT; + } p += len; + ret = mbedtls_asn1_get_tag(&p, pk_end, &len, MBEDTLS_ASN1_BIT_STRING); + if ((ret != 0) || (p + len != pk_end)) { + return IMG_PARSER_ERR_FORMAT; + } + p = pk_end; + /* * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, */ |