commit 512818b1d2173e0ea906316075a6e01fd1654fac
author Demi Marie Obenour <demiobenour@gmail.com> Sun Nov 27 22:48:55 2022 -0500
committer Dave Rodgman <dave.rodgman@arm.com> Fri Feb 10 12:56:10 2023 +0000
tree fbeaf576a90c25320142f838bd46b3efb0d2c8d2
parent a22749e7496ff9211d8c201fe7633cbd291261d3

pkcs7: check that content lengths fill whole buffer

Otherwise invalid data could be accepted.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>

library/pkcs7.c

diff --git a/library/pkcs7.c b/library/pkcs7.c
index 4fdbe36..ec5d569 100644
--- a/library/pkcs7.c
+++ b/library/pkcs7.c
@@ -58,6 +58,9 @@
                                | MBEDTLS_ASN1_CONTEXT_SPECIFIC);
     if (ret != 0) {
         ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_FORMAT, ret);
+    } else if ((size_t) (end - *p) != *len) {
+        ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS7_INVALID_FORMAT,
+                                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
     }
 
     return ret;