x509-cert: Fix underflow on empty input in Certificate::load_pem_chain (#1965)

lukevalenta · web-flow · commit 6e6ed0324c08 · 2025-07-26T10:15:00.000-06:00
diff --git a/x509-cert/src/certificate.rs b/x509-cert/src/certificate.rs
@@ -411,7 +411,7 @@ impl<P: Profile> CertificateInner<P> {
             }
         }
 
-        while position < input.len() - 1 {
+        while position + 1 < input.len() {
             let rest = &input[position..];
             let end_pos = find_boundary(rest, end_boundary)
                 .ok_or(pem::Error::PostEncapsulationBoundary)?

Original file line number	Diff line number	Diff line change
`@@ -411,7 +411,7 @@ impl<P: Profile> CertificateInner<P> {`
`411`	`411`	`}`
`412`	`412`	`}`
`413`	`413`
`414`		`- while position < input.len() - 1 {`
	`414`	`+ while position + 1 < input.len() {`
`415`	`415`	`let rest = &input[position..];`
`416`	`416`	`let end_pos = find_boundary(rest, end_boundary)`
`417`	`417`	`.ok_or(pem::Error::PostEncapsulationBoundary)?`