go: fix CVE-2025-58187

Due to the design of the name constraint checking algorithm, the processing
time of some inputs scals non-linearly with respect to the size of the certificate.
This affects programs which validate arbitrary certificate chains.

(From OE-Core rev: ce1626d1f1e232bc6da81e89088d0c0f5f3c52b4)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 350 insertions, 0 deletions

diff --git a/meta/recipes-devtools/go/go-1.22.12.inc b/meta/recipes-devtools/go/go-1.22.12.inc
index 38992219c8..a1c14ea684 100644
--- a/meta/recipes-devtools/go/go-1.22.12.inc
+++ b/meta/recipes-devtools/go/go-1.22.12.inc
@@ -22,6 +22,7 @@ SRC_URI += "\
     file://CVE-2025-47907.patch \
     file://CVE-2025-47906.patch \
     file://CVE-2025-58185.patch \
+    file://CVE-2025-58187.patch \
 "
 SRC_URI[main.sha256sum] = "012a7e1f37f362c0918c1dfa3334458ac2da1628c4b9cf4d9ca02db986e17d71"
 
diff --git a/meta/recipes-devtools/go/go/CVE-2025-58187.patch b/meta/recipes-devtools/go/go/CVE-2025-58187.patch
new file mode 100644
index 0000000000..d3b7dd5264
--- /dev/null
+++ b/meta/recipes-devtools/go/go/CVE-2025-58187.patch
@@ -0,0 +1,349 @@
+From f334417e71f8b078ad64035bddb6df7f8910da6c Mon Sep 17 00:00:00 2001
+From: Neal Patel <nealpatel@google.com>
+Date: Mon, 15 Sep 2025 16:31:22 -0400
+Subject: [PATCH] [release-branch.go1.24] crypto/x509: improve domain name
+ verification
+
+Don't use domainToReverseLabels to check if domain names are
+valid, since it is not particularly performant, and can contribute to DoS
+vectors. Instead just iterate over the name and enforce the properties we
+care about.
+
+This also enforces that DNS names, both in SANs and name constraints,
+are valid. We previously allowed invalid SANs, because some
+intermediates had these weird names (see #23995), but there are
+currently no trusted intermediates that have this property, and since we
+target the web PKI, supporting this particular case is not a high
+priority.
+
+Thank you to Jakub Ciolek for reporting this issue.
+
+Fixes CVE-2025-58187
+For #75681
+Fixes #75714
+
+Change-Id: I6ebce847dcbe5fc63ef2f9a74f53f11c4c56d3d1
+Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2820
+Reviewed-by: Damien Neil <dneil@google.com>
+Reviewed-by: Roland Shoemaker <bracewell@google.com>
+Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2982
+Reviewed-by: Nicholas Husin <husin@google.com>
+Reviewed-on: https://go-review.googlesource.com/c/go/+/709839
+Auto-Submit: Michael Pratt <mpratt@google.com>
+Reviewed-by: Carlos Amedee <carlos@golang.org>
+TryBot-Bypass: Michael Pratt <mpratt@google.com>
+
+CVE: CVE-2025-58187
+
+Upstream-Status: Backport [https://github.com/golang/go/commit/f334417e71f8b078ad64035bddb6df7f8910da6c]
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ src/crypto/x509/name_constraints_test.go | 66 ++------------------
+ src/crypto/x509/parser.go                | 77 ++++++++++++++----------
+ src/crypto/x509/parser_test.go           | 43 +++++++++++++
+ src/crypto/x509/verify.go                |  1 +
+ 4 files changed, 95 insertions(+), 92 deletions(-)
+
+diff --git a/src/crypto/x509/name_constraints_test.go b/src/crypto/x509/name_constraints_test.go
+index 78263fc..9aaa6d7 100644
+--- a/src/crypto/x509/name_constraints_test.go
++++ b/src/crypto/x509/name_constraints_test.go
+@@ -1456,63 +1456,7 @@ var nameConstraintsTests = []nameConstraintsTest{
+                expectedError: "incompatible key usage",
+        },
+
+-       // An invalid DNS SAN should be detected only at validation time so
+-       // that we can process CA certificates in the wild that have invalid SANs.
+-       // See https://github.com/golang/go/issues/23995
+-
+-       // #77: an invalid DNS or mail SAN will not be detected if name constraint
+-       // checking is not triggered.
+-       {
+-               roots: make([]constraintsSpec, 1),
+-               intermediates: [][]constraintsSpec{
+-                       {
+-                               {},
+-                       },
+-               },
+-               leaf: leafSpec{
+-                       sans: []string{"dns:this is invalid", "email:this @ is invalid"},
+-               },
+-       },
+-
+-       // #78: an invalid DNS SAN will be detected if any name constraint checking
+-       // is triggered.
+-       {
+-               roots: []constraintsSpec{
+-                       {
+-                               bad: []string{"uri:"},
+-                       },
+-               },
+-               intermediates: [][]constraintsSpec{
+-                       {
+-                               {},
+-                       },
+-               },
+-               leaf: leafSpec{
+-                       sans: []string{"dns:this is invalid"},
+-               },
+-               expectedError: "cannot parse dnsName",
+-       },
+-
+-       // #79: an invalid email SAN will be detected if any name constraint
+-       // checking is triggered.
+-       {
+-               roots: []constraintsSpec{
+-                       {
+-                               bad: []string{"uri:"},
+-                       },
+-               },
+-               intermediates: [][]constraintsSpec{
+-                       {
+-                               {},
+-                       },
+-               },
+-               leaf: leafSpec{
+-                       sans: []string{"email:this @ is invalid"},
+-               },
+-               expectedError: "cannot parse rfc822Name",
+-       },
+-
+-       // #80: if several EKUs are requested, satisfying any of them is sufficient.
++       // #77: if several EKUs are requested, satisfying any of them is sufficient.
+        {
+                roots: make([]constraintsSpec, 1),
+                intermediates: [][]constraintsSpec{
+@@ -1527,7 +1471,7 @@ var nameConstraintsTests = []nameConstraintsTest{
+                requestedEKUs: []ExtKeyUsage{ExtKeyUsageClientAuth, ExtKeyUsageEmailProtection},
+        },
+
+-       // #81: EKUs that are not asserted in VerifyOpts are not required to be
++       // #78: EKUs that are not asserted in VerifyOpts are not required to be
+        // nested.
+        {
+                roots: make([]constraintsSpec, 1),
+@@ -1546,7 +1490,7 @@ var nameConstraintsTests = []nameConstraintsTest{
+                },
+        },
+
+-       // #82: a certificate without SANs and CN is accepted in a constrained chain.
++       // #79: a certificate without SANs and CN is accepted in a constrained chain.
+        {
+                roots: []constraintsSpec{
+                        {
+@@ -1563,7 +1507,7 @@ var nameConstraintsTests = []nameConstraintsTest{
+                },
+        },
+
+-       // #83: a certificate without SANs and with a CN that does not parse as a
++       // #80: a certificate without SANs and with a CN that does not parse as a
+        // hostname is accepted in a constrained chain.
+        {
+                roots: []constraintsSpec{
+@@ -1582,7 +1526,7 @@ var nameConstraintsTests = []nameConstraintsTest{
+                },
+        },
+
+-       // #84: a certificate with SANs and CN is accepted in a constrained chain.
++       // #81: a certificate with SANs and CN is accepted in a constrained chain.
+        {
+                roots: []constraintsSpec{
+                        {
+diff --git a/src/crypto/x509/parser.go b/src/crypto/x509/parser.go
+index 812b0d2..9a3bcd6 100644
+--- a/src/crypto/x509/parser.go
++++ b/src/crypto/x509/parser.go
+@@ -378,10 +378,14 @@ func parseSANExtension(der cryptobyte.String) (dnsNames, emailAddresses []string
+                        if err := isIA5String(email); err != nil {
+                                return errors.New("x509: SAN rfc822Name is malformed")
+                        }
++                       parsed, ok := parseRFC2821Mailbox(email)
++                       if !ok || (ok && !domainNameValid(parsed.domain, false)) {
++                               return errors.New("x509: SAN rfc822Name is malformed")
++                       }
+                        emailAddresses = append(emailAddresses, email)
+                case nameTypeDNS:
+                        name := string(data)
+-                       if err := isIA5String(name); err != nil {
++                       if err := isIA5String(name); err != nil || (err == nil && !domainNameValid(name, false)) {
+                                return errors.New("x509: SAN dNSName is malformed")
+                        }
+                        dnsNames = append(dnsNames, string(name))
+@@ -391,14 +395,9 @@ func parseSANExtension(der cryptobyte.String) (dnsNames, emailAddresses []string
+                                return errors.New("x509: SAN uniformResourceIdentifier is malformed")
+                        }
+                        uri, err := url.Parse(uriStr)
+-                       if err != nil {
++                       if err != nil || (err == nil && uri.Host != "" && !domainNameValid(uri.Host, false)) {
+                                return fmt.Errorf("x509: cannot parse URI %q: %s", uriStr, err)
+                        }
+-                       if len(uri.Host) > 0 {
+-                               if _, ok := domainToReverseLabels(uri.Host); !ok {
+-                                       return fmt.Errorf("x509: cannot parse URI %q: invalid domain", uriStr)
+-                               }
+-                       }
+                        uris = append(uris, uri)
+                case nameTypeIP:
+                        switch len(data) {
+@@ -538,15 +537,7 @@ func parseNameConstraintsExtension(out *Certificate, e pkix.Extension) (unhandle
+                                        return nil, nil, nil, nil, errors.New("x509: invalid constraint value: " + err.Error())
+                                }
+
+-                               trimmedDomain := domain
+-                               if len(trimmedDomain) > 0 && trimmedDomain[0] == '.' {
+-                                       // constraints can have a leading
+-                                       // period to exclude the domain
+-                                       // itself, but that's not valid in a
+-                                       // normal domain name.
+-                                       trimmedDomain = trimmedDomain[1:]
+-                               }
+-                               if _, ok := domainToReverseLabels(trimmedDomain); !ok {
++                               if !domainNameValid(domain, true) {
+                                        return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse dnsName constraint %q", domain)
+                                }
+                                dnsNames = append(dnsNames, domain)
+@@ -587,12 +578,7 @@ func parseNameConstraintsExtension(out *Certificate, e pkix.Extension) (unhandle
+                                                return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse rfc822Name constraint %q", constraint)
+                                        }
+                                } else {
+-                                       // Otherwise it's a domain name.
+-                                       domain := constraint
+-                                       if len(domain) > 0 && domain[0] == '.' {
+-                                               domain = domain[1:]
+-                                       }
+-                                       if _, ok := domainToReverseLabels(domain); !ok {
++                                       if !domainNameValid(constraint, true) {
+                                                return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse rfc822Name constraint %q", constraint)
+                                        }
+                                }
+@@ -608,15 +594,7 @@ func parseNameConstraintsExtension(out *Certificate, e pkix.Extension) (unhandle
+                                        return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse URI constraint %q: cannot be IP address", domain)
+                                }
+
+-                               trimmedDomain := domain
+-                               if len(trimmedDomain) > 0 && trimmedDomain[0] == '.' {
+-                                       // constraints can have a leading
+-                                       // period to exclude the domain itself,
+-                                       // but that's not valid in a normal
+-                                       // domain name.
+-                                       trimmedDomain = trimmedDomain[1:]
+-                               }
+-                               if _, ok := domainToReverseLabels(trimmedDomain); !ok {
++                               if !domainNameValid(domain, true) {
+                                        return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse URI constraint %q", domain)
+                                }
+                                uriDomains = append(uriDomains, domain)
+@@ -1197,3 +1175,40 @@ func ParseRevocationList(der []byte) (*RevocationList, error) {
+
+        return rl, nil
+ }
++
++// domainNameValid does minimal domain name validity checking. In particular it
++// enforces the following properties:
++//   - names cannot have the trailing period
++//   - names can only have a leading period if constraint is true
++//   - names must be <= 253 characters
++//   - names cannot have empty labels
++//   - names cannot labels that are longer than 63 characters
++//
++// Note that this does not enforce the LDH requirements for domain names.
++func domainNameValid(s string, constraint bool) bool {
++       if len(s) == 0 && constraint {
++               return true
++       }
++       if len(s) == 0 || (!constraint && s[0] == '.') || s[len(s)-1] == '.' || len(s) > 253 {
++               return false
++       }
++       lastDot := -1
++       if constraint && s[0] == '.' {
++               s = s[1:]
++       }
++
++       for i := 0; i <= len(s); i++ {
++               if i == len(s) || s[i] == '.' {
++                       labelLen := i
++                       if lastDot >= 0 {
++                               labelLen -= lastDot + 1
++                       }
++                       if labelLen == 0 || labelLen > 63 {
++                               return false
++                       }
++                       lastDot = i
++               }
++       }
++
++       return true
++}
+diff --git a/src/crypto/x509/parser_test.go b/src/crypto/x509/parser_test.go
+index b31f9cd..a6cdfb8 100644
+--- a/src/crypto/x509/parser_test.go
++++ b/src/crypto/x509/parser_test.go
+@@ -6,6 +6,7 @@ package x509
+
+ import (
+        "encoding/asn1"
++       "strings"
+        "testing"
+
+        cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1"
+@@ -101,3 +102,45 @@ func TestParseASN1String(t *testing.T) {
+                })
+        }
+ }
++
++func TestDomainNameValid(t *testing.T) {
++       for _, tc := range []struct {
++               name       string
++               dnsName    string
++               constraint bool
++               valid      bool
++       }{
++               {"empty name, name", "", false, false},
++               {"empty name, constraint", "", true, true},
++               {"empty label, name", "a..a", false, false},
++               {"empty label, constraint", "a..a", true, false},
++               {"period, name", ".", false, false},
++               {"period, constraint", ".", true, false}, // TODO(roland): not entirely clear if this is a valid constraint (require at least one label?)
++               {"valid, name", "a.b.c", false, true},
++               {"valid, constraint", "a.b.c", true, true},
++               {"leading period, name", ".a.b.c", false, false},
++               {"leading period, constraint", ".a.b.c", true, true},
++               {"trailing period, name", "a.", false, false},
++               {"trailing period, constraint", "a.", true, false},
++               {"bare label, name", "a", false, true},
++               {"bare label, constraint", "a", true, true},
++               {"254 char label, name", strings.Repeat("a.a", 84) + "aaa", false, false},
++               {"254 char label, constraint", strings.Repeat("a.a", 84) + "aaa", true, false},
++               {"253 char label, name", strings.Repeat("a.a", 84) + "aa", false, false},
++               {"253 char label, constraint", strings.Repeat("a.a", 84) + "aa", true, false},
++               {"64 char single label, name", strings.Repeat("a", 64), false, false},
++               {"64 char single label, constraint", strings.Repeat("a", 64), true, false},
++               {"63 char single label, name", strings.Repeat("a", 63), false, true},
++               {"63 char single label, constraint", strings.Repeat("a", 63), true, true},
++               {"64 char label, name", "a." + strings.Repeat("a", 64), false, false},
++               {"64 char label, constraint", "a." + strings.Repeat("a", 64), true, false},
++               {"63 char label, name", "a." + strings.Repeat("a", 63), false, true},
++               {"63 char label, constraint", "a." + strings.Repeat("a", 63), true, true},
++       } {
++               t.Run(tc.name, func(t *testing.T) {
++                       if tc.valid != domainNameValid(tc.dnsName, tc.constraint) {
++                               t.Errorf("domainNameValid(%q, %t) = %v; want %v", tc.dnsName, tc.constraint, !tc.valid, tc.valid)
++                       }
++               })
++       }
++}
+diff --git a/src/crypto/x509/verify.go b/src/crypto/x509/verify.go
+index 2d2a271..4502d4c 100644
+--- a/src/crypto/x509/verify.go
++++ b/src/crypto/x509/verify.go
+@@ -360,6 +360,7 @@ func parseRFC2821Mailbox(in string) (mailbox rfc2821Mailbox, ok bool) {
+ // domainToReverseLabels converts a textual domain name like foo.example.com to
+ // the list of labels in reverse order, e.g. ["com", "example", "foo"].
+ func domainToReverseLabels(domain string) (reverseLabels []string, ok bool) {
++       reverseLabels = make([]string, 0, strings.Count(domain, ".")+1)
+        for len(domain) > 0 {
+                if i := strings.LastIndexByte(domain, '.'); i == -1 {
+                        reverseLabels = append(reverseLabels, domain)
+--
+2.40.0