From 84786152175e28f504f11fc26720a1034af81d88 Mon Sep 17 00:00:00 2001
From: Scott Miller <smiller@hashicorp.com>
Date: Wed, 15 Sep 2021 11:59:12 -0500
Subject: [PATCH] Use the system rand reader for CA root and intermediate
 generation (#12559)

* Use the system rand reader for CA root and intermediate generation

* changelog
---
 builtin/logical/pki/cert_util.go         | 10 ++++++----
 builtin/logical/pki/path_intermediate.go |  2 +-
 builtin/logical/pki/path_issue_sign.go   |  3 ++-
 builtin/logical/pki/path_root.go         |  2 +-
 changelog/12559.txt                      |  3 +++
 5 files changed, 13 insertions(+), 7 deletions(-)
 create mode 100644 changelog/12559.txt

diff --git a/builtin/logical/pki/cert_util.go b/builtin/logical/pki/cert_util.go
index 6df174a89d3e8..52f0a33e0c812 100644
--- a/builtin/logical/pki/cert_util.go
+++ b/builtin/logical/pki/cert_util.go
@@ -11,6 +11,7 @@ import (
 	"encoding/base64"
 	"encoding/pem"
 	"fmt"
+	"io"
 	"net"
 	"net/url"
 	"regexp"
@@ -449,7 +450,8 @@ func generateCert(ctx context.Context,
 	b *backend,
 	input *inputBundle,
 	caSign *certutil.CAInfoBundle,
-	isCA bool) (*certutil.ParsedCertBundle, error) {
+	isCA bool,
+	randomSource io.Reader) (*certutil.ParsedCertBundle, error) {
 
 	if input.role == nil {
 		return nil, errutil.InternalError{Err: "no role found in data bundle"}
@@ -494,7 +496,7 @@ func generateCert(ctx context.Context,
 		}
 	}
 
-	parsedBundle, err := certutil.CreateCertificate(data)
+	parsedBundle, err := certutil.CreateCertificateWithRandomSource(data, randomSource)
 	if err != nil {
 		return nil, err
 	}
@@ -504,7 +506,7 @@ func generateCert(ctx context.Context,
 
 // N.B.: This is only meant to be used for generating intermediate CAs.
 // It skips some sanity checks.
-func generateIntermediateCSR(b *backend, input *inputBundle) (*certutil.ParsedCSRBundle, error) {
+func generateIntermediateCSR(b *backend, input *inputBundle, randomSource io.Reader) (*certutil.ParsedCSRBundle, error) {
 	creation, err := generateCreationBundle(b, input, nil, nil)
 	if err != nil {
 		return nil, err
@@ -514,7 +516,7 @@ func generateIntermediateCSR(b *backend, input *inputBundle) (*certutil.ParsedCS
 	}
 
 	addBasicConstraints := input.apiData != nil && input.apiData.Get("add_basic_constraints").(bool)
-	parsedBundle, err := certutil.CreateCSR(creation, addBasicConstraints)
+	parsedBundle, err := certutil.CreateCSRWithRandomSource(creation, addBasicConstraints, randomSource)
 	if err != nil {
 		return nil, err
 	}
diff --git a/builtin/logical/pki/path_intermediate.go b/builtin/logical/pki/path_intermediate.go
index 7ae17cd973ea3..4b75e2bb75f89 100644
--- a/builtin/logical/pki/path_intermediate.go
+++ b/builtin/logical/pki/path_intermediate.go
@@ -75,7 +75,7 @@ func (b *backend) pathGenerateIntermediate(ctx context.Context, req *logical.Req
 		req:     req,
 		apiData: data,
 	}
-	parsedBundle, err := generateIntermediateCSR(b, input)
+	parsedBundle, err := generateIntermediateCSR(b, input, b.Backend.GetRandomReader())
 	if err != nil {
 		switch err.(type) {
 		case errutil.UserError:
diff --git a/builtin/logical/pki/path_issue_sign.go b/builtin/logical/pki/path_issue_sign.go
index 28d3c54b39420..575e6ea104267 100644
--- a/builtin/logical/pki/path_issue_sign.go
+++ b/builtin/logical/pki/path_issue_sign.go
@@ -2,6 +2,7 @@ package pki
 
 import (
 	"context"
+	"crypto/rand"
 	"encoding/base64"
 	"fmt"
 	"time"
@@ -219,7 +220,7 @@ func (b *backend) pathIssueSignCert(ctx context.Context, req *logical.Request, d
 	if useCSR {
 		parsedBundle, err = signCert(b, input, signingBundle, false, useCSRValues)
 	} else {
-		parsedBundle, err = generateCert(ctx, b, input, signingBundle, false)
+		parsedBundle, err = generateCert(ctx, b, input, signingBundle, false, rand.Reader)
 	}
 	if err != nil {
 		switch err.(type) {
diff --git a/builtin/logical/pki/path_root.go b/builtin/logical/pki/path_root.go
index 1964013d4c963..253168810d0e0 100644
--- a/builtin/logical/pki/path_root.go
+++ b/builtin/logical/pki/path_root.go
@@ -155,7 +155,7 @@ func (b *backend) pathCAGenerateRoot(ctx context.Context, req *logical.Request,
 		apiData: data,
 		role:    role,
 	}
-	parsedBundle, err := generateCert(ctx, b, input, nil, true)
+	parsedBundle, err := generateCert(ctx, b, input, nil, true, b.Backend.GetRandomReader())
 	if err != nil {
 		switch err.(type) {
 		case errutil.UserError:
diff --git a/changelog/12559.txt b/changelog/12559.txt
new file mode 100644
index 0000000000000..9bcd4e8901d52
--- /dev/null
+++ b/changelog/12559.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+secrets/pki: Use entropy augmentation when available when generating root and intermediate CA key material.
+```
\ No newline at end of file