diff --git a/src/include/openssl/pkcs7.h b/src/include/openssl/pkcs7.h
index 6e5e433..eaba29e 100644
--- a/src/include/openssl/pkcs7.h
+++ b/src/include/openssl/pkcs7.h
@@ -12,5 +12,71 @@
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
 
-/* This header is provided in order to make compiling against code that expects
-   OpenSSL easier. */
+#ifndef OPENSSL_HEADER_PKCS7_H
+#define OPENSSL_HEADER_PKCS7_H
+
+#include <openssl/base.h>
+
+#include <openssl/stack.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+/* PKCS#7.
+ *
+ * This library contains functions for extracting information from PKCS#7
+ * structures (RFC 2315). */
+
+DECLARE_STACK_OF(CRYPTO_BUFFER)
+DECLARE_STACK_OF(X509)
+DECLARE_STACK_OF(X509_CRL)
+
+/* PKCS7_get_raw_certificates parses a PKCS#7, SignedData structure from |cbs|
+ * and appends the included certificates to |out_certs|. It returns one on
+ * success and zero on error. */
+OPENSSL_EXPORT int PKCS7_get_raw_certificates(
+    STACK_OF(CRYPTO_BUFFER) *out_certs, CBS *cbs, CRYPTO_BUFFER_POOL *pool);
+
+/* PKCS7_get_certificates behaves like |PKCS7_get_raw_certificates| but parses
+ * them into |X509| objects. */
+OPENSSL_EXPORT int PKCS7_get_certificates(STACK_OF(X509) *out_certs, CBS *cbs);
+
+/* PKCS7_bundle_certificates appends a PKCS#7, SignedData structure containing
+ * |certs| to |out|. It returns one on success and zero on error. */
+OPENSSL_EXPORT int PKCS7_bundle_certificates(
+    CBB *out, const STACK_OF(X509) *certs);
+
+/* PKCS7_get_CRLs parses a PKCS#7, SignedData structure from |cbs| and appends
+ * the included CRLs to |out_crls|. It returns one on success and zero on
+ * error. */
+OPENSSL_EXPORT int PKCS7_get_CRLs(STACK_OF(X509_CRL) *out_crls, CBS *cbs);
+
+/* PKCS7_bundle_CRLs appends a PKCS#7, SignedData structure containing
+ * |crls| to |out|. It returns one on success and zero on error. */
+OPENSSL_EXPORT int PKCS7_bundle_CRLs(CBB *out, const STACK_OF(X509_CRL) *crls);
+
+/* PKCS7_get_PEM_certificates reads a PEM-encoded, PKCS#7, SignedData structure
+ * from |pem_bio| and appends the included certificates to |out_certs|. It
+ * returns one on success and zero on error. */
+OPENSSL_EXPORT int PKCS7_get_PEM_certificates(STACK_OF(X509) *out_certs,
+                                              BIO *pem_bio);
+
+/* PKCS7_get_PEM_CRLs reads a PEM-encoded, PKCS#7, SignedData structure from
+ * |pem_bio| and appends the included CRLs to |out_crls|. It returns one on
+ * success and zero on error. */
+OPENSSL_EXPORT int PKCS7_get_PEM_CRLs(STACK_OF(X509_CRL) *out_crls,
+                                      BIO *pem_bio);
+
+
+#if defined(__cplusplus)
+}  /* extern C */
+#endif
+
+#define PKCS7_R_BAD_PKCS7_VERSION 100
+#define PKCS7_R_NOT_PKCS7_SIGNED_DATA 101
+#define PKCS7_R_NO_CERTIFICATES_INCLUDED 102
+#define PKCS7_R_NO_CRLS_INCLUDED 103
+
+#endif  /* OPENSSL_HEADER_PKCS7_H */