Add |RSA_[padding_add|verify]_PKCS1_PSS to decrepit.

These functions are just like the _mgf1 versions but omit one of the
parameters. It's easier to add them than to patch the callers in some
cases.

Change-Id: Idee5b81374bf15f2ea89b7e0c06400c2badbb275
Reviewed-on: https://boringssl-review.googlesource.com/7362
Reviewed-by: David Benjamin <davidben@google.com>

decrepit/rsa/rsa_decrepit.c

diff --git a/decrepit/rsa/rsa_decrepit.c b/decrepit/rsa/rsa_decrepit.c
index c238f46..a88bc4b 100644
--- a/decrepit/rsa/rsa_decrepit.c
+++ b/decrepit/rsa/rsa_decrepit.c
@@ -84,3 +84,13 @@
   RSA_free(rsa);
   return NULL;
 }
+
+int RSA_padding_add_PKCS1_PSS(RSA *rsa, uint8_t *EM, const uint8_t *mHash,
+                              const EVP_MD *Hash, int sLen) {
+  return RSA_padding_add_PKCS1_PSS_mgf1(rsa, EM, mHash, Hash, NULL, sLen);
+}
+
+int RSA_verify_PKCS1_PSS(RSA *rsa, const uint8_t *mHash, const EVP_MD *Hash,
+                         const uint8_t *EM, int sLen) {
+  return RSA_verify_PKCS1_PSS_mgf1(rsa, mHash, Hash, NULL, EM, sLen);
+}

include/openssl/rsa.h

diff --git a/include/openssl/rsa.h b/include/openssl/rsa.h
index c41523c..3798f48 100644
--- a/include/openssl/rsa.h
+++ b/include/openssl/rsa.h
@@ -466,6 +466,18 @@
  * not, or a negative value on error. */
 OPENSSL_EXPORT int i2d_RSAPrivateKey(const RSA *in, uint8_t **outp);
 
+/* RSA_padding_add_PKCS1_PSS acts like |RSA_padding_add_PKCS1_PSS_mgf1| but the
+ * |mgf1Hash| parameter of the latter is implicitly set to |Hash|. */
+OPENSSL_EXPORT int RSA_padding_add_PKCS1_PSS(RSA *rsa, uint8_t *EM,
+                                             const uint8_t *mHash,
+                                             const EVP_MD *Hash, int sLen);
+
+/* RSA_verify_PKCS1_PSS acts like |RSA_verify_PKCS1_PSS_mgf1| but the
+ * |mgf1Hash| parameter of the latter is implicitly set to |Hash|. */
+OPENSSL_EXPORT int RSA_verify_PKCS1_PSS(RSA *rsa, const uint8_t *mHash,
+                                        const EVP_MD *Hash, const uint8_t *EM,
+                                        int sLen);
+
 
 struct rsa_meth_st {
   struct openssl_method_common_st common;