Merge the RSA_ENC and RSA_SIGN certificate slots.

The distinction was not well-enforced in the code. In fact, it wasn't
even possible to use the RSA_SIGN slot because ssl_set_pkey and
ssl_set_cert would always use the RSA_ENC slot.

A follow-up will fold away the mechanism altogether, but this is an easy
initial simplfication.

BUG=486295

Change-Id: I66b5bf3e6dc243dac7c75924c1c1983538e49060
Reviewed-on: https://boringssl-review.googlesource.com/5349
Reviewed-by: Adam Langley <agl@google.com>

ssl/internal.h

@@ -255,10 +255,9 @@ ssl_create_cipher_list(const SSL_PROTOCOL_METHOD *ssl_method,
                        const char *rule_str);
 
 /* SSL_PKEY_* denote certificate types. */
-#define SSL_PKEY_RSA_ENC 0
-#define SSL_PKEY_RSA_SIGN 1
-#define SSL_PKEY_ECC 2
-#define SSL_PKEY_NUM 3
+#define SSL_PKEY_RSA 0
+#define SSL_PKEY_ECC 1
+#define SSL_PKEY_NUM 2
 
 /* ssl_cipher_get_value returns the cipher suite id of |cipher|. */
 uint16_t ssl_cipher_get_value(const SSL_CIPHER *cipher);

ssl/s3_both.c

@@ -505,7 +505,7 @@ int ssl3_cert_verify_hash(SSL *s, uint8_t *out, size_t *out_len,
 int ssl_cert_type(EVP_PKEY *pkey) {
   switch (pkey->type) {
     case EVP_PKEY_RSA:
-      return SSL_PKEY_RSA_ENC;
+      return SSL_PKEY_RSA;
     case EVP_PKEY_EC:
       return SSL_PKEY_ECC;
     default:

ssl/s3_srvr.c

@@ -1692,7 +1692,7 @@ int ssl3_get_client_key_exchange(SSL *s) {
     uint8_t good;
     size_t rsa_size, decrypt_len, premaster_index, j;
 
-    pkey = s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey;
+    pkey = s->cert->pkeys[SSL_PKEY_RSA].privatekey;
     if (pkey == NULL || pkey->type != EVP_PKEY_RSA || pkey->pkey.rsa == NULL) {
       al = SSL_AD_HANDSHAKE_FAILURE;
       OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange,

ssl/ssl_cert.c

@@ -158,7 +158,7 @@ CERT *ssl_cert_new(void) {
   }
   memset(ret, 0, sizeof(CERT));
 
-  ret->key = &ret->pkeys[SSL_PKEY_RSA_ENC];
+  ret->key = &ret->pkeys[SSL_PKEY_RSA];
   return ret;
 }
 

ssl/ssl_cipher.c

@@ -1682,7 +1682,7 @@ int ssl_cipher_get_cert_index(const SSL_CIPHER *cipher) {
   if (alg_a & SSL_aECDSA) {
     return SSL_PKEY_ECC;
   } else if (alg_a & SSL_aRSA) {
-    return SSL_PKEY_RSA_ENC;
+    return SSL_PKEY_RSA;
   }
 
   return -1;

ssl/ssl_lib.c

@@ -1835,7 +1835,7 @@ static int ssl_has_key(SSL *s, size_t idx) {
 void ssl_get_compatible_server_ciphers(SSL *s, uint32_t *out_mask_k,
                                        uint32_t *out_mask_a) {
   CERT *c = s->cert;
-  int rsa_enc, rsa_sign, dh_tmp;
+  int have_rsa_cert, dh_tmp;
   uint32_t mask_k, mask_a;
   int have_ecc_cert, ecdsa_ok;
   X509 *x;
@@ -1849,19 +1849,16 @@ void ssl_get_compatible_server_ciphers(SSL *s, uint32_t *out_mask_k,
 
   dh_tmp = (c->dh_tmp != NULL || c->dh_tmp_cb != NULL);
 
-  rsa_enc = ssl_has_key(s, SSL_PKEY_RSA_ENC);
-  rsa_sign = ssl_has_key(s, SSL_PKEY_RSA_SIGN);
+  have_rsa_cert = ssl_has_key(s, SSL_PKEY_RSA);
   have_ecc_cert = ssl_has_key(s, SSL_PKEY_ECC);
   mask_k = 0;
   mask_a = 0;
 
-  if (rsa_enc) {
-    mask_k |= SSL_kRSA;
-  }
   if (dh_tmp) {
     mask_k |= SSL_kDHE;
   }
-  if (rsa_enc || rsa_sign) {
+  if (have_rsa_cert) {
+    mask_k |= SSL_kRSA;
     mask_a |= SSL_aRSA;
   }
 
@@ -1899,11 +1896,7 @@ void ssl_get_compatible_server_ciphers(SSL *s, uint32_t *out_mask_k,
 }
 
 static int ssl_get_server_cert_index(const SSL *s) {
-  int idx;
-  idx = ssl_cipher_get_cert_index(s->s3->tmp.new_cipher);
-  if (idx == SSL_PKEY_RSA_ENC && !s->cert->pkeys[SSL_PKEY_RSA_ENC].x509) {
-    idx = SSL_PKEY_RSA_SIGN;
-  }
+  int idx = ssl_cipher_get_cert_index(s->s3->tmp.new_cipher);
   if (idx == -1) {
     OPENSSL_PUT_ERROR(SSL, ssl_get_server_cert_index, ERR_R_INTERNAL_ERROR);
   }
@@ -1927,12 +1920,9 @@ EVP_PKEY *ssl_get_sign_pkey(SSL *s, const SSL_CIPHER *cipher) {
   CERT *c = s->cert;
   int idx = -1;
 
-  if (alg_a & SSL_aRSA) {
-    if (c->pkeys[SSL_PKEY_RSA_SIGN].privatekey != NULL) {
-      idx = SSL_PKEY_RSA_SIGN;
-    } else if (c->pkeys[SSL_PKEY_RSA_ENC].privatekey != NULL) {
-      idx = SSL_PKEY_RSA_ENC;
-    }
+  if ((alg_a & SSL_aRSA) &&
+      (c->pkeys[SSL_PKEY_RSA].privatekey != NULL)) {
+    idx = SSL_PKEY_RSA;
   } else if ((alg_a & SSL_aECDSA) &&
              (c->pkeys[SSL_PKEY_ECC].privatekey != NULL)) {
     idx = SSL_PKEY_ECC;