Allow provider sigalgs in SignatureAlgorithms conf

Though support for provider-based signature algorithms was added in
ee58915 this functionality did not work with the SignatureAlgorithms
configuration command. If SignatureAlgorithms is set then the provider
sigalgs are not used and instead it used the default value.

This PR adds a check against the provider-base sigalg list when parsing
the SignatureAlgorithms value.

Based-on-patch-by: Martin Schmatz <mrt@zurich.ibm.com>
Fixes #22761

Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from #22779)

(cherry picked from commit 4169d58)

ssl/s3_lib.c

@@ -3685,13 +3685,13 @@ long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
         return tls1_set_sigalgs(sc->cert, parg, larg, 0);
 
     case SSL_CTRL_SET_SIGALGS_LIST:
-        return tls1_set_sigalgs_list(sc->cert, parg, 0);
+        return tls1_set_sigalgs_list(s->ctx, sc->cert, parg, 0);
 
     case SSL_CTRL_SET_CLIENT_SIGALGS:
         return tls1_set_sigalgs(sc->cert, parg, larg, 1);
 
     case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
-        return tls1_set_sigalgs_list(sc->cert, parg, 1);
+        return tls1_set_sigalgs_list(s->ctx, sc->cert, parg, 1);
 
     case SSL_CTRL_GET_CLIENT_CERT_TYPES:
         {
@@ -3968,13 +3968,13 @@ long ssl3_ctx_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg)
         return tls1_set_sigalgs(ctx->cert, parg, larg, 0);
 
     case SSL_CTRL_SET_SIGALGS_LIST:
-        return tls1_set_sigalgs_list(ctx->cert, parg, 0);
+        return tls1_set_sigalgs_list(ctx, ctx->cert, parg, 0);
 
     case SSL_CTRL_SET_CLIENT_SIGALGS:
         return tls1_set_sigalgs(ctx->cert, parg, larg, 1);
 
     case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
-        return tls1_set_sigalgs_list(ctx->cert, parg, 1);
+        return tls1_set_sigalgs_list(ctx, ctx->cert, parg, 1);
 
     case SSL_CTRL_SET_CLIENT_CERT_TYPES:
         return ssl3_set_req_cert_type(ctx->cert, parg, larg);

ssl/ssl_lib.c

@@ -3061,7 +3061,7 @@ long SSL_CTX_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg)
             return tls1_set_groups_list(ctx, NULL, NULL, parg);
         case SSL_CTRL_SET_SIGALGS_LIST:
         case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
-            return tls1_set_sigalgs_list(NULL, parg, 0);
+            return tls1_set_sigalgs_list(ctx, NULL, parg, 0);
         default:
             return 0;
         }

ssl/ssl_local.h

@@ -2801,7 +2801,7 @@ __owur int tls_use_ticket(SSL_CONNECTION *s);
 
 void ssl_set_sig_mask(uint32_t *pmask_a, SSL_CONNECTION *s, int op);
 
-__owur int tls1_set_sigalgs_list(CERT *c, const char *str, int client);
+__owur int tls1_set_sigalgs_list(SSL_CTX *ctx, CERT *c, const char *str, int client);
 __owur int tls1_set_raw_sigalgs(CERT *c, const uint16_t *psigs, size_t salglen,
                                 int client);
 __owur int tls1_set_sigalgs(CERT *c, const int *salg, size_t salglen,

ssl/t1_lib.c

@@ -714,6 +714,7 @@ int ssl_load_sigalgs(SSL_CTX *ctx)
 
     /* now populate ctx->ssl_cert_info */
     if (ctx->sigalg_list_len > 0) {
+        OPENSSL_free(ctx->ssl_cert_info);
         ctx->ssl_cert_info = OPENSSL_zalloc(sizeof(lu) * ctx->sigalg_list_len);
         if (ctx->ssl_cert_info == NULL)
             return 0;
@@ -2854,6 +2855,7 @@ typedef struct {
     size_t sigalgcnt;
     /* TLSEXT_SIGALG_XXX values */
     uint16_t sigalgs[TLS_MAX_SIGALGCNT];
+    SSL_CTX *ctx;
 } sig_cb_st;
 
 static void get_sigorhash(int *psig, int *phash, const char *str)
@@ -2878,7 +2880,7 @@ static void get_sigorhash(int *psig, int *phash, const char *str)
 static int sig_cb(const char *elem, int len, void *arg)
 {
     sig_cb_st *sarg = arg;
-    size_t i;
+    size_t i = 0;
     const SIGALG_LOOKUP *s;
     char etmp[TLS_MAX_SIGSTRING_LEN], *p;
     int sig_alg = NID_undef, hash_alg = NID_undef;
@@ -2908,16 +2910,32 @@ static int sig_cb(const char *elem, int len, void *arg)
      * in the table.
      */
     if (p == NULL) {
-        for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
-             i++, s++) {
-            if (s->name != NULL && strcmp(etmp, s->name) == 0) {
-                sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
-                break;
+        /* Load provider sigalgs */
+        if (sarg->ctx != NULL) {
+            /* Check if a provider supports the sigalg */
+            for (i = 0; i < sarg->ctx->sigalg_list_len; i++) {
+                if (sarg->ctx->sigalg_list[i].sigalg_name != NULL
+                    && strcmp(etmp,
+                              sarg->ctx->sigalg_list[i].sigalg_name) == 0) {
+                    sarg->sigalgs[sarg->sigalgcnt++] =
+                        sarg->ctx->sigalg_list[i].code_point;
+                    break;
+                }
             }
         }
-        if (i == OSSL_NELEM(sigalg_lookup_tbl)) {
-            /* Ignore unknown algorithms if ignore_unknown */
-            return ignore_unknown;
+        /* Check the built-in sigalgs */
+        if (sarg->ctx == NULL || i == sarg->ctx->sigalg_list_len) {
+            for (i = 0, s = sigalg_lookup_tbl;
+                 i < OSSL_NELEM(sigalg_lookup_tbl); i++, s++) {
+                if (s->name != NULL && strcmp(etmp, s->name) == 0) {
+                    sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
+                    break;
+                }
+            }
+            if (i == OSSL_NELEM(sigalg_lookup_tbl)) {
+                /* Ignore unknown algorithms if ignore_unknown */
+                return ignore_unknown;
+            }
         }
     } else {
         *p = 0;
@@ -2957,10 +2975,14 @@ static int sig_cb(const char *elem, int len, void *arg)
  * Set supported signature algorithms based on a colon separated list of the
  * form sig+hash e.g. RSA+SHA512:DSA+SHA512
  */
-int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
+int tls1_set_sigalgs_list(SSL_CTX *ctx, CERT *c, const char *str, int client)
 {
     sig_cb_st sig;
     sig.sigalgcnt = 0;
+
+    if (ctx != NULL && ssl_load_sigalgs(ctx)) {
+        sig.ctx = ctx;
+    }
     if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
         return 0;
     if (sig.sigalgcnt == 0) {