openssl/0049-Selectively-disallow-SHA1-signatures.patch

From 4f9167db05cade673f98f1a00efd57136e97b460 Mon Sep 17 00:00:00 2001
From: rpm-build <rpm-build>
Date: Wed, 6 Mar 2024 19:17:15 +0100
Subject: [PATCH 22/49] 0049-Allow-disabling-of-SHA1-signatures.patch

Patch-name: 0049-Allow-disabling-of-SHA1-signatures.patch
Patch-id: 49
Patch-status: |
    # # Selectively disallow SHA1 signatures rhbz#2070977
From-dist-git-commit: 4334bc837fbc64d14890fdc51679a80770d498ce
---
 crypto/context.c                              | 14 ++++
 crypto/evp/evp_cnf.c                          | 13 +++
 crypto/evp/m_sigver.c                         | 79 +++++++++++++++++++
 crypto/evp/pmeth_lib.c                        | 15 ++++
 doc/man5/config.pod                           | 13 +++
 include/crypto/context.h                      |  3 +
 include/internal/cryptlib.h                   |  3 +-
 include/internal/sslconf.h                    |  4 +
 providers/common/securitycheck.c              | 20 +++++
 providers/common/securitycheck_default.c      |  9 ++-
 providers/implementations/signature/dsa_sig.c | 11 ++-
 .../implementations/signature/ecdsa_sig.c     |  4 +
 providers/implementations/signature/rsa_sig.c | 20 ++++-
 ssl/t1_lib.c                                  |  8 ++
 util/libcrypto.num                            |  2 +
 15 files changed, 209 insertions(+), 9 deletions(-)

diff --git a/crypto/context.c b/crypto/context.c
index fb4816d89b..c04920fe14 100644
--- a/crypto/context.c
+++ b/crypto/context.c
@@ -83,6 +83,8 @@ struct ossl_lib_ctx_st {
     void *fips_prov;
 #endif
 
+    void *legacy_digest_signatures;
+
     unsigned int ischild:1;
 };
 
@@ -223,6 +225,10 @@ static int context_init(OSSL_LIB_CTX *ctx)
         goto err;
 #endif
 
+    ctx->legacy_digest_signatures = ossl_ctx_legacy_digest_signatures_new(ctx);
+    if (ctx->legacy_digest_signatures == NULL)
+        goto err;
+
     /* Low priority. */
 #ifndef FIPS_MODULE
     ctx->child_provider = ossl_child_prov_ctx_new(ctx);
@@ -366,6 +372,11 @@ static void context_deinit_objs(OSSL_LIB_CTX *ctx)
     }
 #endif
 
+    if (ctx->legacy_digest_signatures != NULL) {
+        ossl_ctx_legacy_digest_signatures_free(ctx->legacy_digest_signatures);
+        ctx->legacy_digest_signatures = NULL;
+    }
+
     /* Low priority. */
 #ifndef FIPS_MODULE
     if (ctx->child_provider != NULL) {
@@ -663,6 +674,9 @@ void *ossl_lib_ctx_get_data(OSSL_LIB_CTX *ctx, int index)
         return ctx->fips_prov;
 #endif
 
+    case OSSL_LIB_CTX_LEGACY_DIGEST_SIGNATURES_INDEX:
+        return ctx->legacy_digest_signatures;
+
     default:
         return NULL;
     }
diff --git a/crypto/evp/evp_cnf.c b/crypto/evp/evp_cnf.c
index 0e7fe64cf9..b9d3b6d226 100644
--- a/crypto/evp/evp_cnf.c
+++ b/crypto/evp/evp_cnf.c
@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <openssl/crypto.h>
 #include "internal/cryptlib.h"
+#include "internal/sslconf.h"
 #include <openssl/conf.h>
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
@@ -57,6 +58,18 @@ static int alg_module_init(CONF_IMODULE *md, const CONF *cnf)
                 ERR_raise(ERR_LIB_EVP, EVP_R_SET_DEFAULT_PROPERTY_FAILURE);
                 return 0;
             }
+        } else if (strcmp(oval->name, "rh-allow-sha1-signatures") == 0) {
+            int m;
+
+            /* Detailed error already reported. */
+            if (!X509V3_get_value_bool(oval, &m))
+                return 0;
+
+            if (!ossl_ctx_legacy_digest_signatures_allowed_set(
+                    NCONF_get0_libctx((CONF *)cnf), m > 0, 0)) {
+                ERR_raise(ERR_LIB_EVP, EVP_R_SET_DEFAULT_PROPERTY_FAILURE);
+                return 0;
+            }
         } else {
             ERR_raise_data(ERR_LIB_EVP, EVP_R_UNKNOWN_OPTION,
                            "name=%s, value=%s", oval->name, oval->value);
diff --git a/crypto/evp/m_sigver.c b/crypto/evp/m_sigver.c
index 3a979f4bd4..fd3a4b79df 100644
--- a/crypto/evp/m_sigver.c
+++ b/crypto/evp/m_sigver.c
@@ -15,6 +15,73 @@
 #include "internal/provider.h"
 #include "internal/numbers.h"   /* includes SIZE_MAX */
 #include "evp_local.h"
+#include "crypto/context.h"
+
+typedef struct ossl_legacy_digest_signatures_st {
+    int allowed;
+} OSSL_LEGACY_DIGEST_SIGNATURES;
+
+void ossl_ctx_legacy_digest_signatures_free(void *vldsigs)
+{
+    OSSL_LEGACY_DIGEST_SIGNATURES *ldsigs = vldsigs;
+
+    if (ldsigs != NULL) {
+        OPENSSL_free(ldsigs);
+    }
+}
+
+void *ossl_ctx_legacy_digest_signatures_new(OSSL_LIB_CTX *ctx)
+{
+    OSSL_LEGACY_DIGEST_SIGNATURES* ldsigs = OPENSSL_zalloc(sizeof(OSSL_LEGACY_DIGEST_SIGNATURES));
+    /* Warning: This patch differs from the same patch in CentOS and RHEL here,
+     * because the default on Fedora is to allow SHA-1 and support disabling
+     * it, while CentOS/RHEL disable it by default and allow enabling it. */
+    ldsigs->allowed = 0;
+    return ldsigs;
+}
+
+static OSSL_LEGACY_DIGEST_SIGNATURES *ossl_ctx_legacy_digest_signatures(
+        OSSL_LIB_CTX *libctx, int loadconfig)
+{
+#ifndef FIPS_MODULE
+    if (loadconfig && !OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL))
+        return NULL;
+#endif
+
+    return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_LEGACY_DIGEST_SIGNATURES_INDEX);
+}
+
+int ossl_ctx_legacy_digest_signatures_allowed(OSSL_LIB_CTX *libctx, int loadconfig)
+{
+    OSSL_LEGACY_DIGEST_SIGNATURES *ldsigs
+        = ossl_ctx_legacy_digest_signatures(libctx, loadconfig);
+
+ #ifndef FIPS_MODULE
+     if (ossl_safe_getenv("OPENSSL_ENABLE_SHA1_SIGNATURES") != NULL)
+        /* used in tests */
+         return 1;
+ #endif
+
+    /* Warning: This patch differs from the same patch in CentOS and RHEL here,
+     * because the default on Fedora is to allow SHA-1 and support disabling
+     * it, while CentOS/RHEL disable it by default and allow enabling it. */
+    return ldsigs != NULL ? ldsigs->allowed : 0;
+}
+
+int ossl_ctx_legacy_digest_signatures_allowed_set(OSSL_LIB_CTX *libctx, int allow,
+                                                  int loadconfig)
+{
+    OSSL_LEGACY_DIGEST_SIGNATURES *ldsigs
+        = ossl_ctx_legacy_digest_signatures(libctx, loadconfig);
+
+    if (ldsigs == NULL) {
+        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    ldsigs->allowed = allow;
+    return 1;
+}
 
 #ifndef FIPS_MODULE
 
@@ -253,6 +320,18 @@ static int do_sigver_init(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
         }
     }
 
+    if (ctx->reqdigest != NULL
+            && !EVP_PKEY_is_a(locpctx->pkey, SN_hmac)
+            && !EVP_PKEY_is_a(locpctx->pkey, SN_tls1_prf)
+            && !EVP_PKEY_is_a(locpctx->pkey, SN_hkdf)) {
+        int mdnid = EVP_MD_nid(ctx->reqdigest);
+        if (!ossl_ctx_legacy_digest_signatures_allowed(locpctx->libctx, 0)
+                && (mdnid == NID_sha1 || mdnid == NID_md5_sha1)) {
+            ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_DIGEST);
+            goto err;
+        }
+    }
+
     if (ver) {
         if (signature->digest_verify_init == NULL) {
             ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
diff --git a/crypto/evp/pmeth_lib.c b/crypto/evp/pmeth_lib.c
index 268b1617e3..248f655d0f 100644
--- a/crypto/evp/pmeth_lib.c
+++ b/crypto/evp/pmeth_lib.c
@@ -33,6 +33,7 @@
 #include "internal/ffc.h"
 #include "internal/numbers.h"
 #include "internal/provider.h"
+#include "internal/sslconf.h"
 #include "evp_local.h"
 
 #ifndef FIPS_MODULE
@@ -951,6 +952,20 @@ static int evp_pkey_ctx_set_md(EVP_PKEY_CTX *ctx, const EVP_MD *md,
         return -2;
     }
 
+    if (EVP_PKEY_CTX_IS_SIGNATURE_OP(ctx)
+            && md != NULL
+            && ctx->pkey != NULL
+            && !EVP_PKEY_is_a(ctx->pkey, SN_hmac)
+            && !EVP_PKEY_is_a(ctx->pkey, SN_tls1_prf)
+            && !EVP_PKEY_is_a(ctx->pkey, SN_hkdf)) {
+        int mdnid = EVP_MD_nid(md);
+        if ((mdnid == NID_sha1 || mdnid == NID_md5_sha1)
+                && !ossl_ctx_legacy_digest_signatures_allowed(ctx->libctx, 0)) {
+            ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_DIGEST);
+            return -1;
+        }
+    }
+
     if (fallback)
         return EVP_PKEY_CTX_ctrl(ctx, -1, op, ctrl, 0, (void *)(md));
 
diff --git a/doc/man5/config.pod b/doc/man5/config.pod
index bd05736220..ed34ff4b9c 100644
--- a/doc/man5/config.pod
+++ b/doc/man5/config.pod
@@ -304,6 +304,17 @@ Within the algorithm properties section, the following names have meaning:
 The value may be anything that is acceptable as a property query
 string for EVP_set_default_properties().
 
+=item B<rh-allow-sha1-signatures>
+
+The value is a boolean that can be B<yes> or B<no>.  If the value is not set,
+it behaves as if it was set to B<no>.
+
+When set to B<no>, any attempt to create or verify a signature with a SHA1
+digest will fail.  For compatibility with older versions of OpenSSL, set this
+option to B<yes>.  This setting also affects TLS, where signature algorithms
+that use SHA1 as digest will no longer be supported if this option is set to
+B<no>.
+
 =item B<fips_mode> (deprecated)
 
 The value is a boolean that can be B<yes> or B<no>.  If the value is
diff --git a/include/crypto/context.h b/include/crypto/context.h
index 7369a730fb..55b74238c8 100644
--- a/include/crypto/context.h
+++ b/include/crypto/context.h
@@ -46,3 +46,6 @@ void ossl_release_default_drbg_ctx(void);
 #if defined(OPENSSL_THREADS)
 void ossl_threads_ctx_free(void *);
 #endif
+
+void *ossl_ctx_legacy_digest_signatures_new(OSSL_LIB_CTX *);
+void ossl_ctx_legacy_digest_signatures_free(void *);
diff --git a/include/internal/cryptlib.h b/include/internal/cryptlib.h
index 64851fd8ed..8e01a77ddc 100644
--- a/include/internal/cryptlib.h
+++ b/include/internal/cryptlib.h
@@ -117,7 +117,8 @@ typedef struct ossl_ex_data_global_st {
 # define OSSL_LIB_CTX_CHILD_PROVIDER_INDEX          18
 # define OSSL_LIB_CTX_THREAD_INDEX                  19
 # define OSSL_LIB_CTX_DECODER_CACHE_INDEX           20
-# define OSSL_LIB_CTX_MAX_INDEXES                   20
+# define OSSL_LIB_CTX_LEGACY_DIGEST_SIGNATURES_INDEX 21
+# define OSSL_LIB_CTX_MAX_INDEXES                   21
 
 OSSL_LIB_CTX *ossl_lib_ctx_get_concrete(OSSL_LIB_CTX *ctx);
 int ossl_lib_ctx_is_default(OSSL_LIB_CTX *ctx);
diff --git a/include/internal/sslconf.h b/include/internal/sslconf.h
index fd7f7e3331..05464b0655 100644
--- a/include/internal/sslconf.h
+++ b/include/internal/sslconf.h
@@ -18,4 +18,8 @@ int conf_ssl_name_find(const char *name, size_t *idx);
 void conf_ssl_get_cmd(const SSL_CONF_CMD *cmd, size_t idx, char **cmdstr,
                       char **arg);
 
+/* Methods to support disabling all signatures with legacy digests */
+int ossl_ctx_legacy_digest_signatures_allowed(OSSL_LIB_CTX *libctx, int loadconfig);
+int ossl_ctx_legacy_digest_signatures_allowed_set(OSSL_LIB_CTX *libctx, int allow,
+                                                  int loadconfig);
 #endif
diff --git a/providers/common/securitycheck.c b/providers/common/securitycheck.c
index 0d3acdbe56..fe694c4e96 100644
--- a/providers/common/securitycheck.c
+++ b/providers/common/securitycheck.c
@@ -19,6 +19,7 @@
 #include <openssl/core_names.h>
 #include <openssl/obj_mac.h>
 #include "prov/securitycheck.h"
+#include "internal/sslconf.h"
 
 /*
  * FIPS requires a minimum security strength of 112 bits (for encryption or
@@ -243,6 +244,15 @@ int ossl_digest_get_approved_nid_with_sha1(OSSL_LIB_CTX *ctx, const EVP_MD *md,
             mdnid = -1; /* disallowed by security checks */
     }
 # endif /* OPENSSL_NO_FIPS_SECURITYCHECKS */
+
+#ifndef FIPS_MODULE
+    if (!ossl_ctx_legacy_digest_signatures_allowed(ctx, 0))
+        /* SHA1 is globally disabled, check whether we want to locally allow
+         * it. */
+        if (mdnid == NID_sha1 && !sha1_allowed)
+            mdnid = -1;
+#endif
+
     return mdnid;
 }
 
diff --git a/providers/common/securitycheck_default.c b/providers/common/securitycheck_default.c
index 246323493e..2ca7a59f39 100644
--- a/providers/common/securitycheck_default.c
+++ b/providers/common/securitycheck_default.c
@@ -15,6 +15,7 @@
 #include <openssl/obj_mac.h>
 #include "prov/securitycheck.h"
 #include "internal/nelem.h"
+#include "internal/sslconf.h"
 
 /* Disable the security checks in the default provider */
 int ossl_securitycheck_enabled(OSSL_LIB_CTX *libctx)
@@ -29,9 +30,10 @@ int ossl_tls1_prf_ems_check_enabled(OSSL_LIB_CTX *libctx)
 }
 
 int ossl_digest_rsa_sign_get_md_nid(OSSL_LIB_CTX *ctx, const EVP_MD *md,
-                                    ossl_unused int sha1_allowed)
+                                    int sha1_allowed)
 {
     int mdnid;
+    int ldsigs_allowed;
 
     static const OSSL_ITEM name_to_nid[] = {
         { NID_md5,       OSSL_DIGEST_NAME_MD5       },
@@ -42,8 +44,11 @@ int ossl_digest_rsa_sign_get_md_nid(OSSL_LIB_CTX *ctx, const EVP_MD *md,
         { NID_ripemd160, OSSL_DIGEST_NAME_RIPEMD160 },
     };
 
-    mdnid = ossl_digest_get_approved_nid_with_sha1(ctx, md, 1);
+    ldsigs_allowed = ossl_ctx_legacy_digest_signatures_allowed(ctx, 0);
+    mdnid = ossl_digest_get_approved_nid_with_sha1(ctx, md, sha1_allowed || ldsigs_allowed);
     if (mdnid == NID_undef)
         mdnid = ossl_digest_md_to_nid(md, name_to_nid, OSSL_NELEM(name_to_nid));
+    if (mdnid == NID_md5_sha1 && !ldsigs_allowed)
+        mdnid = -1;
     return mdnid;
 }
diff --git a/providers/implementations/signature/dsa_sig.c b/providers/implementations/signature/dsa_sig.c
index b89a0f6836..e0c26a13e4 100644
--- a/providers/implementations/signature/dsa_sig.c
+++ b/providers/implementations/signature/dsa_sig.c
@@ -125,12 +125,17 @@ static int dsa_setup_md(PROV_DSA_CTX *ctx,
         mdprops = ctx->propq;
 
     if (mdname != NULL) {
-        int sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);
         WPACKET pkt;
         EVP_MD *md = EVP_MD_fetch(ctx->libctx, mdname, mdprops);
-        int md_nid = ossl_digest_get_approved_nid_with_sha1(ctx->libctx, md,
-                                                            sha1_allowed);
+        int md_nid;
         size_t mdname_len = strlen(mdname);
+#ifdef FIPS_MODULE
+        int sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);
+#else
+        int sha1_allowed = 0;
+#endif
+        md_nid = ossl_digest_get_approved_nid_with_sha1(ctx->libctx, md,
+                                                            sha1_allowed);
 
         if (md == NULL || md_nid < 0) {
             if (md == NULL)
diff --git a/providers/implementations/signature/ecdsa_sig.c b/providers/implementations/signature/ecdsa_sig.c
index f158105e71..62355b89fe 100644
--- a/providers/implementations/signature/ecdsa_sig.c
+++ b/providers/implementations/signature/ecdsa_sig.c
@@ -247,7 +247,11 @@ static int ecdsa_setup_md(PROV_ECDSA_CTX *ctx, const char *mdname,
                        "%s could not be fetched", mdname);
         return 0;
     }
+#ifdef FIPS_MODULE
     sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);
+#else
+    sha1_allowed = 0;
+#endif
     md_nid = ossl_digest_get_approved_nid_with_sha1(ctx->libctx, md,
                                                     sha1_allowed);
     if (md_nid < 0) {
diff --git a/providers/implementations/signature/rsa_sig.c b/providers/implementations/signature/rsa_sig.c
index c1405f47ea..aeda1a7758 100644
--- a/providers/implementations/signature/rsa_sig.c
+++ b/providers/implementations/signature/rsa_sig.c
@@ -25,6 +25,7 @@
 #include "internal/cryptlib.h"
 #include "internal/nelem.h"
 #include "internal/sizes.h"
+#include "internal/sslconf.h"
 #include "crypto/rsa.h"
 #include "prov/providercommon.h"
 #include "prov/implementations.h"
@@ -33,6 +34,7 @@
 #include "prov/securitycheck.h"
 
 #define RSA_DEFAULT_DIGEST_NAME OSSL_DIGEST_NAME_SHA1
+#define RSA_DEFAULT_DIGEST_NAME_NONLEGACY OSSL_DIGEST_NAME_SHA2_256
 
 OSSL_FUNC_signature_newctx_fn rsa_newctx;
 static OSSL_FUNC_signature_sign_init_fn rsa_sign_init;
@@ -301,10 +303,15 @@ static int rsa_setup_md(PROV_RSA_CTX *ctx, const char *mdname,
 
     if (mdname != NULL) {
         EVP_MD *md = EVP_MD_fetch(ctx->libctx, mdname, mdprops);
+        int md_nid;
+        size_t mdname_len = strlen(mdname);
+#ifdef FIPS_MODULE
         int sha1_allowed = (ctx->operation != EVP_PKEY_OP_SIGN);
-        int md_nid = ossl_digest_rsa_sign_get_md_nid(ctx->libctx, md,
+#else
+        int sha1_allowed = 0;
+#endif
+        md_nid = ossl_digest_rsa_sign_get_md_nid(ctx->libctx, md,
                                                      sha1_allowed);
-        size_t mdname_len = strlen(mdname);
 
         if (md == NULL
             || md_nid <= 0
@@ -1392,8 +1399,15 @@ static int rsa_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
     prsactx->pad_mode = pad_mode;
 
     if (prsactx->md == NULL && pmdname == NULL
-        && pad_mode == RSA_PKCS1_PSS_PADDING)
+        && pad_mode == RSA_PKCS1_PSS_PADDING) {
         pmdname = RSA_DEFAULT_DIGEST_NAME;
+#ifndef FIPS_MODULE
+        if (!ossl_ctx_legacy_digest_signatures_allowed(prsactx->libctx, 0)) {
+            pmdname = RSA_DEFAULT_DIGEST_NAME_NONLEGACY;
+        }
+#endif
+    }
+
 
     if (pmgf1mdname != NULL
         && !rsa_setup_mgf1_md(prsactx, pmgf1mdname, pmgf1mdprops))
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 631e1fdef9..05dd7c5595 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -20,6 +20,7 @@
 #include <openssl/bn.h>
 #include <openssl/provider.h>
 #include <openssl/param_build.h>
+#include "internal/sslconf.h"
 #include "internal/nelem.h"
 #include "internal/sizes.h"
 #include "internal/tlsgroups.h"
@@ -1506,6 +1507,7 @@ int ssl_setup_sigalgs(SSL_CTX *ctx)
     uint16_t *tls12_sigalgs_list = NULL;
     EVP_PKEY *tmpkey = EVP_PKEY_new();
     int ret = 0;
+    int ldsigs_allowed;
 
     if (ctx == NULL)
         goto err;
@@ -1521,6 +1523,7 @@ int ssl_setup_sigalgs(SSL_CTX *ctx)
         goto err;
 
     ERR_set_mark();
+    ldsigs_allowed = ossl_ctx_legacy_digest_signatures_allowed(ctx->libctx, 0);
     /* First fill cache and tls12_sigalgs list from legacy algorithm list */
     for (i = 0, lu = sigalg_lookup_tbl;
          i < OSSL_NELEM(sigalg_lookup_tbl); lu++, i++) {
@@ -1542,6 +1545,11 @@ int ssl_setup_sigalgs(SSL_CTX *ctx)
             cache[i].enabled = 0;
             continue;
         }
+        if ((lu->hash == NID_sha1 || lu->hash == NID_md5_sha1)
+                && !ldsigs_allowed) {
+            cache[i].enabled = 0;
+            continue;
+        }
 
         if (!EVP_PKEY_set_type(tmpkey, lu->sig)) {
             cache[i].enabled = 0;
diff --git a/util/libcrypto.num b/util/libcrypto.num
index ef97803327..8046454025 100644
--- a/util/libcrypto.num
+++ b/util/libcrypto.num
@@ -5536,3 +5536,5 @@ X509_STORE_CTX_set_get_crl              5663	3_2_0	EXIST::FUNCTION:
 X509_STORE_CTX_set_current_reasons      5664	3_2_0	EXIST::FUNCTION:
 OSSL_STORE_delete                       5665	3_2_0	EXIST::FUNCTION:
 BIO_ADDR_copy                           5666	3_2_0	EXIST::FUNCTION:SOCK
+ossl_ctx_legacy_digest_signatures_allowed ?	3_0_1	EXIST::FUNCTION:
+ossl_ctx_legacy_digest_signatures_allowed_set ?	3_0_1	EXIST::FUNCTION:
-- 
2.44.0