1 files changed, 119 insertions, 1 deletions

diff --git a/src/lib/libcrypto/rsa/rsa_ameth.c b/src/lib/libcrypto/rsa/rsa_ameth.c
index ce3e9b3509..f71cee8ec1 100644
--- a/src/lib/libcrypto/rsa/rsa_ameth.c
+++ b/src/lib/libcrypto/rsa/rsa_ameth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_ameth.c,v 1.19 2018/08/24 20:22:15 tb Exp $ */
+/* $OpenBSD: rsa_ameth.c,v 1.20 2019/10/31 13:56:29 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -433,6 +433,124 @@ rsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
         return 1;
 }
 
+/* Allocate and set algorithm ID from EVP_MD, defaults to SHA1. */
+static int
+rsa_md_to_algor(X509_ALGOR **palg, const EVP_MD *md)
+{
+        if (md == NULL || EVP_MD_type(md) == NID_sha1)
+                return 1;
+        *palg = X509_ALGOR_new();
+        if (*palg == NULL)
+                return 0;
+        X509_ALGOR_set_md(*palg, md);
+        return 1;
+}
+
+/* Allocate and set MGF1 algorithm ID from EVP_MD. */
+static int
+rsa_md_to_mgf1(X509_ALGOR **palg, const EVP_MD *mgf1md)
+{
+        X509_ALGOR *algtmp = NULL;
+        ASN1_STRING *stmp = NULL;
+
+        *palg = NULL;
+        if (mgf1md == NULL || EVP_MD_type(mgf1md) == NID_sha1)
+                return 1;
+        /* need to embed algorithm ID inside another */
+        if (!rsa_md_to_algor(&algtmp, mgf1md))
+                goto err;
+        if (ASN1_item_pack(algtmp, &X509_ALGOR_it, &stmp) == NULL)
+                 goto err;
+        *palg = X509_ALGOR_new();
+        if (*palg == NULL)
+                goto err;
+        X509_ALGOR_set0(*palg, OBJ_nid2obj(NID_mgf1), V_ASN1_SEQUENCE, stmp);
+        stmp = NULL;
+ err:
+        ASN1_STRING_free(stmp);
+        X509_ALGOR_free(algtmp);
+        if (*palg)
+                return 1;
+        return 0;
+}
+
+/* Convert algorithm ID to EVP_MD, defaults to SHA1. */
+static const EVP_MD *
+rsa_algor_to_md(X509_ALGOR *alg)
+{
+        const EVP_MD *md;
+
+        if (!alg)
+                return EVP_sha1();
+        md = EVP_get_digestbyobj(alg->algorithm);
+        if (md == NULL)
+                RSAerror(RSA_R_UNKNOWN_DIGEST);
+        return md;
+}
+
+/* convert algorithm ID to EVP_MD, default SHA1 */
+RSA_PSS_PARAMS *
+rsa_pss_params_create(const EVP_MD *sigmd, const EVP_MD *mgf1md, int saltlen)
+{
+        RSA_PSS_PARAMS *pss = RSA_PSS_PARAMS_new();
+
+        if (pss == NULL)
+                goto err;
+        if (saltlen != 20) {
+                pss->saltLength = ASN1_INTEGER_new();
+                if (pss->saltLength == NULL)
+                        goto err;
+                if (!ASN1_INTEGER_set(pss->saltLength, saltlen))
+                        goto err;
+        }
+        if (!rsa_md_to_algor(&pss->hashAlgorithm, sigmd))
+                goto err;
+        if (mgf1md == NULL)
+                mgf1md = sigmd;
+        if (!rsa_md_to_mgf1(&pss->maskGenAlgorithm, mgf1md))
+                goto err;
+        if (!rsa_md_to_algor(&pss->maskHash, mgf1md))
+                goto err;
+        return pss;
+ err:
+        RSA_PSS_PARAMS_free(pss);
+        return NULL;
+}
+
+int
+rsa_pss_get_param(const RSA_PSS_PARAMS *pss, const EVP_MD **pmd,
+    const EVP_MD **pmgf1md, int *psaltlen)
+{
+        if (pss == NULL)
+                return 0;
+        *pmd = rsa_algor_to_md(pss->hashAlgorithm);
+        if (*pmd == NULL)
+                return 0;
+        *pmgf1md = rsa_algor_to_md(pss->maskHash);
+        if (*pmgf1md == NULL)
+                return 0;
+        if (pss->saltLength) {
+                *psaltlen = ASN1_INTEGER_get(pss->saltLength);
+                if (*psaltlen < 0) {
+                        RSAerror(RSA_R_INVALID_SALT_LENGTH);
+                        return 0;
+                }
+        } else {
+                *psaltlen = 20;
+        }
+
+        /*
+         * low-level routines support only trailer field 0xbc (value 1) and
+         * PKCS#1 says we should reject any other value anyway.
+         */
+        if (pss->trailerField && ASN1_INTEGER_get(pss->trailerField) != 1) {
+                RSAerror(RSA_R_INVALID_TRAILER);
+                return 0;
+        }
+
+        return 1;
+}
+
 /* Customised RSA item verification routine. This is called
  * when a signature is encountered requiring special handling. We
  * currently only handle PSS.