diff --git a/crypto/evp/algorithm.c b/crypto/evp/algorithm.c
new file mode 100644
index 0000000..4ec111b
--- /dev/null
+++ b/crypto/evp/algorithm.c
@@ -0,0 +1,162 @@
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.] */
+
+#include <openssl/evp.h>
+
+#include <assert.h>
+
+#include <openssl/asn1.h>
+#include <openssl/err.h>
+#include <openssl/obj.h>
+#include <openssl/x509.h>
+
+#include "internal.h"
+
+
+/* These functions use error codes under the ASN1 and X509 namespaces for
+ * compatibility with OpenSSL. */
+
+int EVP_DigestSignAlgorithm(EVP_MD_CTX *ctx, X509_ALGOR *algor) {
+  const EVP_MD *digest;
+  EVP_PKEY *pkey;
+  int sign_nid, paramtype;
+
+  digest = EVP_MD_CTX_md(ctx);
+  pkey = EVP_PKEY_CTX_get0_pkey(ctx->pctx);
+  if (!digest || !pkey) {
+    OPENSSL_PUT_ERROR(EVP, EVP_DigestSignAlgorithm,
+                      EVP_R_CONTEXT_NOT_INITIALISED);
+    return 0;
+  }
+
+  if (pkey->ameth->digest_sign_algorithm) {
+    switch (pkey->ameth->digest_sign_algorithm(ctx, algor)) {
+      case EVP_DIGEST_SIGN_ALGORITHM_ERROR:
+        return 0;
+      case EVP_DIGEST_SIGN_ALGORITHM_SUCCESS:
+        return 1;
+      case EVP_DIGEST_SIGN_ALGORITHM_DEFAULT:
+        /* Use default behavior. */
+        break;
+      default:
+        assert(0);
+    }
+  }
+
+  /* Default behavior: look up the OID for the algorithm/hash pair and encode
+   * that. */
+  if (!OBJ_find_sigid_by_algs(&sign_nid, EVP_MD_type(digest),
+                              pkey->ameth->pkey_id)) {
+    OPENSSL_PUT_ERROR(EVP, EVP_DigestSignAlgorithm,
+                      X509_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED);
+    return 0;
+  }
+
+  if (pkey->ameth->pkey_flags & ASN1_PKEY_SIGPARAM_NULL) {
+    paramtype = V_ASN1_NULL;
+  } else {
+    paramtype = V_ASN1_UNDEF;
+  }
+
+  X509_ALGOR_set0(algor, OBJ_nid2obj(sign_nid), paramtype, NULL);
+  return 1;
+}
+
+int EVP_DigestVerifyInitFromAlgorithm(EVP_MD_CTX *ctx,
+                                      X509_ALGOR *algor,
+                                      EVP_PKEY *pkey) {
+  int digest_nid, pkey_nid;
+  const EVP_PKEY_ASN1_METHOD *ameth;
+  const EVP_MD *digest;
+
+  /* Convert signature OID into digest and public key OIDs */
+  if (!OBJ_find_sigid_algs(OBJ_obj2nid(algor->algorithm), &digest_nid,
+                           &pkey_nid)) {
+    OPENSSL_PUT_ERROR(EVP, EVP_DigestVerifyInitFromAlgorithm,
+                      ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
+    return 0;
+  }
+
+  /* Check public key OID matches public key type */
+  ameth = EVP_PKEY_asn1_find(NULL, pkey_nid);
+  if (ameth == NULL || ameth->pkey_id != pkey->ameth->pkey_id) {
+    OPENSSL_PUT_ERROR(EVP, EVP_DigestVerifyInitFromAlgorithm,
+                      ASN1_R_WRONG_PUBLIC_KEY_TYPE);
+    return 0;
+  }
+
+  /* NID_undef signals that there are custom parameters to set. */
+  if (digest_nid == NID_undef) {
+    if (!pkey->ameth || !pkey->ameth->digest_verify_init_from_algorithm) {
+      OPENSSL_PUT_ERROR(EVP, EVP_DigestVerifyInitFromAlgorithm,
+                        ASN1_R_UNKNOWN_SIGNATURE_ALGORITHM);
+      return 0;
+    }
+
+    return pkey->ameth->digest_verify_init_from_algorithm(ctx, algor, pkey);
+  }
+
+  /* Otherwise, initialize with the digest from the OID. */
+  digest = EVP_get_digestbynid(digest_nid);
+  if (digest == NULL) {
+    OPENSSL_PUT_ERROR(EVP, EVP_DigestVerifyInitFromAlgorithm,
+                      ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);
+    return 0;
+  }
+
+  return EVP_DigestVerifyInit(ctx, NULL, digest, NULL, pkey);
+}
+