3 files changed, 13 insertions, 5 deletions

diff --git a/doc/luaossl.pdf b/doc/luaossl.pdf
index e310cbe..c2b2418 100644
--- a/doc/luaossl.pdf
+++ b/doc/luaossl.pdf
diff --git a/doc/luaossl.tex b/doc/luaossl.tex
index c8917d7..b7b8c15 100644
--- a/doc/luaossl.tex
+++ b/doc/luaossl.tex
@@ -487,6 +487,10 @@ Returns the public key component as an \module{openssl.pkey} object.
 
 Sets the public key component referenced by the \module{openssl.pkey} object $key$.
 
+\subsubsection[\fn{x509:getPublicKeyDigest}]{\fn{x509:getPublicKeyDigest([$type$])}}
+
+Returns the digest of the public key as a binary string. $type$ is an optional string describing the digest type, and defaults to ``sha1''.
+
 \subsubsection[\fn{x509:sign}]{\fn{x509:sign($key$ [, $type$])}}
 
 Signs and updates the instance certificate using the \module{openssl.pkey} $key$. $type$ is an optional string describing the digest type. See \module{pkey:sign}, regarding which types of digests are valid. If $type$ is omitted than a default type is used---``sha1'' for RSA keys, ``dss1'' for DSA keys, and ``ecdsa-with-SHA1'' for EC keys.
diff --git a/src/openssl.c b/src/openssl.c
index 8e95622..646e2ae 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -3722,18 +3722,22 @@ static int xc_setPublicKey(lua_State *L) {
 
 
 static int xc_getPublicKeyDigest(lua_State *L) {
-        ASN1_BIT_STRING *pk = ((X509 *) checksimple(L, 1, X509_CERT_CLASS))->cert_info->key->public_key;
-
+        ASN1_BIT_STRING *pk = ((X509 *)checksimple(L, 1, X509_CERT_CLASS))->cert_info->key->public_key;
+        const char *id = luaL_optstring(L, 2, "sha1");
+        const EVP_MD *md;
         unsigned char digest[EVP_MAX_MD_SIZE];
         unsigned int len;
 
-        if (!EVP_Digest(pk->data, pk->length, digest, &len, EVP_sha1(), NULL))
+        if (!(md = EVP_get_digestbyname(id)))
+                return luaL_error(L, "x509.cert:getPublicKeyDigest: %s: invalid digest type", id);
+
+        if (!EVP_Digest(pk->data, pk->length, digest, &len, md, NULL))
                 return auxL_error(L, auxL_EOPENSSL, "x509.cert:getPublicKeyDigest");
 
-        lua_pushlstring(L, (char *) digest, len);
+        lua_pushlstring(L, (char *)digest, len);
 
         return 1;
-} /* xc_setPublicKeyDigest() */
+} /* xc_getPublicKeyDigest() */
 
 
 static const EVP_MD *xc_signature(lua_State *L, int index, EVP_PKEY *key) {