Adding upstream version 15.4.upstream/15.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 829 insertions, 0 deletions

diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
new file mode 100644
index 0000000..cf31551
--- /dev/null
+++ b/contrib/pgcrypto/openssl.c
@@ -0,0 +1,829 @@
+/*
+ * openssl.c
+ *		Wrapper for OpenSSL library.
+ *
+ * Copyright (c) 2001 Marko Kreen
+ * All rights reserved.
+ *
+ * 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 above 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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.
+ *
+ * contrib/pgcrypto/openssl.c
+ */
+
+#include "postgres.h"
+
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+#include "px.h"
+#include "utils/memutils.h"
+#include "utils/resowner.h"
+
+/*
+ * Max lengths we might want to handle.
+ */
+#define MAX_KEY		(512/8)
+#define MAX_IV		(128/8)
+
+/*
+ * Hashes
+ */
+
+/*
+ * To make sure we don't leak OpenSSL handles on abort, we keep OSSLDigest
+ * objects in a linked list, allocated in TopMemoryContext. We use the
+ * ResourceOwner mechanism to free them on abort.
+ */
+typedef struct OSSLDigest
+{
+	const EVP_MD *algo;
+	EVP_MD_CTX *ctx;
+
+	ResourceOwner owner;
+	struct OSSLDigest *next;
+	struct OSSLDigest *prev;
+} OSSLDigest;
+
+static OSSLDigest *open_digests = NULL;
+static bool digest_resowner_callback_registered = false;
+
+static void
+free_openssl_digest(OSSLDigest *digest)
+{
+	EVP_MD_CTX_destroy(digest->ctx);
+	if (digest->prev)
+		digest->prev->next = digest->next;
+	else
+		open_digests = digest->next;
+	if (digest->next)
+		digest->next->prev = digest->prev;
+	pfree(digest);
+}
+
+/*
+ * Close any open OpenSSL handles on abort.
+ */
+static void
+digest_free_callback(ResourceReleasePhase phase,
+					 bool isCommit,
+					 bool isTopLevel,
+					 void *arg)
+{
+	OSSLDigest *curr;
+	OSSLDigest *next;
+
+	if (phase != RESOURCE_RELEASE_AFTER_LOCKS)
+		return;
+
+	next = open_digests;
+	while (next)
+	{
+		curr = next;
+		next = curr->next;
+
+		if (curr->owner == CurrentResourceOwner)
+		{
+			if (isCommit)
+				elog(WARNING, "pgcrypto digest reference leak: digest %p still referenced", curr);
+			free_openssl_digest(curr);
+		}
+	}
+}
+
+static unsigned
+digest_result_size(PX_MD *h)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+	int			result = EVP_MD_CTX_size(digest->ctx);
+
+	if (result < 0)
+		elog(ERROR, "EVP_MD_CTX_size() failed");
+
+	return result;
+}
+
+static unsigned
+digest_block_size(PX_MD *h)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+	int			result = EVP_MD_CTX_block_size(digest->ctx);
+
+	if (result < 0)
+		elog(ERROR, "EVP_MD_CTX_block_size() failed");
+
+	return result;
+}
+
+static void
+digest_reset(PX_MD *h)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+
+	if (!EVP_DigestInit_ex(digest->ctx, digest->algo, NULL))
+		elog(ERROR, "EVP_DigestInit_ex() failed");
+}
+
+static void
+digest_update(PX_MD *h, const uint8 *data, unsigned dlen)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+
+	if (!EVP_DigestUpdate(digest->ctx, data, dlen))
+		elog(ERROR, "EVP_DigestUpdate() failed");
+}
+
+static void
+digest_finish(PX_MD *h, uint8 *dst)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+
+	if (!EVP_DigestFinal_ex(digest->ctx, dst, NULL))
+		elog(ERROR, "EVP_DigestFinal_ex() failed");
+}
+
+static void
+digest_free(PX_MD *h)
+{
+	OSSLDigest *digest = (OSSLDigest *) h->p.ptr;
+
+	free_openssl_digest(digest);
+	pfree(h);
+}
+
+static int	px_openssl_initialized = 0;
+
+/* PUBLIC functions */
+
+int
+px_find_digest(const char *name, PX_MD **res)
+{
+	const EVP_MD *md;
+	EVP_MD_CTX *ctx;
+	PX_MD	   *h;
+	OSSLDigest *digest;
+
+	if (!px_openssl_initialized)
+	{
+		px_openssl_initialized = 1;
+		OpenSSL_add_all_algorithms();
+	}
+
+	if (!digest_resowner_callback_registered)
+	{
+		RegisterResourceReleaseCallback(digest_free_callback, NULL);
+		digest_resowner_callback_registered = true;
+	}
+
+	md = EVP_get_digestbyname(name);
+	if (md == NULL)
+		return PXE_NO_HASH;
+
+	/*
+	 * Create an OSSLDigest object, an OpenSSL MD object, and a PX_MD object.
+	 * The order is crucial, to make sure we don't leak anything on
+	 * out-of-memory or other error.
+	 */
+	digest = MemoryContextAlloc(TopMemoryContext, sizeof(*digest));
+
+	ctx = EVP_MD_CTX_create();
+	if (!ctx)
+	{
+		pfree(digest);
+		return PXE_CIPHER_INIT;
+	}
+	if (EVP_DigestInit_ex(ctx, md, NULL) == 0)
+	{
+		EVP_MD_CTX_destroy(ctx);
+		pfree(digest);
+		return PXE_CIPHER_INIT;
+	}
+
+	digest->algo = md;
+	digest->ctx = ctx;
+	digest->owner = CurrentResourceOwner;
+	digest->next = open_digests;
+	digest->prev = NULL;
+	open_digests = digest;
+
+	/* The PX_MD object is allocated in the current memory context. */
+	h = palloc(sizeof(*h));
+	h->result_size = digest_result_size;
+	h->block_size = digest_block_size;
+	h->reset = digest_reset;
+	h->update = digest_update;
+	h->finish = digest_finish;
+	h->free = digest_free;
+	h->p.ptr = (void *) digest;
+
+	*res = h;
+	return 0;
+}
+
+/*
+ * Ciphers
+ *
+ * We use OpenSSL's EVP* family of functions for these.
+ */
+
+/*
+ * prototype for the EVP functions that return an algorithm, e.g.
+ * EVP_aes_128_cbc().
+ */
+typedef const EVP_CIPHER *(*ossl_EVP_cipher_func) (void);
+
+/*
+ * ossl_cipher contains the static information about each cipher.
+ */
+struct ossl_cipher
+{
+	int			(*init) (PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv);
+	ossl_EVP_cipher_func cipher_func;
+	int			block_size;
+	int			max_key_size;
+};
+
+/*
+ * OSSLCipher contains the state for using a cipher. A separate OSSLCipher
+ * object is allocated in each px_find_cipher() call.
+ *
+ * To make sure we don't leak OpenSSL handles on abort, we keep OSSLCipher
+ * objects in a linked list, allocated in TopMemoryContext. We use the
+ * ResourceOwner mechanism to free them on abort.
+ */
+typedef struct OSSLCipher
+{
+	EVP_CIPHER_CTX *evp_ctx;
+	const EVP_CIPHER *evp_ciph;
+	uint8		key[MAX_KEY];
+	uint8		iv[MAX_IV];
+	unsigned	klen;
+	unsigned	init;
+	const struct ossl_cipher *ciph;
+
+	ResourceOwner owner;
+	struct OSSLCipher *next;
+	struct OSSLCipher *prev;
+} OSSLCipher;
+
+static OSSLCipher *open_ciphers = NULL;
+static bool cipher_resowner_callback_registered = false;
+
+static void
+free_openssl_cipher(OSSLCipher *od)
+{
+	EVP_CIPHER_CTX_free(od->evp_ctx);
+	if (od->prev)
+		od->prev->next = od->next;
+	else
+		open_ciphers = od->next;
+	if (od->next)
+		od->next->prev = od->prev;
+	pfree(od);
+}
+
+/*
+ * Close any open OpenSSL cipher handles on abort.
+ */
+static void
+cipher_free_callback(ResourceReleasePhase phase,
+					 bool isCommit,
+					 bool isTopLevel,
+					 void *arg)
+{
+	OSSLCipher *curr;
+	OSSLCipher *next;
+
+	if (phase != RESOURCE_RELEASE_AFTER_LOCKS)
+		return;
+
+	next = open_ciphers;
+	while (next)
+	{
+		curr = next;
+		next = curr->next;
+
+		if (curr->owner == CurrentResourceOwner)
+		{
+			if (isCommit)
+				elog(WARNING, "pgcrypto cipher reference leak: cipher %p still referenced", curr);
+			free_openssl_cipher(curr);
+		}
+	}
+}
+
+/* Common routines for all algorithms */
+
+static unsigned
+gen_ossl_block_size(PX_Cipher *c)
+{
+	OSSLCipher *od = (OSSLCipher *) c->ptr;
+
+	return od->ciph->block_size;
+}
+
+static unsigned
+gen_ossl_key_size(PX_Cipher *c)
+{
+	OSSLCipher *od = (OSSLCipher *) c->ptr;
+
+	return od->ciph->max_key_size;
+}
+
+static unsigned
+gen_ossl_iv_size(PX_Cipher *c)
+{
+	unsigned	ivlen;
+	OSSLCipher *od = (OSSLCipher *) c->ptr;
+
+	ivlen = od->ciph->block_size;
+	return ivlen;
+}
+
+static void
+gen_ossl_free(PX_Cipher *c)
+{
+	OSSLCipher *od = (OSSLCipher *) c->ptr;
+
+	free_openssl_cipher(od);
+	pfree(c);
+}
+
+static int
+gen_ossl_decrypt(PX_Cipher *c, int padding, const uint8 *data, unsigned dlen,
+				 uint8 *res, unsigned *rlen)
+{
+	OSSLCipher *od = c->ptr;
+	int			outlen,
+				outlen2;
+
+	if (!od->init)
+	{
+		if (!EVP_DecryptInit_ex(od->evp_ctx, od->evp_ciph, NULL, NULL, NULL))
+			return PXE_CIPHER_INIT;
+		if (!EVP_CIPHER_CTX_set_padding(od->evp_ctx, padding))
+			return PXE_CIPHER_INIT;
+		if (!EVP_CIPHER_CTX_set_key_length(od->evp_ctx, od->klen))
+			return PXE_CIPHER_INIT;
+		if (!EVP_DecryptInit_ex(od->evp_ctx, NULL, NULL, od->key, od->iv))
+			return PXE_CIPHER_INIT;
+		od->init = true;
+	}
+
+	if (!EVP_DecryptUpdate(od->evp_ctx, res, &outlen, data, dlen))
+		return PXE_DECRYPT_FAILED;
+	if (!EVP_DecryptFinal_ex(od->evp_ctx, res + outlen, &outlen2))
+		return PXE_DECRYPT_FAILED;
+	*rlen = outlen + outlen2;
+
+	return 0;
+}
+
+static int
+gen_ossl_encrypt(PX_Cipher *c, int padding, const uint8 *data, unsigned dlen,
+				 uint8 *res, unsigned *rlen)
+{
+	OSSLCipher *od = c->ptr;
+	int			outlen,
+				outlen2;
+
+	if (!od->init)
+	{
+		if (!EVP_EncryptInit_ex(od->evp_ctx, od->evp_ciph, NULL, NULL, NULL))
+			return PXE_CIPHER_INIT;
+		if (!EVP_CIPHER_CTX_set_padding(od->evp_ctx, padding))
+			return PXE_CIPHER_INIT;
+		if (!EVP_CIPHER_CTX_set_key_length(od->evp_ctx, od->klen))
+			return PXE_CIPHER_INIT;
+		if (!EVP_EncryptInit_ex(od->evp_ctx, NULL, NULL, od->key, od->iv))
+			return PXE_CIPHER_INIT;
+		od->init = true;
+	}
+
+	if (!EVP_EncryptUpdate(od->evp_ctx, res, &outlen, data, dlen))
+		return PXE_ENCRYPT_FAILED;
+	if (!EVP_EncryptFinal_ex(od->evp_ctx, res + outlen, &outlen2))
+		return PXE_ENCRYPT_FAILED;
+	*rlen = outlen + outlen2;
+
+	return 0;
+}
+
+/* Blowfish */
+
+/*
+ * Check if strong crypto is supported. Some OpenSSL installations
+ * support only short keys and unfortunately BF_set_key does not return any
+ * error value. This function tests if is possible to use strong key.
+ */
+static int
+bf_check_supported_key_len(void)
+{
+	static const uint8 key[56] = {
+		0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87, 0x78, 0x69,
+		0x5a, 0x4b, 0x3c, 0x2d, 0x1e, 0x0f, 0x00, 0x11, 0x22, 0x33,
+		0x44, 0x55, 0x66, 0x77, 0x04, 0x68, 0x91, 0x04, 0xc2, 0xfd,
+		0x3b, 0x2f, 0x58, 0x40, 0x23, 0x64, 0x1a, 0xba, 0x61, 0x76,
+		0x1f, 0x1f, 0x1f, 0x1f, 0x0e, 0x0e, 0x0e, 0x0e, 0xff, 0xff,
+		0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+	};
+
+	static const uint8 data[8] = {0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10};
+	static const uint8 res[8] = {0xc0, 0x45, 0x04, 0x01, 0x2e, 0x4e, 0x1f, 0x53};
+	uint8		out[8];
+	EVP_CIPHER_CTX *evp_ctx;
+	int			outlen;
+	int			status = 0;
+
+	/* encrypt with 448bits key and verify output */
+	evp_ctx = EVP_CIPHER_CTX_new();
+	if (!evp_ctx)
+		return 0;
+	if (!EVP_EncryptInit_ex(evp_ctx, EVP_bf_ecb(), NULL, NULL, NULL))
+		goto leave;
+	if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, 56))
+		goto leave;
+	if (!EVP_EncryptInit_ex(evp_ctx, NULL, NULL, key, NULL))
+		goto leave;
+
+	if (!EVP_EncryptUpdate(evp_ctx, out, &outlen, data, 8))
+		goto leave;
+
+	if (memcmp(out, res, 8) != 0)
+		goto leave;				/* Output does not match -> strong cipher is
+								 * not supported */
+	status = 1;
+
+leave:
+	EVP_CIPHER_CTX_free(evp_ctx);
+	return status;
+}
+
+static int
+bf_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	unsigned	bs = gen_ossl_block_size(c);
+	static int	bf_is_strong = -1;
+
+	/*
+	 * Test if key len is supported. BF_set_key silently cut large keys and it
+	 * could be a problem when user transfer crypted data from one server to
+	 * another.
+	 */
+
+	if (bf_is_strong == -1)
+		bf_is_strong = bf_check_supported_key_len();
+
+	if (!bf_is_strong && klen > 16)
+		return PXE_KEY_TOO_BIG;
+
+	/* Key len is supported. We can use it. */
+	od->klen = klen;
+	memcpy(od->key, key, klen);
+
+	if (iv)
+		memcpy(od->iv, iv, bs);
+	else
+		memset(od->iv, 0, bs);
+	return 0;
+}
+
+/* DES */
+
+static int
+ossl_des_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	unsigned	bs = gen_ossl_block_size(c);
+
+	od->klen = 8;
+	memset(od->key, 0, 8);
+	memcpy(od->key, key, klen > 8 ? 8 : klen);
+
+	if (iv)
+		memcpy(od->iv, iv, bs);
+	else
+		memset(od->iv, 0, bs);
+	return 0;
+}
+
+/* DES3 */
+
+static int
+ossl_des3_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	unsigned	bs = gen_ossl_block_size(c);
+
+	od->klen = 24;
+	memset(od->key, 0, 24);
+	memcpy(od->key, key, klen > 24 ? 24 : klen);
+
+	if (iv)
+		memcpy(od->iv, iv, bs);
+	else
+		memset(od->iv, 0, bs);
+	return 0;
+}
+
+/* CAST5 */
+
+static int
+ossl_cast_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	unsigned	bs = gen_ossl_block_size(c);
+
+	od->klen = klen;
+	memcpy(od->key, key, klen);
+
+	if (iv)
+		memcpy(od->iv, iv, bs);
+	else
+		memset(od->iv, 0, bs);
+	return 0;
+}
+
+/* AES */
+
+static int
+ossl_aes_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	unsigned	bs = gen_ossl_block_size(c);
+
+	if (klen <= 128 / 8)
+		od->klen = 128 / 8;
+	else if (klen <= 192 / 8)
+		od->klen = 192 / 8;
+	else if (klen <= 256 / 8)
+		od->klen = 256 / 8;
+	else
+		return PXE_KEY_TOO_BIG;
+
+	memcpy(od->key, key, klen);
+
+	if (iv)
+		memcpy(od->iv, iv, bs);
+	else
+		memset(od->iv, 0, bs);
+
+	return 0;
+}
+
+static int
+ossl_aes_ecb_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	int			err;
+
+	err = ossl_aes_init(c, key, klen, iv);
+	if (err)
+		return err;
+
+	switch (od->klen)
+	{
+		case 128 / 8:
+			od->evp_ciph = EVP_aes_128_ecb();
+			break;
+		case 192 / 8:
+			od->evp_ciph = EVP_aes_192_ecb();
+			break;
+		case 256 / 8:
+			od->evp_ciph = EVP_aes_256_ecb();
+			break;
+		default:
+			/* shouldn't happen */
+			err = PXE_CIPHER_INIT;
+			break;
+	}
+
+	return err;
+}
+
+static int
+ossl_aes_cbc_init(PX_Cipher *c, const uint8 *key, unsigned klen, const uint8 *iv)
+{
+	OSSLCipher *od = c->ptr;
+	int			err;
+
+	err = ossl_aes_init(c, key, klen, iv);
+	if (err)
+		return err;
+
+	switch (od->klen)
+	{
+		case 128 / 8:
+			od->evp_ciph = EVP_aes_128_cbc();
+			break;
+		case 192 / 8:
+			od->evp_ciph = EVP_aes_192_cbc();
+			break;
+		case 256 / 8:
+			od->evp_ciph = EVP_aes_256_cbc();
+			break;
+		default:
+			/* shouldn't happen */
+			err = PXE_CIPHER_INIT;
+			break;
+	}
+
+	return err;
+}
+
+/*
+ * aliases
+ */
+
+static PX_Alias ossl_aliases[] = {
+	{"bf", "bf-cbc"},
+	{"blowfish", "bf-cbc"},
+	{"blowfish-cbc", "bf-cbc"},
+	{"blowfish-ecb", "bf-ecb"},
+	{"blowfish-cfb", "bf-cfb"},
+	{"des", "des-cbc"},
+	{"3des", "des3-cbc"},
+	{"3des-ecb", "des3-ecb"},
+	{"3des-cbc", "des3-cbc"},
+	{"cast5", "cast5-cbc"},
+	{"aes", "aes-cbc"},
+	{"rijndael", "aes-cbc"},
+	{"rijndael-cbc", "aes-cbc"},
+	{"rijndael-ecb", "aes-ecb"},
+	{NULL}
+};
+
+static const struct ossl_cipher ossl_bf_cbc = {
+	bf_init,
+	EVP_bf_cbc,
+	64 / 8, 448 / 8
+};
+
+static const struct ossl_cipher ossl_bf_ecb = {
+	bf_init,
+	EVP_bf_ecb,
+	64 / 8, 448 / 8
+};
+
+static const struct ossl_cipher ossl_bf_cfb = {
+	bf_init,
+	EVP_bf_cfb,
+	64 / 8, 448 / 8
+};
+
+static const struct ossl_cipher ossl_des_ecb = {
+	ossl_des_init,
+	EVP_des_ecb,
+	64 / 8, 64 / 8
+};
+
+static const struct ossl_cipher ossl_des_cbc = {
+	ossl_des_init,
+	EVP_des_cbc,
+	64 / 8, 64 / 8
+};
+
+static const struct ossl_cipher ossl_des3_ecb = {
+	ossl_des3_init,
+	EVP_des_ede3_ecb,
+	64 / 8, 192 / 8
+};
+
+static const struct ossl_cipher ossl_des3_cbc = {
+	ossl_des3_init,
+	EVP_des_ede3_cbc,
+	64 / 8, 192 / 8
+};
+
+static const struct ossl_cipher ossl_cast_ecb = {
+	ossl_cast_init,
+	EVP_cast5_ecb,
+	64 / 8, 128 / 8
+};
+
+static const struct ossl_cipher ossl_cast_cbc = {
+	ossl_cast_init,
+	EVP_cast5_cbc,
+	64 / 8, 128 / 8
+};
+
+static const struct ossl_cipher ossl_aes_ecb = {
+	ossl_aes_ecb_init,
+	NULL,						/* EVP_aes_XXX_ecb(), determined in init
+								 * function */
+	128 / 8, 256 / 8
+};
+
+static const struct ossl_cipher ossl_aes_cbc = {
+	ossl_aes_cbc_init,
+	NULL,						/* EVP_aes_XXX_cbc(), determined in init
+								 * function */
+	128 / 8, 256 / 8
+};
+
+/*
+ * Special handlers
+ */
+struct ossl_cipher_lookup
+{
+	const char *name;
+	const struct ossl_cipher *ciph;
+};
+
+static const struct ossl_cipher_lookup ossl_cipher_types[] = {
+	{"bf-cbc", &ossl_bf_cbc},
+	{"bf-ecb", &ossl_bf_ecb},
+	{"bf-cfb", &ossl_bf_cfb},
+	{"des-ecb", &ossl_des_ecb},
+	{"des-cbc", &ossl_des_cbc},
+	{"des3-ecb", &ossl_des3_ecb},
+	{"des3-cbc", &ossl_des3_cbc},
+	{"cast5-ecb", &ossl_cast_ecb},
+	{"cast5-cbc", &ossl_cast_cbc},
+	{"aes-ecb", &ossl_aes_ecb},
+	{"aes-cbc", &ossl_aes_cbc},
+	{NULL}
+};
+
+/* PUBLIC functions */
+
+int
+px_find_cipher(const char *name, PX_Cipher **res)
+{
+	const struct ossl_cipher_lookup *i;
+	PX_Cipher  *c = NULL;
+	EVP_CIPHER_CTX *ctx;
+	OSSLCipher *od;
+
+	name = px_resolve_alias(ossl_aliases, name);
+	for (i = ossl_cipher_types; i->name; i++)
+		if (strcmp(i->name, name) == 0)
+			break;
+	if (i->name == NULL)
+		return PXE_NO_CIPHER;
+
+	if (!cipher_resowner_callback_registered)
+	{
+		RegisterResourceReleaseCallback(cipher_free_callback, NULL);
+		cipher_resowner_callback_registered = true;
+	}
+
+	/*
+	 * Create an OSSLCipher object, an EVP_CIPHER_CTX object and a PX_Cipher.
+	 * The order is crucial, to make sure we don't leak anything on
+	 * out-of-memory or other error.
+	 */
+	od = MemoryContextAllocZero(TopMemoryContext, sizeof(*od));
+	od->ciph = i->ciph;
+
+	/* Allocate an EVP_CIPHER_CTX object. */
+	ctx = EVP_CIPHER_CTX_new();
+	if (!ctx)
+	{
+		pfree(od);
+		return PXE_CIPHER_INIT;
+	}
+
+	od->evp_ctx = ctx;
+	od->owner = CurrentResourceOwner;
+	od->next = open_ciphers;
+	od->prev = NULL;
+	open_ciphers = od;
+
+	if (i->ciph->cipher_func)
+		od->evp_ciph = i->ciph->cipher_func();
+
+	/* The PX_Cipher is allocated in current memory context */
+	c = palloc(sizeof(*c));
+	c->block_size = gen_ossl_block_size;
+	c->key_size = gen_ossl_key_size;
+	c->iv_size = gen_ossl_iv_size;
+	c->free = gen_ossl_free;
+	c->init = od->ciph->init;
+	c->encrypt = gen_ossl_encrypt;
+	c->decrypt = gen_ossl_decrypt;
+	c->ptr = od;
+
+	*res = c;
+	return 0;
+}