diff -Nurd -x'*~' serf-0.7.2.orig/buckets/ssl_buckets.c serf-0.7.2/buckets/ssl_buckets.c
--- serf-0.7.2.orig/buckets/ssl_buckets.c	2011-01-22 09:00:48.000000000 -0500
+++ serf-0.7.2/buckets/ssl_buckets.c	2020-01-01 22:29:04.000000000 -0500
@@ -58,6 +58,9 @@
                (patch) <= APR_PATCH_VERSION))
 #endif /* APR_VERSION_AT_LEAST */
 
+#if defined(OPENSSL_VERSION_NUMBER) && OPENSSL_VERSION_NUMBER >= 0x10100000L
+#define USE_OPENSSL_1_1_API
+#endif
 /*#define SSL_VERBOSE*/
 
 /*
@@ -145,6 +148,7 @@
     SSL_CTX *ctx;
     SSL *ssl;
     BIO *bio;
+    BIO_METHOD *biom;
 
     serf_ssl_stream_t encrypt;
     serf_ssl_stream_t decrypt;
@@ -189,10 +193,28 @@
     int depth;
 };
 
+static void bio_set_data(BIO *bio, void *data)
+{
+#ifdef USE_OPENSSL_1_1_API
+    BIO_set_data(bio, data);
+#else
+    bio->ptr = data;
+#endif
+}
+
+static void *bio_get_data(BIO *bio)
+{
+#ifdef USE_OPENSSL_1_1_API
+    return BIO_get_data(bio);
+#else
+    return bio->ptr;
+#endif
+}
+
 /* Returns the amount read. */
 static int bio_bucket_read(BIO *bio, char *in, int inlen)
 {
-    serf_ssl_context_t *ctx = bio->ptr;
+    serf_ssl_context_t *ctx = bio_get_data(bio);
     const char *data;
     apr_status_t status;
     apr_size_t len;
@@ -228,7 +250,7 @@
 /* Returns the amount written. */
 static int bio_bucket_write(BIO *bio, const char *in, int inl)
 {
-    serf_ssl_context_t *ctx = bio->ptr;
+    serf_ssl_context_t *ctx = bio_get_data(bio);
     serf_bucket_t *tmp;
 
 #ifdef SSL_VERBOSE
@@ -247,7 +269,7 @@
 /* Returns the amount read. */
 static int bio_file_read(BIO *bio, char *in, int inlen)
 {
-    apr_file_t *file = bio->ptr;
+    apr_file_t *file = bio_get_data(bio);
     apr_status_t status;
     apr_size_t len;
 
@@ -272,7 +294,7 @@
 /* Returns the amount written. */
 static int bio_file_write(BIO *bio, const char *in, int inl)
 {
-    apr_file_t *file = bio->ptr;
+    apr_file_t *file = bio_get_data(bio);
     apr_size_t nbytes;
 
     BIO_clear_retry_flags(bio);
@@ -290,10 +312,16 @@
 
 static int bio_bucket_create(BIO *bio)
 {
+#ifdef USE_OPENSSL_1_1_API
+    BIO_set_shutdown(bio, 1);
+    BIO_set_init(bio, 1);
+    BIO_set_data(bio, NULL);
+#else
     bio->shutdown = 1;
     bio->init = 1;
     bio->num = -1;
     bio->ptr = NULL;
+#endif
 
     return 1;
 }
@@ -327,6 +355,7 @@
     return ret;
 }
 
+#ifndef USE_OPENSSL_1_1_API
 static BIO_METHOD bio_bucket_method = {
     BIO_TYPE_MEM,
     "Serf SSL encryption and decryption buckets",
@@ -356,6 +385,53 @@
     NULL /* sslc does not have the callback_ctrl field */
 #endif
 };
+#endif
+static BIO_METHOD *bio_meth_bucket_new(void)
+{
+    BIO_METHOD *biom = NULL;
+
+#ifdef USE_OPENSSL_1_1_API
+    biom = BIO_meth_new(BIO_TYPE_MEM,
+                        "Serf SSL encryption and decryption buckets");
+    if (biom) {
+        BIO_meth_set_write(biom, bio_bucket_write);
+        BIO_meth_set_read(biom, bio_bucket_read);
+        BIO_meth_set_ctrl(biom, bio_bucket_ctrl);
+        BIO_meth_set_create(biom, bio_bucket_create);
+        BIO_meth_set_destroy(biom, bio_bucket_destroy);
+    }
+#else
+    biom = &bio_bucket_method;
+#endif
+
+    return biom;
+}
+static BIO_METHOD *bio_meth_file_new(void)
+{
+    BIO_METHOD *biom = NULL;
+
+#ifdef USE_OPENSSL_1_1_API
+    biom = BIO_meth_new(BIO_TYPE_FILE,
+                        "Wrapper around APR file structures");
+    BIO_meth_set_write(biom, bio_file_write);
+    BIO_meth_set_read(biom, bio_file_read);
+    BIO_meth_set_gets(biom, bio_file_gets);
+    BIO_meth_set_ctrl(biom, bio_bucket_ctrl);
+    BIO_meth_set_create(biom, bio_bucket_create);
+    BIO_meth_set_destroy(biom, bio_bucket_destroy);
+#else
+    biom = &bio_file_method;
+#endif
+
+    return biom;
+}
+
+static void bio_meth_free(BIO_METHOD *biom)
+{
+#ifdef USE_OPENSSL_1_1_API
+    BIO_meth_free(biom);
+#endif
+}
 
 static int
 validate_server_certificate(int cert_valid, X509_STORE_CTX *store_ctx)
@@ -693,16 +769,20 @@
 #endif
 
     if (!val) {
-#if APR_HAS_THREADS
+#if APR_HAS_THREADS && !defined(USE_OPENSSL_1_1_API)
         int i, numlocks;
 #endif
+#ifdef USE_OPENSSL_1_1_API
+        OPENSSL_malloc_init();
+#else
         CRYPTO_malloc_init();
+#endif
         ERR_load_crypto_strings();
         SSL_load_error_strings();
         SSL_library_init();
         OpenSSL_add_all_algorithms();
 
-#if APR_HAS_THREADS
+#if APR_HAS_THREADS && !defined(USE_OPENSSL_1_1_API)
         numlocks = CRYPTO_num_locks();
         apr_pool_create(&ssl_pool, NULL);
         ssl_locks = apr_palloc(ssl_pool, sizeof(apr_thread_mutex_t*)*numlocks);
@@ -742,6 +822,7 @@
         const char *cert_path;
         apr_file_t *cert_file;
         BIO *bio;
+        BIO_METHOD *biom;
         PKCS12 *p12;
         int i;
         int retrying_success = 0;
@@ -756,7 +837,7 @@
         }
 
         if (status || !cert_path) {
-          break;
+            break;
         }
 
         /* Load the x.509 cert file stored in PKCS12 */
@@ -767,8 +848,9 @@
             continue;
         }
 
-        bio = BIO_new(&bio_file_method);
-        bio->ptr = cert_file;
+        biom = bio_meth_file_new();
+        bio = BIO_new(biom);
+        bio_set_data(bio, cert_file);
 
         ctx->cert_path = cert_path;
         p12 = d2i_PKCS12_bio(bio, NULL);
@@ -778,6 +860,7 @@
 
         if (i == 1) {
             PKCS12_free(p12);
+            bio_meth_free(biom);
             ctx->cached_cert = *cert;
             ctx->cached_cert_pw = *pkey;
             if (!retrying_success && ctx->cert_cache_pool) {
@@ -813,6 +896,7 @@
                         i = PKCS12_parse(p12, password, pkey, cert, NULL);
                         if (i == 1) {
                             PKCS12_free(p12);
+                            bio_meth_free(biom);
                             ctx->cached_cert = *cert;
                             ctx->cached_cert_pw = *pkey;
                             if (!retrying_success && ctx->cert_cache_pool) {
@@ -840,6 +924,7 @@
                     }
                 }
                 PKCS12_free(p12);
+                bio_meth_free(biom);
                 return 0;
             }
             else {
@@ -847,6 +932,7 @@
                        ERR_GET_FUNC(err),
                        ERR_GET_REASON(err));
                 PKCS12_free(p12);
+                bio_meth_free(biom);
             }
         }
     }
@@ -925,8 +1011,9 @@
     SSL_CTX_set_options(ssl_ctx->ctx, SSL_OP_ALL);
 
     ssl_ctx->ssl = SSL_new(ssl_ctx->ctx);
-    ssl_ctx->bio = BIO_new(&bio_bucket_method);
-    ssl_ctx->bio->ptr = ssl_ctx;
+    ssl_ctx->biom = bio_meth_bucket_new();
+    ssl_ctx->bio = BIO_new(ssl_ctx->biom);
+    bio_set_data(ssl_ctx->bio, ssl_ctx);
 
     SSL_set_bio(ssl_ctx->ssl, ssl_ctx->bio, ssl_ctx->bio);
 
@@ -955,7 +1042,6 @@
 static apr_status_t ssl_free_context(
     serf_ssl_context_t *ssl_ctx)
 {
-    apr_pool_t *p;
 
     /* If never had the pending buckets, don't try to free them. */
     if (ssl_ctx->decrypt.pending != NULL) {
@@ -967,12 +1053,11 @@
 
     /* SSL_free implicitly frees the underlying BIO. */
     SSL_free(ssl_ctx->ssl);
+    bio_meth_free(ssl_ctx->biom);
     SSL_CTX_free(ssl_ctx->ctx);
 
-    p = ssl_ctx->pool;
 
     serf_bucket_mem_free(ssl_ctx->allocator, ssl_ctx);
-    apr_pool_destroy(p);
 
     return APR_SUCCESS;
 }
@@ -1011,7 +1096,6 @@
     apr_pool_t *pool)
 {
     FILE *fp = fopen(file_path, "r");
-        
     if (fp) {
         X509 *ssl_cert = PEM_read_X509(fp, NULL, NULL, NULL);
         fclose(fp);
@@ -1266,9 +1350,10 @@
     const serf_ssl_certificate_t *cert,
     apr_pool_t *pool)
 {
-    char *binary_cert, *p;
+    char *binary_cert;
     char *encoded_cert;
     int len;
+    unsigned char *unused;
 
     /* find the length of the DER encoding. */
     len = i2d_X509(cert->ssl_cert, NULL);
@@ -1277,8 +1362,8 @@
     }
 
     binary_cert = apr_palloc(pool, len);
-    p = binary_cert;
-    len = i2d_X509(cert->ssl_cert, &p); /* p is incremented */
+    unused = (unsigned char *)binary_cert;
+    len = i2d_X509(cert->ssl_cert, &unused);  /* unused is incremented  */
     if (len < 0) {
         return NULL;
     }