diff --git a/include/git2/common.h b/include/git2/common.h
index dda821c7c..006f7eeb1 100644
--- a/include/git2/common.h
+++ b/include/git2/common.h
@@ -130,57 +130,81 @@ GIT_EXTERN(int) git_libgit2_version(int *major, int *minor, int *rev);
 GIT_EXTERN(const char *) git_libgit2_prerelease(void);
 
 /**
- * Combinations of these values describe the features with which libgit2
- * was compiled
+ * Configurable features of libgit2; either optional settings (like
+ * threading), or features that can be enabled by one of a number of
+ * different backend "providers" (like HTTPS, which can be provided by
+ * OpenSSL, mbedTLS, or system libraries).
  */
 typedef enum {
-  /**
-   * If set, libgit2 was built thread-aware and can be safely used from multiple
-   * threads.
-   */
-	GIT_FEATURE_THREADS	= (1 << 0),
-  /**
-   * If set, libgit2 was built with and linked against a TLS implementation.
-   * Custom TLS streams may still be added by the user to support HTTPS
-   * regardless of this.
-   */
-	GIT_FEATURE_HTTPS	= (1 << 1),
-  /**
-   * If set, libgit2 was built with and linked against libssh2. A custom
-   * transport may still be added by the user to support libssh2 regardless of
-   * this.
-   */
-	GIT_FEATURE_SSH		= (1 << 2),
-  /**
-   * If set, libgit2 was built with support for sub-second resolution in file
-   * modification times.
-   */
-	GIT_FEATURE_NSEC	= (1 << 3)
+	/**
+	 * libgit2 is thread-aware and can be used from multiple threads
+	 * (as described in the documentation).
+	 */
+	GIT_FEATURE_THREADS        = (1 << 0),
+
+	/** HTTPS remotes */
+	GIT_FEATURE_HTTPS          = (1 << 1),
+
+	/** SSH remotes */
+	GIT_FEATURE_SSH	           = (1 << 2),
+
+	/** Sub-second resolution in index timestamps */
+	GIT_FEATURE_NSEC           = (1 << 3),
+
+	/** HTTP parsing; always available */
+	GIT_FEATURE_HTTP_PARSER    = (1 << 4),
+
+	/** Regular expression support; always available */
+	GIT_FEATURE_REGEX          = (1 << 5),
+
+	/** Internationalization support for filename translation */
+	GIT_FEATURE_I18N           = (1 << 6),
+
+	/** NTLM support over HTTPS */
+	GIT_FEATURE_AUTH_NTLM      = (1 << 7),
+
+	/** Kerberos (SPNEGO) authentication support over HTTPS */
+	GIT_FEATURE_AUTH_NEGOTIATE = (1 << 8),
+
+	/** zlib support; always available */
+	GIT_FEATURE_COMPRESSION    = (1 << 9),
+
+	/** SHA1 object support; always available */
+	GIT_FEATURE_SHA1           = (1 << 10),
+
+	/** SHA256 object support */
+	GIT_FEATURE_SHA256         = (1 << 11)
 } git_feature_t;
 
 /**
  * Query compile time options for libgit2.
  *
  * @return A combination of GIT_FEATURE_* values.
- *
- * - GIT_FEATURE_THREADS
- *   Libgit2 was compiled with thread support. Note that thread support is
- *   still to be seen as a 'work in progress' - basic object lookups are
- *   believed to be threadsafe, but other operations may not be.
- *
- * - GIT_FEATURE_HTTPS
- *   Libgit2 supports the https:// protocol. This requires the openssl
- *   library to be found when compiling libgit2.
- *
- * - GIT_FEATURE_SSH
- *   Libgit2 supports the SSH protocol for network operations. This requires
- *   the libssh2 library to be found when compiling libgit2
- *
- * - GIT_FEATURE_NSEC
- *   Libgit2 supports the sub-second resolution in file modification times.
  */
 GIT_EXTERN(int) git_libgit2_features(void);
 
+/**
+ * Query the backend details for the compile-time feature in libgit2.
+ *
+ * This will return the "backend" for the feature, which is useful for
+ * things like HTTPS or SSH support, that can have multiple backends
+ * that could be compiled in.
+ *
+ * For example, when libgit2 is compiled with dynamic OpenSSL support,
+ * the feature backend will be `openssl-dynamic`. The feature backend
+ * names reflect the compilation options specified to the build system
+ * (though in all lower case). The backend _may_ be "builtin" for
+ * features that are provided by libgit2 itself.
+ *
+ * If the feature is not supported by the library, this API returns
+ * `NULL`.
+ *
+ * @param feature the feature to query details for
+ * @return the provider details, or NULL if the feature is not supported
+ */
+GIT_EXTERN(const char *) git_libgit2_feature_backend(
+	git_feature_t feature);
+
 /**
  * Global library options
  *
diff --git a/src/libgit2/libgit2.c b/src/libgit2/libgit2.c
index 1375d87af..de72cfe7d 100644
--- a/src/libgit2/libgit2.c
+++ b/src/libgit2/libgit2.c
@@ -92,6 +92,177 @@ int git_libgit2_features(void)
 #endif
 #ifdef GIT_USE_NSEC
 		| GIT_FEATURE_NSEC
+#endif
+		| GIT_FEATURE_HTTP_PARSER
+		| GIT_FEATURE_REGEX
+#ifdef GIT_USE_ICONV
+		| GIT_FEATURE_I18N
+#endif
+#if defined(GIT_NTLM) || defined(GIT_WIN32)
+		| GIT_FEATURE_AUTH_NTLM
+#endif
+#if defined(GIT_GSSAPI) || defined(GIT_GSSFRAMEWORK) || defined(GIT_WIN32)
+		| GIT_FEATURE_AUTH_NEGOTIATE
+#endif
+		| GIT_FEATURE_COMPRESSION
+		| GIT_FEATURE_SHA1
+#ifdef GIT_EXPERIMENTAL_SHA256
+		| GIT_FEATURE_SHA256
 #endif
 	;
 }
+
+const char *git_libgit2_feature_backend(git_feature_t feature)
+{
+	switch (feature) {
+	case GIT_FEATURE_THREADS:
+#if defined(GIT_THREADS) && defined(GIT_WIN32)
+		return "win32";
+#elif defined(GIT_THREADS)
+		return "pthread";
+#endif
+		break;
+
+	case GIT_FEATURE_HTTPS:
+#if defined(GIT_HTTPS) && defined(GIT_OPENSSL)
+		return "openssl";
+#elif defined(GIT_HTTPS) && defined(GIT_OPENSSL_DYNAMIC)
+		return "openssl-dynamic";
+#elif defined(GIT_HTTPS) && defined(GIT_MBEDTLS)
+		return "mbedtls";
+#elif defined(GIT_HTTPS) && defined(GIT_SECURE_TRANSPORT)
+		return "securetransport";
+#elif defined(GIT_HTTPS) && defined(GIT_SCHANNEL)
+		return "schannel";
+#elif defined(GIT_HTTPS) && defined(GIT_WINHTTP)
+		return "winhttp";
+#elif defined(GIT_HTTPS)
+		GIT_ASSERT_WITH_RETVAL(!"Unknown HTTPS backend", NULL);
+#endif
+		break;
+
+	case GIT_FEATURE_SSH:
+#if defined(GIT_SSH_EXEC)
+		return "exec";
+#elif defined(GIT_SSH_LIBSSH2)
+		return "libssh2";
+#elif defined(GIT_SSH)
+		GIT_ASSERT_WITH_RETVAL(!"Unknown SSH backend", NULL);
+#endif
+		break;
+
+	case GIT_FEATURE_NSEC:
+#if defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIMESPEC)
+		return "mtimespec";
+#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIM)
+		return "mtim";
+#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIME_NSEC)
+		return "mtime";
+#elif defined(GIT_USE_NSEC) && defined(GIT_WIN32)
+		return "win32";
+#elif defined(GIT_USE_NSEC)
+		GIT_ASSERT_WITH_RETVAL(!"Unknown high-resolution time backend", NULL);
+#endif
+		break;
+
+	case GIT_FEATURE_HTTP_PARSER:
+#if defined(GIT_HTTPPARSER_HTTPPARSER)
+		return "httpparser";
+#elif defined(GIT_HTTPPARSER_LLHTTP)
+		return "llhttp";
+#elif defined(GIT_HTTPPARSER_BUILTIN)
+		return "builtin";
+#endif
+		GIT_ASSERT_WITH_RETVAL(!"Unknown HTTP parser backend", NULL);
+		break;
+
+	case GIT_FEATURE_REGEX:
+#if defined(GIT_REGEX_REGCOMP_L)
+		return "regcomp_l";
+#elif defined(GIT_REGEX_REGCOMP)
+		return "regcomp";
+#elif defined(GIT_REGEX_PCRE)
+		return "pcre";
+#elif defined(GIT_REGEX_PCRE2)
+		return "pcre2";
+#elif defined(GIT_REGEX_BUILTIN)
+		return "builtin";
+#endif
+		GIT_ASSERT_WITH_RETVAL(!"Unknown regular expression backend", NULL);
+		break;
+
+	case GIT_FEATURE_I18N:
+#if defined(GIT_USE_ICONV)
+		return "iconv";
+#endif
+		break;
+
+	case GIT_FEATURE_AUTH_NTLM:
+#if defined(GIT_NTLM)
+		return "ntlmclient";
+#elif defined(GIT_WIN32)
+		return "sspi";
+#endif
+		break;
+
+	case GIT_FEATURE_AUTH_NEGOTIATE:
+#if defined(GIT_GSSAPI)
+		return "gssapi";
+#elif defined(GIT_WIN32)
+		return "sspi";
+#endif
+		break;
+
+	case GIT_FEATURE_COMPRESSION:
+#if defined(GIT_COMPRESSION_ZLIB)
+		return "zlib";
+#elif defined(GIT_COMPRESSION_BUILTIN)
+		return "builtin";
+#else
+		GIT_ASSERT_WITH_RETVAL(!"Unknown compression backend", NULL);
+#endif
+		break;
+
+	case GIT_FEATURE_SHA1:
+#if defined(GIT_SHA1_COLLISIONDETECT)
+		return "builtin";
+#elif defined(GIT_SHA1_OPENSSL)
+		return "openssl";
+#elif defined(GIT_SHA1_OPENSSL_FIPS)
+		return "openssl-fips";
+#elif defined(GIT_SHA1_OPENSSL_DYNAMIC)
+		return "openssl-dynamic";
+#elif defined(GIT_SHA1_MBEDTLS)
+		return "mbedtls";
+#elif defined(GIT_SHA1_COMMON_CRYPTO)
+		return "commoncrypto";
+#elif defined(GIT_SHA1_WIN32)
+		return "win32";
+#else
+		GIT_ASSERT_WITH_RETVAL(!"Unknown SHA1 backend", NULL);
+#endif
+		break;
+
+	case GIT_FEATURE_SHA256:
+#if defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_BUILTIN)
+		return "builtin";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL)
+		return "openssl";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL_FIPS)
+		return "openssl-fips";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL_DYNAMIC)
+		return "openssl-dynamic";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_MBEDTLS)
+		return "mbedtls";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_COMMON_CRYPTO)
+		return "commoncrypto";
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_WIN32)
+		return "win32";
+#elif defined(GIT_EXPERIMENTAL_SHA256)
+		GIT_ASSERT_WITH_RETVAL(!"Unknown SHA256 backend", NULL);
+#endif
+		break;
+	}
+
+	return NULL;
+}
diff --git a/tests/libgit2/core/features.c b/tests/libgit2/core/features.c
index 366eea1a3..b7cd6014a 100644
--- a/tests/libgit2/core/features.c
+++ b/tests/libgit2/core/features.c
@@ -25,4 +25,202 @@ void test_core_features__basic(void)
 #else
 	cl_assert((caps & GIT_FEATURE_NSEC) == 0);
 #endif
+
+	cl_assert((caps & GIT_FEATURE_HTTP_PARSER) != 0);
+	cl_assert((caps & GIT_FEATURE_REGEX) != 0);
+
+#if defined(GIT_USE_ICONV)
+	cl_assert((caps & GIT_FEATURE_I18N) != 0);
+#endif
+
+#if defined(GIT_NTLM) || defined(GIT_WIN32)
+	cl_assert((caps & GIT_FEATURE_AUTH_NTLM) != 0);
+#endif
+#if defined(GIT_GSSAPI) || defined(GIT_GSSFRAMEWORK) || defined(GIT_WIN32)
+	cl_assert((caps & GIT_FEATURE_AUTH_NEGOTIATE) != 0);
+#endif
+
+	cl_assert((caps & GIT_FEATURE_COMPRESSION) != 0);
+	cl_assert((caps & GIT_FEATURE_SHA1) != 0);
+
+#if defined(GIT_EXPERIMENTAL_SHA256)
+	cl_assert((caps & GIT_FEATURE_SHA256) != 0);
+#endif
+
+	/*
+	 * Ensure that our tests understand all the features;
+	 * this test tries to ensure that if there's a new feature
+	 * added that the backends test (below) is updated as well.
+	 */
+	cl_assert((caps & ~(GIT_FEATURE_THREADS |
+	                    GIT_FEATURE_HTTPS |
+	                    GIT_FEATURE_SSH |
+	                    GIT_FEATURE_NSEC |
+	                    GIT_FEATURE_HTTP_PARSER |
+	                    GIT_FEATURE_REGEX |
+	                    GIT_FEATURE_I18N |
+	                    GIT_FEATURE_AUTH_NTLM |
+	                    GIT_FEATURE_AUTH_NEGOTIATE |
+	                    GIT_FEATURE_COMPRESSION |
+	                    GIT_FEATURE_SHA1 |
+	                    GIT_FEATURE_SHA256
+			    )) == 0);
+}
+
+void test_core_features__backends(void)
+{
+	const char *threads = git_libgit2_feature_backend(GIT_FEATURE_THREADS);
+	const char *https = git_libgit2_feature_backend(GIT_FEATURE_HTTPS);
+	const char *ssh = git_libgit2_feature_backend(GIT_FEATURE_SSH);
+	const char *nsec = git_libgit2_feature_backend(GIT_FEATURE_NSEC);
+	const char *http_parser = git_libgit2_feature_backend(GIT_FEATURE_HTTP_PARSER);
+	const char *regex = git_libgit2_feature_backend(GIT_FEATURE_REGEX);
+	const char *i18n = git_libgit2_feature_backend(GIT_FEATURE_I18N);
+	const char *ntlm = git_libgit2_feature_backend(GIT_FEATURE_AUTH_NTLM);
+	const char *negotiate = git_libgit2_feature_backend(GIT_FEATURE_AUTH_NEGOTIATE);
+	const char *compression = git_libgit2_feature_backend(GIT_FEATURE_COMPRESSION);
+	const char *sha1 = git_libgit2_feature_backend(GIT_FEATURE_SHA1);
+	const char *sha256 = git_libgit2_feature_backend(GIT_FEATURE_SHA256);
+
+#if defined(GIT_THREADS) && defined(GIT_WIN32)
+	cl_assert_equal_s("win32", threads);
+#elif defined(GIT_THREADS)
+	cl_assert_equal_s("pthread", threads);
+#else
+	cl_assert(threads == NULL);
+#endif
+
+#if defined(GIT_HTTPS) && defined(GIT_OPENSSL)
+	cl_assert_equal_s("openssl", https);
+#elif defined(GIT_HTTPS) && defined(GIT_OPENSSL_DYNAMIC)
+	cl_assert_equal_s("openssl-dynamic", https);
+#elif defined(GIT_HTTPS) && defined(GIT_MBEDTLS)
+	cl_assert_equal_s("mbedtls", https);
+#elif defined(GIT_HTTPS) && defined(GIT_SECURE_TRANSPORT)
+	cl_assert_equal_s("securetransport", https);
+#elif defined(GIT_HTTPS) && defined(GIT_SCHANNEL)
+	cl_assert_equal_s("schannel", https);
+#elif defined(GIT_HTTPS) && defined(GIT_WINHTTP)
+	cl_assert_equal_s("winhttp", https);
+#elif defined(GIT_HTTPS)
+	cl_assert(0);
+#else
+	cl_assert(https == NULL);
+#endif
+
+#if defined(GIT_SSH) && defined(GIT_SSH_EXEC)
+	cl_assert_equal_s("exec", ssh);
+#elif defined(GIT_SSH) && defined(GIT_SSH_LIBSSH2)
+	cl_assert_equal_s("libssh2", ssh);
+#elif defined(GIT_SSH)
+	cl_assert(0);
+#else
+	cl_assert(ssh == NULL);
+#endif
+
+#if defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIMESPEC)
+	cl_assert_equal_s("mtimespec", nsec);
+#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIM)
+	cl_assert_equal_s("mtim", nsec);
+#elif defined(GIT_USE_NSEC) && defined(GIT_USE_STAT_MTIME_NSEC)
+	cl_assert_equal_s("mtime", nsec);
+#elif defined(GIT_USE_NSEC) && defined(GIT_WIN32)
+	cl_assert_equal_s("win32", nsec);
+#elif defined(GIT_USE_NSEC)
+	cl_assert(0);
+#else
+	cl_assert(nsec == NULL);
+#endif
+
+#if defined(GIT_HTTPPARSER_HTTPPARSER)
+	cl_assert_equal_s("httpparser", http_parser);
+#elif defined(GIT_HTTPPARSER_LLHTTP)
+	cl_assert_equal_s("llhttp", http_parser);
+#elif defined(GIT_HTTPPARSER_BUILTIN)
+	cl_assert_equal_s("builtin", http_parser);
+#else
+	cl_assert(0);
+#endif
+
+#if defined(GIT_REGEX_REGCOMP_L)
+	cl_assert_equal_s("regcomp_l", regex);
+#elif defined(GIT_REGEX_REGCOMP)
+	cl_assert_equal_s("regcomp", regex);
+#elif defined(GIT_REGEX_PCRE)
+	cl_assert_equal_s("pcre", regex);
+#elif defined(GIT_REGEX_PCRE2)
+	cl_assert_equal_s("pcre2", regex);
+#elif defined(GIT_REGEX_BUILTIN)
+	cl_assert_equal_s("builtin", regex);
+#else
+	cl_assert(0);
+#endif
+
+#if defined(GIT_USE_ICONV)
+	cl_assert_equal_s("iconv", i18n);
+#else
+	cl_assert(i18n == NULL);
+#endif
+
+#if defined(GIT_NTLM)
+	cl_assert_equal_s("ntlmclient", ntlm);
+#elif defined(GIT_WIN32)
+	cl_assert_equal_s("sspi", ntlm);
+#else
+	cl_assert(ntlm == NULL);
+#endif
+
+#if defined(GIT_GSSAPI)
+	cl_assert_equal_s("gssapi", negotiate);
+#elif defined(GIT_WIN32)
+	cl_assert_equal_s("sspi", negotiate);
+#else
+	cl_assert(negotiate == NULL);
+#endif
+
+#if defined(GIT_COMPRESSION_BUILTIN)
+	cl_assert_equal_s("builtin", compression);
+#elif defined(GIT_COMPRESSION_ZLIB)
+	cl_assert_equal_s("zlib", compression);
+#else
+	cl_assert(0);
+#endif
+
+#if defined(GIT_SHA1_COLLISIONDETECT)
+	cl_assert_equal_s("builtin", sha1);
+#elif defined(GIT_SHA1_OPENSSL)
+	cl_assert_equal_s("openssl", sha1);
+#elif defined(GIT_SHA1_OPENSSL_FIPS)
+	cl_assert_equal_s("openssl-fips", sha1);
+#elif defined(GIT_SHA1_OPENSSL_DYNAMIC)
+	cl_assert_equal_s("openssl-dynamic", sha1);
+#elif defined(GIT_SHA1_MBEDTLS)
+	cl_assert_equal_s("mbedtls", sha1);
+#elif defined(GIT_SHA1_COMMON_CRYPTO)
+	cl_assert_equal_s("commoncrypto", sha1);
+#elif defined(GIT_SHA1_WIN32)
+	cl_assert_equal_s("win32", sha1);
+#else
+	cl_assert(0);
+#endif
+
+#if defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_BUILTIN)
+	cl_assert_equal_s("builtin", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL)
+	cl_assert_equal_s("openssl", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL_FIPS)
+	cl_assert_equal_s("openssl-fips", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_OPENSSL_DYNAMIC)
+	cl_assert_equal_s("openssl-dynamic", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_MBEDTLS)
+	cl_assert_equal_s("mbedtls", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_COMMON_CRYPTO)
+	cl_assert_equal_s("commoncrypto", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256) && defined(GIT_SHA256_WIN32)
+	cl_assert_equal_s("win32", sha256);
+#elif defined(GIT_EXPERIMENTAL_SHA256)
+	cl_assert(0);
+#else
+	cl_assert(sha256 == NULL);
+#endif
 }