Add an HKDF (RFC 5869) implementation
diff --git a/tests/suites/test_suite_hkdf.data b/tests/suites/test_suite_hkdf.data
new file mode 100644
index 0000000..b58ec93
--- /dev/null
+++ b/tests/suites/test_suite_hkdf.data
@@ -0,0 +1,27 @@
+HKDF RFC5869 Test Vector #1
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":"3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865"
+
+HKDF RFC5869 Test Vector #2
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff":"b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87"
+
+HKDF RFC5869 Test Vector #3
+depends_on:MBEDTLS_SHA256_C
+test_hkdf:6:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"":"8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8"
+
+HKDF RFC5869 Test Vector #4
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":"085a01ea1b10f36933068b56efa5ad81a4f14b822f5b091568a9cdd4f155fda2c22e422478d305f3f896"
+
+HKDF RFC5869 Test Vector #5
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f":"606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf":"b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff":"0bd770a74d1160f7c9f12cd5912a06ebff6adcae899d92191fe4305673ba2ffe8fa3f1a4e5ad79f3f334b3b202b2173c486ea37ce3d397ed034c7f9dfeb15c5e927336d0441f4c4300e2cff0d0900b52d3b4"
+
+HKDF RFC5869 Test Vector #6
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"":"":"0ac1af7002b3d761d1e55298da9d0506b9ae52057220a306e07b6b87e8df21d0ea00033de03984d34918"
+
+HKDF RFC5869 Test Vector #7
+depends_on:MBEDTLS_SHA1_C
+test_hkdf:4:"0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c":"":"":"2c91117204d745f3500d636a62f64f0ab3bae548aa53d423b0d1f27ebba6f5e5673a081d70cce7acfc48"
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
new file mode 100644
index 0000000..c6cd870
--- /dev/null
+++ b/tests/suites/test_suite_hkdf.function
@@ -0,0 +1,39 @@
+/* BEGIN_HEADER */
+#include "mbedtls/hkdf.h"
+/* END_HEADER */
+
+/* BEGIN_DEPENDENCIES
+ * depends_on:MBEDTLS_HKDF_C
+ * END_DEPENDENCIES
+ */
+
+/* BEGIN_CASE */
+void test_hkdf( int md_alg, char *hex_ikm_string, char *hex_salt_string,
+ char *hex_info_string, char *hex_okm_string )
+{
+ int ret;
+ size_t ikm_len, salt_len, info_len, okm_len;
+ unsigned char ikm[1024] = { '\0' };
+ unsigned char salt[1024] = { '\0' };
+ unsigned char info[1024] = { '\0' };
+ unsigned char expected_okm[1024] = { '\0' };
+ unsigned char okm[1024] = { '\0' };
+ unsigned char okm_string[1000] = { '\0' };
+
+ const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
+ TEST_ASSERT( md != NULL );
+
+ ikm_len = unhexify( ikm, hex_ikm_string );
+ salt_len = unhexify( salt, hex_salt_string );
+ info_len = unhexify( info, hex_info_string );
+ okm_len = unhexify( expected_okm, hex_okm_string );
+
+ ret = mbedtls_hkdf( md, salt, salt_len, ikm, ikm_len, info, info_len, okm,
+ okm_len);
+ TEST_ASSERT( ret == 0 );
+
+ // Run hexify on it so that it looks nicer if the assertion fails
+ hexify( okm_string, okm, okm_len );
+ TEST_ASSERT( !strcmp( (char *)okm_string, hex_okm_string ) );
+}
+/* END_CASE */