Added lightweight implementation of libgcrypt. (#1444)

Implementation borrowed from the
https://github.com/ARMmbed/mbedtls.git project (v3.1.0)

Speed testing (Xeon(R) CPU E3-1230 V2 @ 3.30GHz):

gcrypt-gnu         Test md   2897 ms enc   2777 ms dec    942 ms
gcrypt-int         Test md   3668 ms enc   1312 ms dec   2836 ms
gcrypt-int-noaesni Test md   3652 ms enc   1916 ms dec   4458 ms

gcrypt-gnu-nonopt  Test md   3763 ms enc   4978 ms dec   3999 ms

gcrypt-gnu-nonopt - libgcrypt compiled without hardware acceleration
  --disable-padlock-support --disable-aesni-support \
  --disable-shaext-support --disable-pclmul-support \
  --disable-sse41-support --disable-drng-support \
  --disable-avx-support --disable-avx2-support \
  --disable-neon-support --disable-arm-crypto-support \
  --disable-ppc-crypto-support
  --disable-amd64-as-feature-detection

1 files changed, 89 insertions, 0 deletions

diff --git a/src/lib/third_party/include/gcrypt_light.h b/src/lib/third_party/include/gcrypt_light.h
new file mode 100644
index 000000000..de77c8e38
--- /dev/null
+++ b/src/lib/third_party/include/gcrypt_light.h
@@ -0,0 +1,89 @@
+
+#ifndef GCRY_LIGHT_H
+#define GCRY_LIGHT_H
+
+#define LIBGCRYPT_INTERNAL
+
+#define HMAC_SHA256_DIGEST_SIZE 32  /* Same as SHA-256's output size. */
+#define SHA256_DIGEST_SIZE 32
+#define GCRY_MD_BUFF_SIZE 256
+
+#define GCRY_CIPHER_AES128 7
+#define GCRY_CIPHER_AES256 8
+#define GCRY_CIPHER_MODE_ECB 1
+#define GCRY_CIPHER_MODE_GCM 8 
+
+#define GCRY_MD_SHA256 8
+#define GCRY_MD_FLAG_HMAC 2
+#define GPG_ERR_NO_ERROR 0
+#define GPG_ERR_KEY -1
+#define GPG_ERR_ANY -2
+#define GPG_ERR_INV_ARG -3
+#define GCRYCTL_INITIALIZATION_FINISHED_P 1,0
+#define GCRYCTL_INITIALIZATION_FINISHED 2
+#define GCRYCTL_RESET 3
+
+#define GCRY_AES_KEY_SIZE 32
+#define GCRY_AES_AUTH_SIZE 128
+#define GCRY_AES_TAG_SIZE 32
+#define GCRY_AES_IV_SIZE 12
+
+typedef int gcry_error_t;
+typedef gcry_error_t gpg_error_t;
+
+struct gcry_md_hd {
+	uint8_t  key[64],out[HMAC_SHA256_DIGEST_SIZE];
+	uint8_t  data_buf[GCRY_MD_BUFF_SIZE];
+	uint32_t key_len;
+	uint32_t data_len;
+};
+typedef struct gcry_md_hd * gcry_md_hd_t;
+
+struct gcry_cipher_hd {
+    int     algo,mode;
+    size_t  keylen,authlen,taglen,ivlen;
+    uint8_t s_key:1,s_auth:1,s_iv:1,s_crypt_ok:1;
+    uint8_t auth[GCRY_AES_AUTH_SIZE];
+    uint8_t tag[GCRY_AES_TAG_SIZE];
+    uint8_t iv[GCRY_AES_IV_SIZE];
+    union {
+        struct mbedtls_aes_context *ecb;
+        struct mbedtls_gcm_context *gcm;
+    }  ctx;
+};
+
+typedef struct gcry_cipher_hd * gcry_cipher_hd_t;
+
+int          gcry_control (int, int);
+const char   *gcry_check_version(void *);
+char         *gpg_strerror_r(gcry_error_t, char *, size_t);
+
+gcry_error_t gcry_md_open  (gcry_md_hd_t *h, int algo, int flags);
+void         gcry_md_close (gcry_md_hd_t h);
+void         gcry_md_reset (gcry_md_hd_t h);
+
+gcry_error_t gcry_md_setkey (gcry_md_hd_t h, const uint8_t *key, size_t key_len);
+gcry_error_t gcry_md_write  (gcry_md_hd_t h, const uint8_t *data, size_t data_len);
+uint8_t      *gcry_md_read  (gcry_md_hd_t h, int flag);
+
+size_t       gcry_md_get_algo_dlen (int algo);
+int          gcry_md_get_algo (gcry_md_hd_t h);
+
+gcry_error_t gcry_cipher_open  (gcry_cipher_hd_t *handle, int algo, int mode, unsigned int flags);
+void         gcry_cipher_close (gcry_cipher_hd_t h);
+gcry_error_t gcry_cipher_ctl    (gcry_cipher_hd_t h, int cmd, void *data, size_t len);
+gcry_error_t gcry_cipher_reset (gcry_cipher_hd_t h);
+gcry_error_t gcry_cipher_setiv (gcry_cipher_hd_t h, const void *iv, size_t ivlen);
+gcry_error_t gcry_cipher_setkey (gcry_cipher_hd_t h, const void *key, size_t keylen);
+gcry_error_t gcry_cipher_checktag (gcry_cipher_hd_t h, const void *intag, size_t taglen);
+gcry_error_t gcry_cipher_authenticate (gcry_cipher_hd_t h, const void *abuf, size_t abuflen);
+gcry_error_t gcry_cipher_encrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
+                                  const void *in, size_t inlen);
+gcry_error_t gcry_cipher_decrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
+                                  const void *in, size_t inlen);
+
+size_t       gcry_cipher_get_algo_keylen (int algo);
+
+#endif /* GCRY_LIGHT_H */
+
+/* vim: set ts=4 sw=4 et foldmethod=marker foldmarker={{{{,}}}}: */