Add crypto backend for signal-protocol

1 files changed, 136 insertions, 0 deletions

diff --git a/src/omemo/crypto.h b/src/omemo/crypto.h
new file mode 100644
index 00000000..759cef69
--- /dev/null
+++ b/src/omemo/crypto.h
@@ -0,0 +1,136 @@
+#include <signal/signal_protocol_types.h>
+
+#define SG_CIPHER_AES_GCM_NOPADDING 1000
+
+int omemo_crypto_init(void);
+/**
+* Callback for a secure random number generator.
+* This function shall fill the provided buffer with random bytes.
+*
+* @param data pointer to the output buffer
+* @param len size of the output buffer
+* @return 0 on success, negative on failure
+*/
+int omemo_random_func(uint8_t *data, size_t len, void *user_data);
+
+/**
+* Callback for an HMAC-SHA256 implementation.
+* This function shall initialize an HMAC context with the provided key.
+*
+* @param hmac_context private HMAC context pointer
+* @param key pointer to the key
+* @param key_len length of the key
+* @return 0 on success, negative on failure
+*/
+int omemo_hmac_sha256_init_func(void **hmac_context, const uint8_t *key, size_t key_len, void *user_data);
+
+/**
+* Callback for an HMAC-SHA256 implementation.
+* This function shall update the HMAC context with the provided data
+*
+* @param hmac_context private HMAC context pointer
+* @param data pointer to the data
+* @param data_len length of the data
+* @return 0 on success, negative on failure
+*/
+int omemo_hmac_sha256_update_func(void *hmac_context, const uint8_t *data, size_t data_len, void *user_data);
+
+/**
+* Callback for an HMAC-SHA256 implementation.
+* This function shall finalize an HMAC calculation and populate the output
+* buffer with the result.
+*
+* @param hmac_context private HMAC context pointer
+* @param output buffer to be allocated and populated with the result
+* @return 0 on success, negative on failure
+*/
+int omemo_hmac_sha256_final_func(void *hmac_context, signal_buffer **output, void *user_data);
+
+/**
+* Callback for an HMAC-SHA256 implementation.
+* This function shall free the private context allocated in
+* hmac_sha256_init_func.
+*
+* @param hmac_context private HMAC context pointer
+*/
+void omemo_hmac_sha256_cleanup_func(void *hmac_context, void *user_data);
+
+/**
+* Callback for a SHA512 message digest implementation.
+* This function shall initialize a digest context.
+*
+* @param digest_context private digest context pointer
+* @return 0 on success, negative on failure
+*/
+int omemo_sha512_digest_init_func(void **digest_context, void *user_data);
+
+/**
+* Callback for a SHA512 message digest implementation.
+* This function shall update the digest context with the provided data.
+*
+* @param digest_context private digest context pointer
+* @param data pointer to the data
+* @param data_len length of the data
+* @return 0 on success, negative on failure
+*/
+int omemo_sha512_digest_update_func(void *digest_context, const uint8_t *data, size_t data_len, void *user_data);
+
+/**
+* Callback for a SHA512 message digest implementation.
+* This function shall finalize the digest calculation, populate the
+* output buffer with the result, and prepare the context for reuse.
+*
+* @param digest_context private digest context pointer
+* @param output buffer to be allocated and populated with the result
+* @return 0 on success, negative on failure
+*/
+int omemo_sha512_digest_final_func(void *digest_context, signal_buffer **output, void *user_data);
+
+/**
+* Callback for a SHA512 message digest implementation.
+* This function shall free the private context allocated in
+* sha512_digest_init_func.
+*
+* @param digest_context private digest context pointer
+*/
+void omemo_sha512_digest_cleanup_func(void *digest_context, void *user_data);
+
+/**
+* Callback for an AES encryption implementation.
+*
+* @param output buffer to be allocated and populated with the ciphertext
+* @param cipher specific cipher variant to use, either SG_CIPHER_AES_CTR_NOPADDING or SG_CIPHER_AES_CBC_PKCS5
+* @param key the encryption key
+* @param key_len length of the encryption key
+* @param iv the initialization vector
+* @param iv_len length of the initialization vector
+* @param plaintext the plaintext to encrypt
+* @param plaintext_len length of the plaintext
+* @return 0 on success, negative on failure
+*/
+int omemo_encrypt_func(signal_buffer **output,
+    int cipher,
+    const uint8_t *key, size_t key_len,
+    const uint8_t *iv, size_t iv_len,
+    const uint8_t *plaintext, size_t plaintext_len,
+    void *user_data);
+
+/**
+* Callback for an AES decryption implementation.
+*
+* @param output buffer to be allocated and populated with the plaintext
+* @param cipher specific cipher variant to use, either SG_CIPHER_AES_CTR_NOPADDING or SG_CIPHER_AES_CBC_PKCS5
+* @param key the encryption key
+* @param key_len length of the encryption key
+* @param iv the initialization vector
+* @param iv_len length of the initialization vector
+* @param ciphertext the ciphertext to decrypt
+* @param ciphertext_len length of the ciphertext
+* @return 0 on success, negative on failure
+*/
+int omemo_decrypt_func(signal_buffer **output,
+    int cipher,
+    const uint8_t *key, size_t key_len,
+    const uint8_t *iv, size_t iv_len,
+    const uint8_t *ciphertext, size_t ciphertext_len,
+    void *user_data);