From e2135fc3eb5827ba83563daebad3cdd9d92f07b0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9bastien=20Helleu?= Date: Sat, 29 Feb 2020 10:49:38 +0100 Subject: core: add functions to compute binary/hex hash of data --- src/core/wee-secure.c | 140 ++++++++++++++++++++++++++++++++++++++++++-------- src/core/wee-secure.h | 3 ++ 2 files changed, 122 insertions(+), 21 deletions(-) (limited to 'src') diff --git a/src/core/wee-secure.c b/src/core/wee-secure.c index 39b09aa90..18a8ee52b 100644 --- a/src/core/wee-secure.c +++ b/src/core/wee-secure.c @@ -65,6 +65,104 @@ char *secure_decrypt_error[] = { "memory", "buffer", "key", "cipher", "setkey", int secure_data_encrypted = 0; +/* + * Computes hash of data, as binary buffer. + * + * Note: "*hash" must be freed after use. + */ + +void +secure_hash_binary (const char *data, int length_data, int hash_algo, + char **hash, int *length_hash) +{ + gcry_md_hd_t *hd_md; + int hd_md_opened; + unsigned char *ptr_hash; + + if (!hash || !length_hash) + return; + + hd_md = NULL; + hd_md_opened = 0; + *hash = NULL; + *length_hash = 0; + + if (!data || (length_data < 1)) + goto hash_binary_end; + + hd_md = malloc (sizeof (gcry_md_hd_t)); + if (!hd_md) + goto hash_binary_end; + + if (gcry_md_open (hd_md, hash_algo, 0) != 0) + goto hash_binary_end; + + hd_md_opened = 1; + + gcry_md_write (*hd_md, data, length_data); + ptr_hash = gcry_md_read (*hd_md, hash_algo); + if (!ptr_hash) + goto hash_binary_end; + + *length_hash = gcry_md_get_algo_dlen (hash_algo); + *hash = malloc (*length_hash); + if (!*hash) + { + *length_hash = 0; + goto hash_binary_end; + } + memcpy (*hash, ptr_hash, *length_hash); + +hash_binary_end: + if (hd_md) + { + if (hd_md_opened) + gcry_md_close (*hd_md); + free (hd_md); + } +} + +/* + * Computes hash of data, as text (string with hexadecimal). + * + * Returns a string with the hash as hexadecimal, NULL if error. + * + * Note: result must be freed after use. + */ + +char * +secure_hash (const char *data, int length_data, int hash_algo) +{ + char *hash, *result; + int length_hash, i; + const char *hexa = "0123456789abcdef"; + + hash = NULL; + length_hash = 0; + result = NULL; + + secure_hash_binary (data, length_data, hash_algo, &hash, &length_hash); + if (!hash || (length_hash < 1)) + goto hash_end; + + result = malloc (((length_hash) * 2) + 1); + if (!result) + goto hash_end; + + for (i = 0; i < length_hash; i++) + { + result[i * 2] = hexa[(hash[i] & 0xFF) / 16]; + result[(i * 2) + 1] = hexa[(hash[i] & 0xFF) % 16]; + } + result[(length_hash * 2)] = '\0'; + +hash_end: + if (hash) + free (hash); + + return result; +} + /* * Derives a key from salt + passphrase (using a hash). * @@ -187,7 +285,7 @@ secure_encrypt_data (const char *data, int length_data, length_key = gcry_cipher_get_algo_keylen (cipher); key = malloc (length_key); if (!key) - goto encend; + goto encrypt_end; if (CONFIG_BOOLEAN(secure_config_crypt_salt)) gcry_randomize (salt, SECURE_SALT_SIZE, GCRY_STRONG_RANDOM); else @@ -202,14 +300,14 @@ secure_encrypt_data (const char *data, int length_data, if (!secure_derive_key (salt, passphrase, key, length_key)) { rc = -2; - goto encend; + goto encrypt_end; } /* compute hash of data */ if (gcry_md_open (hd_md, hash_algo, 0) != 0) { rc = -3; - goto encend; + goto encrypt_end; } hd_md_opened = 1; length_hash = gcry_md_get_algo_dlen (hash_algo); @@ -218,14 +316,14 @@ secure_encrypt_data (const char *data, int length_data, if (!ptr_hash) { rc = -3; - goto encend; + goto encrypt_end; } /* build a buffer with hash + data */ length_hash_data = length_hash + length_data; hash_and_data = malloc (length_hash_data); if (!hash_and_data) - goto encend; + goto encrypt_end; memcpy (hash_and_data, ptr_hash, length_hash); memcpy (hash_and_data + length_hash, data, length_data); @@ -233,32 +331,32 @@ secure_encrypt_data (const char *data, int length_data, if (gcry_cipher_open (hd_cipher, cipher, GCRY_CIPHER_MODE_CFB, 0) != 0) { rc = -4; - goto encend; + goto encrypt_end; } hd_cipher_opened = 1; if (gcry_cipher_setkey (*hd_cipher, key, length_key) != 0) { rc = -5; - goto encend; + goto encrypt_end; } if (gcry_cipher_encrypt (*hd_cipher, hash_and_data, length_hash_data, NULL, 0) != 0) { rc = -6; - goto encend; + goto encrypt_end; } /* create buffer and copy salt + encrypted hash/data into this buffer*/ *length_encrypted = SECURE_SALT_SIZE + length_hash_data; *encrypted = malloc (*length_encrypted); if (!*encrypted) - goto encend; + goto encrypt_end; memcpy (*encrypted, salt, SECURE_SALT_SIZE); memcpy (*encrypted + SECURE_SALT_SIZE, hash_and_data, length_hash_data); rc = 0; -encend: +encrypt_end: if (hd_md) { if (hd_md_opened) @@ -347,27 +445,27 @@ secure_decrypt_data (const char *buffer, int length_buffer, length_key = gcry_cipher_get_algo_keylen (cipher); key = malloc (length_key); if (!key) - goto decend; + goto decrypt_end; if (!secure_derive_key (buffer, passphrase, key, length_key)) { rc = -3; - goto decend; + goto decrypt_end; } /* decrypt hash + data */ decrypted_hash_data = malloc (length_buffer - SECURE_SALT_SIZE); if (!decrypted_hash_data) - goto decend; + goto decrypt_end; if (gcry_cipher_open (hd_cipher, cipher, GCRY_CIPHER_MODE_CFB, 0) != 0) { rc = -4; - goto decend; + goto decrypt_end; } hd_cipher_opened = 1; if (gcry_cipher_setkey (*hd_cipher, key, length_key) != 0) { rc = -5; - goto decend; + goto decrypt_end; } if (gcry_cipher_decrypt (*hd_cipher, decrypted_hash_data, @@ -376,14 +474,14 @@ secure_decrypt_data (const char *buffer, int length_buffer, length_buffer - SECURE_SALT_SIZE) != 0) { rc = -6; - goto decend; + goto decrypt_end; } /* check if hash is OK for decrypted data */ if (gcry_md_open (hd_md, hash_algo, 0) != 0) { rc = -7; - goto decend; + goto decrypt_end; } hd_md_opened = 1; gcry_md_write (*hd_md, decrypted_hash_data + length_hash, @@ -392,25 +490,25 @@ secure_decrypt_data (const char *buffer, int length_buffer, if (!ptr_hash) { rc = -7; - goto decend; + goto decrypt_end; } if (memcmp (ptr_hash, decrypted_hash_data, length_hash) != 0) { rc = -8; - goto decend; + goto decrypt_end; } /* return the decrypted data */ *length_decrypted = length_buffer - SECURE_SALT_SIZE - length_hash; *decrypted = malloc (*length_decrypted); if (!*decrypted) - goto decend; + goto decrypt_end; memcpy (*decrypted, decrypted_hash_data + length_hash, *length_decrypted); rc = 0; -decend: +decrypt_end: if (hd_md) { if (hd_md_opened) diff --git a/src/core/wee-secure.h b/src/core/wee-secure.h index 884fad8ca..303e0c9e5 100644 --- a/src/core/wee-secure.h +++ b/src/core/wee-secure.h @@ -55,6 +55,9 @@ extern int secure_cipher[]; extern int secure_data_encrypted; extern char *secure_decrypt_error[]; +extern void secure_hash_binary (const char *data, int length_data, + int hash_algo, char **hash, int *length_hash); +extern char *secure_hash (const char *data, int length_data, int hash_algo); extern int secure_encrypt_data (const char *data, int length_data, int hash_algo, int cipher, const char *passphrase, char **encrypted, -- cgit v1.2.3