Fix typos in C header files

Signed-off-by: Tobias Nießen <tniessen@tnie.de>
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 603d985..a4479d7 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -421,7 +421,7 @@
  * of mbedtls_sha1_context, so your implementation of mbedtls_sha1_process must be compatible
  * with this definition.
  *
- * \note If you use the AES_xxx_ALT macros, then is is recommended to also set
+ * \note If you use the AES_xxx_ALT macros, then it is recommended to also set
  *       MBEDTLS_AES_ROM_TABLES in order to help the linker garbage-collect the AES
  *       tables.
  *
@@ -1807,7 +1807,7 @@
 /**
  * \def MBEDTLS_SSL_DTLS_SRTP
  *
- * Enable support for negotation of DTLS-SRTP (RFC 5764)
+ * Enable support for negotiation of DTLS-SRTP (RFC 5764)
  * through the use_srtp extension.
  *
  * \note This feature provides the minimum functionality required
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 149bda0..dd400a0 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -1176,7 +1176,7 @@
  *
  * \param grp_id    The ECP group identifier.
  * \param key       The destination key.
- * \param buf       The the buffer containing the binary representation of the
+ * \param buf       The buffer containing the binary representation of the
  *                  key. (Big endian integer for Weierstrass curves, byte
  *                  string for Montgomery curves.)
  * \param buflen    The length of the buffer in bytes.
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index 7936f6b..94b95fc 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -154,8 +154,8 @@
  *
  * \param high      high-level error code. See error.h for more details.
  * \param low       low-level error code. See error.h for more details.
- * \param file      file where this error code addition occured.
- * \param line      line where this error code addition occured.
+ * \param file      file where this error code addition occurred.
+ * \param line      line where this error code addition occurred.
  */
 static inline int mbedtls_error_add( int high, int low,
                                      const char *file, int line )
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 40814e6..b9b2e04 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -2496,7 +2496,7 @@
  *
  * \param conf          The SSL configuration.
  * \param prot_version  Protocol version. One of MBEDTLS_SSL_MINOR_VERSION_x macros.
- * \return              Ciphersuites pointer if succesful.
+ * \return              Ciphersuites pointer if successful.
  * \return              \c NULL if no ciphersuites where found.
  */
 const int *mbedtls_ssl_get_protocol_version_ciphersuites(
@@ -4188,7 +4188,7 @@
 /**
  * \brief          TLS-PRF function for key derivation.
  *
- * \param prf      The tls_prf type funtion type to be used.
+ * \param prf      The tls_prf type function type to be used.
  * \param secret   Secret for the key derivation function.
  * \param slen     Length of the secret.
  * \param label    String label for the key derivation function,
@@ -4198,7 +4198,7 @@
  * \param dstbuf   The buffer holding the derived key.
  * \param dlen     Length of the output buffer.
  *
- * \return         0 on sucess. An SSL specific error on failure.
+ * \return         0 on success. An SSL specific error on failure.
  */
 int  mbedtls_ssl_tls_prf( const mbedtls_tls_prf_types prf,
                           const unsigned char *secret, size_t slen,
diff --git a/include/mbedtls/ssl_ticket.h b/include/mbedtls/ssl_ticket.h
index bf5fc97..a882eed 100644
--- a/include/mbedtls/ssl_ticket.h
+++ b/include/mbedtls/ssl_ticket.h
@@ -97,7 +97,7 @@
  *                  Recommended value: 86400 (one day).
  *
  * \note            It is highly recommended to select a cipher that is at
- *                  least as strong as the the strongest ciphersuite
+ *                  least as strong as the strongest ciphersuite
  *                  supported. Usually that means a 256-bit key.
  *
  * \note            The lifetime of the keys is twice the lifetime of tickets.