Implement psa_sign_message and psa_verify_message functions

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>

include/psa/crypto.h

@@ -2889,6 +2889,123 @@ psa_status_t psa_aead_abort(psa_aead_operation_t *operation);
  * @{
  */
 
+/**
+ * \brief Sign a message with a private key. For hash-and-sign algorithms,
+ *        this includes the hashing step.
+ *
+ * \note To perform a multi-part hash-and-sign signature algorithm, first use
+ *       a multi-part hash operation and then pass the resulting hash to
+ *       psa_sign_hash(). PSA_ALG_GET_HASH(\p alg) can be used to determine the
+ *       hash algorithm to use.
+ *
+ * \param[in] key               Identifier of the key to use for the operation.
+ *                              It must be an asymmetric key pair. The key must
+ *                              allow the usage #PSA_KEY_USAGE_SIGN_MESSAGE.
+ * \param[in] alg               An asymmetric signature algorithm (PSA_ALG_XXX
+ *                              value such that #PSA_ALG_IS_SIGN_MESSAGE(\p alg)
+ *                              is true), that is compatible with the type of
+ *                              \p key.
+ * \param[in] input             The input message to sign.
+ * \param[in] input_length      Size of the \p input buffer in bytes.
+ * \param[out] signature        Buffer where the signature is to be written.
+ * \param[in] signature_size    Size of the \p signature buffer in bytes. This
+ *                              must be appropriate for the selected
+ *                              algorithm and key:
+ *                              - The required signature size is
+ *                                #PSA_SIGN_OUTPUT_SIZE(key_type, key_bits, \p alg)
+ *                                where key_type and key_bits are the type and
+ *                                bit-size respectively of key.
+ *                              - #PSA_SIGNATURE_MAX_SIZE evaluates to the
+ *                                maximum signature size of any supported
+ *                                signature algorithm.
+ * \param[out] signature_length On success, the number of bytes that make up
+ *                              the returned signature value.
+ *
+ * \retval #PSA_SUCCESS
+ * \retval #PSA_ERROR_INVALID_HANDLE
+ * \retval #PSA_ERROR_NOT_PERMITTED
+ *         The key does not have the #PSA_KEY_USAGE_SIGN_MESSAGE flag,
+ *         or it does not permit the requested algorithm.
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL
+ *         The size of the \p signature buffer is too small. You can
+ *         determine a sufficient buffer size by calling
+ *         #PSA_SIGN_OUTPUT_SIZE(\c key_type, \c key_bits, \p alg)
+ *         where \c key_type and \c key_bits are the type and bit-size
+ *         respectively of \p key.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_STORAGE_FAILURE
+ * \retval #PSA_ERROR_DATA_CORRUPT
+ * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_INSUFFICIENT_ENTROPY
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_sign_message( mbedtls_svc_key_id_t key,
+                               psa_algorithm_t alg,
+                               const uint8_t * input,
+                               size_t input_length,
+                               uint8_t * signature,
+                               size_t signature_size,
+                               size_t * signature_length );
+
+/** \brief Verify the signature of a message with a public key, using
+ *         a hash-and-sign verification algorithm.
+ *
+ * \note To perform a multi-part hash-and-sign signature verification
+ *       algorithm, first use a multi-part hash operation to hash the message
+ *       and then pass the resulting hash to psa_verify_hash().
+ *       PSA_ALG_GET_HASH(\p alg) can be used to determine the hash algorithm
+ *       to use.
+ *
+ * \param[in] key               Identifier of the key to use for the operation.
+ *                              It must be a public key or an asymmetric key
+ *                              pair. The key must allow the usage
+ *                              #PSA_KEY_USAGE_VERIFY_MESSAGE.
+ * \param[in] alg               An asymmetric signature algorithm (PSA_ALG_XXX
+ *                              value such that #PSA_ALG_IS_SIGN_MESSAGE(\p alg)
+ *                              is true), that is compatible with the type of
+ *                              \p key.
+ * \param[in] input             The message whose signature is to be verified.
+ * \param[in] input_length      Size of the \p input buffer in bytes.
+ * \param[out] signature        Buffer containing the signature to verify.
+ * \param[in] signature_length  Size of the \p signature buffer in bytes.
+ *
+ * \retval #PSA_SUCCESS
+ * \retval #PSA_ERROR_INVALID_HANDLE
+ * \retval #PSA_ERROR_NOT_PERMITTED
+ *         The key does not have the #PSA_KEY_USAGE_SIGN_MESSAGE flag,
+ *         or it does not permit the requested algorithm.
+ * \retval #PSA_ERROR_INVALID_SIGNATURE
+ *         The calculation was performed successfully, but the passed signature
+ *         is not a valid signature.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
+ * \retval #PSA_ERROR_COMMUNICATION_FAILURE
+ * \retval #PSA_ERROR_HARDWARE_FAILURE
+ * \retval #PSA_ERROR_CORRUPTION_DETECTED
+ * \retval #PSA_ERROR_STORAGE_FAILURE
+ * \retval #PSA_ERROR_DATA_CORRUPT
+ * \retval #PSA_ERROR_DATA_INVALID
+ * \retval #PSA_ERROR_BAD_STATE
+ *         The library has not been previously initialized by psa_crypto_init().
+ *         It is implementation-dependent whether a failure to initialize
+ *         results in this error code.
+ */
+psa_status_t psa_verify_message( mbedtls_svc_key_id_t key,
+                                 psa_algorithm_t alg,
+                                 const uint8_t * input,
+                                 size_t input_length,
+                                 const uint8_t * signature,
+                                 size_t signature_length );
+
 /**
  * \brief Sign a hash or short message with a private key.
  *
@@ -2942,7 +3059,7 @@ psa_status_t psa_sign_hash(mbedtls_svc_key_id_t key,
                            size_t *signature_length);
 
 /**
- * \brief Verify the signature a hash or short message using a public key.
+ * \brief Verify the signature of a hash or short message using a public key.
  *
  * Note that to perform a hash-and-sign signature algorithm, you must
  * first calculate the hash by calling psa_hash_setup(), psa_hash_update()

include/psa/crypto_values.h

@@ -1487,6 +1487,23 @@
      PSA_ALG_IS_ECDSA(alg) || PSA_ALG_IS_HASH_EDDSA(alg) ||             \
      PSA_ALG_IS_VENDOR_HASH_AND_SIGN(alg))
 
+
+/** Whether the specified algorithm is a signature algorithm that can be used
+ * with psa_sign_message() and psa_verify_message().
+ *
+ * \param alg An algorithm identifier (value of type #psa_algorithm_t).
+ *
+ * \return 1 if alg is a signature algorithm that can be used to sign a
+ *         message. 0 if alg is a signature algorithm that can only be used
+ *         to sign an already-calculated hash. 0 if alg is not a signature
+ *         algorithm. This macro can return either 0 or 1 if alg is not a
+ *         supported algorithm identifier.
+ */
+#define PSA_ALG_IS_SIGN_MESSAGE(alg)                                    \
+    (PSA_ALG_IS_RSA_PSS(alg) || PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) ||    \
+     PSA_ALG_IS_ECDSA(alg) || PSA_ALG_IS_HASH_EDDSA(alg) ||             \
+     PSA_ALG_IS_VENDOR_HASH_AND_SIGN(alg))
+
 /** Get the hash used by a hash-and-sign signature algorithm.
  *
  * A hash-and-sign algorithm is a signature algorithm which is
@@ -2063,6 +2080,26 @@ static inline int mbedtls_svc_key_id_is_null( mbedtls_svc_key_id_t key )
  */
 #define PSA_KEY_USAGE_DECRYPT                   ((psa_key_usage_t)0x00000200)
 
+/** Whether the key may be used to sign a message.
+ *
+ * This flag allows the key to be used for a MAC calculation operation or for
+ * an asymmetric message signature operation, if otherwise permitted by the
+ * key’s type and policy.
+ *
+ * For a key pair, this concerns the private key.
+ */
+#define PSA_KEY_USAGE_SIGN_MESSAGE              ((psa_key_usage_t)0x00000400)
+
+/** Whether the key may be used to verify a message.
+ *
+ * This flag allows the key to be used for a MAC verification operation or for
+ * an asymmetric message signature verification operation, if otherwise
+ * permitted by the key’s type and policy.
+ *
+ * For a key pair, this concerns the public key.
+ */
+#define PSA_KEY_USAGE_VERIFY_MESSAGE            ((psa_key_usage_t)0x00000800)
+
 /** Whether the key may be used to sign a message.
  *
  * This flag allows the key to be used for a MAC calculation operation

library/psa_crypto.c

@@ -1556,6 +1556,8 @@ static psa_status_t psa_validate_key_policy( const psa_key_policy_t *policy )
                              PSA_KEY_USAGE_COPY |
                              PSA_KEY_USAGE_ENCRYPT |
                              PSA_KEY_USAGE_DECRYPT |
+                             PSA_KEY_USAGE_SIGN_MESSAGE |
+                             PSA_KEY_USAGE_VERIFY_MESSAGE |
                              PSA_KEY_USAGE_SIGN_HASH |
                              PSA_KEY_USAGE_VERIFY_HASH |
                              PSA_KEY_USAGE_DERIVE ) ) != 0 )
@@ -2840,6 +2842,140 @@ cleanup:
 /* Asymmetric cryptography */
 /****************************************************************/
 
+psa_status_t psa_sign_message( mbedtls_svc_key_id_t key,
+                               psa_algorithm_t alg,
+                               const uint8_t * input,
+                               size_t input_length,
+                               uint8_t * signature,
+                               size_t signature_size,
+                               size_t * signature_length )
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+    size_t hash_length;
+    uint8_t hash[PSA_HASH_MAX_SIZE];
+
+    *signature_length = 0;
+
+    if( ! PSA_ALG_IS_SIGN_MESSAGE( alg ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if ( ! PSA_ALG_IS_HASH( PSA_ALG_SIGN_GET_HASH( alg ) ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    /* Immediately reject a zero-length signature buffer. This guarantees
+     * that signature must be a valid pointer. (On the other hand, the hash
+     * buffer can in principle be empty since it doesn't actually have
+     * to be a hash.) */
+    if( signature_size == 0 )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+    status = psa_get_and_lock_key_slot_with_policy( key, &slot,
+                                                    PSA_KEY_USAGE_SIGN_MESSAGE,
+                                                    alg );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+    if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) )
+    {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    psa_key_attributes_t attributes = {
+      .core = slot->attr
+    };
+
+    status = psa_driver_wrapper_hash_compute( PSA_ALG_SIGN_GET_HASH( alg ),
+                                              input, input_length,
+                                              hash, sizeof( hash ),
+                                              &hash_length );
+
+    if( status != PSA_SUCCESS )
+    {
+        memset( hash, 0, sizeof( hash ) );
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_sign_hash(
+        &attributes, slot->key.data, slot->key.bytes,
+        alg, hash, hash_length,
+        signature, signature_size, signature_length );
+
+    memset( hash, 0, hash_length );
+
+exit:
+    /* Fill the unused part of the output buffer (the whole buffer on error,
+     * the trailing part on success) with something that isn't a valid signature
+     * (barring an attack on the signature and deliberately-crafted input),
+     * in case the caller doesn't check the return status properly. */
+    if( status == PSA_SUCCESS )
+        memset( signature + *signature_length, '!',
+                signature_size - *signature_length );
+    else
+        memset( signature, '!', signature_size );
+    /* If signature_size is 0 then we have nothing to do. We must not call
+     * memset because signature may be NULL in this case. */
+
+    unlock_status = psa_unlock_key_slot( slot );
+
+    return( ( status == PSA_SUCCESS ) ? unlock_status : status );
+}
+
+psa_status_t psa_verify_message( mbedtls_svc_key_id_t key,
+                                 psa_algorithm_t alg,
+                                 const uint8_t * input,
+                                 size_t input_length,
+                                 const uint8_t * signature,
+                                 size_t signature_length )
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+    size_t hash_length;
+    uint8_t hash[PSA_HASH_MAX_SIZE];
+
+    if( ! PSA_ALG_IS_SIGN_MESSAGE( alg ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if ( ! PSA_ALG_IS_HASH( PSA_ALG_SIGN_GET_HASH( alg ) ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_and_lock_key_slot_with_policy( key, &slot,
+                                                    PSA_KEY_USAGE_VERIFY_MESSAGE,
+                                                    alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    psa_key_attributes_t attributes = {
+      .core = slot->attr
+    };
+
+    status = psa_driver_wrapper_hash_compute( PSA_ALG_SIGN_GET_HASH( alg ),
+                                              input, input_length,
+                                              hash, sizeof( hash ),
+                                              &hash_length );
+
+    if( status != PSA_SUCCESS )
+    {
+        memset( hash, 0, sizeof( hash ) );
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_verify_hash(
+        &attributes, slot->key.data, slot->key.bytes,
+        alg, hash, hash_length,
+        signature, signature_length );
+
+    memset( hash, 0, hash_length );
+
+exit:
+    unlock_status = psa_unlock_key_slot( slot );
+
+    return( ( status == PSA_SUCCESS ) ? unlock_status : status );
+}
+
 psa_status_t psa_sign_hash_internal(
     const psa_key_attributes_t *attributes,
     const uint8_t *key_buffer, size_t key_buffer_size,

programs/psa/psa_constant_names_generated.c

@@ -394,6 +394,13 @@ static int psa_snprint_key_usage(char *buffer, size_t buffer_size,
         append(&buffer, buffer_size, &required_size, "PSA_KEY_USAGE_SIGN_HASH", 23);
         usage ^= PSA_KEY_USAGE_SIGN_HASH;
     }
+    if (usage & PSA_KEY_USAGE_SIGN_MESSAGE) {
+        if (required_size != 0) {
+            append(&buffer, buffer_size, &required_size, " | ", 3);
+        }
+        append(&buffer, buffer_size, &required_size, "PSA_KEY_USAGE_SIGN_MESSAGE", 26);
+        usage ^= PSA_KEY_USAGE_SIGN_MESSAGE;
+    }
     if (usage & PSA_KEY_USAGE_VERIFY_HASH) {
         if (required_size != 0) {
             append(&buffer, buffer_size, &required_size, " | ", 3);
@@ -401,6 +408,13 @@ static int psa_snprint_key_usage(char *buffer, size_t buffer_size,
         append(&buffer, buffer_size, &required_size, "PSA_KEY_USAGE_VERIFY_HASH", 25);
         usage ^= PSA_KEY_USAGE_VERIFY_HASH;
     }
+    if (usage & PSA_KEY_USAGE_VERIFY_MESSAGE) {
+        if (required_size != 0) {
+            append(&buffer, buffer_size, &required_size, " | ", 3);
+        }
+        append(&buffer, buffer_size, &required_size, "PSA_KEY_USAGE_VERIFY_MESSAGE", 28);
+        usage ^= PSA_KEY_USAGE_VERIFY_MESSAGE;
+    }
     if (usage != 0) {
         if (required_size != 0) {
             append(&buffer, buffer_size, &required_size, " | ", 3);