diff --git a/plat/st/stm32mp1/include/boot_api.h b/plat/st/stm32mp1/include/boot_api.h
index 0d397bd..1054609 100644
--- a/plat/st/stm32mp1/include/boot_api.h
+++ b/plat/st/stm32mp1/include/boot_api.h
@@ -333,6 +333,8 @@
 	uint32_t binary_type;
 	/* Pad up to 128 byte total size */
 	uint8_t pad[16];
+	/* Followed by extension header */
+	uint8_t ext_header[];
 #endif
 #if STM32MP15
 	/*
@@ -363,4 +365,45 @@
 #endif
 } __packed boot_api_image_header_t;
 
+typedef uint8_t boot_api_sha256_t[BOOT_API_SHA256_DIGEST_SIZE_IN_BYTES];
+
+typedef struct {
+	/* Extension header type:
+	 * BOOT_API_FSBL_DECRYPTION_HEADER_MAGIC_NB or
+	 * BOOT_API_AUTHENTICATION_HEADER_MAGIC_NB
+	 * BOOT_API_PADDING_HEADER_MAGIC_NB
+	 */
+	uint32_t type;
+	/* Extension header len in byte */
+	uint32_t len;
+	/* parameters of this extension */
+	uint8_t  params[];
+} __packed boot_extension_header_t;
+
+typedef struct {
+	/* Idx of ECDSA public key to be used in table */
+	uint32_t pk_idx;
+	/* Number of ECDSA public key in table */
+	uint32_t nb_pk;
+	/*
+	 * Type of ECC algorithm to use  :
+	 * value 1 : for P-256 NIST algorithm
+	 * value 2 : for Brainpool 256 algorithm
+	 * See definitions 'BOOT_API_ECDSA_ALGO_TYPE_XXX' above.
+	 */
+	uint32_t ecc_algo_type;
+	/* ECDSA public key to be used to check signature. */
+	uint8_t ecc_pubk[BOOT_API_ECDSA_PUB_KEY_LEN_IN_BYTES];
+	/* table of Hash of Algo+ECDSA public key */
+	boot_api_sha256_t pk_hashes[];
+} __packed boot_ext_header_params_authentication_t;
+
+typedef struct {
+	/* Size of encryption key (128 or 256) */
+	uint32_t key_size;
+	uint32_t derivation_cont;
+	/* 128 msb bits of plain payload SHA256 */
+	uint32_t hash[4];
+} __packed boot_ext_header_params_encrypted_fsbl_t;
+
 #endif /* BOOT_API_H */